Hello and greetings from myself and from RoLUE to ATM.

I have never colonised a 15 spot but I assume you did it for extra deut gain? This can be offset with fusion, not that I recommend using fusion, I have none. Without deleting the colony for a more favourable spot closer to the sun I would leave it until you can upgrade the solar. The risk of too many SS is too high at this stage for my liking unless you have turtled with plenty of plasmas. As for the economics of SS Vs Solar at this point... well that would require maths.

Good luck and o'speed.

Restricting the problem only to your spot 15 planet, the possibilities are substantially 3:
(1) Fusion Reactor
(2) Solar plant
(3) satellites

(Forgive my writing style, i have to find a clear way to bring you some data)

You wrote about solar plant 25, so let's take as starting mines levels 24 20 17 That are quite balanced and nearly fully covered by the solar plant 25 (only 10 energy missing).
That let's assume we want to reach 28 24 21 (because i think you don't have these levels yet)
With the results of this scenario, you can get an idea about what's the way to go also for higher levels.

The difference in energy consumption is 4.082. What's the cost for each option?

(1) Fusion Reactor
We start from 0, so we'll have to build it up to lvl 17 for 4.296 energy (Remember that here this is not affected by Plasma Tech). The total cost is about:
24.590.000 half / 9.830.000 cry / deu 4.920.000. Plus an hourly consuption of 859 deut.
We'll see that this is absolutely the worst choice, speaking about costs. And in general with this retro version the fusion reactor sucks hard compared to everything else at each level.

(2) Solar plant
We start from lvl 25, we'll upgrade it up to lvl 29 (+43 satellites for soome missing energy, easy to defend).
The total cost of these 4 levels of solar plant is about:
15.380.000 met / 6.150.000 cry + something for the sats. No deut consumption.
Compared to fusion reactor, we cut the cost by nearly 50%.

(3) Satellites
Here there's a little problem because the sats usually need to be defended and the amount of defenses is very subjective and situational.
We'll need 584 satellites, an appetible amount. Let me assume that we will defend it with:
1.160 rocket launchers / 290 light lasers / 290 heavy lasers / 29 gauss cannons / 20 plasma turrets. (Proportion is about 2 RL / LL and HL 0,5 / 0,05 GC and PT per satellite).
This defense is quite heavy, and should defend the sats and the daily production, plus 50 large cargoes, from nearly every fleet actually on the server.
The total cost of this option is:
1.160.000 cry / 290.000 deut for the sats + 6.525.000 met / 2.610.000 cry / 928.000 deut for the defenses.
As you can see, even with that expensive defense, it's nearly half the cost of the option (2).
Also consider that you already probably have some defenses and this will lower the cost of this option. While for (1) and (2) you'll probably need do build some extra def, with extra costs.





So the suggestion is "run satellites, heavy defend them and you'll still spend a lot less than running plants".

Then probably, if you don't have fields problems, also upgrading 2-3 levels of solar plant before starting satellites is a viable solution. Because until level 27 the solar plant is still more performing than 7 energy sats + the defenses that they need.



I hope that this helped you.






P.S.
I'd like to know what's the level of your synthesizer and the hourly production, because my formulas give me weird results with your -50°C max temperature, so we can see if it's worth to colonize colder spots.

Nice, it seems to me that (for miners) super cold planets are much more performing early game, until you can supply energy with solar plants.
With the defense proportion above, after 8/9 months of game a 50°C planet will reach a very cold one and then slightly pass it over time because of the lower energy cost and because in this server the deut can be traded only at 2:1:1.

Definitely worth for fleeters, but not really for miners that plan to play for at least one year, in my opinion.

But at this point abandoning is not an option anymore, mainly because you'll also lose an important moon.