Solar Power Plants already exist, they simply provide resources, although you could make them act as a resupply unit, hm delete std resupply and make the solar power plant do that job! As for components, its related to having the ability to sell them to, or buy them from Traders. Also because you can build them, and perhaps move them to were they are wanted. Also if you upgrade your tech and they become obsolete, you can sell them to traders who might sell them to someone else, perhaps even to the Mercenaries LOL
Probably you should read up on it here ->
http://www.kenvsthecity.com/se45/