Solar power is actually a decent option (number crunching)

[YertyL]

So I just started a game in creative mode just to check maintenance numbers, and came to a weird conclusion: Solar power is actually a decent option.

So, at first you would think the following: A large wind turbine produces 10 power for 1 machine part maintenance, and a large solar cell produces 5 power for 1 metal maintenance, but you can convert 1 metal to 1 MP, and solar does not produce at night, and wind also gets a cheap upgrade for +33% and elevation bonuses? Clear win for wind, right?

Well, it's actually not that clear cut. First off the actual production cost: A mine has a base production of 20 metal per sol with 12 workers and 5 power, and a machine parts factory produces 12 MP with 15 workers and 50 power. So producing 10 machine parts takes about 15/12*10+6=18.5 workers and 50/12*10+2.5=44.17 power in total (half a mine and a 10/12 of a factory), while producing 10 metals only takes 6 workers and 2.5 power. A machine part is more than three times as expensive as a unit of metal (slightly more in workers and much more in power). A big factor in the early game is also that you get metals almost for free from the surface and meteors.
Secondly, the maintenance number is misleading. Solar panels do not incur maintenance when they are closed at night, and with the dust repulsion tech, they actually clean themselves. So when I watched the "last serviced" numbers, it turns out that with dust repulsion solar cells last about twice as long as regular buildings (and about 1.5 times as long without). The actual maintenance is more like 0.66/0.5 metals. Which still leaves the issue of upgrades and batteries.

So let's compare the example I looked at. At 12% elevation 7 large wind turbines with polymer blades produced almost exactly 100 energy (7*14.9=104.3) for a maintenance of 7 machine parts. You can also get 100 constant energy with 30 large solar cells and 5 power accumulators or one atomic accumulator -- the accumulators charge 50 surplus during the day and releases 100 at night. Maintenance is between 20 metal and 5 polymers (no tech) and 15 +2 (dust repulsion and atomic accumulator).
If we take the rough calculus of 1 machine part costing as much as 3 metals and a bit more than a polymer unit, that means that in this situation the cost is about the same without dust repulsion and better for solar with. There are a few factors that can alter this calculation:

1. With a big elevation bonus, wind still seems superior. On rough maps you can connect tunnels to "wind farms" up high.
2. On the other hand, in the early to mid game when you get metal and some polymers almost for free and do not have a machine parts factory yet, solar is way cheaper.
3. This is particularly true if you use the exotic minerals upgrade from the B&B expansion, which doubles the output of solar and thus halves the metal maintenance. On low elevation you pay almost exactly in metal what you pay in machine parts for wind (7.5), making solar much, much cheaper.
4. On the other hand, with green planet in the late game you get +100% production on wind and -50% production on solar, making wind the clear winner again

So overall? Early game favors solar, as you pay very few advanced resources. Late game, a high percentage of atmosphere can strongly favor wind. In between, I would say it depends on the specific situation -- how big are your elevation bonuses, have you built a machine parts factory yet, how much metal and/or exotic minerals do you have to spare? IMO cold waves favor solar power, as you can cheaply build additional power that cleans itself when you turn it off, while dust storms favor at least some wind turbines -- although you also get some dust storm power with an atomic accumulator.
But overall, it is really more of a situational decision than the clear win for wind you may see at first glance.

 

[Egodeus]

You can also get some dust storm power by placing solar panels inside a dome. The smallest domes that only require concrete for maintenance are my favourites.