[An update on the solar solo mine would be groovy too.]
When building a Solar power grid or using microhydro one must plan for peak electrical use. I prefer Microhydro, but the cost of solar is getting much cheaper every year. Normally, one would float charge batteries and than burn off extra electricity to heat water , but I find that solar water heaters are better suited for this task, and excess electricity that would normally be discarded is used to mine bitcoin.
What would be the best of all worlds is using those ASICs to heat water as well to close the loop and recycle the waste heat.
Originally and all the way up through the GPU era, mining was something that could be done profitably part time, so taking advantage of off-peak cheap electricity was an excellent use case. Now however, miners are so damn expensive, that if they are not running 24/7 you can run a real risk of never being able to recoup your capital investment.
It is a race to break even before your miners are obsolete, halving cuts revenue, or the market crashes. I guess if you live somewhere cold, you could still run obsolete mining equipment as a space heater, sell them as a curiosity or mine some altcoin with a SHA256 hashing protocol and a much lower difficulty, but other than that, it's a race.
WE HAVE A CHICKEN AND EGG PROBLEM. Miners outside of China are reluctant to invest substantially in new mining gear because they face an uphill battle competing with Chinese mines with electricity and labor cost advantage.
Miners are also reluctant to build up because the code development uncertainty and scaling uncertainty. It's hard to make long term plans with so many unknowns. So mining concentration may not be corrected until there is code development decentralization.
Then we have the problem that code development centralization (with Core) is an established practice, something that will not be easily changed, if at all. Miners do not want to switch to Classic or other alternative because they fear (rightly IMHO) that a switch will cause market volatility or an outright crash.
They can't do something even if they know or suspect it is in their long-term best interest if they need to keep mining revenue high enough to pay for their gear operations in a shorter time period.
The vaccine could cause the death of the patient before it cures it. I think this is a risk worth taking, but I'm not a miner. It is up to them. Without taking the medicine, there is limited potential for growth and price appreciation.
Any miners want to weigh in on this?
Mining concentration in China harms security, censorship resistance and network performance (due to limited bandwidth) It makes Bitcoin a less attractive investment. Only substantial changes to the code will change this, IMHO. Classic is really the only alternative, given Core's bias towards the status quo.