Cost of energy on Mars
The cost of energy on Mars is one of the prime parameters required to analyse martina settlement scenarios. To go beyond generalizations and actually evaluate one scenario against another, the cost of energy and the cost of transportation to and from Mars need to be known, or at least estimated to compare on a common basis.
There can be no absolute answer to this question, as the cost of energy will vary depending on the source and the level of development of the colony. If all the energy producing equipment comes from Earth, the cost will be higher than if it is produced in-situ. As the settlement grows larger, economies o scale will come into play to reduce energy costs. As automation increases, and productivity increases accordingly, the cost of energy may go down significantly. Self replication of production equipment may eventually bring down the cost of energy to very small values. This will allow the realization of projects using energy on a scale that will be, literally, cosmic.
But before such a grand time comes, we can estimate a preliminary value for the cost of solar energy on Mars for a growing settlement of a few hundred to a few thousand settlers. To do this we also need the Cost of Transportation to Mars. A simple method for this is to use the cost proposed by SpaceX for their transportation system, 500$ per kg to Mars,