Green Gravity Labs want to drop dense weights down mine shafts and harness the kinetic energy released to generate electricity. Once fallen the weights would be returned to elevation utilising renewable energy.
Concentrated solar power (CSP) traditionally uses large arrays of mirrors to direct sunlight onto a tall central receiver tower, which then creates heat that is stored in various liquids for use when the sun is not shining to generate electricity. CSP offers storage that traditional solar (PV) systems do not, however they have been historically big and expensive. An Australian company has developed a smaller, cheaper CSP and PV combination, with a 70% efficiency rate (on par with pumped hydro). The pilot project is currently operating in Carwarp, Victoria, Australia. https://reneweconomy.com.au/the-australian-solar-tech-that-may-have-found-a-low-cost-solution-to-deep-storage/
Industrial processes typically produce a lot of heat. This heat can be captured and re-used to reduce overall energy consumption with readily available technology such as heat pumps. However, industrial heat has not typically played a part in green hydrogen production. A new process to be trialled at BlueScope's Port Kembla Steelworks will seek to prove a new tubular solid oxide electrolysis (SOE) technology from CSIRO can reduce electricity demand by 30% compared to conventional green hydrogen production processes. https://www.csiro.au/en/news/All/News/2023/August/Hadean