Có một số lỗi chính tả trong đoạn văn bạn đã cung cấp. Dưới đây là phiên bản đã sửa:

"We use a lot of energy at home and it costs us a lot. To save energy, we should use low-energy light bulbs. We should also turn off all electrical appliances when not using them. We should travel on foot or by bike as it helps us not only save energy but also protect the environment. In sum, we should use renewable energy sources as much as possible and save energy."