John, the BBC article is claiming that a heatpump costs as much to run as a gas boiler (with good insulation), so a poorly insulated house would cost more.
A poorly insulated house would cost more in both energy sources. Comparing like for like i.e. take out the gas boiler fit the heatpump the heat energy in terms of kWh of heat generated will be the same.
Do you have any experience or knowledge to contradict this?
Absolutely it's pretty straight forward. My gas supply from Octopus in winter time is 9.8p per kWh. My Electricity during peak times is 29.6p
The gas boiler I have has an efficiency of 91% so the actual cost per kWh of heat is 10.76p plus a little more for pumps, valves and boiler controls around 60w of electrical energy bringing the gas boiler cost to 12.5p kWh.
Now the heatpump, running on peak energy cost of 29.6p per kWh produces an average of 3 kW of heat for 1 kW of electrical input, the cost of the heat from it is 9.86p per kWh of heat. In addition to this though, the off peak time (6 hrs) is only 7.5p. The 6 hrs only costs 2.5p per kWh of heat. If you average this over the day (usually heatpumps are run 24/7 ramping up overnight and back down again during the day), the average is 24.07p which gives us 8p per kWh of heat from the heat pump.
It is true to say better insulation will help dramtically but that is true for any fuel / boiler combination.
(Obviously I am talking without solar / battery)
Yes of course, this just puts the icing on the cake, battery storage alone gives me all of my electricity at 7.5p kWh or less and heat pumps run at 2.5p kWh or better.
That isn't the issue. The issue is how much of the UK housing stock is suitable for heat pumps, given that successful heat pump installations depend on significant insulation, larger radiators and pipework (to handle the lower temperatures) and space to put the unit.
We were quoted for a heatpump installation including bigger radiators and a new hot water cylinder etc. Me being very analytical by nature looked at running our gas central heating system at similar flow temperatures to a heatpump (45 deg C, most heatpumps are 50 deg C or slightly more). The results were surprising, even though the boiler was running 24/7, it was using less gas than previous weeks even though the outdoor temperature was lower and house was warmer. So in some cases the disruption and need to change rads is a myth, a bit like EV batteries need changing at 8 years at a horrendous cost.
It can certainly be retrofitted but at a cost and with disruption often requiring internal redecoration. That's fine for some but not for all.
Absolutely agree
We rebuilt our house completely between 2015-2018 before most of these government decisions were taken. A simple gas boiler and conventional radiator system was by far the best option at the time. We did not spend that money to then have to replace the whole system a few years later, forget it.
You maybe dont need to, invest £9 in an infrared thermometer, look at the water pipes coming out of your boiler, turn the boiler thermostat down to 40 deg C, leave the boiler on 24/7 in winter time and see how the house temperatures are. Thats the real proof of whats needed as opposed to the heatpump installers that make a good living from their work. I didnt go for the grant, I bought a used but very good Mistubishi Ecodan air - water heatpump from ebay. It was located at the back of my house behind a wall, the flow and return pipes through the wall and connected directly onto the boiler flow and return pipes, a 7 kW electrical supply run to it and the job was done, cost me less than £2100 to do. Now awaiting winter time to see how well it works.
If every house was insulated to that standard the country would cut its usage of fossil fuels drastically even if they went right on using the heating systems they already have.
Absolutely 100%
My gas engineer said that very good insulation is essential if we want to install a heat pump.
My gas engineer told me EV's will not catch on, theyre very expensive to run and in danger of burning your house down. But, as with all these thing myths are often repeated by people who really dont understand them, they just repeat hearsay.
Here some real life stories of heatpump use that reflect my own findings.:
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robinmcalpine.org
