Understanding the Cost of Heating: How Much Do You Pay for a KWH of Heat?

Wayne
Apr 20
2 min read

Oxbow, the manufacturer of Red, has confirmed the figures below.

Even the sealed bags of Red cost less than £0.12 per KWH, including VAT at 5%.

£0.12 per KWH, excluding VAT, is £0.11428571. This is usually how the price per KWH is quoted on your electric or gas bill.

In these times of money-saving, as we emerge from the cost-of-living crisis, solid fuels like Oxbow’s range are a better value per KWH.

If you’re buying solid fuel from a supermarket, you might be paying more for per KWH because some fuels don’t have as high a MJ/kg as the Oxbow range.

From our last testing the net was 28.719 Mj/kg

This equates to 7.9775 KWH per kilo (multiply by 0.277777778)

A 50kg bag therefore has 398.875kwh

Based on a 100% efficiency stove – £0.08762143/kwh

Assuming 75% efficiency – 299.156kwh

Gives a price of - £0.11682867/kwh

Again the exact figures of Red were 72.6 for Fixed Carbon

72.6% x 3.67 – 2.66442kg of Carbon Dioxide per kg of Red

So one kg of Red produces 2.66442kg of CO2 and 7.9775KWH

This equates to 0.33399185kg of CO2/KWH

Based on 75% efficiency – 0.44532246 of CO2/KWH

You can use the following links to understand theory behind the calculations.

The transmission and generation (T&D) emissions factor for grid electricity has increased from 2023 figure of 0.01792 kg CO2e per kWh to 0.01830 kg CO2e per kWh.

https://www.itpenergised.com/new-2024-uk-grid-emissions-factors/#:~:text=The%20transmission%20and%20generation%20(T%26D,CO2e%20per%20kWh .

If you install a heat pump into a house that is not airtight and is uninsulated it can actually produce more CO2 per square meter than a gas boiler.

https://buildingenergyexperts.co.uk/resources/should-i-buy-an-air-source-heat-pump/#:~:text=If%20you%20install%20a%20heat,heat%20generated%20to%20be%20retained.

Carbon to carbon dioxide formula from:

https://www.360energy.net/resources/post/how-using-energy-creates-carbon-emissions#:~:text=Bituminous%20coal%2C%20on%20the%20other,2.42%20kg%20of%20carbon%20dioxide

Kilowatt-hours formula from :

https://www.freeconvert.com/unit/megajoules-to-kilowatt-hour

Stove efficiency from:

https://www.stovax.com/highly-efficient-stoves-fires/solid-fuel/#:~:text=With%20efficiency%20levels%20of%20up,suit%20many%20different%20home%20styles.