Two layers of glass in the window will be stopped the heat going out.

 ___________ energy is produced by collecting sunlight and converting it into electricity.

There are many available ___________ power sources in Vietnam including sun, wind, water, etc.

When you save energy, you not only save money, you also reduce the demand for ___________ such as coal, oil, and natural gas and that is a great way to play a part in saving the planet.

In India, the demand for ___________ has always been more than the supply.

 ___________ can be an excellent source of free, renewable energy for poor farmers.

The government has warned that Britain will face power ___________ in the coming winters.

Laos and Cambodia have big plans for building up to 11 ___________ on the lower Mekong.