Harnessing Flexibility from Hot and Cold: Heat Storage and Hybrid Systems Can Play a Major Role

As has been often reported, electricity systems with high levels of variable wind and solar power generation would benefit from demand flexibility. What is not as often mentioned is that electrification of the transport and heat sectors could exacerbate the need for flexibility, if they are implemented as inflexible loads. This demand could also be made more flexible, but it comes with a cost. The main issue is to identify the cases in which the benefits will outweigh those costs, a matter that will naturally depend on the evolution of specific energy systems. In this article, we lay out some generic principles and characteristics related to heatsector flexibility and demonstrate its possibilities using specific examples. While we generally use the word heat here, most of the discussions also apply to cool, which, after all, is just another form of temperature difference.