It’s well known that Germany is a world leader in solar and wind power. There’s a fair amount of unwarranted criticism levied at renewables, and generally it seems there is not nearly as much positive press. For that reason, it might be surprising to hear that an energy cooperative in Germany has been providing clean energy to the country for 14 years. (It will be 15 in January 2015.)
The cooperative, Greenpeace Energy, was founded in 1999 and started supplying clean electricity in 2000. Today, it has over 100,000 customers and 9,000 of those are businesses.
It also supports the construction of renewable energy plants — 11 wind farms and 3 photovoltaic systems, so far. These 14 facilities have a power capacity of 65 MW. Most of this capacity is from wind power.
There are 23,000 members in the cooperative and the cost to join is €55. Total revenue in 2012 was €95 million. 70 employees work for the organization. The sources for its electricity are hydro and wind power.
Energy storage is also an interest of the cooperative’s. In particular, it is interested in something called windgas, or using electricity to produce hydrogen which can be stored for months and supplied to the gas grid for heating homes, cooking, running gas-powered cars, and so forth. “This technical constraint is, however, expected to be eased in the future. But even while the constraint applies, the storage capacity for renewable energy in the gas grid is enormous: 45 times the total capacity of all pumped-storage hydroelectricity in Germany today.”
So, what is the capacity of all pumped-storage hydroelectricity in Germany today? A research paper published in 2011 said that number is about 7 GW. The pumped storage capacity in Germany might have changed since then. 45 multiplied by 7 GW is 315 GW of potential storage for renewable energy in the gas grid.
These figures may not be all that accurate today, but they do show the cooperative’s interest in energy storage — not just clean energy production. Renewable energy storage lately seems to be in the form of larger and larger battery systems, but windgas, as the Greenpeace cooperative calls it, is an intriguing alternative and has key benefits. Battery storage is competitive for short timeframes, perhaps up to a day, while hydrogen storage works well for much longer periods of time. Battery storage is likely to win out for short-term needs, while hydrogen storage is one of the only seasonal storage options that is being considered in Germany (perhaps the only one being seriously considered).