A question on storage. One of the big issues with solar/wind is variability of supply - hence the need for base load generation or storage. I was looking at the eye-watering estimates for the new nuclear stations and wondered how that compared with, say, enough batteries to store a week's worth of energy from a power station. I appreciate there will be loads of practical considerations as well (e.g. how big would it be??) but as a starting point how do the costs compare?
I’d add transmission costs to storage costs, especially if we “have wind farms further offshore.”
According to the chairman of Iberdrola, “for every dollar invested in renewables, is needed another dollar invested already in grid transmission and distribution.”
Hinkley Point is an example of eye-watering costs of nuclear power. It is a poorly negotiated, badly managed, on again/off again project that has taken far too long to build. It's a prime example of how not to go about building nuclear.
But it's total cost at $10 million/Mw compares favourably with offshore wind at $5 million/Mw when you take into account the capacity factor and the lifetime. It will generate twice as much power per $ invested compared to the wind turbine.
This point is slightly unfair though, because my view is that there's no need for us to cut fossil fuels to zero, and a bit of fossil fuel backup is way better than storage right now. If we cut fossil fuel usage 90% and keep 10% it'll be easy to remove the remaining 10% from the air directly.
This is really interesting, thank you. Is the right conclusion that further falls in the cost of solar/wind won't make a huge amount of difference but if the cost of battery storage continues to fall that could have a massive impact?
No. Batteries are never going to be the solution for anything other than very short term storage. See the Royal Society paper on storage needs for a renewables based grid. You would need to covert almost all the world's 1.4bn vehicles to EVs and park them up to provide enough backup for just the UK.
Apparently we need between 60 and 100 TWh of storage to balance fluctuations in renewable energy - which is about 400,000 of the Australian storage facilities that Tesla supplied in Australia. I would, however, hesitate to say "never" given the speed of development and price decrease of batteries (and other storage methods).
I've read the paper and its appendices and the studies to which they refer when the study was released. I would caution that they have continued to make many ambitious assumptions as a result of which their estimate should be considered as being on the low side. Although they make allowances for long run weather patterns on the amount of generation they assume a constant demand pattern taken from 2018 which was not a challenging year, and that we would always be able to avoid demand increasing due to cold weather beyond a normal winter short cold snap that they assume is bridged by demand flexibility, while the performance of turbines is assumed to increase, as if they could command extra wind. Prolonged cold snaps also tend to coincide with prolonged periods of Dunkelflaute (no wind, very little sun), adding substantially to the demand on storage.
They do acknowledge that the problem is way beyond what batteries can manage.
"The scale
is over 1000 times that currently provided
by pumped hydro in the UK, and far more
than could conceivably be provided by
conventional batteries."
The sheer resource requirement puts it beyond reach, never mind the cost. They might have pointed out that we don't have the geography for several thousand Dinorwigs either. Even the hydrogen idea ignores that the storage required would equal about half the total gas storage in Europe - just for the UK. What would Europe do?
Oct 30, 2023·edited Oct 30, 2023Liked by Hannah Ritchie
Some of the comments have alluded to this. Some in a nice way and some in a not so nice way. I think this adage applies, "Just because you can, doesn't mean you should."
Because of variability both seasonal and daily for renewables, you have to overbuild. This is seen clearly in the graph on pg. 25 where the annual generation for an all renewable system is the largest. This also comes with increased cost. An important point is that this study is already a couple years old and the results would probably be different today. The point being that experts in system studies are continually reassessing the situation. However, as Dr. John Bistline wrote in an NYT op-ed concerning the U.S, we shouldn't worry so much about the final mix of technologies but we should do the things we know we need to do,
"For the coming decade, rapidly reducing coal electricity and building extensive wind, solar and storage systems are low-cost strategies in many places, regardless of how much energy might or might not eventually come from renewables."
Also, the land-use requirements in the US seem much higher. From Ezra Klein's podcast:
Jesse Jenkins: ...[In] The most cost-effective of our net-zero scenarios, [wind] spans an area that is equal to Illinois, Indiana, Ohio, Kentucky, and Tennessee put together. And the solar farms are an area the size of Connecticut, Rhode Island, and Massachusetts.
Unfortunately the fantasy is being cruelly exposed by the collapse of most of the offshore wind projects on the East Coast. 2.4GW at Southcoast just being the latest. There is a huge divergence between academic fantasy and the real world.
Really? You might want to look at the big picture before cherry-picking one setback for offshore wind. The 2.6 GW project offshore from Virginia just got the green light and is still on track. Besides, offshore wind was only ever supposed to provide a few percent in the total picture by 2050 based on most system studies I've seen.
Yes, really. Have you been hiding behind a rock? The progress on the COVW was a permit from the Bureau of Offshore Energy Management, which was no more than an attempt to pretend that the Biden policy was still intact in the face of the evidence. COVW have selected Siemens Gamesa for their turbines - a company in deep trouble that has just asked the German government for a €16bn bailout, and which needs big increases in its prices and maintenance charges. COVW was already a $10bn project in 2021 - almost $4,000/MW which was already above costs in the North Sea. The begging bowl is already out for more subsidies/tax credits, and they don't even know what their turbines are really going to cost, particularly with the maintenance problems that have recently been admitted by Siemens which add not only cost but downtime awaiting repair, eating into performance. Big turbines turn out to have bigger problems with stresses and wear as well as construction cost, and ultimately may not be economic.
Ørsted pulled out of 2 wind farms off NJ totalling another 2.4GW a few days ago. NY refused to agree increased prices for 4.2GW of projects that will now also not proceed. The only cherry that has been picked is the naivety of the administration which matches that of DESNZ in the UK.
Leaving aside MacKay's assessment (and perhaps bleak cynicism) about the monetary and political costs of the possible supply stack, surely the real killer in SEWTHA for renewable-only plans was the amount of storage needed?
MayKay's figure for the duration of wind lulls (5 windless days, which would require 1200 GWh (1.2 TWh) of storage) was taken from Irish data, and was far lower than that used by the Energy Research Partnership (in "Managing Flexibility Whilst Decarbonising the GB Electricity System") which found that windless periods can last up to 3 weeks, requiring storage of 6-8 TWh. I seem to recall a more recent study which looked not just at wind lulls but prolonged weeks-months of low wind and found the storage requirements even higher.
In trying to deal with this problem MacKay, arguably, erred on the side of optimism, wishing up a fleet of EVs with swappable batteries (like that Taiwanese electric moped company David Roberts talked about a wile back). Of course these didn't materialise and even the next best - V2G and bidirectional chargers everywhere - would seem to be decades away.
So, yes: it's interesting that we could generate all the energy we need, albeit not when we need it, but storage is still the bottleneck between theory and practice. And I'd guess that that comes down to electricity to hydrogen and back, and whether we have enough underground salt caverns or whatever to store the amount we need for several months' worth of low wind.
Insulation may help, but unfortunately it is not free. It's a £2 trillion project to insulate the UK housing stock to net zero standards. Much of that would not be economic. The £10m insulation project on Grenfell Tower had a payback period of over 200 years before financing costs, and it was well short of Net Zero standards.
The value of the insulation depends on the price of energy. Since both UK FIRES and the Royal Society have now published reports based on the UK having 40% less energy, per capita, in 2050, it seems like the price of energy is going to go up. But it's definitely a puzzle. An interesting interview with an economist:
Insulation is just another case of....and then there's magic. The resources to provide it would be vast, unaffordable, lacking in economic sense, and in reality infeasible.
If that were the case we would already have the insulation, as they do in Scandinavia where it was built in from the beginning. In Russia they just burn more coal and gas. If you live on the top floor of your block you will open windows to let some of the heat out even when it is minus 10 Centigrade outside.
Hi Hannah. Among other points I might make later (interest rates, metals, geopolitics, energy duration, the fact these machines will need to be rebuilt in 20-30 years etc), I'll just point out for now, that -again - you're using the word 'energy' when you should say 'electricity'. Big difference. Electricity is only 20-21% of global energy use and 19% in case of UK (O'Callaghan states this correctly)
With numbers you can proof anything with an invalid model. The electricity Britain needs is not a valid operationalisation of the energy Britain needs. And with a reductionist model of sustainability you can disregard unsustainable practices. Where are the environmental consequences of producing the materials needed to produce solar panels and wind turbines? The low cost solar panels do not appear out of thin air. Production processes are used for mining the ores and producing the materials needed. These processes pollute and hence are not sustainable. And of course all these processes require energy. Currently mostly in the form of thermal energy from burning fossil fuels.
Which aligns with UK FIRES Absolute Zero (2019): https://ukfires.org/impact/publications/reports/ which lists electricity supply as *580 TWh/year.* Thank you for your work, we are deeply appreciative.
My experience is that it is safer to wait for the response of the expert community to policy analyses.
MacKay actually used 20% efficiency for the efficiency of PVs, price notwithstanding. He looked at all energy needs, including food, but presumably the UK will remain a net food and stuff importer for some years.
The big difference between MacKay and newer UK numbers were MacKay's estimates for floating turbines, from what I found. Current estimates are much higher.
I see a range of US numbers for wind capacity factors from official organizations, frustrating. I don't know how much of improved capacity factor for recent projects is due to improved designs or newer wind turbines are in better condition, they will age later, let alone the ubiquitous "wind is up/down in recent years".
Well before California got to 20% solar power, the wholesale price paid per kWh electricity when the sun is out (1-2¢/kWh) had fallen well below the cost of new solar (just counting rooftop and industrial solar from in-state, not that bought from out of state). This occurs with wind in windy areas, although to a lesser extent. The wholesale price of electricity in the late afternoon and evening rose, a lot.
When renewables surpluses get large prices descend into negative territory. National Grid paid Dutch solar farms €500/MWh to switch off at one point this year so as not to have to import on the BritNed interconnector which would have caused a host of problems for local oversupply and grid constraints. The bill goes to consumers for "balancing services".
In contrast to many of the commenters, these numbers look good to me as a first order approximation. My strongest argument is about the demand side. I think it is likely that the demand will actually be much higher than the 'high' demand assumed. Why? Four things jump out: 1) mitigating the effects of climate change already baked in. 2) Building the infrastructure to remove existing carbon from the atmosphere. 3) Powering the AIs that are going to help us figure out how to do those things and much more. 4) Stuff we don't even know about that we haven't been able to contemplate because the energy needed was never there.
Given those and only those, we might be looking at an order of magnitude more demand.
UK primary energy demand peaked at around 200mtoe, or about 2,400TWh over 20 years ago. Since then our population has expanded and us likely to be a third higher by 2050 thanks to the consequences of immigration. It is really hard to believe that we will willingly accept the diminution in living standards implicit on only a quarter of that which would take us back to LDC status.
1. The lowest priced solar CfD operational is currently worth £106/MWh.
2. The idea of an offshore wind capacity factor of 50% is absurd. The fleet average has been 40% or thereabouts for 10 years now. Big wind turbines are wearing out *very* quickly.
3. Floating offshore wind is probably the most expensive way of generating electricity deployed at scale. The levelised cost of Kincardine Windfarm, for example, is around £288/MWh.
4. Do you understand that if you have supply equal to double demand, your unit costs increase? Wind power at £288/MWh into hydrogen storage comes out at £822/MWh (35% round trip efficiency). It will be more expensive still if the windfarm is curtailed half the time. Utter madness.
5. Do you understand that if you put windfarms far out at sea, the costs increase? Presenting figures as a percentage of the UK's EEZ could be construed as being highly deceptive.
6. Do you understand that as windfarms move away from highland areas onto farmland, the load factor will go down? Claiming 48% is easy, but looks absurd when the current figure is less than 30%.
1. The strike price in the latest CfD for solar was £47 / MWh.
2. As I mentioned in the article, I laid out the underlying numbers the paper used so you can adjust for different factors. If you think 50% CF is too high, just reduce it to 40%...
3. Most of your other points relate to floating offshore wind (far from land). Again, as I mentioned, feel free to just take it out completely. The resources are still large, and when combined with other solutions (nuclear, storage, possibly small hydro) can make up a good chunk of our energy system.
Obviously going by strike price is unreasonable, as most of the price to consumers will be pylons, balancing costs and storage (which rise exponentially past the 40% threshold), along with the forgone productivity of lost land (it uses 50x the space as nuclear). None of these are included in the strike price.
Montford's point on the end to end efficiency of hydrogen storage is particularly pertinent, as solar availability correlates negatively with demand.
Very cool Hannah, Dave McKay's book has been a big inspiration for me too and I'm eternally grateful that it was available for free online. And it's good to update those figures indeed. If I remember correctly, he did put his caveat on his big "NO" that much cheaper floaters for floating wind would be a joker. Delivering such cheap platforms is indeed one of the most exciting engineering problems of the day for northern Europe - they are not there yet, and I'm afraid prospects for those currently in the water are rather challenging.
That being said, I think this whole hullaballoo about 100% vs 70% renewables is more of an academic pastime than a real issue. The problem facing us still is going to 50% renewables, down from 80% fossil today (energy, not electricity).
Actually getting much beyond 60% renewables in electricity supply will prove very difficult and costly. At that point curtailment (or even more costly storage) starts to grow rapidly because renewables production starts exceeding instantaneous demand on windy/sunny days. No system has really gone beyond that, even when soused in subsidies (e.g. El Hierro, Graciosa, King Island - all supposed renewables poster boys).
Attempts to attack other energy use have simply resulted in export of industry to coal using China, which takes advantage of the much lower energy cost and greater reliability. Net result: increased emissions.
Everything I have read suggests getting to 85% renewables should be very doable without addressing most of the concerns brought up over the last few %. The focus this decade should really be on building out renewable sources as fast as possible. It’s worth noting that additional renewable sources can also make future contributions to the potential for renewables. Floating solar in particular might increase the area available considerably and doesn’t seem to have been considered. Then there’s also still geothermal and tidal etc.
The problem with this reasoning is that 'the last 15%' has to include 100% of supply for some periods. Basically it's a duplicate system, with storage and transmission, as big as the everyday system. This redundancy is what led MacKay to advocate nuclear. But the horse is out of the barn, so figuring out hydrogen at scale has to go extremely fast now, as pointed out here:
You can consider every consumer and every EV etc as a potential energy storage device that can flex to adjust demand. Imagine what 10 million BEV cars can store if charged on a windy day. Raising and lowering consumption to match demand with generation is far more doable than nay sayers want to believe. It already happens demand peaks and troughs every day. Many of us already peak shift, peak shave and store power over a period of a week. Likewise we already have interconnector capacity that can meet 25% of the current grid capacity. The last 15% is next decades problem the first 85% is this decades emergency. Firmed power will have a price. Flexibility will also have a price.
No need to imagine the limited potential of V2G. Say you dedicate 20kWh per vehicle to grid support, cutting the available range and cycling the battery more frequently, lowering its life. That gives storage of 200GWh, which is about 20% of demand on a coldish winter day currently. Vehicles are likely to be driven during peak rush hour demand, limiting resupply at a crucial time. It's about 0.2% of the 100TWh the RS indicated.
The Royal Society report goes through the options. The limit is always a few cold weeks with no sun or wind, and the crisis is having that happen across the interconnected grid, after a few years of un-refilled storage with inadequate H2. Your car is not going to help. Passive house retrofits would be awesome, though, as described here: https://x.com/nworbmot/status/1503730412270596097?s=20
In New York, where my project is, the legacy natural gas system seems like it will hang on for a long time, but the puzzle there is how to scale down demand to that of the RE system without having customers and utilities simply continue to burn the gas. In which case, we're not actually decarbonizing.
This is a great and very forthright interview -- more candor from everyone would be politically wise, and just the enormous spread in what people predict is a sign that something's wrong:
There are other reports that you could look at on this topic, rather than keep sitting the same one. Try NG future energy scenarios and Ember. Both have scenarios where the UK can (or I guess could have with alternate policies) feasibly get to sub 5% fossil electricity generation this decade by rapidly increasing renewables. In both cases they test the scenario against the possible weather scenarios. It’s a standard method.
And why always hydrogen. There are other more efficient storage technologies. Hydrogen is far from optimal as either an option for energy storage or as an energy carrier.
The Future Energy Scenaroos and the work by EMBER are laughable attempts at propaganda. They are not serious work. They are full of optimistic assumptions, putting it politely, and they do not seriously consider real world constraints. Even the RS work suffers because aside from looking at a long run of real weather for generation (but not demand), it uses assumptions drawn from the FES.
If there's something better than hydrogen it would be ideal to find out now, before the huge investment kicks in. Professor Allwood is a hydrogen skeptic. Cued: https://www.youtube.com/watch?v=WOIXnJ8OzXY&t=2320s
As for other reports, here's a plan for the EU (Victoria, Zeyen, Brown 2022), but it still entails vast amounts of hydrogen.
Right now the storage question in New York is a blank spot, though H2 is the likely candidate. California also has a blank spot, with H2 as the likely candidate.
For me, hydrogen is difficult to store and has poor round trip efficiency. Pumped hydro, Flow batteries, compressed air/CO2 storage all offer better round trip efficiency than hydrogen and are easier to work with.
Good point Paul! I’m not sure what the UK stats would be - a future article for Hannah to research? ;-) (I love your work Hannah and am spreading it all over the internet.) There is more than enough area for Solar. Speaking globally, it’s only 0.1% of the land on earth. Grazing cattle is about 30% - 300 times more land! https://theconversation.com/really-australia-its-not-that-hard-10-reasons-why-renewable-energy-is-the-future-130459 If a renewable sceptic is worried about land use, suggest to them that just halving their beef intake would save orders of magnitude more land than their feigned concerns about solar panels. Then solar on half humanity’s rooftops would be all today’s electricity grid. http://theconversation.com/solar-panels-on-half-the-worlds-roofs-could-meet-its-entire-electricity-demand-new-research-169302 (The other half would start to power transport.) A “Nature” study from June 2022 concludes that floating solar on just 10% of our already existing HYDROPOWER reserves (on a hydro dam already plugged into the grid) would be 4000 GW “equivalent to the electricity-generation capacity of all the fossil-fuel plants in operation worldwide.” (Study behind a paywall.) https://www.nature.com/articles/d41586-022-01525-1 You don’t cover the whole reservoir or it can reduce oxygen levels in the water, causing problems for fish. But we don’t need to. Another study from “Nature” then concluded in March 2023: ”Floating photovoltaic (FPV) systems on reservoirs are advantageous over traditional ground-mounted solar systems in terms of land conservation, efficiency improvement and water loss reduction. Here, based on multiple reservoir databases and a realistic climate-driven photovoltaic system simulation, we estimate the practical potential electricity generation for FPV systems with a 30% coverage on 114,555 global reservoirs is 9,434 ± 29 TWh yr−1. Considering the proximity of most reservoirs to population centres and the potential to develop dedicated local power systems, we find that 6,256 communities and/or cities in 124 countries, including 154 metropolises, could be self-sufficient with local FPV plants. Also beneficial to FPV worldwide is that the reduced annual evaporation could conserve 106 ± 1 km3 of water.” https://www.nature.com/articles/s41893-023-01089-6
While it’s clear a 100% renewables grid requires an overbuild of capacity it is not clear that it will cost more than the status quo with Fossil generation, and quite probably also less than a nuclear future.
I suggest anyone worried about costs of decarbonisation should start from the perspective of a potential savings from the massive subsidies given to FF, and then factor in the mortality and health care costs of carbon emissions.
Who is paying these massive subsidies? They are a figment of imagination. Very real cash subsidies are being paid to renewables, and they get further subsidised by tariff protection against competition (carbon taxes) and not being charged for the costs they add to electricity systems for transmission, stabilisation and backup. Most of the studies make quite fantasy assumptions about renewables costs, and ignore all the consequential costs. Renewables other than hydro require nigh on 100% backup, a huge expansion in grid resources with poor average utilisation, and massive volumes of curtailment (which is cheaper than storage). You soon reach the situation where adding another wind farm sees 80% of its additional output curtailed, which means that the useful 20% costs 5 times a simple LCOE estimate.
The interesting question isn't really can you power [insert name of country here] with wind and solar, but why would you want to? Most of the costs of electricity aren't in the generation but the grid. With nuclear you just plug it in and it works, with wind and solar you need a massive redesign and rebuild effort ... particularly with rooftop solar in places like Australia. A heavy rollout of rooftop PV and batteries is already breaking our grid in South Australia. We are going to have enough trouble opening enough mines fast enough for EV batteries, so why waste precious resources backing up environmentally destructive collectors of electricity like wind and solar? Please consider ...https://www.blog.geoffrussell.com.au/post/energy-spin-and-the-running-of-the-bull-shit
I'm very pro-nuclear (I state quite clearly that I think the optimal mix would be a combination of solar, wind, significant nuclear).
Unfortunately the UK has not been great at building nuclear quickly or cheaply. If you have a grand plan to fix this, and get political and public support for it, I'm all ears. In the meantime, I will continue pushing for sources that are scaling quickly.
Solar, wind and nuclear do not mix, as the French have already worked out. In reality, they depend on hydro and some gas to provide the dispatchable flexibility that is difficult to achieve with nuclear. Plans to try to replace half their nuclear by wind have been abandoned. It would have required an increase in dispatchable flexible generation that would have inevitably ended up being gas, since most of their feasible hydro resource is already exploited.
Thanks Hannah, really good blog to read. I had similar reaction to David MacKay’s work, in that it / he inspired me to go into policy facing work in the civil service, realising my background in science could be useful. Great to get this update to the figures in SEWTHA!
An idea for an extension, which I found helpful when I was working directly in the policy area, if you want to look beyond the totals at dispatchability and get a sense of scale of storage or other technologies needed was to look at the demand curve. If you plot half-hour demand on the grid for the year, ordered from high to low along the x-axis, you get something that looks a bit like a trapezium going from winter peak to a summer lull. You can plot a typical wind and solar profile against that. You’d expect this would show excess supply on the RHS, and an unmet demand in the LHS. You can then ask how much can be shifted around with say 4hrs of storage (very doable with cheaper batteries), and then what residual demand will you need to meet with another tech like gas, or demand response, or nuclear, or closed loop geothermal (which can also act as a kind of storage…). The optimal split depends on a mix of economics and politics. Appreciate this might be a bit too in the weeds though!
In the end there is no substitute for doing a proper study with real weather data at hourly resolution or better spanning many decades. That is what I did 6 years ago, and now the Royal Society has finally started to catch up. Unfortunately their estimates of storage requirements and curtailed surpluses are almost certainly on the low side because of the many highly optimistic assumptions in their analysis, including a failure to look at real world cold weather demand (their demand profile is based on a single year, 2018 not the 37 year weather history or actual demand history), very optimistic cost and capacity factor assumptions (see also the working paper being discussed in thus article), and much else besides.
Still, they have made a start, and no future projection can ignore the issue, which is of course what this study has done, and why it is worthless.
Hannah tries to "work out if Britain could power itself from renewables," which if I understand correctly means whether Britain could get all (or almost all) of its electricity from wind and solar.
This post unfortunately shows the limitations of the author's data-driven approach — the most important factors are left out because they can't be computed as easily as less important ones.
The post considers (1) the amount of energy Britain could get from wind and solar and (2) the cost of wind turbines and solar panels. The post concludes that there are enough resources available and that turbines and solar panels have become much cheaper, therefore yes Britain can get most of its electricity from renewables.
But these aren't remotely the main costs or constraints anymore. The main costs in adding solar and wind to a grid are related to (3) grid transmission and distribution, (4) storage and overbuilding to handle renewables intermittency, and (5) project finance.
Grid transmission and distribution — According to the chairman of Iberdrola, for every dollar invested in renewables, another dollar needs to be invested in grid transmission and distribution.
Handling intermittency — A recent report from the Royal Society explains that we'd likely need to store energy for decades because of long term trends in wind power generation:
> Wind supply can vary over time scales of decades and tens of TWhs of very long-duration storage will be needed. The scale is over 1000 times that currently provided by pumped hydro in the UK, and far more than could conceivably be provided by conventional batteries.
It calls for storing about 100 TWh. The only technology (they claim) to be viable is hydrogen storage.
However, as far as I'm aware, large scale hydrogen production, transport and storage is still in its infancy and therefore we need demonstration projects before estimating its cost with any certainty.
Finance costs — The constant drumbeat of offshore wind project cancellations reminds us that finance costs are important. Since most of the costs are incurred upfront but revenues are recognized over 20+ years, higher interest rates make projects more expensive.
Energy analyst Ira Joseph often issues the following challenge to promoters of small modular nuclear reactors: "Just build one." That is the only way to understand if they are practical and economically viable.
The same goes with any electrical grid that is powered (almost) entirely by renewables. Until one is built and we can evaluate its costs, discussions are likely to focus on some factors of the total cost but miss out more important ones.
I’m all for crunching numbers but expecting wind and solar to decarbonise the UK and provide security of supply is straight out of Ed Miliband dummies guide to energy.
The deployment of either technologies to the levels required to achieve and sustain that level indefinitely are well beyond credibility both from a material resources, manufacturing, construction and maintenance point of view.
David MacKay’s numbers and reasoning still has validity 15 years later.
A question on storage. One of the big issues with solar/wind is variability of supply - hence the need for base load generation or storage. I was looking at the eye-watering estimates for the new nuclear stations and wondered how that compared with, say, enough batteries to store a week's worth of energy from a power station. I appreciate there will be loads of practical considerations as well (e.g. how big would it be??) but as a starting point how do the costs compare?
I’d add transmission costs to storage costs, especially if we “have wind farms further offshore.”
According to the chairman of Iberdrola, “for every dollar invested in renewables, is needed another dollar invested already in grid transmission and distribution.”
https://twitter.com/BloombergNEF/status/1719010207836316015
Hinkley Point is an example of eye-watering costs of nuclear power. It is a poorly negotiated, badly managed, on again/off again project that has taken far too long to build. It's a prime example of how not to go about building nuclear.
But it's total cost at $10 million/Mw compares favourably with offshore wind at $5 million/Mw when you take into account the capacity factor and the lifetime. It will generate twice as much power per $ invested compared to the wind turbine.
https://twitter.com/bswud/status/1674763735993286658
This point is slightly unfair though, because my view is that there's no need for us to cut fossil fuels to zero, and a bit of fossil fuel backup is way better than storage right now. If we cut fossil fuel usage 90% and keep 10% it'll be easy to remove the remaining 10% from the air directly.
This is really interesting, thank you. Is the right conclusion that further falls in the cost of solar/wind won't make a huge amount of difference but if the cost of battery storage continues to fall that could have a massive impact?
No. Batteries are never going to be the solution for anything other than very short term storage. See the Royal Society paper on storage needs for a renewables based grid. You would need to covert almost all the world's 1.4bn vehicles to EVs and park them up to provide enough backup for just the UK.
That paper is really interesting - link here https://royalsociety.org/-/media/policy/projects/large-scale-electricity-storage/Large-scale-electricity-storage-report.pdf
Apparently we need between 60 and 100 TWh of storage to balance fluctuations in renewable energy - which is about 400,000 of the Australian storage facilities that Tesla supplied in Australia. I would, however, hesitate to say "never" given the speed of development and price decrease of batteries (and other storage methods).
I've read the paper and its appendices and the studies to which they refer when the study was released. I would caution that they have continued to make many ambitious assumptions as a result of which their estimate should be considered as being on the low side. Although they make allowances for long run weather patterns on the amount of generation they assume a constant demand pattern taken from 2018 which was not a challenging year, and that we would always be able to avoid demand increasing due to cold weather beyond a normal winter short cold snap that they assume is bridged by demand flexibility, while the performance of turbines is assumed to increase, as if they could command extra wind. Prolonged cold snaps also tend to coincide with prolonged periods of Dunkelflaute (no wind, very little sun), adding substantially to the demand on storage.
They do acknowledge that the problem is way beyond what batteries can manage.
"The scale
is over 1000 times that currently provided
by pumped hydro in the UK, and far more
than could conceivably be provided by
conventional batteries."
The sheer resource requirement puts it beyond reach, never mind the cost. They might have pointed out that we don't have the geography for several thousand Dinorwigs either. Even the hydrogen idea ignores that the storage required would equal about half the total gas storage in Europe - just for the UK. What would Europe do?
Some of the comments have alluded to this. Some in a nice way and some in a not so nice way. I think this adage applies, "Just because you can, doesn't mean you should."
I continue to believe that questions like these are really best left to systems experts that do tradeoff studies, e.g. Net-Zero America Project. Here is a link to their summary, https://netzeroamerica.princeton.edu/img/Princeton%20NZA%20FINAL%20REPORT%20SUMMARY%20(29Oct2021).pdf .
Because of variability both seasonal and daily for renewables, you have to overbuild. This is seen clearly in the graph on pg. 25 where the annual generation for an all renewable system is the largest. This also comes with increased cost. An important point is that this study is already a couple years old and the results would probably be different today. The point being that experts in system studies are continually reassessing the situation. However, as Dr. John Bistline wrote in an NYT op-ed concerning the U.S, we shouldn't worry so much about the final mix of technologies but we should do the things we know we need to do,
"For the coming decade, rapidly reducing coal electricity and building extensive wind, solar and storage systems are low-cost strategies in many places, regardless of how much energy might or might not eventually come from renewables."
https://www.nytimes.com/2022/04/10/opinion/environment/ipcc-report-climate-change-debates.html .
Also, the land-use requirements in the US seem much higher. From Ezra Klein's podcast:
Jesse Jenkins: ...[In] The most cost-effective of our net-zero scenarios, [wind] spans an area that is equal to Illinois, Indiana, Ohio, Kentucky, and Tennessee put together. And the solar farms are an area the size of Connecticut, Rhode Island, and Massachusetts.
Ezra Klein: Holy crap.
Jesse Jenkins:So these are big, big areas.
https://www.mattball.org/2023/01/land-vs-renewable-fantasies.html
Unfortunately the fantasy is being cruelly exposed by the collapse of most of the offshore wind projects on the East Coast. 2.4GW at Southcoast just being the latest. There is a huge divergence between academic fantasy and the real world.
Really? You might want to look at the big picture before cherry-picking one setback for offshore wind. The 2.6 GW project offshore from Virginia just got the green light and is still on track. Besides, offshore wind was only ever supposed to provide a few percent in the total picture by 2050 based on most system studies I've seen.
How about these success story facts?
1. Renewable generation surpassed coal and nuclear in the U.S. electric power sector in 2022, https://www.eia.gov/todayinenergy/detail.php?id=55960 .
2. Add nuclear to the renewables and emission-free carbon sources account for almost 40% of the generation in the U.S.
3. The specific carbon intensity of the US electrical sector has decreased by 40% between 2000 and 2022, falling from 650 kg/MWh to 390 MWh.
Yes, really. Have you been hiding behind a rock? The progress on the COVW was a permit from the Bureau of Offshore Energy Management, which was no more than an attempt to pretend that the Biden policy was still intact in the face of the evidence. COVW have selected Siemens Gamesa for their turbines - a company in deep trouble that has just asked the German government for a €16bn bailout, and which needs big increases in its prices and maintenance charges. COVW was already a $10bn project in 2021 - almost $4,000/MW which was already above costs in the North Sea. The begging bowl is already out for more subsidies/tax credits, and they don't even know what their turbines are really going to cost, particularly with the maintenance problems that have recently been admitted by Siemens which add not only cost but downtime awaiting repair, eating into performance. Big turbines turn out to have bigger problems with stresses and wear as well as construction cost, and ultimately may not be economic.
Ørsted pulled out of 2 wind farms off NJ totalling another 2.4GW a few days ago. NY refused to agree increased prices for 4.2GW of projects that will now also not proceed. The only cherry that has been picked is the naivety of the administration which matches that of DESNZ in the UK.
Leaving aside MacKay's assessment (and perhaps bleak cynicism) about the monetary and political costs of the possible supply stack, surely the real killer in SEWTHA for renewable-only plans was the amount of storage needed?
MayKay's figure for the duration of wind lulls (5 windless days, which would require 1200 GWh (1.2 TWh) of storage) was taken from Irish data, and was far lower than that used by the Energy Research Partnership (in "Managing Flexibility Whilst Decarbonising the GB Electricity System") which found that windless periods can last up to 3 weeks, requiring storage of 6-8 TWh. I seem to recall a more recent study which looked not just at wind lulls but prolonged weeks-months of low wind and found the storage requirements even higher.
In trying to deal with this problem MacKay, arguably, erred on the side of optimism, wishing up a fleet of EVs with swappable batteries (like that Taiwanese electric moped company David Roberts talked about a wile back). Of course these didn't materialise and even the next best - V2G and bidirectional chargers everywhere - would seem to be decades away.
So, yes: it's interesting that we could generate all the energy we need, albeit not when we need it, but storage is still the bottleneck between theory and practice. And I'd guess that that comes down to electricity to hydrogen and back, and whether we have enough underground salt caverns or whatever to store the amount we need for several months' worth of low wind.
Here is a Royal Society study from last month on what you ask. The storage demand is vast, if you factor in four decades of weather data.
https://royalsociety.org/topics-policy/projects/low-carbon-energy-programme/large-scale-electricity-storage/
This study assumes 570 TWh/year of electricity, but maybe society can adapt to having more and less, although winter heating seems non-negotiable.
Insulation helps:
https://x.com/nworbmot/status/1503730412270596097?s=20
Insulation may help, but unfortunately it is not free. It's a £2 trillion project to insulate the UK housing stock to net zero standards. Much of that would not be economic. The £10m insulation project on Grenfell Tower had a payback period of over 200 years before financing costs, and it was well short of Net Zero standards.
The value of the insulation depends on the price of energy. Since both UK FIRES and the Royal Society have now published reports based on the UK having 40% less energy, per capita, in 2050, it seems like the price of energy is going to go up. But it's definitely a puzzle. An interesting interview with an economist:
https://www.alumni.ox.ac.uk/article/professor-hamish-low-brasenose-1990
Insulation is just another case of....and then there's magic. The resources to provide it would be vast, unaffordable, lacking in economic sense, and in reality infeasible.
Insulation is probably less magic than the energy that's necessary otherwise. But agreed that the scale of either side of the solution is daunting.
If that were the case we would already have the insulation, as they do in Scandinavia where it was built in from the beginning. In Russia they just burn more coal and gas. If you live on the top floor of your block you will open windows to let some of the heat out even when it is minus 10 Centigrade outside.
Hi Hannah. Among other points I might make later (interest rates, metals, geopolitics, energy duration, the fact these machines will need to be rebuilt in 20-30 years etc), I'll just point out for now, that -again - you're using the word 'energy' when you should say 'electricity'. Big difference. Electricity is only 20-21% of global energy use and 19% in case of UK (O'Callaghan states this correctly)
Sure, electricity is a small part of total energy use today but this is about projecting future energy resources in 2050.
With large electrification, it will make up a large % of final energy demand.
With numbers you can proof anything with an invalid model. The electricity Britain needs is not a valid operationalisation of the energy Britain needs. And with a reductionist model of sustainability you can disregard unsustainable practices. Where are the environmental consequences of producing the materials needed to produce solar panels and wind turbines? The low cost solar panels do not appear out of thin air. Production processes are used for mining the ores and producing the materials needed. These processes pollute and hence are not sustainable. And of course all these processes require energy. Currently mostly in the form of thermal energy from burning fossil fuels.
Relevant numbers in these,
570 TWh/year:
https://royalsociety.org/topics-policy/projects/low-carbon-energy-programme/large-scale-electricity-storage/
580 TWh/year:
https://ukfires.org/is-absolute-zero-pessimistic-about-uk-energy-supplies/
Please dig into this on hydrogen storage from the Royal Society last month; 2050 electricity supply for the UK is listed as *570 TWh/year*:
https://royalsociety.org/-/media/policy/projects/large-scale-electricity-storage/V1_Large-scale-electricity-storage-report.pdf
Which aligns with UK FIRES Absolute Zero (2019): https://ukfires.org/impact/publications/reports/ which lists electricity supply as *580 TWh/year.* Thank you for your work, we are deeply appreciative.
My experience is that it is safer to wait for the response of the expert community to policy analyses.
MacKay actually used 20% efficiency for the efficiency of PVs, price notwithstanding. He looked at all energy needs, including food, but presumably the UK will remain a net food and stuff importer for some years.
The big difference between MacKay and newer UK numbers were MacKay's estimates for floating turbines, from what I found. Current estimates are much higher.
I see a range of US numbers for wind capacity factors from official organizations, frustrating. I don't know how much of improved capacity factor for recent projects is due to improved designs or newer wind turbines are in better condition, they will age later, let alone the ubiquitous "wind is up/down in recent years".
Well before California got to 20% solar power, the wholesale price paid per kWh electricity when the sun is out (1-2¢/kWh) had fallen well below the cost of new solar (just counting rooftop and industrial solar from in-state, not that bought from out of state). This occurs with wind in windy areas, although to a lesser extent. The wholesale price of electricity in the late afternoon and evening rose, a lot.
Thank you for your work.
When renewables surpluses get large prices descend into negative territory. National Grid paid Dutch solar farms €500/MWh to switch off at one point this year so as not to have to import on the BritNed interconnector which would have caused a host of problems for local oversupply and grid constraints. The bill goes to consumers for "balancing services".
In contrast to many of the commenters, these numbers look good to me as a first order approximation. My strongest argument is about the demand side. I think it is likely that the demand will actually be much higher than the 'high' demand assumed. Why? Four things jump out: 1) mitigating the effects of climate change already baked in. 2) Building the infrastructure to remove existing carbon from the atmosphere. 3) Powering the AIs that are going to help us figure out how to do those things and much more. 4) Stuff we don't even know about that we haven't been able to contemplate because the energy needed was never there.
Given those and only those, we might be looking at an order of magnitude more demand.
Take a look at the Royal Society's report on energy storage. Unless I'm missing something, they assume demand will be 570 TWh/year in 2050.
https://royalsociety.org/topics-policy/projects/low-carbon-energy-programme/large-scale-electricity-storage/
UK FIRES assumes 580 TWh/year.
https://ukfires.org/is-absolute-zero-pessimistic-about-uk-energy-supplies/
UK primary energy demand peaked at around 200mtoe, or about 2,400TWh over 20 years ago. Since then our population has expanded and us likely to be a third higher by 2050 thanks to the consequences of immigration. It is really hard to believe that we will willingly accept the diminution in living standards implicit on only a quarter of that which would take us back to LDC status.
This is very poor. Idiotic in fact.
1. The lowest priced solar CfD operational is currently worth £106/MWh.
2. The idea of an offshore wind capacity factor of 50% is absurd. The fleet average has been 40% or thereabouts for 10 years now. Big wind turbines are wearing out *very* quickly.
3. Floating offshore wind is probably the most expensive way of generating electricity deployed at scale. The levelised cost of Kincardine Windfarm, for example, is around £288/MWh.
4. Do you understand that if you have supply equal to double demand, your unit costs increase? Wind power at £288/MWh into hydrogen storage comes out at £822/MWh (35% round trip efficiency). It will be more expensive still if the windfarm is curtailed half the time. Utter madness.
5. Do you understand that if you put windfarms far out at sea, the costs increase? Presenting figures as a percentage of the UK's EEZ could be construed as being highly deceptive.
6. Do you understand that as windfarms move away from highland areas onto farmland, the load factor will go down? Claiming 48% is easy, but looks absurd when the current figure is less than 30%.
Sorry, but this is embarrassingly awful.
Hi Andrew.
1. The strike price in the latest CfD for solar was £47 / MWh.
2. As I mentioned in the article, I laid out the underlying numbers the paper used so you can adjust for different factors. If you think 50% CF is too high, just reduce it to 40%...
3. Most of your other points relate to floating offshore wind (far from land). Again, as I mentioned, feel free to just take it out completely. The resources are still large, and when combined with other solutions (nuclear, storage, possibly small hydro) can make up a good chunk of our energy system.
£47/MWh in 2012 money, £65 today.
Obviously going by strike price is unreasonable, as most of the price to consumers will be pylons, balancing costs and storage (which rise exponentially past the 40% threshold), along with the forgone productivity of lost land (it uses 50x the space as nuclear). None of these are included in the strike price.
Montford's point on the end to end efficiency of hydrogen storage is particularly pertinent, as solar availability correlates negatively with demand.
Very cool Hannah, Dave McKay's book has been a big inspiration for me too and I'm eternally grateful that it was available for free online. And it's good to update those figures indeed. If I remember correctly, he did put his caveat on his big "NO" that much cheaper floaters for floating wind would be a joker. Delivering such cheap platforms is indeed one of the most exciting engineering problems of the day for northern Europe - they are not there yet, and I'm afraid prospects for those currently in the water are rather challenging.
That being said, I think this whole hullaballoo about 100% vs 70% renewables is more of an academic pastime than a real issue. The problem facing us still is going to 50% renewables, down from 80% fossil today (energy, not electricity).
Actually getting much beyond 60% renewables in electricity supply will prove very difficult and costly. At that point curtailment (or even more costly storage) starts to grow rapidly because renewables production starts exceeding instantaneous demand on windy/sunny days. No system has really gone beyond that, even when soused in subsidies (e.g. El Hierro, Graciosa, King Island - all supposed renewables poster boys).
Attempts to attack other energy use have simply resulted in export of industry to coal using China, which takes advantage of the much lower energy cost and greater reliability. Net result: increased emissions.
You may want to correct the wee typo that currently says "appaling delusion", balanced, as it is, between 'appealing' and 'appalling' :D
Everything I have read suggests getting to 85% renewables should be very doable without addressing most of the concerns brought up over the last few %. The focus this decade should really be on building out renewable sources as fast as possible. It’s worth noting that additional renewable sources can also make future contributions to the potential for renewables. Floating solar in particular might increase the area available considerably and doesn’t seem to have been considered. Then there’s also still geothermal and tidal etc.
The problem with this reasoning is that 'the last 15%' has to include 100% of supply for some periods. Basically it's a duplicate system, with storage and transmission, as big as the everyday system. This redundancy is what led MacKay to advocate nuclear. But the horse is out of the barn, so figuring out hydrogen at scale has to go extremely fast now, as pointed out here:
https://royalsociety.org/topics-policy/projects/low-carbon-energy-programme/large-scale-electricity-storage/
You can consider every consumer and every EV etc as a potential energy storage device that can flex to adjust demand. Imagine what 10 million BEV cars can store if charged on a windy day. Raising and lowering consumption to match demand with generation is far more doable than nay sayers want to believe. It already happens demand peaks and troughs every day. Many of us already peak shift, peak shave and store power over a period of a week. Likewise we already have interconnector capacity that can meet 25% of the current grid capacity. The last 15% is next decades problem the first 85% is this decades emergency. Firmed power will have a price. Flexibility will also have a price.
No need to imagine the limited potential of V2G. Say you dedicate 20kWh per vehicle to grid support, cutting the available range and cycling the battery more frequently, lowering its life. That gives storage of 200GWh, which is about 20% of demand on a coldish winter day currently. Vehicles are likely to be driven during peak rush hour demand, limiting resupply at a crucial time. It's about 0.2% of the 100TWh the RS indicated.
The Royal Society report goes through the options. The limit is always a few cold weeks with no sun or wind, and the crisis is having that happen across the interconnected grid, after a few years of un-refilled storage with inadequate H2. Your car is not going to help. Passive house retrofits would be awesome, though, as described here: https://x.com/nworbmot/status/1503730412270596097?s=20
In New York, where my project is, the legacy natural gas system seems like it will hang on for a long time, but the puzzle there is how to scale down demand to that of the RE system without having customers and utilities simply continue to burn the gas. In which case, we're not actually decarbonizing.
This is a great and very forthright interview -- more candor from everyone would be politically wise, and just the enormous spread in what people predict is a sign that something's wrong:
https://www.resources.org/resources-radio/overcoming-obstacles-in-the-mid-transition-to-clean-energy-with-emily-grubert/
Regarding the enormous spread, look at the range of predictions in Figure 2:
https://ukfires.org/is-absolute-zero-pessimistic-about-uk-energy-supplies/
There are other reports that you could look at on this topic, rather than keep sitting the same one. Try NG future energy scenarios and Ember. Both have scenarios where the UK can (or I guess could have with alternate policies) feasibly get to sub 5% fossil electricity generation this decade by rapidly increasing renewables. In both cases they test the scenario against the possible weather scenarios. It’s a standard method.
And why always hydrogen. There are other more efficient storage technologies. Hydrogen is far from optimal as either an option for energy storage or as an energy carrier.
The Future Energy Scenaroos and the work by EMBER are laughable attempts at propaganda. They are not serious work. They are full of optimistic assumptions, putting it politely, and they do not seriously consider real world constraints. Even the RS work suffers because aside from looking at a long run of real weather for generation (but not demand), it uses assumptions drawn from the FES.
If there's something better than hydrogen it would be ideal to find out now, before the huge investment kicks in. Professor Allwood is a hydrogen skeptic. Cued: https://www.youtube.com/watch?v=WOIXnJ8OzXY&t=2320s
As for other reports, here's a plan for the EU (Victoria, Zeyen, Brown 2022), but it still entails vast amounts of hydrogen.
https://www.sciencedirect.com/science/article/pii/S2542435122001830
The question with testing against weather is: how many decades. The longer the span, the bigger the extremes.
We're in the middle of the discussion in New York State because we've developed an educational product about New York's grid:
https://newyork.thecityatlas.org/lifestyle/energetic-teachers-and-students-2/
Right now the storage question in New York is a blank spot, though H2 is the likely candidate. California also has a blank spot, with H2 as the likely candidate.
The US has just committed $7B to hydrogen:
https://www.reuters.com/world/us/biden-administration-announce-hydrogen-hub-grants-friday-sources-2023-10-10/
In Europe we have ERAA for modelling against.
For me, hydrogen is difficult to store and has poor round trip efficiency. Pumped hydro, Flow batteries, compressed air/CO2 storage all offer better round trip efficiency than hydrogen and are easier to work with.
Good point Paul! I’m not sure what the UK stats would be - a future article for Hannah to research? ;-) (I love your work Hannah and am spreading it all over the internet.) There is more than enough area for Solar. Speaking globally, it’s only 0.1% of the land on earth. Grazing cattle is about 30% - 300 times more land! https://theconversation.com/really-australia-its-not-that-hard-10-reasons-why-renewable-energy-is-the-future-130459 If a renewable sceptic is worried about land use, suggest to them that just halving their beef intake would save orders of magnitude more land than their feigned concerns about solar panels. Then solar on half humanity’s rooftops would be all today’s electricity grid. http://theconversation.com/solar-panels-on-half-the-worlds-roofs-could-meet-its-entire-electricity-demand-new-research-169302 (The other half would start to power transport.) A “Nature” study from June 2022 concludes that floating solar on just 10% of our already existing HYDROPOWER reserves (on a hydro dam already plugged into the grid) would be 4000 GW “equivalent to the electricity-generation capacity of all the fossil-fuel plants in operation worldwide.” (Study behind a paywall.) https://www.nature.com/articles/d41586-022-01525-1 You don’t cover the whole reservoir or it can reduce oxygen levels in the water, causing problems for fish. But we don’t need to. Another study from “Nature” then concluded in March 2023: ”Floating photovoltaic (FPV) systems on reservoirs are advantageous over traditional ground-mounted solar systems in terms of land conservation, efficiency improvement and water loss reduction. Here, based on multiple reservoir databases and a realistic climate-driven photovoltaic system simulation, we estimate the practical potential electricity generation for FPV systems with a 30% coverage on 114,555 global reservoirs is 9,434 ± 29 TWh yr−1. Considering the proximity of most reservoirs to population centres and the potential to develop dedicated local power systems, we find that 6,256 communities and/or cities in 124 countries, including 154 metropolises, could be self-sufficient with local FPV plants. Also beneficial to FPV worldwide is that the reduced annual evaporation could conserve 106 ± 1 km3 of water.” https://www.nature.com/articles/s41893-023-01089-6
You should read more widely. Costs start escalating sharply when you try to go beyond 60% of annual energy coming from wind and solar.
I do…
While it’s clear a 100% renewables grid requires an overbuild of capacity it is not clear that it will cost more than the status quo with Fossil generation, and quite probably also less than a nuclear future.
I suggest anyone worried about costs of decarbonisation should start from the perspective of a potential savings from the massive subsidies given to FF, and then factor in the mortality and health care costs of carbon emissions.
https://www.nature.com/articles/s41467-021-24487-w
Who is paying these massive subsidies? They are a figment of imagination. Very real cash subsidies are being paid to renewables, and they get further subsidised by tariff protection against competition (carbon taxes) and not being charged for the costs they add to electricity systems for transmission, stabilisation and backup. Most of the studies make quite fantasy assumptions about renewables costs, and ignore all the consequential costs. Renewables other than hydro require nigh on 100% backup, a huge expansion in grid resources with poor average utilisation, and massive volumes of curtailment (which is cheaper than storage). You soon reach the situation where adding another wind farm sees 80% of its additional output curtailed, which means that the useful 20% costs 5 times a simple LCOE estimate.
The interesting question isn't really can you power [insert name of country here] with wind and solar, but why would you want to? Most of the costs of electricity aren't in the generation but the grid. With nuclear you just plug it in and it works, with wind and solar you need a massive redesign and rebuild effort ... particularly with rooftop solar in places like Australia. A heavy rollout of rooftop PV and batteries is already breaking our grid in South Australia. We are going to have enough trouble opening enough mines fast enough for EV batteries, so why waste precious resources backing up environmentally destructive collectors of electricity like wind and solar? Please consider ...https://www.blog.geoffrussell.com.au/post/energy-spin-and-the-running-of-the-bull-shit
I'm very pro-nuclear (I state quite clearly that I think the optimal mix would be a combination of solar, wind, significant nuclear).
Unfortunately the UK has not been great at building nuclear quickly or cheaply. If you have a grand plan to fix this, and get political and public support for it, I'm all ears. In the meantime, I will continue pushing for sources that are scaling quickly.
Solar, wind and nuclear do not mix, as the French have already worked out. In reality, they depend on hydro and some gas to provide the dispatchable flexibility that is difficult to achieve with nuclear. Plans to try to replace half their nuclear by wind have been abandoned. It would have required an increase in dispatchable flexible generation that would have inevitably ended up being gas, since most of their feasible hydro resource is already exploited.
Maybe the hundred of billions you want to spend on nuclear submarines might help you keep your head above water.
Thanks Hannah, really good blog to read. I had similar reaction to David MacKay’s work, in that it / he inspired me to go into policy facing work in the civil service, realising my background in science could be useful. Great to get this update to the figures in SEWTHA!
An idea for an extension, which I found helpful when I was working directly in the policy area, if you want to look beyond the totals at dispatchability and get a sense of scale of storage or other technologies needed was to look at the demand curve. If you plot half-hour demand on the grid for the year, ordered from high to low along the x-axis, you get something that looks a bit like a trapezium going from winter peak to a summer lull. You can plot a typical wind and solar profile against that. You’d expect this would show excess supply on the RHS, and an unmet demand in the LHS. You can then ask how much can be shifted around with say 4hrs of storage (very doable with cheaper batteries), and then what residual demand will you need to meet with another tech like gas, or demand response, or nuclear, or closed loop geothermal (which can also act as a kind of storage…). The optimal split depends on a mix of economics and politics. Appreciate this might be a bit too in the weeds though!
In the end there is no substitute for doing a proper study with real weather data at hourly resolution or better spanning many decades. That is what I did 6 years ago, and now the Royal Society has finally started to catch up. Unfortunately their estimates of storage requirements and curtailed surpluses are almost certainly on the low side because of the many highly optimistic assumptions in their analysis, including a failure to look at real world cold weather demand (their demand profile is based on a single year, 2018 not the 37 year weather history or actual demand history), very optimistic cost and capacity factor assumptions (see also the working paper being discussed in thus article), and much else besides.
Still, they have made a start, and no future projection can ignore the issue, which is of course what this study has done, and why it is worthless.
Hannah tries to "work out if Britain could power itself from renewables," which if I understand correctly means whether Britain could get all (or almost all) of its electricity from wind and solar.
This post unfortunately shows the limitations of the author's data-driven approach — the most important factors are left out because they can't be computed as easily as less important ones.
The post considers (1) the amount of energy Britain could get from wind and solar and (2) the cost of wind turbines and solar panels. The post concludes that there are enough resources available and that turbines and solar panels have become much cheaper, therefore yes Britain can get most of its electricity from renewables.
But these aren't remotely the main costs or constraints anymore. The main costs in adding solar and wind to a grid are related to (3) grid transmission and distribution, (4) storage and overbuilding to handle renewables intermittency, and (5) project finance.
Grid transmission and distribution — According to the chairman of Iberdrola, for every dollar invested in renewables, another dollar needs to be invested in grid transmission and distribution.
https://twitter.com/BloombergNEF/status/1719010207836316015
Handling intermittency — A recent report from the Royal Society explains that we'd likely need to store energy for decades because of long term trends in wind power generation:
> Wind supply can vary over time scales of decades and tens of TWhs of very long-duration storage will be needed. The scale is over 1000 times that currently provided by pumped hydro in the UK, and far more than could conceivably be provided by conventional batteries.
It calls for storing about 100 TWh. The only technology (they claim) to be viable is hydrogen storage.
https://royalsociety.org/topics-policy/projects/low-carbon-energy-programme/large-scale-electricity-storage/
However, as far as I'm aware, large scale hydrogen production, transport and storage is still in its infancy and therefore we need demonstration projects before estimating its cost with any certainty.
Finance costs — The constant drumbeat of offshore wind project cancellations reminds us that finance costs are important. Since most of the costs are incurred upfront but revenues are recognized over 20+ years, higher interest rates make projects more expensive.
https://www.bloomberg.com/news/articles/2023-07-22/biggest-offshore-wind-power-plans-in-crisis-iberdrola-orsted-vattenfall-hit
Energy analyst Ira Joseph often issues the following challenge to promoters of small modular nuclear reactors: "Just build one." That is the only way to understand if they are practical and economically viable.
The same goes with any electrical grid that is powered (almost) entirely by renewables. Until one is built and we can evaluate its costs, discussions are likely to focus on some factors of the total cost but miss out more important ones.
I’m all for crunching numbers but expecting wind and solar to decarbonise the UK and provide security of supply is straight out of Ed Miliband dummies guide to energy.
The deployment of either technologies to the levels required to achieve and sustain that level indefinitely are well beyond credibility both from a material resources, manufacturing, construction and maintenance point of view.
David MacKay’s numbers and reasoning still has validity 15 years later.
I totally agree with Andrew Mont ford's assessment.... IDIOTIC AND IGNORING LAWS PHYSICS....