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Germany Finances Major Push Into Home Battery Storage For Solar
mdsolar writes with this bit of news from Green Tech Media "The German government has responded to the next big challenge in its energy transition – storing the output from the solar boom it has created — by doing exactly what it has successfully done to date: greasing the wheels of finance to bring down the cost of new technology. ... Now it is looking at bringing down the cost of the next piece in the puzzle of its energy transition — battery storage. ... KfW’s aim, according to Axel Nawrath, a member of the KfW Bankengruppe executive board, is to ensure that the output of wind and solar must be 'more decoupled' from the grid. ... This is seen as critical as the level of renewable penetration rises to around 40 per cent — a level expected in Germany within the next 10 years. ... According to Papenfuss, households participating in the scheme will spend between €20,000 and €28,000 on solar and storage, depending on the size of the system (the average size is expected to be around 7kW for the solar array and around 4kWh for the battery)."
Personally I prefer my home steam generator. It uses 100% renewable, carbon-cycle, eco-friendly biofuel (wood) to generate steam that drives a turbine generator. I can get about 3kW out of my setup.
Efficiency matters a lot when you're in the burn-fuel-for-power model, because you can always just burn the fuel tomorrow if you need to have the power tomorrow instead of today. For wind and solar power, the power is available when it's available, and you can either consume it, store it, or waste it. Ideally you'd have a proper smart grid (not the kind that's being marketed, which is just a power meter with WiFi) so that you could have things like fridges and freezers run their compressors during supply spikes and leave washing machines and so on programmed to run whenever there is surplus power. In the absence of being able to trigger demand when you have supply, storing it inefficiently is probably better than wasting it.
That said, the majority of my electricity consumption when there is no solar power available is lighting. It would be great to have a DC main with a relatively small battery that could power LED lights overnight. It would probably also let me charge electronic devices more efficiently than going via DC.
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Energy lost in transmission is about 7%, not 50%.
They specifically state they are targeting lead-acid and lithium-ion.
Which is a different kind of disaster waiting to happen. Lead batteries provide about 40Wh of storage capacity per kg of lead. Germany has 40m households, and their average electricity consumption is 10 kWh per household per day. Which means that if, statistically, every household wanted to be able store one day of electricity consumption (which, arguably, isn't enough if you go 100% wind/solar, but anyway), you'd need 10 million tons of lead -- about one annual world production of lead, roughly as much as is contained in all car batteries worldwide combined.
And private households only consume 1/3rd or so of all the electricity produced in Germany (businesses and industry consume the other two 3rds).
AFAICT from this, the whole thing is a total non-starter. It will never scale up to any significant number of homes. A few percent of the households (mostly rich home owners) may do it, collect Government support and feel good about saving the environment. The overall effects will be inconsequential -- so much so that the whole project wasn't worth starting in the first place.
I own a house in Germany, unlike most readers here. To be clear, the money from the KfW is a loan, not a subsidy. The subsidy, if there is one, is that most KfW loans are interest free for the first 10 years.
The irritating thing to this home owner is that there seems to be no end to home improvements that our German government would like for me to implement. Be it tripple-paned windows, foam insulation, solar heating, solar power, and now batteries. And my house is barely 20 years old. I'm not against somebody who wants to put all these things into their home, but for this home owner, none of these things make any economic sense - even with a zero interest loan. This home owner has decided to do exactly nothing. And that in and of itself saves the environment a lot of waste.
AFAIK the problem is economics. The Swiss hate the German solar initiative, because it reduces the demand for their hydro power when the prices are highest during the day. Nighttime electricity prices are much lower. It would be nice if they could come to some sort of an economic agreement. It'd be worth it to the Germans to compensate the Swiss to some extent, because the Germans could save money on batteries. ;D
Sorry, that is nonsense
Hydro power, especially pumped storage, is mainly used as "balancing energy" (sorry, no dictionary has the right english term for "Regelenergie").
So it is always payed well, regardless of "germanies solar power". Before germany had "solar power" we used coal. That means Switzerland is losing nothing due to our switch to solar and wind.
In fact they win. Because NOW we indeed buy energy from Switzerland as "balancing energy".
It would be nice if they could come to some sort of an economic agreement ...
We have such agreements already, otherwise the trade between the EU and Switzerland would not happen
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
I wonder why you forgot to mention that solar is on a Moore's Law-like curve, and hence already cheaper today than some sources of energy in use today and expected to be cheaper than most sources of energy within a decade.
http://www.treehugger.com/slideshows/renewable-energy/important-graph-cost-solar-headed-parity-coal-and-gas/