Heat from green electricity "on demand"

09.02.2024

Source: SWW Group

If the energy and heating transition is to succeed, we need more flexibility, grid serviceability, efficiency and regionality - and, above all, intelligent coupling of the sectors. These are all buzzwords that call for implementation in concrete projects. Projects such as the PowerToHeat plant in the Schönbrunn district of Würzburg. It recently went into operation and is intended to "stabilize the power grid and make the supply of heat even more secure," says Frank Seibold from operator SWW Wunsiedel GmbH.

Goals that Wunsiedel can be considered one of the pioneers in Bavaria and even nationwide in achieving, says First Mayor and SWW Supervisory Board Chairman Nicolas Lahovnik. The expansion of renewable energies is essential for reasons of sustainability and climate protection. However, it means more fluctuations in the supply of electricity. Flexible energy generators and storage systems are needed to compensate for this. A PowerToHeat system with an output of 1000 kilowatts was therefore installed in Schönbrunn's local heating network alongside the wood pellet-fired boiler and the wood gas CHP units. It works in a similar way to a water boiler or instantaneous water heater, says Seibold. "It just has a different dimension and can be regulated from 0 to 1000 kilowatts almost continuously and in real time."

Joice together over the new power-to-heat plant. In the picture from left to right: Thomas Ködel (Head of Energy Generation and Service at SWW Wunsiedel GmbH), Marco Krasser (Managing Director of SWW Wunsiedel GmbH) and Nicolas Lahovnik (Mayor of the town of Wunsiedel).

Stabilizing the grid

In practice, this means that load peaks can be easily balanced out. A conventional boiler in which solid fuels are burned must first heat itself up before it can release energy. This means that some of the valuable heat is lost through the chimney. A PowerToHeat system does away with this and therefore has a very high level of efficiency. For SWW, which has been driving forward the transformation of the energy supply for many years, the system therefore fits in perfectly with the Wunsiedler Weg Energie. SWW Managing Director Marco Krasser sums it up as follows: "Making the best possible use of all available regional energy sources and combining them perfectly while stabilizing the electricity grids. According to the motto: More brains instead of just copper!"

The PowerToHeat system contributes to both goals. If there is too much green electricity from wind and solar power in the grid, it is started up and produces heat. This is either fed immediately into the Schönbrunn local heating network and consumed or "stored" in a large 80,000 liter buffer tank. This means that fewer pellets are needed to generate heat, wind turbines and PV systems do not have to be switched off and the electricity grids are relieved. In technical jargon, the new system turns the central heating plant in Schönbrunn into a regulating force.

If there is too little electricity in the grid, the system is shut down very quickly. Other generators, such as the cogeneration units already installed, then provide the missing electrical energy and the waste heat generated is in turn used in the local heating network. In this way, the electricity and heat sectors are linked together in a sensible way. "The power-to-heat plant in the Schönbrunn heating network gives us a wide range of flexibility options and is the basis for a reliable and secure energy supply," summarizes Krasser. And it is also economical thanks to its function as a regulating force. After all, it is becoming increasingly difficult to balance power generation and consumption precisely at all times, "so plants like the one in Schönbrunn are also valuable in monetary terms."

About SWW Wunsiedel GmbH

SWW Wunsiedel GmbH is a subsidiary of the town of Wunsiedel. Its business areas include the supply of electricity, gas, water and heat as well as telecommunications. The company has set itself the goal of actively shaping the future of energy. The strategies developed for this are known as the WUNsiedler Weg.

Press contact
Christopher Fröhlich
SWW Group
Tel.: 0151 70579746
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