Energy Storage Is a Cost Item, Not Unlike Peaker Plants
Frequent commenter Cameron Atwood writes:
I’m pleased to hear that further strides are being made in storage, and I look forward to seeing specifics emerge on this technique. The more of this progress is made and adopted, building on already proven storage technologies, the more obsolete and empty the red herring of intermittency will become.
I look at storage as just another cost item associated with serving peak load. Btw, this is what makes the zinc-air battery deal (from our list of clean energy investment opportunities) so exciting. The main question is: Can storage cost less than the same size peaker plant? And the answer, it seems, will soon be Yes.
Of course, this isn’t a straightforward trade-off; peaker plants have an array of advantages and disadvantages vis-à-vis storage that make this a slightly more complicated issue, though this high-level comparison is a good place to start.
Intermittency is not a red herring.
Until a few years ago, I strongly supported renewable sources of power. Then, on a motorcycle trip from Albuquerque to Savannah, Georgia, I passed many wind farms and noticed that in many, the turbines were stationary. Then I got to wondering where, if we depended in renewables, our power would come from when the sun was not shining and the wind was not blowing. Previously I had assumed that renewables would not be pushed unless that problem had been solved; I should have known better than to assume anything.
Upon doing extensive reading, I could find to evidence that the intermittency problem had been solved. Oh, there were claims that if enough wind farms and solar systems were interconnected that we’d have reliable power, but I could find no credible studies that supported that position. Determining how much reliable power would be available with renewables would not be easy to do. An adequate study would probably cost at least hundreds of thousands of dollars, or more likely, millions of dollars.
Next, I began to examine nuclear power more closely and learned that there were many ways to design reactors of various types. Soon I discovered the liquid fluoride thorium reactor (LFTR) and it seemed very promising since it could eliminate the usual valid objections to nuclear power that result from our use of pressurized water reactors (PWRs). The integral fast reactor (IFR) is another possibility, but to me the LFTR approach seems better.
Practically all those opposed to nuclear power are not even aware that alternate nuclear technologies can be developed. They base their objections only on the PWR. It’s true that considerable R & D would be required to get different reactor types ready for implementation, but a similar situation also exists with renewables. With currently available technologies, renewables simply will not do the job, especially in countries which have a much higher population density than the U.S.
Storage cannot be compared with peaking plants. Peaking plants do not have to be made larger and larger as power is needed for longer intervals whereas storage systems have to increase in size to provide power for longer intervals.
Wind comes in random cycles. It is possible that with considerable storage and over-building of wind farms, there could be adequate reliable power for a few years then for enough time to deplete storage, the wind would be inadequate so there would be a serious power shortage for weeks. Of course it would be possible to maintain fossil fueled plants to cover in such situations, but the maintenance of the fossil fueled plants would be added to the cost of the renewable systems.
During one of the coldest winters on record, a large off-shore wind farm in the UK provided very little power for a few months because of low wind. That came as a shock, but only because the wind farm was build before doing the necessary research.
Having been involved in the licensing and development of a 1000 Mw closed loop pumped storage project I have seen the model change from a simple arbitrage model to one where the upper and lower ponds are never full or empty. It apparent now that this facility will be use totally for balance, time shift frequency reg and the deferment of transmission build up. The soak periods due to variable renewables in the region will be balanced by load following and frequency reg. Of course the value of these services will be shaped by the market and the elimination of fossil fuel use supported by clean air mandates.The ability for such a large facility to out perform natural gas is inherent with the new variable turbines associated with advanced stator attributes; they are much faster than gas and don’t have to spool up or remain at idle in anticipation of market demands. If ideally located such a facility could service two regional balancing areas without too much trouble.
There is still the problem of extended intervals when there is no wind. There are hourly, daily, seasonal, annual, and longer variations in the amount of wind. Energy storage can help with short term variations in wind, but if every few years the amount of wind is well below normal for a few months, there would be a serious problem.
Probably there would be no way around having a back up system that could provide power 24 hours per day 365 days per year without being affected by the weather. The back up system would have to be capable of providing for a very high percentage of the demand. Probably it would not need to provide for 100% of the demand since renewables plus storage should be able to provide for a significant portion of the demand at all times. Determining how much power the back up system might be called upon to provide would be difficult, but I’d guess that the amount would greatly exceed 50%.
Maintaining a back up system so that it would be ready to operate at any time would add to the cost of power.