It depends on what you want to do as this industry is HUGE. Do you care about metering and working at the solar panel or wind farm level? Or maybe on the actual energy markets that commit and dispatch all generation in a region? Or maybe the vendors that write the software for those markets? Or you could work for the utilities or IPPs that own the generators...or the state public service commission that control state plans. There is also FERC and NERC. There are companies that sell energy storage systems...the list goes on and on.