The German feed-in system has been very effective in increasing renewable power but it is not a long-term option for Europe, says Till BÃ¶hmer of the German Electricity Association.
The German feed-in system, called the Erneuerbare Energieen Gesetz (Renewable Energy Law or EEG) guarantees producers of sustainable power a fixed price per kWh fed into the grid. Since the introduction of the EEG in April 2000, the amount of renewable energy in Germany has more than tripled. Last year saw the production of 20,000 GWh of wind power and 18,000 GWh from other renewable sources. The share of renewables in the electricity mix has increased from 3.01% in 2000 to 10.53% in 2006. The target for 2012 is 20%.
At the same time, the increasing share of renewables confronts the power sector with growing pains. They are facing an increasing input from highly variable sources. For instance, in 2004 the grid feed-in from renewable sources has varied between 1.8 and 14 GW.
Till BÃ¶hmer evaluated the German renewables support at the Eurelectric Conference in Brussels last week. He explained that a power grid always has to be in balance, which means that every 15 minutes the total electricity being fed-in, withdrawn, imported and exported is calculated, on the basis of which the manager of the Balancing Group restores the balance. However, renewable energy sources are as yet not included in the balancing scheme and they are not under the control of the manager. Which was alright when renewable sources made marginal contributions. But this is no longer the case.
BÃ¶hmer thinks the problem is that the feed-in tariff is independent of the electricity demand. A wind park delivers its power to the electricity market for a fixed price, regardless of the need. Even if the excess of wind power is so large that the market crashes and the power is for free (as happened on the night of 18 to 19 January this year), the renewable energy sources still get their fixed price. This causes a growing distortion in the power market.
BÃ¶hmer therefore concludes that a European renewable electricity market system should never be based on a fixed feed-in tariff. He thinks that the renewable power market should be certificate based instead. Certificates disclose the origin of the power for target accounting purposes, but they do not have a fixed price. Instead, their price is a reflection of the market value of sustainable energy, which in turn depends on the national support scheme for green power.
If the market price for wind power were to get too low, BÃ¶hmer has an original suggestion for the green power producers: the plug-and-drive option. It means storing excess wind power in battery stacks, which then can be used as fuel by a fleet of electric vehicles. Driven by the wind.
25 April 2007
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