Solar thermal systems transform the sun's energy into heat using solar collectors. A disadvantage of this system is that it relies heavily on strong sunlight. Therefore when demand is high, eg in winter, heat generated by active solar power is low due to weak sunlight. Photovoltaic cells Photo voltaic cells harness solar power. They generate electricity directly from light without producing any emissions or pollution.
Solar power has domestic, commercial and industrial usage.
Biofuels Biofuels are crops that can be burned to produce to provide power or heat. Wood and straw are both examples of biofuels. Biofuels absorb carbon dioxide while they grow. Tidal movement can be harnessed to an electricity generator. When high tide comes in waves pass through a generator, turbines in a tidal power station generate electricity.