The total installed capacity of an offshore farm becomes its storage capacity, because larger, sea-bed accumulators would form a central power station platform, receiving water under pressure from, say, 100 surrounding energy harvesters.

So, instead of 100 direct-drive PM generators rated at 5-7MW you’d have 4 or 5 normal high speed units at 100MW, driven by perfectly matched water turbines. This is both cheaper and an inherently more efficient engineering design. (and it saves a fortune on high voltage marine cables)

The UK’s Energy Research Partnership and the European Energy Research Alliance are stuck with an orthodox perception of ‘mechanical storage’ as Hydro, Fly Wheels or Compressed Air, but these all consume electricity, as does the option they omitted – the GPM. http://www.gravitypower.net/

Spending billions on generating electricity you can’t use is plain dumb. Storing surplus electricity, to be regenerated when you can use it is an expensive waste. Dispatching power to meet demand earns a premium – a high Capex on before-generator storage facilities would pay for itself, quite quickly.

For more clues, see my profile.

http://cleantechnica.com/2013/03/29/rooftop-solar-could-power-all-australia-homes-more/#comment-846545436

It’s probably fair to say that ALL the electrochemical options are, and always will be, non-starters for grid-scale electricity storage. Surplus peak-wind output will soon be of a different order of magnitude.

Some facts about Hydropower in Norway:-
“Total installed hydro generation capacity in Norway: 29,600 MW (2011)”

Status for Pumped Storage in Norway:-
“Few existing pumped storage plants today.”
“Mostly for seasonal storage.”
“No need for daily pumped storage plants today. (98% hydro)”

From that, I’d assume that surplus renewable electricity from neighbouring countries is mostly consumed on the Norwegian grid and not actually put into PHS?

Statkraft speculate that “50GW of Norwegian hydro (PS) capacity could make Germany 100 per cent renewable by 2050.” (What about the rest of Europe?!)

If you tot up the huge Capex involved in an over-capacity of intermittent renewables, plus building the new electricity storage facilities, plus the necessary interconnectors, AND add in the high annual running costs of such a system – is that really a good idea? And power-to-gas is not any cheaper, is it? http://k.lenz.name/LB/?p=6879

To my mind, there’s only one sensible solution – don’t treat the symptoms. Cure the disease of intermittent generation. It’s not so difficult. Store wind, wave and tidal energy before-generator, then the (system-wide) ‘numbers’ WILL add up, because total installed capacity could be halved, there’d be fewer grid interconnections and less storage capacity would be required. And there would be zero ’round-trip’ loss. Think about it.

From what I’ve read and heared the solar market is transforming away from the feed-in-tarif into something rather like “feed-me-savings + independence”

A KfW-Program could indeed help boasting interesst & awareness, especially since such a program gives local solar companies a great reason to contact their recent clients about the new possibilities.

At the same time companies like SMA really start pushing smart residential energy solutions by cooperating with well known brands for home appliances & residential energy solutions (heating, micro-CHPs,…) .

Increasing energy self sufficiency might become a viral trend (though investment cycles in homes are sometimes abit longer)

Also, even though there are incentives in place to consume more electricity at night and even though PV only produces during day time, coal power plants still produce more power during day time than at night.

Lastly, it’s been mentioned that Germany would require about 20 TWh of storage (roughly a fourth of what Norway already has) for a 100% renewable powered grid. If 1 kWh of storage costs €100, Germany would need to invest €2000 billion in storage. For €2000 billion one can also purchase 2000 GW (!) of wind power.

In other words: It is simply more sensible to overbuild renewable power, introduce demand response (flexible electricity pricing) and to electrify the heating and hot water sector, than to fill up basements with (blind) batteries or to produce gas with renewable power to feed old fossil fuel furnaces.

Much of that will depend on the result of the elections coming up.

Then the program could be ramped up over the next few years until the market matures and the need for subsidies declines – allowing for a slow and controlled phase out of subsidies to leave a mature and successful storage market?

(Knowing politics, it probably is my optimism speaking more than actual probability, but unless there’s evidence to the contrary, that’s what I’m going to stick with, and support that platform…)