Interesting idea,
Add a pollution variable representing the amount of pollution in the atmosphere. This will effect production of solar power.
Pollution starts at 0, and increases throughout the game.
solar produces 2 * (1 - pollution) energy.
When a pollution producing event, pollution goes up. several of theses events would include:
commander dies => +10% pollution
fusion plant dies => +10% pollution
singularity reactor => +40% pollution
strider dies => +~10% pollution
nuclear missile (blocked or not) => 100% pollution
This would decrease solar throughout the game, forcing other types of energy to replace it. Also if a team is only using solar, when a nuclear missiles is fired, they lose all of their energy as their production goes to 0.
