Solar panel efficiency, fabrication technology and manufacturing engineering are important not only in the solar industry but to you, the consumer. New technology and inexpensive materials and production mean more practical, every day applications.
Currently, applications of traditional commercial PV solar panels and solar-energy systems are out of range for most of us, aside from affixing rigid solar panels to the rooftops of our homes. PV technology is used to power spacecraft, to bring electricity into remote villages in developing countries and to power remote buildings (or anything that requires electricity, really).
Thin-film PV technologies have been on the market for about 15 years or so and are the solar technology most of us have come in contact with. Where? If you've ever used a solar-powered calculator, you've experienced the power of thin-film solar cells. Its flexible nature allows it to go places where traditional panels can't, including into private homes and electronic devices, but it's also used in similar energy-producing ways on buildings and in remote locations.
Spray-on solar panels will be sold as a hydrogen film that can be applied as a coating to materials -- potentially everything from a small electronic device to a new way to power an electric car's battery. Similar to the solar technology of today, spray-on panels could be incorporated into buildings themselves, not just rooftops. One day you may buy clothing with solar film woven into the fabric.