The cost of storing energy as heat is a fraction of the cost of storing it as electricity. Methods for long-duration, big-scale storage already exists.
The ability to store excess energy is key in transitioning from a fossil-powered energy system to a system built on sustainable methods of energy generation. This article is a call-out to all the inventive minds and resourceful investors out there. There should many opportunities in this space over the next many years.
To find the golden pot at the end of this rainbow, let me start with a brief run-through of the main storage solutions.
ELECTRICITY can be stored in batteries, by using pumped hydro, in compressed air and liquids, and using fly-wheels.
Batteries are good for meeting short term peak demand, but though billions are spent on inventing and improving ways to store electrons, no solution promises costs that will allow for utility-scale energy to be stored for months, weeks, or even just days. For more detailed insights into battery storage costs, see this excellent analysis from Lazard.
Pumped hydro, where excess energy is used for pumping water from a lower point to a higher point is the most efficient way of large-scale storage of excess energy. But as with batteries pumped hydro is only suited for storing electricity. Further, it does for natural reasons require a topography that allows you to pump the water upwards. For that reason alone, it’s not an option in many geographies.
Boreholes and geothermal, where heated water runs through tubes dug or drilled into the ground thereby heating up the ground and where the heat is discharged by reversing the process, is another cost-efficient way of storing heat at temperatures well-suited for being boosted by heat pumps (see Generation for the role of heat pumps).
The cost of heatis probably the main reason why heat has received so little attention up to now: Storing heat as heat for heat purposes only does not make financial sense if the cost of producing this heat is higher than the cost of generating the same heat using fossil fuels. When heat production without storage can’t compete with fossil fuels, then a solution that includes storage will, of course, be an even worse proposition. And proposing to store heat for electricity production – where most of the stored energy is lost in the conversion into electricity – could be among the world’s least fundable ideas.
Interested in reading more? Please see the links to my other articles below. Additionally, a ‘Like’ from you will also be much appreciated as this should help direct more attention at the many business and climate opportunities the market for heat production offers.
Thank you for reading,