We fitted solar thermal (hot water) panels when re-roofing in 2006. They've been great and very cost effective. Added solar PV around them in 2011. In 2023, using over 10 years import/export data I calculated the optimum extra PV/batteries needed to satisfy most of our power needs and covered a shed in PV. The shed is south facing with a 20 degree roof. The vertical panels help in winter.
The main fly in the ointment is the shadow from one of my mature Ash trees. I planted 800 Ash, among over 2500 trees in my "wildlife area", but they almost all died of There is no way I'm felling a mature tree of any kind, especially Ash! This does mean I get reduced winter generation for a few hours when it's sunny.
Although I am G100 limited to 6.5kW export, the whole of the battery/charge controller system sits on the DC side of the installation (invisible to the grid). So, when it's sunny, I have seen 16kW going into the batteries. Meaning the 28kWh batteries could potentially be charged from empty in under 2 hours.
... the next year (2024) we installed heat pumps. Air to water would have been very tricky in our house, so we went with Air to Air, which many people (v.annoyingly) call "AirCon". Ours are Mitsubishi Electric. Bought 99% for heating, but means we get free cooling, should we need it, in the summer. There is no mains gas here but, over the years, we've used oil, smokeless coal, logs and wood pellets. With Octopus Intelligent Go and batteries we almost never pay over 7ppu for electric.
@ArborealTechie Do you have multiple indoor units? And if so, does each need it's own external unit or is there just one?
@druid This place is quite unusual, due to bits of it being different ages and of different construction. We have a single indoor unit in my office, with a dedicated outdoor unit, paid for by the business. Then there is a "multi-split" outdoor unit, serving three indoor units, two of which have up to 5kW output in large rooms. Then there is a multi-split serving three bedrooms, the kitchen and lounge. Most houses with air to air have a single outdoor unit (afasik).
@ArborealTechie Ah, I see. Does sound complicated. I wonder if it would be possible to upgrade your external units to just one more powerful one instead? Perhaps that could give an energy saving? Just a thought as I have no knowledge of these.
@druid That would be reasonable, except for the topography and the way the different parts of the house are used. This way is more efficient, as we almost never have all three outdoor units in use at the same time. Like I say, it's complicated!😉
Jamie
Druid 🏴