I have 130 watts of solar panels after experimenting with them for 4 years I can say this is not much power. You need to consider many things, does the sky in your area have a lot of clouds, does your yard or neighbors yards have tall trees. Stepping stones will be much lower than roof solar panels so you will have a problem with them getting dirty, when it rains they will be covered with mud, grass will grow over them, a house or car will shade them. My 130 watts will run two 60 watt light bulbs all day that is all it will do. I paid $450 plus sales tax to have enough power to run 2 light bulbs. How many years can you run 2 light bulbs on the local power company for $450? This does not include the cost of installing them and maintenance. A 1000 amp car battery is $130 with a 5 year warranty. A DC to AC inverter costs $35 from Harbor Freight. "IF" my battery gets a full charge during the day, I can run a TV, a light, computer for a few hours every night. That is all the power there is.
Now I am experimenting with wind power using a permanent magnet generator. An 8 foot diameter blade produces several times more power than my solar.