Interesting if you're hosting at home - ok I should perhaps narrow it down further to hosting at home in the UK - and were considering power factor correction capacitors to knock down the electricity costs:
"In a domestic single phase power supply, unlike commerce and industry, you do not pay reactive power charges and you do not have a kVA limit so the only one who would benefit from fitting Power Factor Correction would be the supply company since they would need to supply less "kVA" for a given killowatt consumption.
kW = kVA x pf.
Killowatts are killowatts and the simplest way to save them is to turn things off.
If your machinery is using motors, you may find reducing the voltage to these will save energy especially if they are not fully loaded.
I hope this helps.
Regards"
Really? Running air conditioning or the refrigerator at 120VAC is more energy efficient than running at 126VAC? I suspect not.
Well, I'm only quoting the electricity guy's message to me. England moved from 240v to 230v for residential supplies a few years ago and everything still works just as well on 230 as it did on 240 but just used less electricity doing it. I'm guessing he's alluding to this. Most people here still think it's 240 because that's what they grew up with and they haven't noticed anything different plus the devices invariably say 220-240v on them