323865 The problem is that solar energy costs too much. CK 1 22212 Neptune is the eighth planet of the solar system. CK 1 239872 The ancient Greeks knew as much about the solar system as we do. CK 1 2025425 It uses solar power. Spamster 275029 Let's talk about solar energy. CK 1042257 I wish I had solar-powered car. yessoos 49345 The house is heated by solar energy. CK 2725811 Solar power is the way of the future. Hybrid 1009261 I want a car that runs on solar power. AOCinJAPAN 275097 Solar energy is a new source of energy. CK 499549 Jupiter is the largest planet in the Solar System. blay_paul 453476 The problem is that solar energy is too expensive. saasmath 1832980 The problem is that solar energy just costs too much. ryanwhiting 1314643 The nearest star to our solar system is Proxima Centauri. lugal 22833 We are exploring new sources, such as solar and atomic energy. NekoKanjya 3000760 This technology will drastically lower the cost of solar energy. Hybrid