The north German district heating operator E. ON Hanse presently develops a feed-in model for solar thermal heat for the northeast area of Hamburg. The feasibility of district heating connected solar thermal systems will be achieved by using improved incentive conditions for buildings at other places in the district heating network, to which the solar heat will be allocated.
The project, presented by Karl-Friedrich Henke, CEO of E.ON Hanse Wärme GmbH on the Forum Solarpraxis in Berlin by end of November, could become a precedent in technical and economical regards. For the first time, a huge seasonal thermal energy storage is connected to a large district heating network serving as buffer storage. The 4500 cubicmeter storage was originally built in the year 2000 for the solar district heating system Hamburg-Bramfeld. E.ON Hanse plans also to replace the solar district heating net which was damaged.
At the same time, E. ON Hanse wants to encourage its customers to build solar thermal systems on favorably oriented roofs of existing housing areas in large parts of Hamburg supplying 100 percent of the generated heat in the district heating network. Hereby there is no longer a need for the expensive intermediate storage in the individual buildings. The profitability of the solar thermal heat systems should be realized by allocating their heat production to the primary energy demand of other buildings, which enables them to benefit from the favorable KfW loans or other incentives. The Hamburg’s Wohnungsbaukreditanstalt is interested in the model whereas the negotiations with KfW-Bank are still ongoing.
If the model was implemented, it would open up a similar option to renewable heat as the German feed-in law EEG provides for the feed-in and transmission of biogas.
This text was written by Guido Bröer, one of the editors of Solarthemen, a biweekly magazine in Germany covering news from all sectors of renewable energies. www.solarthemen.de