Energy Transition PE/GE Firms

Wanted to see if anyone had knowledge of PE/GE firms that have been active in the energy transition space?

My understanding is that traditional solar/wind project returns are generally too low for PE, but there has been ESG momentum for other pockets of the energy transition (electrification, energy efficiency, smart cities, etc). Seems like there are a handful of specifically alt energy mandated funds, and potentially the impact funds.