I am an avid green energy supporter and moved to Octopus after being a first comer to Ecotricity, in the days when green energy was new. I have PV and solar thermal on my roof and a battery in the garden. The systems predate FiT & RHI. I export via Octopus’s fixed rate tariff.
I have trained in home energy efficiency (AECB’s CarbonLite Retrofit) and am gradually bringing my home to nZEB/EnerPHit standard. I don’t use PHPP or any other software, I’m just using first principles and over engineering whichever detail I’m working on. Unfortunately my windows are too new to change and with a frame U value of 1.1 W/m²·K and glazing mid point of 0.8 W/m²·K (if I believe the supplier) are not quite up to the job.