Swivelling solar home stars in Madrid contest

International teams have built 19 sun-powered homes in Spain's capital for a contest that shows off futuristic designs, including one house that swivels 180 degrees.

In western Madrid's huge Casa de Campo park, the sun glints off the solar panels of a futuristic mini-village erected in 10 days by university teams from China, Japan, Brazil, Egypt and across Europe.

One home built by a Portuguese team can turn to track the sun's rays, a French-designed house has walls that move electronically, and a Japanese abode has its own rice paddy.

The homes competing in the Solar Decathlon Europe 2012, which opened on Friday, face a 15-day marathon of 10 trials to measure their merits, including energy efficiency, design and comfort.

The winner will be the home that consumes the least natural resources and produces minimal waste during its brief lifetime producing electricity.

The contest is sponsored by private enterprise and by the Spanish government, which subsidises entrants with up to €50,000 (HK$509,000).

One of the most striking entrants is by Portugal's Universidade de Porto, a cork and timber home enfolded by a sloping roof of voltaic solar panels.