You have 2 of my favourites Gridcoin and Sia. My other coin of choice is Solarcoin. I have rooftop solar PV and Solarcoin gives me 1 SLR for every MWh that I generate, thats currently based on an estimate. Its a very cool project though because they have some really big ideas, they are building an IoT monitoring system that will record the production in real time onto the Solarcoin blockchain.
On top of that all my Gridcoin mining is practically 0 cost, doesnt get much better than that.