Although both nuclear and renewables are useful to reduce carbon emissions, nuclear is not included in the most ideal power mix due to its waste management, expensive decommissioning and inherent safety risks. While Germany and Japan consider these risks to be greater than the risk of increased carbon emissions, many other countries balance the risks differently.
Aesop wrote a fable called the Oak and the Reed, where the Oak spoke to the Reeds, saying that they are worse off, since any slight breeze will cause them to bend. The Reeds told him not to worry about them, as the wind would cause them to bow, but not to break, while the Oak could not bend to stronger winds. A hurricane came a little while later. The great Oak, while standing proud at the beginning, fell with a great thunder, as the Reeds bent in pity.
A great wind of change is happening in electricity markets, unlike any the utility industry has seen from its beginning. Natural gas has topped out coal in the U.S. for the first time, as EPA regulations and lower natural gas prices hack away at previous price advantages. With falling costs for renewables, more environmentally concerned customers, and governmental promotion policies, renewables are increasing their share of the energy mix and will only continue to do so.
On the demand side, the internet of things (IOT), home batteries and solar power, electric cars, and the opening up of many electricity markets are making customers more flexible, adaptable, and independent. Drives to improve the efficiency of electrical consumption also have the impact of increasing renewable penetration, as less electricity is used in total for the same installed renewable capacity.
With nuclear power's inability to adjust to power demand, it risks going the way of the great Oak. There are three ways to extend the life of nuclear in the energy mix: either lessen the wind by pricing in nuclear power at a different level, increase the flexibility of nuclear by allowing it to adjust to demand, or build smaller reactors that huddle under the wind, i.e. increase grid flexibility as each incremental reactor is smaller.
Lessening the wind: Pricing in nuclear through policies towards risk and carbon emissions
As the utility grid becomes greener, more flexibility and/or storage is required to allow for the intermittency of wind and solar. The first 5-10 percent can be handled relatively simply, using pricing strategies, flexibility in natural gas plants, and demand management at industrial and commercial facilities. However, once renewable penetration becomes large enough, these strategies cease to suffice.
Once the renewable penetration increases over 60 percent, the challenges related to further decarbonising the grid become exponentially greater, and this is where pricing nuclear makes sense. As Jesse Jenkins, an MIT researcher, points out, "It's not really a fair comparison to say there's all this low-hanging efficiency fruit and we should do that instead of nuclear, we should be doing that instead of running coal plants."
The retirement of Diablo Canyon is one nuclear giant that will be affected by pricing metrics for renewables and intermittency in California's energy market. Coming in at 2,200MW, Diablo supplies almost 1/10th of California's power just by itself. While the decision has been highly politicized, PG&E has recently determined that after 2025, California would only need run Diablo Canyon intermittently.
The state hopes to produce 50 percent of its power from renewable sources by 2030.There is no doubt that a full decarbonisation of the electricity grid as quickly as possible should be the goal. Jesse Jenkins notes, "If we want to be 60 percent overall, then that 60th percentage point of renewables is what you should be comparing to Diablo Canyon, not the first cheapest renewable plant you build, in most cases, those marginal plants are quite expensive."
At these percentages, there are fewer and fewer favourable locations to build renewable generation, more flexibility or storage required in the grid, which all translates into more expensive renewables, despite falling installation costs.
Bending in the wind: demand response in nuclear
As nuclear power plants require large numbers of staff to operate, it often isn't economically feasible to operate nuclear at 50 or 25 percent power. The portion of fixed costs are simply too high, and economically nuclear makes the most sense at 100 percent power. Related: What Will Happen To Turkey's Energy Security Following The Failed Coup?
However, many reactors were designed to operate to be load-following. A case in point is the Westinghouse PWR, which was designed to operate on a 12-3-6-3 daily cycle as required: 12 hours at 100 percent power, then a three hour ramp-down to 50 percent power, six hours at 50 percent, and finally a three-hour ramp-up again. Although uranium fuel is not burned as efficiently in this type of operation, it is better suited for the duck-shaped demand curve that California has. New Westinghouse designs such as the AP1000 have greater demand following capabilities than older designs. Nuclear can do the demand response dance, it just hasn't been asked to the floor.
Huddling under the wind: building small modular reactors
(Click to enlarge)
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As older power reactors are retired, smaller reactors can provide greater flexibility in the grid that the larger designs from previous generations. Indeed, if older reactors are giant oaks, SMRs will be reeds. During load following operations plants like the Westinghouse SMR will be capable of "performing ±10 percent load changes at a rate of ±2 percent per minute to support grid frequency response." Unfortunately, many of the new reactors currently being built will be larger ones, with only Russia, India, China, Pakistan, and Kazakhstan actively building SMRs.
Conclusion
If the goal is to decarbonise the whole electricity grid as quickly as possible, continuing the operation of nuclear reactors makes sense. Further, building new nuclear capacity makes sense at higher total clean power capacity. With today's technology, a grid completely run on wind and solar would be prohibitively expensive. It is a question of philosophy whether, in the coming decades, the difference is made up by nuclear or natural gas.
Gas meshes better with its ability to ramp up and down as required by the grid. However, it is not carbon-free. Shutting down nuclear plants today will cause challenges down the road, when we seek to completely green the grid. A nuclear plant may not follow demand today. But we do not have enough equivalent storage to compensate for the lost green power. It may make sense to curtail green intermittently now, as we build up the flexibility the grid requires to go completely green.
Japan restarting a considerable part of its nuclear fleet this August after its hiatus due to Fukushima shows how difficult even advanced economies are finding going fully green today without nuclear. Germany chose to delay full decarbonisation over stopping its nuclear fleet. The jury is out on how the rest of the world tackles greening its grid.
By Matt Slowikowski for Oilprice.com
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Matt Slowikowski is the founder of the energy analytics blog enernomics.org. He specializes in economic analysis of the energy industry and energy projects. More
Comments
The last piece of the puzzle for complete freedom from fossil fuels is energy storage, but batteries are dropping dramatically in price and installations are growing at a super exponential rate. In 10 years a completely renewable grid will even more obvious if you can't see that now.
What is harder is to ballance the weekly variation. Substantially less power is demanded on the weekend than on week days. To handle this with storage, you need some portion of storage that is economical to cycle weekly. Eventually, batteries can handle this, but it would take on order of 120 GWh of total capacity. EV charging on heavy the weekend and only lightly on weekdays could also help iron out the weekly cycle. But here is also a genuine opportunity for nuclear power. Operating at 25% on Saturday and Sunday, ramp up slowly Monday, hit 100% Tuesday through Thursday, and then ramping down on Friday would really help the weekly cycle.
Finally, the most enduring opportunity for nuclear will be to make up the shortfall of solar and wind generation in December and January. At least in California, these and June and July are the lowest production months for wind. So wind does a poor job of balancing seasonal demand for the state. Solar delivers its peak production in June and July. So it is super for handling demand for airconditioning. But its lowest production months are December and January. Even if California had twice as much solar to handle June and July energy demand, it would still be insufficient for December and January. Batteries are no good for annual cycling. So here we arive at a genuine need for fuels for annual energy storage. The carbon neutral options include biofuels, synthetic gas and hydrogen from electrolysis of surplus electricity, and nuclear. Demand response can also help. Certain industries may find it reasonable to reduce production in the darkest months or locate closer to the equator. But this will be the enduring challenge in a carbon neutral world.
I do not see how the economics of nuclear power can ever work if it is reduced to operating for just a few months each year. So nuclear does need to learn to be more flexible to compete over the next few decades. It is important that taxpayers and ratepayers not be misled into subsidizing nuclear, however. The most compelling reason why is that renewables and soon batteries are much more economical. If the public must subsidize any energy, the return on clean energy is twice as high on renewables than on proping up aging nuclear plants. So it is good to reap as much benefit from existing plants as is profitable to do, but beyond that we need retire geriatric plants and move on to cost effective renewables.
Waste management? Nuclear's waste stream is the best managed of any energy source or industry, with short and long term risks/impacts that are *lower* than those associated with the waste streams of most, if not all, other energy sources. Decommissioning costs? They are fully included in the price and amount to a fraction of a cent/kW-hr. Safety risks? Statistics actually show nuclear to be the safest of all sources, and it's overall environmental impacts are negligible compared to fossil fuels and similar to renewables. The case that nuclear is "less ideal" than renewable power is very weak (renewables have their own issues, such as massive land use, destruction of wildlife, and intermittency which required fossil backup, etc..).
It's astonishing that anyone would characterize the "question" of whether nuclear is better or worse than fossil fuels as something that reasonable people would ever disagree about. Nuclear is thousands of times better than fossil fuels, as all statistics and scientific analyses show. The (apparent) view in Germany and Japan that nuclear's "problems" are worse than global warming (and fossil fuels problems) is patently absurd. Even w/o global warming, the air pollution impacts alone make fossil power generation thousands of times worse than nuclear. Such views are right up there with views that global warming is a hoax, the earth is flat, the Holocaust never happened and cigarettes don't cause cancer. Such views aren't merely wrong, they are unacceptable. Something needs to be done.......
The rest of the article isn't so bad, with one exception. The entire context of discussion is that large renewables penetrations are a given. A fact of life, apparently decreed by God. Given these "facts of life", nuclear's inability to load follow is deemed a negative attribute of nuclear. No, intermittency is a weakness of renewables. But apparently that doesn't matter because renewables were decreed by God. The more correct view is that renewables' intermittency is a serious limitation, and until it can be addressed (by storage, etc...) significant renewables penetration is not advisable.
What we really need are technology-neutral policies that focus on the real objective, i.e., reduced CO2 emissions and reduced public health impacts from pollution. Tax CO2 and health-harming pollution and let the market decide how to respond. (That instead of current policies we now have, which heavily subsidize and outright mandate renewables only.) Would utilities respond by creating a large market penetration of intermittent renewables? There are reasons to doubt that. Would they keep existing, paid for, nuclear plants in operation? Seems obvious that they would.
First of all (something I forgot to mention in my first post), the problem with nuclear load following (operating only part of the time) is not really technical but economical. Since nuclear costs are relatively fixed (whether the plant is on or off) it doesn't make any economic sense to run a nuke part of the time. Thus, with any reactor technology, it will not make sense to build a nuke and run it part of the time. I suppose if fossil fuels were really not allowed at all, it's possible that in long periods when renewables are not producing (like Dec and Jan?) power prices could rise so high that it would make sense to have a reactor on for just those periods, but it's a stretch. The competition (for the reactor) would be mass scale storage.
Anyway, I can't agree with any of your statements about subsidies. You say that we should subsidize renewables because they are (or will be) so cheap? If an energy source is cheap, it does NOT require subsidies. Subsidizing new renewables is NOT the most cost-effective way to reduce emissions. On the contrary, the subsidies required to keep existing nuclear plants open (e.g., in NY) are far lower than those given to renewable energy. Providing small (~1 cent/kW-hr) subsidies to keep existing nuclear plants open is likely the least expensive means of emissions reduction that you will ever find.
Subsidies shouldn't be about picking winners (based on supposed future prospects, etc..). They should be used to give clean sources the proper credit for their non-polluting, non-CO2-emitting nature. Their real purpose should be to correct the market failure associated with the fact that fossil power plants get to emit CO2 and pollute the environment for free. Given this, all non-emitting sources (e.g., renewables and nuclear, both new and existing) should receive the *same* level of subsidy. That will allow those non-emitting sources to compete with each other on a fair, level playing field. If you're right that renewables will be cheaper, then they will win out over nuclear, even with equal subsidies.
Many renewables advocates seem to be talking out of both sides of their mouth, on the one hand talking about how renewables are cheapest, etc.., but then insisting that we keep subsidizing, and outright mandating, renewables only. In other words, saying that they're cheapest but refusing to put that assertion to any kind of market test, i.e., refusing to expose them to competition. You can't have it both ways. Why would people believe or trust you?
Clearly it is you who lacks the ability to stay apprised of current circumstances.
1) Renewables (Intermittents) are far from being economical currently, otherwise they wouldn't have to be so heavily subsidized, and not just here in the U.S., read some German and Spanish publications.
2) Renewables must always have backup due to their intermittency, so they invariably rely on natural gas to pick up the slack, so much for CO2 emissions reductions.
3) I'm certain that you are unaware of the witch’s brew of toxic chemicals associated with the manufacture of PV Solar Panels: Arsenic, Cadmium telluride, Hexafluoroethane, Lead, Polyvinyl fluoride, Trichlorosilane, Nitrogen trifluoride, Sulfur hexafluoride, Copper indium selenide, Copper indium gallium (di)selenide.
4) The land use issues associated with Wind and Solar that are arising everywhere as people begin to see how much of nature must be despoiled for large scale deployment of these technologies.
5) Why would anyone wish to dispose of Unspent Nuclear Fuel that retains over 96% of its initial energy content. Many of the GEN IV Nuclear Reactors, being pursued by over 50 companies and funded by over $1.5 Billion in private capital, possess the ability to utilize this unspent nuclear fuel. Addionally, one type, Molten Salt Reactors uses liquid nuclear fuel which results in a walk-away safe, dynamically stable, load following circumstance with no human intervention.
Harnessing the power of most energy dense elements on the periodic table, possessing an energy density a million times greater than the Carbon-Hydrogen bond is here to stay, it is being embraced by a young generation that refuses to be saddled with the fears and superstitions that has cowered the prior.
You are to be commended for your relentless debunking of so much of what is written by the ill informed. You should not be shouldering this burden alone.
I know you are aware of everything I am now posting, this is too provide information for others to reflect upon.
If the adoption of Wind and Solar is inevitable as though "decreed by God". Let's not forget that the use of the natural elements Uranium and Thorium should be considered inevitable for they too, as natural elements, can be considered "decreed by God." Were they not, the Earth would not possess a magnetosphere that protects it from the Solar Wind, hence our atmosphere would have been eviscerated billions of years ago and life would never have emerged.
We live on a Nuclear Planet, all life evolved under constant exposure to normal background radiation across the planet which was, in the distant past when one celled organisms arose, far greater than today. Because of this all life has cellular (genetic) repair mechanisms.
http://energyforhumanity.org/featured/is-radiation-necessary-for-life/
On another matter, the earlier post by Keepitintheground states, "That's why a majority of electricity generation put on the grid last year was wind and solar. Granted there was a significant amount of natural gas"
From the Energy Information Administration (EIA):
In 2015, electric generating companies expect to add more than 20 gigawatts (GW) of utility-scale generating capacity to the power grid. The additions are dominated by wind (9.8 GW), natural gas (6.3 GW), and solar (2.2 GW), which combine to make up 91% of total additions.
The EIA goes on to state a key proviso, which many either don't know or don't understand:
Because different types of generating capacity have very different utilization rates, with nuclear plants and natural gas combined-cycle generators having utilization factors three to five times those of wind and solar generators, capacity measures alone do not directly show how much generation is actually provided by new capacity of each type.
Keepitintheground also states, "but nuclear is only being added to grids in China and Georgia and its not because of economics. They're being forced down people's throats"
The only mandates (the forcing of things down people's throats) are those provided to Renewables in the Renewable Portfolio Standards (RPS) adopted by many states rather than a Low Carbon Portfolio Standard (LCPS) which would include Nuclear. Due to a backlash from many communities regarding the installation of wind farms and natural gas plants to replace their existing Nuclear facilities the State of New York is considering adopting LCPS or allowing Nuclear to participate in a revised RPS.