Heat Pump Running Cost

Air and Ground Source Heat Pumps, are one of the most efficient forms of Electric heating that currently exists, and upto five times more efficient than a standard convector heater of the same rating.

Whilst Heat Pumps are still not yet efficient enough to compete directly with Gas Central Heating Systems, they are generally far cheaper than LPG and Oil based central heating (upto 60% cheaper in like for like systems), and five times cheaper than Electric Boilers and Underfloor heating. In addition, they offer more flexibility than storage heaters, and often produce far more usable heat. That is assuming that the outside air temperature isn’t too low, because a Heat Pump operates at its peak efficiency with external temperatures at around 6c to 9c, and becomes next to useless when its -5c to -10c

So, how much do Heat Pumps actually cost to run?. Well lets take some working examples.

First of all, its important that you shop around for the best Electricity Tariff for your region, Electricity costs vary drastically from region to region, and I have found prices ranging from 11p KW/H to 19p KW/H just by comparing prices in my own area!. Differences like this, can easily add up to a few hundred pounds per year, so shop around.

The cost of running also depends on the type of system and its Electricity Consumption, as well as how often its used, and how cold it is outside.

A 2.2KW Air Source Heat Pump based boiler will produce around 11KW worth of hot water for Radiators, and consume 2200 Watts from the mains. At a cost of 12p per KW/H, running this system would cost around 27p per hour in Electricity, or £2.11 for an 8 hour ‘running period’.

However a larger central system consuming around 11kw will be fairly expensive, costing around £1.12 per hour to run, however it will generate enough heat to warm an average sized 3 bedroom property.

You can use the following formula to work out the running cost as i’ve done in the above example

(kilo watt loading) X (number of hours running) X (electricity unit cost in pounds) = running cost per hour

And so:-

2.2 (kw) X 1 (hour) X 0.12 (electricity cost in pounds) = £0.264 per hour running cost

Compare this to an average cost of 11kw worth of hot water produced from an Heating oil powered central heating boiler, which would cost 61p per hour to run, or £4.93 for an 8 hour ‘running period’ (based on 56p per litre for oil).

As you can see, running the Heat Pump costs less than half of the price for producing the same amount of heat of an Oil fired heating system, and makes it a very viable option for those with LPG or Oil based systems.

Let’s also compare the cost of the 2.2kw Air Source Heat Pump, compared to 11kw worth of conventional convector heating used on the same 12p kw/h tariff.

11 (kw) x 1 (hour) x 0.12 (Electricity Cost in pence) = £1.32 per hour

So to run 11kw worth of conventional Electric Heating, against the 2.2kw drawn by the Air Source Heat Pump, would cost £1.05 per hour MORE

Remember to use the following formula to work out your own Heat Pump running costs

(kilo watt loading) X (number of hours running) X (electricity unit cost in pounds) = running cost per hour

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