The recent New Build Heat Standard for Scotland has raised some concerns about the ongoing use of wood burning stoves to heat our homes in Scotland. Thanks to lobbying by the Stove Industry Association and other trade bodies, this legislation is now under formal review by Scottish government. Read on to better undertand some of the key facts relating to clearSkies certified stoves and the use of wood fuel.
Key facts – emissions & efficiency:
- A clearSkies certified stove produces up to 90% less particulate emissions than an open fire, and up to 80% less than many older stove models. (Older stove models being classified as closed stoves pre 2001 and stoves that comply with the EN13240 standard introduced in 2001). Source: Kiwa Report No. 60578.
- Modern stoves, such as clearSkies certified models, account for just 1.8% of total UK PM2.5 emissions; when burning dry wood fuel only this reduces to 0.3%. Source: NAEI, 2022
- A clearSkies certified stove will use 1/3 of the total amount of wood fuel required by an open fire to produce 4kW of heat over a 5-hour period.
- A clearSkies certified stove operates at an efficiency level of 80-85%, comparable to the most efficient gas boilers and gas local space heaters.
- All clearSkies certified stoves meet the requirements of Ecodesign, with certification Levels 4 and 5 verifying that the certified appliance’s emissions are lower and the efficiency is higher than those required by Ecodesign requirements.
- All clearSkies stove models certified at Level 3 and above have been verified as complying with Smoke Control Area exemption criteria (Defra exemption) meaning they can be used to burn wood if you live in a Smoke Control Area.
Key facts – carbon reduction
- Wood logs have the lowest carbon emissions factor (CO2eq) of any domestic heating fuel. The CO2eq emission factor (kgCO2e/kWh) of wood logs is 1/19th that of electricity (0.01074 compared to 0.207074) and 1/16th that of mains gas (0.01074 compared to 0.18). Source:
- An alternative comparison is that wood fuels deliver carbon savings compared to fossil fuels and compared to most forms of renewable energy as well. According to the Review of the Scottish Wood Fuel Industry, Sept 2021 conducted on behalf of Scottish Forestry, burning logs generates 4g of CO2 per kW hour, compared to 48g/kWh for wind energy and 123g/kWh for ground source heat pumps (see p.9).
- A modern wood stove emits 94% less CO2 than direct electric heating e.g. an electric fire and just 22% of the total kgCO2e of a heat pump with a coefficient of performance (COP) of 3.5.
- When a heat pump is required to provide heat suddenly, for example during temperature fluctuations, the COP drops and carbon emissions increase even when the latest high temperature heat pumps that achieve a COP of around 3 are deployed – see https://www.bbc.co.uk/news/business-67511954 When a modern stove is paired with a heat pump, not only is the optimal heat pump operation facilitated, but top-up heat from the stove is available on demand to mitigate temperature fluctuations and weather events.
Key facts – grid independence & resilience, fuel poverty & consumer choice
- 170,000 properties (7% of total dwellings) in Scotland are off-gas. Source: Heat in Buildings Strategy.
- Scottish Conservative information indicates 40,000 of those homes are unsuitable for heat pumps.
- 31% of Scottish households live in fuel poverty, with 20% classed as “extreme”. Source: https://fuelpovertypanel.scot
- There has been a 38% increase in the number of Scottish households living in fuel poverty since 2019.
- Having a clearSkies stove as a local space heating appliance ensures heat is always available in the event of a power cut and offers a cushion against fluctuating gas and electricity process.
- Wood fuel is a “bought and paid for” fuel, no direct debit or standing order required, helping to visibly monitor fuel use and aid household fuel budgeting.
- A clearSkies stove can be beneficial for older, poorly insulated properties as they are highly effective at providing space heating and reducing condensation, helping to alleviate mould and damp.
- A real fire can help promote feelings of warmth and security, and provides a focal point for the family benefitting mental wellbeing. Source: National Library of Medicine
- A clearSkies stove as a secondary heat source offers grid resilience and protects the vulnerable by ensuring a reliable source of heat in the event of a power cut.
Key facts – wood fuel industry & biodiversity
- Locally sourced wood fuel (of which Scotland has a plentiful supply) helps support small businesses and reduces the carbon footprint of fuel transport. Source: Small Woods Association
- Wood fuel is a key component of the woodland management cycle and the economies attached to it. It also plays a key role in maintaining woodland diversity, health and resilience. Source: Small Woods Association
- Unmanaged woodland is bad for wildlife. At present 42% of UK woodland is unmanaged. Source: Small Woods Association
