Power for Settlements
Here are some considerations for the power systems used in our lunar settlement stories.
This topic is discussed in detail on the Solar Power page.
One of the hardest things to do on the Moon is to get rid of large amounts of waste heat. In any power generation system you must have both a source power and a sink for waste heat. This is basic thermodynamics and there is no way out of this requirement. Most space missions simply dump waste heat to deep space. On the surface of the Moon, this is not so simple. Half of your view is exposed to the cold of deep space, with the other half occupied by the Moon itself which is radiating at a moderately high temperature during the daytime.
As per spacecraft, shades will be needed to prevent the exposure to the hot spot Sun and a warm spot Earth.
At the pole the average lunar surface temperature will be around 0 C and does not change drastically during the day. Here simple heat radiators can be used as they only need to avoid exposure to a slow moving Sun.
At the equator there is a completely different story. The surface of the Moon rises to about 200 C by mid lunar day. It will be very difficult to dump waste heat at this time, so it will be difficult to keep the living areas cool and do major industrial operations. Equatorial housing may need to be buried extra deep for thermal reasons.
Big Battery Power
Batteries are used for power storage, they are not a primary source of power.
There are at least three separate technologies promising a times-ten improvement in rechargeable batteries currently demonstrated in the laboratory. They are all based on some version of the super capacitor. The value of such a battery for electric cars on Earth alone will be in the hundreds of billions. The only problem is developing mass production techniques. The race is on.
By the time of our stories, it is reasonable to expect really good batteries will be available for use in space. These will give a lunar rover a range of at least 500 kilometers. They will also be able to power reasonable amounts of electronics and modest life support equipment through a 14 Earth day lunar night. They will not allow large industrial operations for this length of time.
More convential batteries that can use local materials are iron/air, aluminum/air and iron salts and water. The first two need little imports the last needs more but the bulk is local.
Heat energy collected from the Sun could be stored via molten salts in insulated containers and made available throughout the Lunar night. Salts in a molten state holds tremendous amount of energy which could be converted to both mechanical and electrical power through the use of a steam turbine or Stirling cycle engine.
Reflectors, salts and insulating containers could all be fabricated from materials on Luna, requiring little or no supplies to be shipped from Earth.
During early stages of lunar exploration, some instruments can be powered by Radioisotope Thermal Generators (RTG). The radioisotopes needed to make them are manufactured at only a few places on Earth and only in small amounts.
In the longer term it may be useful to establish small nuclear power stations on the Moon, particularly in non-polar locations. These will mainly provide power during the long lunar night. Their daylight operation will be limited by their ability to dump waste heat. They will be expensive to build. SPS rectennas would probably be cheaper for larger power requirements.
There has been a suggestion that Low Energy Nuclear Reactions LENR could be a solution to energy problems on the moon and on Earth. If this technology develops confirmed positive results, use on the moon would be enhanced if the necessary elements are found to be common in regolith.
In our stories, solar will be the major power source. RTGs can be used for small science stations. Big batteries may be used for electronics and life support.
Stories set some what farther in the future, may have nuclear power stations. It is reasonable to assume that if Helium 3 from the Moon is an important element of Earth side power generation, then small safe lunar nuclear power plants are a likely possibility.