Paul, you are correct i have neither battery storage nor an air source heat pump. So i will gladly accept your first-hand knowledge in this instance. Your numbers however are frightening and giving me pause for thought as I am in the process of installing a 9kw air source heat pump, 45kwh battery storage and another 5/6 kwh solar array together with my existing 3.6kwh solar array.
9kw Heat pump? thats a large heat loss, is there no way you are able to reduce the heat loss of the property, its always the best route to go regardless of how you heat the home?