The technology behind solar energy is constantly evolving. Portable devices that charge up gadgets from the sun are becoming smaller and more powerful.

There has been a steady growth in small-scale electricity production at home in recent years. In 2008 there was a considerable jump - the number of people looking to generate their own electricity doubled in just 12 months.

Traditionally, homes have harnessed power from the sun through conventional solar panels, but an American company has developed what it hopes is the next generation of panel power.

SRS Energy has created "sole power" tiles, which are coated with thin-film flexible photovoltaic cells. The roof tiles are a dark blue colour to maximise the absorption of sunlight, and will be available from spring 2010.

The tiles are an example of how technology, in the form of new polymers and coatings, has the potential to increase the amount of energy that can be adapted from the sun.