No comments on pumped storage as part of the mix?
How about the need for centralized storage (e.g. CAES, pumped storage) vs distributed (e.g. batteries in PV installs, on the utility poles)?
And given how expensive all these technologies are, isn’t it just cheaper to build excess generation capacity for peak rather than use storage?  When does the tipping point happen in that equation?

Dear Mr. Wesoff -

I have a few friends in the utility business and they are not all similar to Mr. Burns, as you so snidely imply.  My utility friends have a simple agenda — make as much money as they can (OK, maybe your analogy is pretty good…except for the hairlessness).  Utilities EPRI research arm helps direct their decision making towards projects and technology that makes utilities more money.  There’s nothing wrong with this as long as they can sleep at night (fortunately their reactors give off a comforting green glow).

Mr. Burns’ comment that utilities will need to invest $200 billion in transmission and $400 billion in distribution is wonderful for him and his donut-gobbling associates.  He’ll get to earn a return on those assets — assets which are effectively paid for by ratepayers (or taxpayers if the Federal Government pays).  Note that this $600 billion spend does not include any new generating capacity.  Let’s just for now say Mr. Burns needs another $400 billion for generation.

Of course if we directed just some of this $1 trillion dollars to distributed generation power (wind, solar, etc.) that can be deployed quickly, we’ll be able to provide more power for ratepayers at a much lower cost.  Especially if distributed generation batteries become more cost effective.

But distributed generation power cuts back on Mr. Burns’ profits — hence all the lobbying for new transmission & distribution, nuclear, smart grid and stupid coal.

Duh

Thanks for following this, Eric. We often speculate about how storage will end up being integrated with renewables (At the wind/solar project site? At distribution nodes?). I think the consensus in our office is that storage makes more sense at the distribution node level than it does incorporating storage into every renewable generator.

Right, energy storage is now a matter of cost. However, there is cost/kW and cost/kWh - both important and the 2 figures are often mixed, confusing the issue. A few days ago I was reading about NaS storage, and I think there is a mistake in the figure above—a sample 1Mw project cost less than $3000/kW - the MWh figure was not cited in press releases, but the batteries are rated 7Wh/W, so the correct figure would be ~$400/kWh for NaS batteries.

The question above to use storage vs extra generating capacity is valid, and here both $/W and $/Wh are 2 numbers that need to be considered. If a battery costs $3/W, why not build a cheap $1/W gas turbine? Well that figure doesn’t include fuel, and payments are in Wh, and the cost/Wh depends on how often it would be used. It turns out that peaking plants have the highest cost/kWh (like $.50) because they are only used part time, whereas the combined cycle coal plants run full blast 24h/day. So in this economic analysis, besides the $/W and $/Wh, the number of hours/day is important also.

Assume the NaS battery system costs $365/kWh (close), we could pay for the unit in 1 year if the price was $1/kWh. Suppose it is used for only 5h/day average, then we get $1/day at $.20/kWh cost over 1 year. If we need a payback of 5 years, then if the difference in electric price is $.04/kWh between peak/off-peak, then the unit would be cost effective. For grid stabilization (matching short-term supply and demand) the price difference in kWh is quite high, and it might be possible to have multiple charge-discharge cycles/day. There seems to be only sketchy specifications on the costs and economics of NaS available on the net. It seems experimental at this point, with a few subsidized test sites, and the report phase with economic analysis (e.g. Xcel) are still in the future.

Lead acid is cheap/kWh, but the problem is lifetime—they have to be replaced after a few years of usage. Perhaps new technologies could address that. Traditional Li-Ion (laptop batteries) have the same lifetime problem, but the new Li Phosphate/Titanate batteries have high power (low cost/W) and long life but high cost/kWh and no current manufacturing capacity at the MWh size systems.

Compressed air is in theory cheap, but it’s a giant heat pump (refrigerator). When compressed, the air gives off heat into the storage cavern (pumps heat into the ground), then cools when expanded, limiting efficiency. I’ve heard of projects to try to capture, save, and restore the heat, so maybe better efficiency is possible.

We need to get the price of storage down?  Or we need to get the perceived value up?  Looking at the price of storage against only one value is always a looser for storage.  We have hardware and strategies in place now that are less expensive for the one note melodies they play on the grid.  The key for advanced energy storage (AES), like the vanadium redox flow battery, (disclaimer - we’re a strategic partner for Prudent Energy and the VRB-ESS - more information at http://www.Utility-Savings.com) the key is valuing the multiple benefits that come with AES.  Put a MW scale VRB-ESS on the distribution system, and you have frequency regulation, peak shaving/generation shifting, price arbitrage, demand response, emergency power, UPS, black-start, VARS, distributed generation, grid islanding, dispatchable power (from renewable intermittent if paired with those resources) and more.  PV used to be too expensive also, until the social benefits were subsidized.  AES can substitute for multiple expensive capital resources - just counting a few of them in the financial evaluation makes AES a very cost effective (cheap) resource.