This is another space idea. Imagine a barge that would have an orbit around the Sun and the Earth, very elliptical. When it got to the Sun, it would extend solar pannels (possibly solar fabric) and charge itself with solar energy. It would need massive batteries, possibly with a higher energy density than we have available today. When it got back to Earth, it would charge space stations or even send energy directly to Earth wirelessly (somehow) or by landing the batteries.