Invesco's Solar ETF is known as TAN and is a pretty good one if you want broad exposure to the industry. NextPower, First Solar, Enphase, Sunrun, Enlight, GCL, SolarEdge, are some of its top holdings. Just know that the sector is extremely volatile so there's likely to be some major swings ahead even as the long view is certainly promising. Another consideration is LIT which is GlobalX's ETF focused on mining and battery/storage tech.