Electric water heaters are better at storing energy than a Tesla Powerwall

https://www.popularmechanics.com/science/green-tech/a44108982/electric-water-heater-can-store-energy-better-than-tesla-powerwall/

"storing excess wind and solar as heat... 30GWh equivalent 2 million Powerwalls... smart” heat pumps and electric resistance systems in homes across Australia. During off-peak hours, these water heaters can essentially store renewable energy in the form of heat and help balance electricity supply as renewable energy availability fluctuates... widespread adoption of electric-powered water heaters would not only lower emissions, but also save customers some $4 billion (USD) in energy bills"

Related:

Startup's Big Battery Can Electrify Your Home and Make the Grid Greener

https://www.cnet.com/home/energy-and-utilities/startups-big-battery-can-electrify-your-home-and-make-the-grid-greener/

Solar batteries: A new material makes it possible to simultaneously absorb light and store energy

https://techxplore.com/news/2023-07-solar-batteries-material-simultaneously-absorb.html

Anker Introduces Modular Whole-Home Battery System

https://cleantechnica.com/2024/05/12/anker-introduces-modular-whole-home-battery-system/

GM offering new home energy storage options for US EV owners

https://www.streetinsider.com/General+News/GM+offering+new+home+energy+storage+options+for+US+EV+owners/23823759.htm