I havent checked your maths but a few comments
If using electric and have excess solar the per kWh cost is the difference between the feed in tarrif and the purchase price. Off peak is also an option.
Dont forget that if you can go off gas fully you save the substantial connection cost. Gas is also predicted to keep rising in price. With electricity you have the potential with batteries later on as they get cheaper to reduce the pain of price hikes.
If you are aiming for a net zero house then you need to put a price on offsetting the carbon from each option.
If your heating load is small then there is potential to combine heating and hot water from the Sanden. It voids the warranty and you would have to be sure of the heating load calculations but worth considering as it could save some money.
The Sanden when running puts out 4kW of heat you only need 3 hours of that for the hot water and it has another 21 hours in the day to do nothing or.... heat the house. One day i might do this on my place if i decide i need a bit of heating.
Lastly, Bennny can you look up the difference between kW and kWh. You keep using them interchangeably but they are different. You seem to understand the difference and get the math right just not write the Units correctly.
Posted Friday 14 Jul 2017 @ 7:40:00 am from IP
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