They don't need to because it is just a PoC and I don't think it hs been said anywhere that soloar panel between rain tracks would be the unique source of energ

They don't need to because it is just a PoC and I don't think it hs been said anywhere that soloar panel between rain tracks would be the unique source of energy. There are also a lot of vertical sound proofing barriers that could be equipped with panels.