Maximising Savings: Navigating My First Year with Octopus Energy and Heat Pump Running Costs
I am so relieved to find this thread and discover that I am not the only person obsessed with this - Like Steve, I have no issue with looking at the day ahead Agile pricing every day to work out when to schedule usage to get the most out of it.
Thanks @steve81uk for the detailed analysis. As mentioned in @toodles other thread, I too am now looking at the new Cosy tariff and wondering if it may now be better than Agile for us (12kW ASHP, 3.6kWp solar array. Great to have so many choices.
Samsung 12kW gen6 ASHP with 50L volumiser and all new large radiators. 7.2kWp solar (south facing), Tesla PW3 (13.5kW)
Solar generation completely offsets ASHP usage annually. We no longer burn ~1600L of kerosene annually.
Really interesting stuff. We're on the octopus cosy tariff and we have underfloor heating with screed... I'm experimenting with the set back temperatures, but it's hard to decide how hard to run the system during the off-peak period Vs the standard period. We've got the set back during the 3 hour 1600 peak period as minus 10 to ensure it coasts through. But for the 10am to 1pm period I'm not sure if it's best to run it with a bit of a set back, made up for by running it very hard during the half price 1300 to 1600 period. Or keep it pretty much on the curve until 1300 and then only need to bump it up a few degrees during the off-peak.... Any thoughts?
I suppose in a way the UFH fabric is effectively a heat battery. I use an electrical battery (27kW/h capacity) to ride through the 16 hours of Cosy that aren’t at the cheapest rate. Would your floor screed mass provide you with a large enough buffer to do do anything similar perhaps?
Obviously you don’t want to overdo the heating during the 8 cheapest cosy hours but might this go some way towards covering the rest of the day/night. The 16:00 - 19:00 is the real killer but if your heat battery can do those 3 hours, this would be a good start. Are these the lines upon which you are thinking perhaps?
I have a Homely controller in my system and that (unless instructed otherwise) will ‘stock up’ during the 8 cheapest hours of my Cosy tariff and had I not had battery storage, I would be making even more use of that then I do! I use the grid directly as much as I can as obviously I don’t suffer the ~10% AC-DC then DC-AC losses from using the battery. Regards, Toodles.
Toodles, he heats his home with cold draughts and cooks his food with magnets.
Posted by: @toodles
I suppose in a way the UFH fabric is effectively a heat battery.
Yes, this! Thermal mass is key. Ancient civilisations knew a thing or two about using solar reflecting lighter buildings, natural ventilation for cooling & high thermal mass to dampen the diurnal temperature swing in hot climes.
Seems we’ve lost the plot with timber framed buildings finished in solar absorbing colours with architects even scorching naturally light timber cladding to make it dark! They have very low thermal mass translating to very low thermal lag.
@allyfish If there is one thing we learn from history, it is that we don’t bother to learn from history! 😉 Regards, Toodles.
Toodles, he heats his home with cold draughts and cooks his food with magnets.
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