In the absence of an Arc reactor, or a ZPM from stargate, we are constrained to use more realistic sources of energy.
Solar is very good a lower latitudes.
Wind is usually better and more consistent at higher latitudes.
However, Wind has proven viable at grid scale, but uses very large turbines. These are not usable or viable at smaller installations. Hence, for the C&I space, wind has not been a viable source of energy. Do make it a viable source of energy, you need something much lighter, less of a visual disruption (Eye sore), portable, quick setup, QUITE and most importantly safe.
We believe we have technology that goes a long way to meeting these requirements, making it more accessible to the C&I space.
Bio fuels, such as organic wastes, wood, garden trimmings etc is essentially stored solar and can be carbon neutral if new growth replaces used material.
There are some very interesting new technologies being developed, which will make this source of energy more available. Out of interest, after the second world war, most of Europe's vehicles ran directly off wood. Click below to see interesting history of bio fuels