New Compressed Air Energy Storage Plant Coming to California
It appears that planet Earth is on its way to its third implementation of CAES (compressed air energy storage) – one of a handful of different technologies that warehouses off-peak energy production and makes it available for times of greater load. This concept, of course, will eventually be important if our society is to amp up the amount of variable resources (solar and wind) that it integrates into its grid mix.
CAES detractors say that the specific thermodynamics associated with each particular venue normally mean huge penalties in the efficiency by which the caverns are charged and discharged. Others seem less concerned about this issue, and point to the large scale and low cost of operation.
I look at the matter as follows. First, let’s look at the five main “flavors” of renewables: solar, wind, biomass, geothermal, and hydrokinetics, and note that the last three of them have very little variability, leaving solar and wind. Less than 1% of our current grid-mix in the U.S. is solar, but that’s barely relevant, since we don’t need to store solar unless we get to extremely high penetrations, e.g., huge utility-scale installations of PV or solar thermal. That’s because solar is available at roughly the same time as peak load; i.e., the presence of the sun and human activity are approximately concurrent.
That leaves wind, which is the only real candidate for storage, as it’s highly variable and doesn’t coincide well with peak load. But wind is about 4% of the current grid-mix in the U.S., and, at this low penetration rate, storage is a non-issue.
So what about the future? The cost of wind energy is attractive and becoming steadily more so. We’ll want to integrate more of it, won’t we? Yes, but I’m betting that by the time we have enough wind that storage becomes necessary (say 15% – 20%), the cost of batteries will have come down to a point that mechanical solutions like CAES, pumped hydro, advanced rail, flywheels, etc. will be obsolete.
Could I be wrong? Of course. My friends at Doty Windfuels see their solution (synthetic gasoline and diesel) as the real answer here, and trust me, they’re pretty impressive people. But it’s disagreements like these that make good horse races.
P.S. Let me close with a reminder on a separate, though related subject: here’s July’s webinar with Jesse Berst of the Smart Cities Council.
Craig,
It’s important to remember that while the overall U.S. grid penetration of wind is ~4% (for 2012, it will be higher in 2013), there are some states that have as high as 30%.
In most states, pumped hydrostorage; combined with simply varying the flow through the dammed hydropower turbines, is sufficient to integrate the wind power with very little curtailment. But in the plains states that is not feasible… which means curtailment issues start becoming a real problem.
That said, CAES is a ridiculous waste of money. This is especially the case in California – a state with plentiful mountains and hydropower.
The easiest way to determine the relative merit of an energy storage solution when dealing with wind power is the following: Assume a fixed amount of money will be spent (let’s say ~$500 million). There are two options for spending that ~$500 million: 1 would be to put up 500 MW of wind turbines, the other would be to put up 250 MW of wind power and one CAES facility. The 500 MW of wind would (presumably) face curtailment issues, and so might be limited to ~30-33% capacity factor, for a 40-year total of ~52 – 58 TWh. The 250 MW of wind would not face curtailment issues, due to the CAES storage balance, so that option might see ~36-40% capacity, for a 40-year total of 31.5 – 35 TWh.
So by spending the same amount of money, we can see the total amount of generated renewable energy drop by ~40%. (???)
Of course, even when curtailment is not an issue, the CAES plant in question would still be operating throughout the night and day – trying to limit the extraordinary financial losses… so it would also be storing some additional baseload power throughout the night and releasing that during the day – increasing the total capacity of baseload power. In most cases, increasing baseload power capacity means increasing coal power penetration.
This is not a good solution.
For the comparison to WindFuels – the $500 million would still result in ~500 MW of wind, while a different party builds one WindFuels plant capable of turning the curtailed energy into clean fuels. The fact that the WindFuels plant would be a PROFITABLE consumer of variable energy allows the wind power to be built out without constraint.
The use of “BASELOAD” in the above comment should be defined, otherwise it is in my opinion just a sneaky way to suggest that using nuclear is somehow a good thing or even required, which is something that California does not need; especially when you look at the Trillion Dollar Eco-Disaster Risk that a single nuclear generating station poses…
Remember Fukushima and what is is still doing to Japan and the Pacific Ocean!
CaptD,
Baseload is defined: it’s energy generation that is operated at a rate independent of variations in the demand load.
Most baseload is either coal or nuclear. If you want to cut nuclear, it just means you increase coal usage. If you’re worried about safety in the face of a 9.0 earthquake, the most potentially destructive energy source is a hydropower dam. Nuclear is pretty safe if it doesn’t get hit by a massive earthquake and a tsunami.
Craig: I totally agree with Doty’s assessment. It helps turn wind a business and also turns cheaper energy into liquid fuels, which will be extremely important if we take into account the future availability of oil.
Wind energy is still going to grow, the storage part will be a little difficult to say how or when we will be using it in an economical way, so liquid fuels is a better strategic option, economic and political (if you manage to teach politicians, and keep the fossil guys away enough).
Compressed air sounds magnificent, until you see how much power is lost in the thermodynamics.
I have read about another CAES solution, which uses geothermal heat to combine cooling and re-heating the air to recuperate the lost energy between compressing and decompressing the air, that solution looks more liable, but then, you are using two types of energy and maybe using the geothermal directly would be cheaper. (Must do the numbers)
I prefer wind.
There are other CAES technologies out there that do not require huge geological locations.
This one is probably combined with a Gas Power plant to improve its efficiency by 30%
Lightsail recently invested in by Bill Gates.
SustainX small modular plants that also save the heat energy.
Hydrostor in Canada underwater air bags
All of these have efficiencies claimed to be close to those of pumped Hydro.
What’s the overall efficiency of synfuel or biofuel production which is then burnt in a Internal combustion engine?
Thanks Craig:
The smart cities webinar was very good I recommend listening.
Do we need to store electricity in order to regenerate it as electricity again, in the future? I don’t think so. What we need is substitutes for gasoline and diesel. If Congress will pass OFS, mandating the automotive industry building GEM flexfuel cars, we will need electrofuels.
I agree with Glenn Doty on that. However, in contrast I think methanol/DME is the best pathway.
Jan-Gerhard,
Methanol will certainly be blended into the final mix, but there will never be a time when we are willing to allow truly poisonous fuel with low vapor pressure to be the dominate fuel… The very first person that passes out and is rushed to the ER because the vapor hood on the pump wasn’t working right… and the lawsuits will never end.
Besides, we need several hundred products that are currently derived from petroleum. Synthesizing a petroleum gets us all of these products, synthesizing methanol gets us one of the lesser-used products.
That said, there will be plenty of synthesized methanol in the future economy, I just don’t think it or DME will replace gasoline.
The efficiency of syn-fuel is mute in the face of CO2 pollution, unless that fuel is hydrogen..
Phil,
Digging up carbon from the ground and burning it harms the environment (increases CO2 concentrations)… That’s fossil fuels.
If you collect carbon from the atmosphere, and convert that to fuels, then burn it, there is no difference in the amount of CO2 in the atmosphere as a result of the operation.
Renewable synfuels are carbon neutral. The only difference between renewable synfuel and hydrogen is the synfuels cost less, and are easier to store and transport.
Roy,
It’s about economics. If your storage solution cannot pay its capital cost back in a reasonable amount of time, it’s just cheaper to make more energy generation and let the excess energy be sold at a loss.
That’s where we are with CAES, it’s cheaper to produce 70% more energy from wind than it is to make a CAES “solution” to recover the ~10-20% excess energy that could potentially be stored for later use. Remember that we’re talking about purchasing energy – perhaps for between $10/MWh – $40/MWh, and selling that energy back for between $100/MWh – $150/MWh, on a system that would not be cycled more than twice per day, and would usually be cycled only once per day. If the system cost is ~$2,000,000/MW, it would take between 12 and 30 years to pay back the capital, before considering O&M – which is considerable. To just invest in another wind turbine only costs <$1,000,000/MW, and can achieve a much higher capacity factor and has a greater longevity and lower O&M. It's cheaper to just produce more energy.
As for the technologies you highlit,
Lightsail and SustainX are going to have much shorter longevity than typical CAES, and much higher capital costs. The water/steam would be corrosive, requiring stainless and superalloy turbines, compressors, pipes, etc… and there's no reason to believe that they can even approach their claim of 90% round-trip efficiency (70% is more likely).
The hydrostar idea is simply a farce. Their fantasy drawing is completely absurd (lifting force of the air bags would be impossible to tether, the most expensive and vulnerable component of the system would be the air tube connecting the compressor/expander to the air bag, so you cannot have more than one air bag, etc…). The more viable project path was laid out a couple of years ago with a giant bag half full of sand laying on the ocean floor.
In order to accomplish that farcical nonsense, they'd have to fusion weld a multiple-km seam underwater, after paying for two multi-km2 extreme heavy-duty plastic/rubber sheets… they have to lay them out without damage, and then there is the constant liability risk of a small puncture or tear opening up on an inflating/deflating plastic bag…. That's a tremendous O&M risk for a plastic bag that is subjected to constant saltwater attack and constant pressure variation.
The best way to storage is the machine automation of the most efficient, produced with abundant and safe raw materials. This will come about when solar and wind reach max grid integration. At just 1/4th of solar’s 2012 growth rate, this should be 20% in less than 30 years (due to lessened subsidy and increased automation). This is solar alone.
We need not recycle excess CO2 just once (as with wind based fuels at THAT time) when we should have the extra energy required to literally remove the total excess CO2 via mineral sequestration just a few years hence via dirt cheap parts made by machine automation.
After all, this clean energy thing should be ALL about the required transition to carbon negative. The vast automation of “every” machine and part necessary must be considered and re-considered into an ever evolving blueprint BEFORE the renewables reach “max grid”, and that allows future outdated visions to be canceled out. For example, (just a thought) trillions of dollars worth of utility scale battery storage made by automated machine assembly lines in 2017 could be replaced by just 10% of the cost with even more efficient and long lasting battery storage in 2027 by advanced (and presently unimaginable) 3d printing techniques in common with the collection medium, as well…
Guys: As Doty rightly says, it’s not only our transportation fuel that we will be needing, it’s all the hundreds of plastics, fertilizers, and you name it. If we just go in and find out how oil derivatives have invaded our everyday products, lifesaving and entertainment, you name it, it’s all over!
On the other hand, biofuels are not going to go too far, either because they are not as productive (and costly, because of that) or because they end up taking our food supply directly or indirectly. We need to replace oil because it’s a energy dense liquid fuel, it’s the best chance we have.
I have an idea that we wont last long if we keep on looking in the wrong direction.
Wind and solar energy might be intermittent but on their own,combining them with other technologies like tide, wave, hydro, and grouping them, they will provide a steady and cheaper solution (and greener, of course) than what we are using now.
If we analyze things deeper, like:
Why is wind not as good during the day? for example, we might find solutions.
Solar has come a long way because of that.
Peak oil is here, even if we take the famous fracking into account, we need to focus on solutions now, before it’s too late.
Also, electric cars displace the need for utility scale storage to some major degree. We need to aggressively pursue the industrial scale extraction of the raw materials needed coupled with the least environmentally damaging approach.
It is in these machine technologies that will enable the carbon negative economy.
I guess I have two different accounts, one is fireofenergy and the other is Robert Bernal
I have been reading all these discussions for yrars and the solutions seem elegant. What I have not seen is a discussion of some simple solution like outlawing drive through vending at banks, fast food, drug stores, and the like. All these cars idling for no reason other than laziness. How about raising the driving age nationwide to 21 or high school completion.
More laws at the bottom will only cause more social problems. What we need are laws at the top such as a price on carbon which will make necessary the thing that is better than any law… INNOVATION.
@ Glen I was not trying to promote any technology just show examples that are available right now in the CAES arena to counter Craig’s post that there are only 3 Worldwide.
I actually agree that increased production capacity makes more sense economically as does creating a more valuable product with any excess production.
I also agree that hydrogen is difficult to store and is impractical for individual cars although more viable for larger commercial vehicles or Ocean vessels.
If your wind farm and Methanol plant went another step to include a methanol fueled power plant.
Removing the cost and environmental risks from transporting the fuel by using it onsite.
This could address Winds availability and consistency of production issues.
There is a market for demand response and reserve capacity built into the grid system now.
I also believe that more Wind installations will reduce the inconsistency of supply issues across an entire grid system as would more solar installations.
Balancing all these variable supplies is the hard part hence the need for Energy Storage.
An HVDC grid connecting wind farms as the Chinese are building can also be used to funnel extra production to your Methanol plant and vice versa.