Q: Is this a mod of excellent quality?
A: It seems pretty all right! Mind you, I am not a programmer, and there are various limitations with the game engine that forced me to rely on small hacks for some of the mod's new features. But I have taken a long time with this mod adaptation and tested it extensively before and after releasing it.

Q: Why did you remove so many things from the original mod?
A: For more realistic balancing, and to declutter.

• The thermal solar power is a simple technology that is available early on, but even the basic tier of panels was much more efficient than the Solar Panel and even came with its own generous - and lossless - heat storage! They worked during the night and easily out-competed alternatives. (It could have been interesting if they were just particularly efficient for production of heat over electricity, but the game isn't set up to take advantage of such a difference.)
• I don't really like the idea of tier unlocks that just give you the same thing, but better, as a reward for your patience and/or materials invested. I mainly want efficiency gains to be derived from increase in the setup complexity as well as meaningful choices. While a more complex manufacturing process could justify it to some extent, I don't want renewable power pr. area produced to get unrealistically high, especially since land use seems integral to game balance in relation to base defense. I also just like being minimal about buildings added to the game and its menus and not create entities that will only be used for a short while in the early-game.
• I wanted to establish a natural limit to the temperature that could be achieved with flat (or could we pretend they are parabolic?) thermal panels, especially compared to energy-dense coal that only heats steam to 165°C in the boiler. To overcome heat losses at higher temperatures, something like concentrated solar towers would realistically be needed. So I removed the higher tiers of panels, heat exchangers and steam engines. I let other mods fill the gap before nuclear energy with more interesting solutions instead.
• As for the Heat Accumulator, there were many things I didn't like, but with the new heat loss mechanism, it seems to do almost nothing to solve the problem of intermittency. It may store great amounts of heat, but it takes a very long time to heat up and temperatures will still quickly fall below the threshold of 165°C during the night, halting power production. There are much more useful forms of energy storage (*cough* lossless steam storage *cough*), so I removed it, along with the Evaporation Pond (it had placeholder graphics anyway).
• The recycler seems less needed with fewer buildings, so I removed it as well. In any case, Reverse Factory can be used instead.

Q: The information in the tooltip for the panels seems a bit odd!
A: That's not a question. But yes, there is some useless information mixed in due to prototype constraints, which are hard-coded. With some small hacks I managed to properly display the max heat energy output and even create a makeshift sunlight indicator inspired by Cheese's Concentrated Solar! To ensure good performance with many panels and avoid some potential issues with on_tick scripts, it only displays a snapshot of the current light level while its gui is open. It works by emptying and then filling the buffer with a proportionate amount of "solar-fluid" (the fluid content goes down ever so slowly, since only a consumption rate above 0 is allowed). The fluid could remain on crash, death or disconnection while the gui is open, but it's inconsequential and easily resolved by clicking the entity again or using the "/tspl reset" command (it also resets if mod configuration is changed).

Q: How is mod compatibility?
A: I play with a lot of mods, and it works fine with all of them, including the ones I have recommended. The recipes and tech tree can even optionally be adapted in a pre-defined way to the overhaul mods Industrial Revolution 3, Krastorio 2, Sea Block and Space Exploration. Balancing in relation to these overhaul mods is difficult, since there are a lot of things to consider (like the tech tree, recipe cost, manufacturing complexity, available tiers and overall intention), but I have tried to adapt the mod and suggest some energy parameter values in the settings that should very roughly give the solar thermal complex parity with the first tier of Solar PV + Accu.

Regarding other mods: Bob's Power still works fine. However, Nullius seems to prevent the activation of this mod's content no matter what, for reasons I haven't figured out yet. There also seems to be some issue with Realistic Reactors that can cause a crash under certain circumstances when thermal panels or heat pipes are removed, and I have no idea how to fix that on my end.

Aside from that, there are potential issues with fast-replaceable groups in relation to other mods, so that is an optional feature turned off by default.

Q: What is the performance impact on the game?
A: For the sake of my creative goals, there is a fairly complex temperature script being applied to every thermal solar panel once every second, and then there is related management of heat, fluids, entities etc. On my PC (i5-12400F, RTX3070) it seems that producing 1GW of electricity around the clock with only the solar thermal complex (and no coal backup) could increase CPU time usage with an average of maybe 5.3 ms/tick. I realize that this matters in mega-factories, and this is the very reason I created the large version of the Thermal Solar Panel. Using that seems to reduce the overall impact to about 1.3 ms/tick, which works fine for me. Of course, on an extreme scale, Solar Panel + Accu remains the better option due to their minimal and virtually non-scaling UPS impact.

Q: Anyway, how do you calculate the actual, average output of the thermal solar panel?
A: Try the formula below, which is a pretty accurate "best fit" solution I created from a few experimental data-points. Assuming the use of the small thermal panels in an arrangement like seen in the info-page's screenshot, it can be calculated thusly:

Efficiency Ratio = 0.7 - 7 / ( EnergyOutputSetting - 27.5 )

Average Energy Output = EnergyOutputSetting * EfficiencyRatio

This is a horizontally asymptotic function that intersects the x-axis at 37.5kW and approaches a 0.7 efficiency ratio at infinity. The ratio should be around 0.525 at 67.5kW and around 0.67 at 250kW. The efficiency is a bit higher for the large panels in practice, for technical reasons.

Q: Will you make any further changes to the mod?
A: I may want to tweak balance here and there, expand mod integration or even improve graphics further. I probably won't make higher tiers, though. I could be interested in adding content that helps increase power production efficiency a bit further with more complex setups in the late-game, but I also want to be super careful not to break game balance, overly complicate the mod or muddle the theme of it. I have made some serious attempts but they haven't panned out so far. Anyway, in relation to vanilla Factorio, the mod feels largely complete as it is now.