I like energy solutions that are purpose specific and practical. Using photovoltaic cells to charge a huge expensive deep cell battery and then using the electric energy to provide some lighting for a retail outlet is a good promotional tool, but a big window provides light directly from the sun.
I use solar power at my house to heat the water for my shower. Using electricity to heat water is very inefficient, especially if you have a system that keeps a tank of water hot all the time for on demand use. We have a windmill beside our house that pumps water into a reservoir to be used for irrigating fields. This is a great system, the need for water is higher when the wind is blowing because the airflow speeds up evaporation.

I have a cousin back in Canada that uses a large windmill to generate electricity. The wind energy where he lives is pretty dependable. He had the thing built for several months before Nova Scotia Power to install the necessary wo way meter and various other flow managing stuff that I don’t completely understand. My cousin was impatient and wanted to see his house all lit up by the wind power. If I remember the story correctly, he singed a few things from an overload. I have to share this cool video of a windmill being constructed.
I have already made a post about the exciting news about a breakthrough in the efforts to make less expensive and more durable panels to convert solar energy into electricity.
Hopefully some auto makers will create models with panels as standard equipment. All the gadgets like GPS and MP3 players could run off the sun. Energy resources information is available at EnergyResourcesNet.com.