雅思口语实时真题：房子如何节能？

How canhouses save energy?

To saveenergy, I think a lot can be done with the roof. For example, we can installsolar panels on the roof, and the electricity generated by them could be usedby the house. But unfortunately the conversion rate of the solar energy is stillrather low nowadays because of the technological barriers, so that it isimpossible for the house to be self-sufficient at this moment, which I am surewill change. However, there are methods that are easy to implement. In my city,people like to grow some plants on the roofs. This could reduce the temperatureof the house, thus decrease people’s dependence on air-conditioner, which isknown for its high electricity consumption.