And try not to spread any more disinformation about the cost of renewable electricity and pump-up storage. Or the efficiency of CAES.

But as I am more convinced by every post you make that you don’t actually have a clue and are just going by gut feeling and cherrypicking (seasoned by ideology no doubt). I have done my homework, I have studied plenty of LCA documentation to know the numbers, so my questions were more rhetorical in order to eek out what type of renewable-peddler I was dealing with.

Nice chatting to you, nice to know I still can expose the fraudsters for what they are…enjoy your fossil fueled future, thats what the renewable bandwagon will ensure, nothing more.

Storage is not something we need solved today. Our grids can absorb 25% to 40% wind and solar before storage becomes an issue and that is years away.
I’m not sure what your issue is, perhaps you’re just naturally an unpleasant, argumentative person who doesn’t have sufficient skills to carry on a civil discussion.

What might be available down the line is interesting (from a technical point of view) but not relevant to what is available today and actually can allow “sustainable” development.

So what you are saying is that what we have is pump up hydro (insanely expensive), compressed air (inefficient) and batteries (expensive and environmentally questionable)?

If you want to compare lithium processing to, say, uranium extraction and processing or coal mining then do some research. To be honest, I’m not willing to spend my time doing the job for you.

As for how efficient your heat pump is also doesn’t interest me. The topic is the least cost method to store energy, not the most efficient way to heat/cool your house.

Obviously what a company claims may turn out not to be factual. That’s why I’ve said that we will have to wait for the future to arrive in order to know how things will turn out.

My heatpump gives me a 3,5-4:1 or 350-400% heat from electric energy conversion, so I am not impressed…and what a company claims to attract investors is not really what I would call “reliable” data.

You seem to be asking for 100% reliable answers for what the future holds. You’ll have to wait until we get there.

I’m trying to tell you what we have on hand right now – pump-up hydro, CAES w/o heat storage, lithium-ion and flow batteries. Those are the technologies now connected to the grid and operating.

And I’m trying to give you some idea of what seems to be coming. EOS batteries were an example of new battery technology which is currently being manufactured but not yet proved out in real world use.

Possibly coming is Ambri’s liquid metal battery. It’s reportedly working in prototype and they are developing better chemistries and setting up manufacturing. If this one pans out we would have large scale quite inexpensive storage.

But if none of the EOS/Ambri new technologies work we would be fine with what does work, pump-up and flow batteries for large scale scale storage and lithium-ion for grid smoothing.

“The prices offered by wind projects to utility purchasers averaged $40/MWh for projects negotiating contracts 2011 and 2012, spurring demand for wind energy.”

http://newscenter.lbl.gov/news-releases/2013/08/06/new-study-finds-that-the-price-of-wind-energy-in-the-united-states-is-near-an-all-time-low/

http://www1.eere.energy.gov/wind/pdfs/2012_wind_technologies_market_report.pdf

$40/MWh means $0.04/kWh. Add back in the $0.022 PTC (which lasts only ten years) and it’s $0.051/kWh for a 20 year PPA.

This is a low number. It’s not just the LCOE of wind. It includes real estate, transmission, taxes and wind farm owner profits. It’s the “delivered to the door” cost of electricity, not just the generation price. Taking all those factors into account the actual average generation cost is probably about 4c/kWh.

Then solar –

“The cost of large-scale solar projects has fallen by one third in the last five years and big solar now competes with wind energy in the solar-rich south-west of the United States, according to new research.

The study by the Lawrence Berkeley National Laboratory entitled “Utility-Scale Solar 2012: An Empirical Analysis of Project Cost, Performance, and Pricing Trends in the United States” – says the cost of solar is still falling and contracts for some solar projects are being struck as low as $50/MWh (including a 30 percent federal tax credit).”

“Another interesting observation from LBNL is that most of the contracts written in recent years do not escalate in nominal dollars over the life of the contract. This means that in real dollar terms, the pricing of the contract actually declines.

This means that towards the end of their contracts, the solar plants (including PV, CSP and CPV) contracted in 2013 will on average will be delivering electricity at less than $40/MWh. This is likely to be considerably less than fossil fuel plants at the same time, given the expected cost of fuels and any environmental regulations.”

http://reneweconomy.com.au/2013/big-solar-now-competing-with-wind-energy-on-costs-75962

Capacity factor is a red herring. Price of produced electricity and time of delivery/dispatchability are the important metrics.

Tons of zinc per kWh? What sort of a question is that?

10 cents a kWh sounds impressive, but not when you add the 10-15 cents/kWh generation costs from wind. So you need a battery capacity to deal with the intermittency problem of wind/solar, which has a capacity factor of 25% and ~18% (not accounting for weather) so quite a large installed overcapacity is required to fill the energy need, not to mention the infrastructure to deal with overproduction as well…

Sounds very expensive, and how many tons of zinc are we talking about, per kWh capacity? It would not surprise me if coal would beat such a system on environmental performance…

LIghtSail, one of the companies bringing heat storage CAES to the grid reports a 70% round-trip efficiency.

Perhaps you should get up to speed before damaging your credibility.

Eos Energy Solutions is manufacturing a zinc-air battery. If it works as stated it will provide low cost storage.

They are claiming $160/kWh and >10,000 100% DoD cycles. A 30 year calender life. That’s considerably cheaper than lithium-ion batteries and much higher cycle life.

“Eos zinc-air battery is environmentally safe, in that it relies on materials that are nontoxic and nonflammable. (CEO Michael) Oster has said, “You could flush it down a drain; you could drink it.””

Their batteries are going to be field tested on multiple grids around the world in the coming months. ConEd (NYC) is one of the test grids.

In a video on their site they claim a total cost of ~10 cents per kWh to store electricity. That’s a complete accounting which even includes battery owner profits.

Storing ~ 3c/kWh wind for a dime is a price-beater. It’s cheaper than new coal or nuclear. It’s cheaper than gas peaker power.

The efficiency losses in compressed air storage are huge, considering the environmental impact of your primary energy source, compressed air will give you, at best a 1:3 ratio. Water spray will only marginally increase your efficiency as expansion of the gas can be done using heat exchangers with ambient air.

Right now a lot of battery storage is being done with lithium-ion batteries. The materials are recyclable and do not give off any harmful ‘whatevers’ during use. However lithium-ion batteries may be superseded by other chemistries.

You’re asking for numbers which simply are not yet available.

Compressed air? Certainly. There are two CAES (comressed air energy storage) systems up and running now. They’ve been operating for decades.

CAES, the old style, has an efficiency flaw in that the heat generated during air compression is lost, energy is lost.

Newer CAES technology uses a spray of water into the compression cylinder, the water absorbs the heat, the water is drained away and stored. The heat from the stored water is then used to reheat and expand air during the generation cycle.

Will this be a dominate storage method? Too early to tell.

What we can say is that none of the currently developing storage methods pump CO2 into the atmosphere or produce highly dangerous waste streams. We’re clearly on the right track but it’s too early to determine the final destination.

What is the environmental impact of any presumed energy storage device available today?

Compressed air? Are you serious?

The term “Minimal” lacks definition, supply referenced numbers please.

It’s not clear what form(s) large scale storage will take. There are many emerging technologies and it’s not clear which will win out. Cost and environmental impact will play the major roles in decision making.

Right now the least expensive storage method is pump-up hydro. We can install closed loop pump-up on existing dams and in abandoned rock quarries as well as open pit and deep earth mines. Or we can build new sites where there sufficient elevation changes can be found. As long as we wouldn’t be flooding valuable land the impact is low.

The most promising storage technologies (chemical batteries, liquid metal batteries, compressed air) are being designed as shipping container sized units. These can be hauled from the factory to “industrial” areas and plugged into the grid. The materials used will likely be recyclable.

http://www.youtube.com/watch?feature=player_embedded&v=Yjdp9jctZgY