Power to Heat OWL: Using renewable energies flexibly

OWL offers a technically simple transferable means of introducing flexible timings for electrical heating systems (such as night storage heaters) in private households. This process enables heating installations to be synchronised, to a certain extent, with the fluctuating electricity generation from renewable sources. This allows surplus green electricity to be utilised in a reasonable way and the pressure on the grid to be reduced.

To maintain a stable grid, electricity generation and consumption must always be in balance. On windy and sunny days, it can happen that more electricity is produced than can be consumed. At present, electricity generation from wind turbines and PV installations is simply turned off to maintain balance in the grid. This is because transmission grids, which can transmit excess electricity to other areas that can use the power, have not been sufficiently extended. This tendency is currently increasing with the extension of renewable energy sources throughout Germany.

Engine for progress:

  • Exploitation of load transfer potential in the heating sector
  • Solution using simple technology
  • Contribution to stability of the electricity grid

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Photo: Westfalen Weser Netz

In the control centre of Westfalen Weser Netz, all data on current electricity generation and regional consumption converge to provide continual security of electricity supply to customers. Broadcast signals for electric heating are also sent to the grid from here.

Matching power loads to green electricity production

Instead of switching off electricity generation from renewables on windy days, the ”Power to Heat OWL” project proposes another solution to maintain the balance in the grid. The project has developed smart controls for electrical heating in private households. Involving only low hardware costs, this enables the electrical load to be controlled according to the green energy available. So if a lot of green electricity is being generated, the heating system receives a signal to make it draw on cheaper excess power, for example to replenish the buffer heat storage.

Making existing installations more flexible through simple means

Since there is a clear connection between the lowest exchange price and an oversupply of renewable energy in the grid, it is appropriate to use the price determined at the electricity exchange as an indicator for high green electricity generation. In a field trial for the project, the directly exchange-price-dependent switching of different types of electric heating in private households was carried out for the first time. For the transferring of the switching times, the inexpensive and proven ripple technology was used which enables energy supply companies to remotely control and flexibly match electricity users. This simple approach to the optimisation of load management enables existing heating systems to be made more flexible without their control technology needing to be changed.

Sector linking for a stable electricity grid

The first results of the field trial show that, depending on the heating system, up to 70 per cent of heating load could be shifted to time slots with high renewable electricity generation. This is especially positive, since most notably in the heating sector there is considerable hidden potential for load transfer and therefore an important contribution to the successful transformation of the energy system. But the customers benefit as well. By providing flexible loading, they are making a useful contribution to the grid and benefit by receiving in return more favourable power procurement costs.

Photo: WestfalenWIND Strom

“At WestfalenWIND Strom, we aim to make optimum use of our renewably produced electricity. Excess energy can be used in the heating sector, among others. The use of storage in the heating sector is much more economical than the provision of battery storage. The Power to Heat OWL project offers a good approach to this and an optimistic outlook for further projects.”

Dipl.-Ing. Johannes Lackmann, Director of Technology, WestfalenWIND Strom GmbH

Partners and sponsors

  • Universität Paderborn - Kompetenzzentrum für nachhaltige Energietechnik
  • WestfalenWIND Strom GmbH
  • Westfalen Weser Netz GmbH
  • Energie Impuls OWL e.V.

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