@pauldavies83 I did say when we moved here being new to ASHP that we would need to give it a full year to work out a proper budget. I just wish we had had better instructions when we moved in as we have been using it in the wrong way and only just noticed when the smart meter was installed how expensive it has been. Our developer has told us that on this site, when the pumps were being planned for this site, electricity was cheaper than gas. The government should be subsidising those of us who opt for eco friendly heating methods, and the suppliers should be reducing their costs too as an incentive otherwise nobody will move from gas ever.

@justinsb bit of an oxymoron there. Reducing the flow temp will mean the heat pump stays on longer, but will be cheaper to run. Cycling as I understand it is actually very bad for efficiency, as the compressor has to get going - leading to the power spike you see in the cycle. If you want the ASHP to cycle more, you need to raise the flow temperatures.

I would personally start with adjusting the weather compensation down and seeing the effect on the costs. the HP shouldn't be working as hard, or have as many defrost cycles when the water is cooler.

If you look at the last couple of days on this graph, the Flow Temp is way up, but I don't think that it needs to be that high. I think tha the house will be plenty warm enough with a Flow Temp of 36°C or 37°C, as opposed to 40°C. I'm hoping that dropping it slightly will instantly show up in today's electricity usage (I'm checking my Smart Meter twice a day, to keep tabs on real world costs).

@justinsb it should show up immediately, however your house will have latent heat. Realistically your heat demand is going to rise as the temperature falls. All you can do is tweak down, wait a day or two, tweak down again etc etc 

Posted by: @justinsb

If you look at the last couple of days on this graph, the Flow Temp is way up, but I don't think that it needs to be that high. I think tha the house will be plenty warm enough with a Flow Temp of 36°C or 37°C, as opposed to 40°C. I'm hoping that dropping it slightly will instantly show up in today's electricity usage (I'm checking my Smart Meter twice a day, to keep tabs on real world costs).

 

Sorry Justin, but you are mistaken.

On our gas boiler system the required radiator temperature has had to go up from approximately 35C to just over 40C during the past few days. The heat energy produced by your heating system needs to balance the heat demand of your home. If you look at the modelling tool that I produced, you will clearly see that the energy demand increases quite dramatically as the ambient air temperature falls.

The only ways to lower the required water flow temperature and improve the efficiency of your ASHP, would be to lower the desired indoor air temperature, reduce the heat demand with improved insulation, and/or increase the output rating of your heat emitters. Just lowering the water flow temperature will cause the indoor air temperature to be reduced.

The good news is that the ambient air temperature is predicted to rise for a day or so.

@pauldavies83 

At the moment over 50% of the electrical energy being generated is from fossil fuels, 48.8% gas and 3.9% coal, so the ASHP's are not running on completely 'green' energy.

A combined cycle gas turbine generating unit is at best approximately 50% efficient, so each kW of electrical energy generated requires 2kW of gas to produce. That is one of the reasons why electricity is more expensive than gas.

So maybe we should remove the government gas subsidy and apply it to renewables (and even Nuclear if necessary, another can of worms). Otherwise how do we ever wean ourselves off it? Not by spending £10k+ on heating systems that "may be a fraction cheaper than gas" to run.

(FWIW I rely on bottled LPG which costs an absolute fortune, and given the recent electricity price spike I'm having second thoughts about moving to an ASHP as I imagine the price of electricity will rise again by the time my fix ends in April).

(sorry for dragging this off topic a bit 😬)

@pauldavies83 

I've heard talk of a special tariff for ASHPs. If they removed the green levy, that would be a good start. But then that might be considered double-dipping for those already getting RHI.

It’s cold.  Cold enough for my wife to want a log fire in the lounge.

We still have snow in Derbyshire. My garden.

9/10 for the scenery. How's the leccy consumption ?

@kev-m 

9?

Leccy consumption is……….. high.

@morgan,

for a 10 I'd be expecting some wildlife; a cute little baby deer maybe?