Alan Clarke, Technical Support Manager at Heatrae Sadia, discusses the benefits of electric heating systems and the future these appliances have in UK off-grid homes.
It is estimated that around two million UK homes (15%) are not connected to the mains gas network. Rural developments and high-rise buildings are driving this percentage ever higher, which has led to a rise in demand for electric wet central heating boilers and cylinders.
Decarbonising the grid and ‘greening’ our heating and hot water systems has been one of the most widely discussed issues in our sector so far this year. After all, this is the year that the Chancellor announced that he was launching ‘The Future Homes Standard’ in 2025, which will set minimum environmental standards for all new housing.
Industry leaders, bodies, and associations are all making their voices heard to promote the benefits of ‘greening the grid’. However, throughout all of this debate, electric boilers haven’t necessarily been given the due consideration they deserve.
We’ve already seen a step-change in the way electricity is perceived by the government and industry. Indeed, the publication of Standard Assessment Procedure (SAP) 10, which will replace the outdated SAP 2012 calculation, will see the favourability of electric heating increase. As it stands currently, SAP 2012 assumes 2.4 times the amount of carbon is produced when using electricity within a home, as opposed to gas.
The revised standard reduces electricity’s annual average CO2 emission factor from 0.519 kgCO2/kWh to 0.233 kgCO2/kWh (a 55% reduction) and places the energy source just behind gas (0.210 kgCO2/kWh).
Demonstrating the favourable view of electricity, the initial proposal for electricity’s carbon emission factor was just 0.398 kgCO2/kWh. Evidently, the government senses the opportunity that electricity represents and has worked to encourage an uptake in electrical appliances.
Through no fault of their own, homes that have historically been unable to access the mains gas grid have been penalised for making use of electrical heating. The changing mindset of government and some within the industry could bring about positive change for electrical boilers.
Electric boilers offer a valuable means of heating and hot water provision for those who lack a connection to the gas grid. The dual capabilities of some electric boilers makes them the ideal choice for those living in rural developments.
Take, for example, Heatrae Sadia’s Electromax, which has been designed to provide both controllable wet central heating supply and hot water using only a mains electrical connection and a cold-water supply. Additionally, unlike the use of an electric heat pump which may require adjustments to be made to radiators and piping, electric boilers use standard radiators and thermostatic radiator valves. This means the homeowner will face little to no disruption should they choose to opt for an electric boiler over, for example, a heat pump.
The growing popularity of high-rise living and apartments has been a boon for electrical wet central heating. It has moved on greatly from the inflexible, mainly uncontrollable, night storage heaters that it was once associated with. Heaters which store energy overnight and release it during the day (whether or not it’s needed) are not an appropriate solution for today’s off-grid consumer.
Compact and efficient, electric flow boilers are controlled and operated by a programmer and thermostat, working in a similar way to a traditional gas-fired boiler. Some electric boiler boilers can even modulate in the same way as a gas combi boiler, improving operating efficiency.
To deliver hot water to high-rise properties, the electric boiler can be paired with a direct cylinder. This is significant as the Greater London Assembly (GLA) has recently taken the decision to proactively make use of the updated SAP 10 carbon emission factors. A more contemporary approach to electrical hot water generation within residential dwellings will therefore likely be taken – as such it is likely to become a better proposition for major multi-occupancy dwelling developments that are not linked to the mains gas grid.
The heating industry is undergoing rapid change. Debate thunders on with no firm answer to the challenge of greening our heating supplies. It is heartening however to see growing interest in electric heating. For off-mains gas grid homes, electric boilers and wet central heating systems afford homeowners an opportunity – we must be willing to consider all serious heating solutions and be open to the idea of alternatives. After all, a common theme in the off-grid debate is that no one size fits all.