Just a balance suggestion: Maybe make these very power hungry so even though they are more efficient than the regular ones, you really have to pay a premium in power. Some colonies have tons of space and so will spam power to make these but other might opt out. I just don't think its balanced to have 300% growth rate and only 200 watts of power usage, when the regular one does 130% growth rate for 120 watts of power I believe. In other words, make it cost more so you really have to think about whether its worth it.