- Jan 1, 2018
- Reaction score
- Hive Type
- Number of Hives
- 40 plus 25 that I maintain for clients.
The 5MwH is the amount bought in plus your own production on top?
Yes the 5000kwh is from my energy supplier any of my production is additional.
Any idea how much of the 5.4kw ASHP comes out of PV?
To be honest no but as you say in winter, when the heat pump is in use, there is minimal PV supply. However the heat pump is often supplied with PV power in the summer when it detects the need for hot water. It kicks in and replenishes the tank with water up to 42deg. Once the system is satisfied the PV will kick in to carry on heating the water via the immersion heater. This is the most efficient way of heating the water as the heat pump is about 200% efficient in water heating mode. ( at a guess I would say maybe 10% of energy is supplied to the ASHP by PV.)
In winter the PV power and hours are low and possibly do not overlap heat need unless you accumulate heat during the day have enough thermal mass & insulation to stay warm at night or reduce heat needs. Can that be, or is it, that sort of thing designed in, programmed in; part of the plan and discussions?
Due to the vagaries of the British weather I would say that designing in use of PV to power heat pumps would be difficult.
Regarding the house staying warm at night, my house has 3 thermostatically controlled underfloor zones on the ground floor and radiators with thermostat valves on the first floor.
The zones are set to 16degs overnight and I have never known the heating to come on overnight in the 7 years since it was installed.
In the morning the zones are activated at 30 min intervals from 5.30am to enable the heat pump to work at its most efficient, heating small volumes of water rather than having the whole system at one hit.
Our burner is also to the small end and likewise tends heat the house with the lounge door open, plus I only burn 3 or 4 logs per night by running down between logs, 5 or 6 kg maybe so nothing like flat out. I do get complaints that the heating has not come on and so some room is not warm enough but then our insulation is currently really poor with solid walls.
I do the same with the logs but it did take me a couple of winters before I sussed how to best use the burner.