Solar panels

Solar panels produce 6 kWh of power. Dust gathers on the panels over time, but the panels may be repaired at no cost. They also provide constant entertainment and exercise for your astronauts. Solar panels play their part in minimizing risk to get the Colony Planning challenge. Simply build more than is needed, and even mass dirty panels will not take your electricity down below zero.
 * cost: 2 supplies
 * produces: 6 kWh