Electric Heating Explained
In UK households heating/hotwater systems are most commonly based on gas, or oil/LPG in off grid locations. The reason is quite simply that for many years gas/oil/LPG has been considerably cheaper than electricity (commonly 4 times cheaper). The truth, however, is that for unit of power versus unit of heat produced, electrical systems are more efficient. In a gas/oil/LPG system heat is lost via the flue and pipework. Furthermore, oil and gas are both dwindling resources, with the government’s Carbon Plan showing virtually no role for domestic natural gas by 2050. It hopefully goes without saying that whilst electric heating will see efficiency gains over gas (around 10%), this will not help your carbon footprint if you do not get your supply from a renewable source (your own or a renewables only tariff).
The term ‘electric heating’ encompasses a huge range of products, and due to the reach of the electricity grid and typically widely wired infrastructure in homes, most are available to most people. However, we would still recommend a heat pump as the best alternative. Heat pumps can be some 3.5 times more efficient than the best other electric heating and can often be retrofitted to existing central heating system. Whilst having quite high upfront costs heat pumps can benefit from government subsidy under both the Green Homes Grant and the Renewable Heat Incentive. In addition heat pumps can also supply your hot water.
So assuming that either you are looking at electric heating as “infill heating” or eliminated the option of heat pumps , the following is a discussion on the other alternatives.
How Does Electric Heating Work?
Heating is achieved via convection or radiation and each has its own distinct benefits. Convection involves warming the surrounding air and its biggest benefit is quick results, although in addition your room can be any shape or layout and it can still be effectively heated. The main drawback is that the heated air is quite prone to loss through open doors, windows, and poor insulation, forcing your heating system to compensate. Radiant heat, alternatively, travels through the air until it’s absorbed by a person, object or surface. Whilst far less susceptible to heat loss, it takes longer for rooms to reach the desired temperatures. In addition, radiant heat needs “a line of site” to the object to be heated meaning in complex housing layouts the designed system will also need to be complex.
Due to the relative use of gas versus electricity, until quite recently, electrical heating products were commonly manual and often basic, with efficiency loss caused by the use of less than optimal materials and technology, often result in overheating. This is no longer the case with most mid and high range product offering good controllability, automation and even intelligence. Many will also offer interfaces for control by smart speakers/screens.
For energy efficiency infrared panels win. Operating on lower power and less likely to suffer heat loss, they range from single room “infill heating”, to full house zonally controlled heating. From freestanding to wall mounted, they typically require less space than traditional “radiators” and have such design innovations as doubling as a mirror. As they are slower to reach desired temperature considerable effort has gone into thermostat control, scheduling control and remote control interfaces which deserve investigation when choosing a product.
Infrared vs. Economy 7 and 10 Tariffs
It is still the case that due to the economy 7 and 10 tariffs storage heaters can be a cost efficient option and again in recent times they have been improved in terms of controllability, design and efficiency, although still some way behind infrared panels. In addition as the smart grid becomes more developed there is a question as to whether these economy tariffs will/should continue, and critically these tariffs are very costly outside economy hours.
For both of these heating options your hot water needs will have to be provided by a separate system. As with gas both instant and water tank systems are available. Again we would recommend infrared systems for the same reason previously stated. The instant systems can struggle providing required water pressures due to the limited amount of water flow, but will not “waste” hot water. The hot water tank systems must be well insulated to avoid loss of the relatively expensive hot water.
With the need to meet the COP agreed goals and the recommended acceleration of these goals electrical heating with undoubtedly evolve quickly.