Dam, we're with octopus and we pay 30p/kWh for import.

Atm it's about roughly 35-40 cents per kWh. That's much higher than most places in the US which Google is telling me is 16 cents per kWh.

I just had some installed. ~~Guaranteed 80% efficiency for 20 years.~~ I heavily doubt they will last 60 years.

Had energy storage installed as well. Only guaranteed 90% (~4500 cycles) for 10 years.

EDIT: double checked the data sheet. They are actually 86% for 25 years with a rated 0.5% per year degradation rate.

Solar panels aren't truly renewable since they degrade over time and need to be replaced after around 20-30 years. Yes they can be recycled, but so can (and is) nuclear waste.

Everything has a cost and you can't escape entropy.