How to obtain Solaris achievement?

You need not only remove your steam engines from your system, but you also need to wait an hour. That is, you will be awarded the achievement once the steam engines disappear from the power tab with the scaling set to one hour.

Specifically; in order to get the Solaris achievement, you need to have 47 Solar Panels connected without any Steam engine's for at least an hour.

Maths for above if you're interested.

One solar panel provides 60 kW (peak).

KiloWatts can be directly converted to GJ/h: 1kW = 1000 J/s ∴ 1kw = 0.0036 GJ/h.

∴ One solar panel provides: 60 kw = 60*0.0036 = 0.216 GJ/h

Since we need 10 GJ/h -> 10 (GJ/h)/ 0.216 (GJ/h/panel) = 46.3 Panels, since we can't have a partial solar panel, we round up to 47.

As far as i am aware you need to be actually using the power the panels produce to enough of an extent it brings it over 10 GW hours.

To calculate the number of panels to get 10 GW hours are is follows:

10 * 1,000,000 = 10000000 (to get the kw hours) (10000000 / 60) / 60 = 2777.7777777777777777777777777778 (to get kw seconds) 2777.7777777777777777777777777778 / 60 = 46.29629(as a solar panel produces 60 kw)

Then we ceil that as we have to have an integer for our solar panel count and we get 47 solar panels producing 2820 kw seconds, or 10.152 GW hours.

Keep in mind the game uses KW or MW or GW seconds as defualt which is why i converted to them in the calculations.