I think it should be said what you are trying to fix exactly.
The exact thing I'm trying to fix is:
Currently it is almost always an optimal choice in the mid-late game to build tons of backup energy reactors and keep them in low power mode because:
- It gives you effectively instantaneous ability to recover from loss of energy production.
- It has a minimal in-game cost (just the m+c cost of the initial reactor builds, which can be paid at any time rather than at the time of crisis).
- Normally there would also be the ongoing cost of running the reactors, but this can be negated by the player putting the extras in low-power and accepting the non-in-game cost of just pausing and fiddling whenever there's a need to take reactors out of low power.
Removing the ability to put them in low-power would make it so that you could still have that resilience to sudden energy production loss (without the non-in-game cost), but the degree of redundancy would become a strategic choice: how much ongoing m+c are you willing to spend on that safety margin? That in turn pushes the broader strategic question: how much territory are you willing to take to provide the m+c needed by your energy production and your ship production?
It's true I don't want to be flipping around power buttons in a manner fit for small children, but at the same time, it could be devastating to lose a planet that has reactors on it if it costs a lot to replace them.
I'm not suggesting increasing their cost, if that's what you mean. If the upfront costs are imposing I'd be willing to decrease them, but I don't think they're currently a problem.
If you lose that power, you still would have to pause the game and make sure that your home planet force Field is still working, and then you would have to start pruning your fleet or your defenses to get enough power to do the necessary. This could be a huge disadvantage that doesn't really add a lot of fun or choice. In effect, you would have to have a few extra reactors running in all times to guard against this,
Correct, you'd have to make the choice that best balanced your desire to have maximum resources devoted to ship production (and thus military progress) and your desire to not be vulnerable to a quick-kill (or at least serious setback) from an AI raid on your energy production.
which would drain your resources and slow down the production metagame. Which is already slow enough, especially in multiplayer.
It is certainly a valid concern to avoid situations where you don't have much choice but to sit there and wait for your resources to catch up; that's why we've increased the startup resource base so much over the years (you should have seen it in 1.0, heh). On the other hand, it is valid for that ability-to-produce-all-you-want to be dependent on other choices you make (otherwise we should just take m+c out of the design). Specifically: if you need more m+c (and/or energy) to maintain ship production, you have the choice to take more territory (this choice is not as available in the very early game). You can also choose to increase that income via research (econ command station II/III, m harvester II/III, c harvester II/III). Those also have costs, so they're non-obvious choice, but that's the kind of choice we're going for. If the m+c situation _in general_ is too slow, that would be something we'd need to address apart from this issue of energy.
edit: I should emphasize, doing this would change the 'switch to low power' game to the unit level, and it would not change the fact there is still an optimum reactor to build.
This was exactly the reason I was against the idea of removing the low-power option months ago when it came up, but I've realized that it is a very different situation: with low-power you have a guaranteed no-cost ability to just switch them back on. It's trivial and child's play, like you've said, and only has the non-in-game cost of pause-and-fiddle. But building fresh reactors costs m+c, and some combination of game-time and engineer-seconds, which are quite valid in-game costs. There's still the pause-and-fiddle of having to build those reactors, but any time the AI has you on the ropes in a sense like energy-grid-brownouts you're going to have to deal with it personally; to avoid that don't get knocked onto the ropes.