08 - Can renewable energy power all our homes?
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85% of homes use fossil fuels for heating (largely in the form of gas boilers). One way the UK and many other countries plan to switch from fossil fuels to renewable energy for heating is by using heat pumps. These use similar technology to air conditioning (but in reverse) absorbing heat from a cooler place e.g. the ground to increase the temperature in a home.
However, heat pumps require electricity to run. If a lot of households switched to heat pumps instead of gas boilers to heat their homes, the national electricity grid may need to be strengthened to ensure there is enough electricity available throughout the day.
In order to understand this further researchers at UCL and Loughborough (led by Dr. Jenny Crawley) used the UK Renewable Heat Premium Payment dataset, which records the electricity consumption of nearly 700 existing domestic heat pump installations every 2 minutes, to understand how much electricity they use and what time of day this is used.
Because this new data set contained so many more homes than any previous studies they were able to create a much more accurate understanding of what the electricity demands on local and national electricity grids might be if there was the mass take-up of heat pumps that is predicted.
The researchers found that heat pumps cause two main peaks in electricity demand per day, in the morning and evening. The size of the peaks will require the national grid to be strengthened. However they were able to demonstrate that the level of strengthening required is not as high as previously thought for several reasons:
- The highest heat pump peak is in the morning whereas the current national grid peak is in the evening so when heat pumps are added to the existing grid there will not be as much of a problem as there could have been.
- Many people keep their heat pumps running all the time which means their buildings are kept warm; resulting in lower peaks than there might otherwise have been.
- The heat pumps in this dataset did not use clever control strategies to shift their energy use to off-peak times, which more and more heat pumps will do in the future.