I use the non pressure vacuum tubes direct water heater, is cheap, around $250 - $350 of material cost.
But buying the electric power production made of solar pannels is a bad idea due to high risks.
I have the hughe place for such pannels in industrial zone, but for realize something big, You need have some $1.000.000. and if You have them not - no one cares of You.
At the small range problems stay still close due to effects of lightnings.
Risks of deal with such Solar pannels are big.
In this time people prefer POS mining and margin lending, this activity needs small electric energy use.