A number of my friends are considering or have already installed a Tepeo zero emissions boiler (ZEB) with storage as a low carbon heating solution for their home. This is less disruptive than installing a heat pump but it is only 100% efficient compared to 300% or so for a heat pump. It relies on cheap electricity to keep energy bills at a sensible level – either economy 7 overnight, or similar, or relying on prices fluctuating during the day with a tariff based on wholesale prices, such as Octopus Agile. I shall call all of these tariffs ‘cheap time’, for brevity.
Cheap time tariffs could become cheaper – or more expensive
Historically, overnight demand is lower than during the day, and hence prices are lower because there is no need to run the expensive peaking plant. This has enabled tariffs such as Economy 7 to work well for homes with storage heating. Hitherto this has been only a small fraction of heating demand: I estimate just 2.2% of domestic heating demand in England [1]. However, there is going to be lots more demand for cheap time power due to switching to low carbon transport and the need for electricity storage to take account of intermittent renewables. Cheap-time tariffs could become cheaper, because renewable power is cheap, or more expensive, because there is more demand for it. On balance I fear the latter is more likely.