Essays
As simple as possible, but no simpler.
Einfall is the German word for ‘insight’, ‘invasion’, or ‘bright idea’, which she discovered while reading the wonderful ‘How to Solve It”, by Polya.
Insights by Danielle Fong
a wick for ideas
As simple as possible, but no simpler.
Einfall is the German word for ‘insight’, ‘invasion’, or ‘bright idea’, which she discovered while reading the wonderful ‘How to Solve It”, by Polya.
Hello danielle,
You are really special! I believe that God has given you special gifts that would be a blessing to many others. I look forward to your great contribution!
Jeremy
How large would an air storage unit need to be to store the energy produced by the average run of the mill wind farm. The world is full of ideas like this so the future seems very bright!
You probably want 6-8 hours of storage per turbine, which is 6 – 8 standard shipping containers work of air tanks. A fair amount but not too much, at half the cost of a turbine.
Danielle, I wouldn’t mind talking to you. There’s a designer in Vancouver who has some great ideas for compressed air. I’d also like to send you a design proposal. My email is waub@hotmail.com
Brennan.
how fast the energy storage system could response to support the grid? how fast the transient rensponse compared to electrochemical battery storage?
I am working on AC-module for solar system…your idea is a bright future.
Depends on the arrangement. We might put this behind a VFD for sub-cycle response time — otherwise we have the same timing characteristics as diesel gensets which can respond in < 4 seconds.
That’s wonderful…Battery storage is not good for our environment. It contains poisoneous materials. I am pretty curious and concern about the rensponse time and transient stability, How it works with VFD? Actually I have made one small VFD (Variable frequency drives), I implement Space Vector Modulation for generating pure sinusoidal waveform. But it is a small scale VFD (less than 1 KW).
How does lightsail energy’s compressed air energy storage compare to pumped hydroelectric energy storage. Cheaper, better? Neither?
More flexible, cheaper on a power basis, more geographically locatable, about as efficient, more dense, provides heating, cooling, recovers heat and converts to electricity.
Have you thought about how this could be deployed at existing coal-fired power plants to capture all the waste heat that remains unused?
Yes, it’s a good idea. But utilities aren’t fast moving…
wow. you’re really hawt.
Danielle,
Congratulations on a brilliant idea with the compressed air storage technology! Does it increase efficiency to change the nozzle type as it does with combustion engines? Also, could this technology be reduced in size to make it usable as a power source in cars?
Yes, and yes.
Hi Danielle….wondering about 2 things:
1)How hot is the water which is generated by the compression process?
2)If the water is stored, rather than used immediately for heat, how long does it retain its heat, with economically-practical levels of insulation?
Thanks
It depends — we aim for about a 30 C ∆T.
If you lose the whole ∆T, it is as if the atmosphere is your thermal battery. The efficiency scales down by T_atm/T_hot but it is not so bad — about 10% relative efficiency, or a 6-7% loss.
Also: Danielle, are you familiar with GE’s “ADELE” project? They also are attempting to capture and re-use the heat from compression—the main difference, from what I can tell, is that they’re routing air through some sort of ceramic material and storing the heat in the material, rather than using water. I believe their lead guy on this is Matthias Finkenrath in Germany.
It would be interesting to see a comparison of the pros & cons of the two methods.
Yes. As you can imagine the distinctions between using water instead of air, and storing heat at 600 C, are legion. It’s a completely different set of mechanical challenges.
I think ours are easier. PLus we can use waste heat. But this comparison is not obvious.
From the outside it looks like our velocity of development compares favorably with ADELE, but it is hard to tell.
I’m glad I asked Google who this Danielle Fong on LinkedIn is – this is a fabulous (both in significance and style) collection of insights that you’ve shared here.
The potential of the LightSail tech is enormous, both as marginal/balancing power and as a way to end the gratuitous waste of vast quantities of low grade heat, and your thoughts in June 08 regarding choice of work (futility of BigCo), the importance of being honest (pessimism to Californians?), and the admirable but ineffectual and distracting nature of hippies really resonated with me.
Utilities may be slow moving by SFBay standards, with screwed up priorities created by oversights in their privatisation/the regulatory framework which governs them, but they’re far from stupid and irrational. Doubly so when compared with consumers or governments – and they’re more solvent too… ;-)
Who “hurts most” in the industry?
In the UK it is private developers/generators chasing (absurd) government subsidises for renewables. They are installing generation equipment in the middle of nowhere and on the end of a fairy marginal grid connection. The grid companies (National Grid and Distribution Network Operators) have the ultimate say as to whether connection to the grid is permitted or not and how much it’ll cost to upgrade the infrastructure, so anything that you can do to mitigate those costs (or up-rate your generation for a given cost) is very much of interest. These folks are already installing “experimental” generation equipment so “experimental” time-shifting equipment isn’t too much of a leap for them.
Larger industrial customers are also in a position to manipulate pricing structures. I know that Milford Haven Refinery for example used to be (probably still is, but my father no longer works there) paid more to reduce their electrical demand during peak periods than it cost to run emergency Aggreko diesel generators – so whenever possible they took the cash and went off-grid. There would be no operational problem for them if they didin’t either – they would just make slightly less cash. Far less of a deal than a (regulated) utility that was required to rely upon the time shifting equipment to meet demand, with the regulation being the primary reason that the utility didn’t want the Aggrekos (or time shifting tech) sat on their balance sheets.
Is there a market for “buffered emergency generator sets” comprising packaged storage and generator? An asset that you require for operational purposes (backup generator) that you can now turn into an income stream rather than merely a cost?
Frequency stabilisation? Active harmonic cancellation? Driving a nicely packaged load/source via IGBTs to clean up the AC sine wave and reduce the transmission losses/upgrade grid capacity during peak periods?
I’ll add LightSail to the list to watch anyhow! Should you find yourself in presenting in England I’d love to be in the audience. The (tea) kettle is always on should you find yourself lost in Cambridge too. :-)
Yes, it is a very contorted market structure. Oh well.
Yes, there is a good market for what you suggest. There are a zillion markets, though, so the judgment comes in the form of picking the right one :-)
Hi Danielle,
Very impressive work! Have you worked out the equipment cost for each kWh energy capacity? Just wondering how this comparing with batteries. So each of your storage system will include a motor, a water tank, a pressurized air tank, nozzles, compressors and pipes. How well do you regulate your output electricity to match the grid? When you say you are 90% thermal dynamic efficient, do you mean you can consume 100kWh electricity at the begining and generate 90kWh electricity back into the grid? Thanks a lot!
Congratulate you on your curiosity; sorry for the short supply.
Mostly; it’s not proven till volume manufacture.
We beat all existing battery systems on capex by about 3 – 10x (except lead acid), and LCOE by 4x – 40x.
Theoretically sub-second variation is possible with some fancy power electronics. We’re giving ourselves several minutes for our first product though.
It means that purely thermodynamic losses only account for 10% electricity loss, whereas it would account for far more in traditional CAES systems. We are still working on reducing pumping losses, friction, etc.