Solar is definitely the way to go if you can afford a $30,000 solar system.
Ive been looking into Proof of Stake altcoins like NXT.org. Both systems have their issues but PoS doesnt have the need for massive equipment and power requirements that Proof of Work altcoins need to function. PoS makes more sense to me since people are invested in the currency, not the equipment & power needed to support it.
Yet ONLY pos, can lead to holding and not using it as an currency.