Wind, Solar and Storage Will Take Too Long To Build
Antinuclear activists often claim that nuclear power takes too long to build, but in reality it will take much longer to build wind, solar and the necessary storage.
In my last Substack article, I showed how the UK government had seriously underestimated the cost of offshore wind. That has now been shown to be true, the maximum CfD price for the next round of bidding for offshore wind has been increased to £73/MWh in 2012 prices which corresponds to a value of about £85 in 2021, almost twice what the UK government was telling us it was going to cost.
In the article before that one, I criticized a report published by The Royal Society because it used cost projections based on UK government data that did not reflect reality, the biggest discrepancy being the assumed cost of offshore wind power. I also pointed out that, if realistic price data had been used in the report, nuclear power would have been shown to be less expensive than renewables.
Today, I am going to address one of the other aspects of nuclear power that anti-nuclear activists claim rules it out of consideration as a replacement for fossil fuels. I am talking about the statement often heard that “nuclear takes too long to build”.
It’s true that some nuclear plants have taken an exceptionally long time to reach completion. Vogtle and Watts Bar in the USA and Olkiluoto 3 in Finland are examples that are often quoted by anti-nuclear activists. But those plants were delayed by on-again, off-again government interference and changing regulations.
France built 56 reactors in 15 years in response to the oil crisis in the 1970s. Each phase of Ontario’s Bruce and Pickering power stations (4 reactors per phase) took about 8 years from start of construction to commissioning and each unit of the recently completed Barakah 5.6 Gw power station in the UAE took 8 years and the entire 4-unit project took 12 years.
The chart below from this site summarises the build times for many of the reactors currently in operation. Two-thirds of existing nuclear reactors had construction times of less than eight years, and the very long construction times are the exception, not the rule.
The Royal Society in the UK forecasts that the country will need to generate 570 Twh/year of electricity in the Net Zero case. That number assumes an “electrify everything” approach with all gas heating converted to electric heat pumps.
The UK recently announced, with much fanfare, an extra $1.5 billion in grants for heat pump installations. That’s enough for 50,000 homes per year over the four-year period of the grants. At that rate, it will take 560 years to reach that “electrify everything” target, but leaving that aside, let’s assume it is done and see what we need for a nuclear approach rather than a wind and solar approach.
570 Twh/year is equal to an average of 65 Gw of power, the peak demand is likely to be around 103 Gw and the minimum demand is around 35 Gw. You would not build nuclear power to meet the peak demand, you would use batteries to cover the daily peaks and hydrogen for seasonal storage to smooth out the utilization of the nuclear plants. The optimum setup for an all-nuclear generating system with battery and hydrogen storage would have the following components:
· 85 GW of nuclear power.
· 1 GW of hydrolysers for hydrogen production.
· 5.4 TWh of hydrogen storage in underground salt caverns.
· 18 GW of generating capacity from a combination of batteries and hydrogen-fueled combustion engines.
The UK has only 5.9 GW of currently operating nuclear power and another 3.25 GW under construction. The UK plan for net zero includes 24 GW of nuclear power by 2050. That would have to be more than tripled to provide an all-nuclear generating system.
It would take an enormous effort to build enough nuclear capacity by 2050, but there is precedent for such a move. After the Arab oil embargo and oil price shocks of the early 1970s, France, a country with few energy resources of its own, successfully undertook a program of nuclear construction of equal magnitude.
At the opposite end of the spectrum, what it would take to build an electrical system that relied completely on wind and solar, for the same output power? We can determine the required system by simulating the grid operation over a 37-year period using historical wind and solar data and adjusting the components to give us the lowest-cost solution. This is what we get:
· 265 GW of wind
· 53 GW of solar
· 36 GW of hydrolysers to make hydrogen.
· 115 TWh of hydrogen storage in underground salt caverns
· 99 GW of generation capacity using a combination of batteries and hydrogen-fueled combustion engines.
· A massive build-out of transmission capacity
The first thing that strikes you is the quantity of generating capacity is much higher for the wind and solar case. There are three reasons for that:
1. Capacity factors for UK wind are around 40%, and for solar, only about 10%, so the total installed capacity can only produce the equivalent of 111 GW of continuous power.
2. A lot of the energy gets converted to hydrogen for storage, and that takes 3 KWh of input energy for every KWh of output.
3. Periods when wind and solar are producing at close to maximum output are relatively rare, only a few hundred hours per year. It is not economical to build hydrolyzers that only operate a few hundred hours per year, so a portion of the energy must be curtailed.
The extra generating capacity is needed to compensate for the low capacity factors, the inefficiency of the hydrogen storage and the curtailment.
Over a 15-year period since 2008, the UK has installed 30 GW of wind power, an average of 2 GW per year equally split between onshore and offshore. Continuing at that rate would require 132 years to build the necessary wind turbines, but the turbines would be reaching the end of their life faster than they are being built, so that rate of building would never reach the necessary capacity.
The COP28 commitment to triple renewable capacity by 2035, assuming it is applied equally to wind and solar, would require an increase in wind power construction to 5 GW per year over the next twelve years, a 250% increase in the rate of construction. That rate would also never reach the necessary capacity because a 265 GW system needs more than 10 GW/year of additions just to replace the turbines that are wearing out.
To reach 265 GW by 2050, starting in 2024 and assuming a 25-year turbine life, you would have to build more than 15 GW per year. Adding to the difficulty, the offshore turbines will have to be built further from shore and in deeper water, and the land-based turbines will struggle to find suitable locations.
So, reaching net zero by 2050 using wind and solar also requires more than tripling the committed construction rate.
At the same time, hydrogen manufacturing and storage would have to be built. This is where the huge difference between the nuclear option and the wind/solar option resides. Note the hydrolyser capacity is 36 times higher for the wind/solar option and the storage requirement is 20 times higher.
In their paper on energy storage, The Royal Society recommended the use of solution-mined salt caverns in salt formations under Yorkshire, Cheshire and Wessex. The caverns would look something like the picture below:
They are constructed by pumping water down a pipe into the salt layer 1.7 km. below the surface, dissolving the salt and extracting the brine. A blanket of nitrogen maintains the pressure to prevent the dome from collapsing. The whole process takes about two years to construct a cavern.
In their report, The Royal Society calculated that 900 salt caverns would be needed to provide the necessary hydrogen storage. Though I have seen references to the need for those caverns, I have not come across any announcement or commitment to start building them. They would have to be funded from the public purse because no private corporation would take the risk of building a massive storage system that would only be fully used about once a decade, and depends entirely on the weather for its operation.
Hydrogen production would presumably be located close to the salt caverns to minimize the hydrogen piping. Transmission lines would be needed to connect to the hydrolysers which consume, at their peak, an amount of power equal to the average power consumption of the entire country today.
Wind and solar production can, at times, be close to zero, and those times may coincide with periods of high demand, so a backup system of batteries and hydrogen generators needs to be able to meet the peak demand with very little help from wind and solar.
Generation of electricity from hydrogen would probably use internal combustion engines, they have the cheapest capital cost, relatively high efficiency and they can start and ramp up very quickly.
The world’s biggest combustion engine power plant is a 573 MW plant in Jordan, powered by 38 Wartsila multi-fuel engines.
Total capacity required would be 99 GW, but batteries could be used to shave the evening peak load, the maximum load handled by the hydrogen generators would be more like 75 GW.
130 power stations like the one in the picture above, with almost 5,000 generators would be needed to back up a system that is based on wind and solar.
A wind and solar-based grid will also need a much bigger and more complex system of transmission and distribution. In the nuclear option, power station locations can be optimized to minimize the transmission requirements, but in the wind and solar case the power is not always generated at the same location.
Wind turbines will be distributed in the windiest locations in the country, and in the ocean around the country. Solar will be mostly in the south. But the wind isn’t always blowing in the same place all the time, the sun only shines during the day, and the whole system needs to also transmit power to the entire country plus the hydrolyzers, and from the hydrogen-fueled generators to the rest of the country. It would be a very inefficient system with about three times more transmission capacity than would be needed for the nuclear option.
If you have been paying attention so far, you must have realized that the wind and solar option for net zero is just as unattainable as the nuclear option.
The excuse that nuclear power takes too long to build is just not valid.