Hybrid heating solutions offer potential to off-grid homes

3rd Jul 2017


Steve Sutton, Technical Manager, HHIC takes a look at hybrid heating systems for off-grid living.

The pace of change in our world is accelerating to the point where it threatens to outgrow economic growth. Throughout most of the time, since civilisation began, change progressed slowly. But since mid-century, the pace of change has been breath-taking.

More data (facts, information and statistics) have been created in the past two years than in the entire previous history of the human race. Digest that for a minute…..

Every industry must keep up with the demand caused by the pace of change. The heating industry is no different. Now is the time to rethink the way we heat our homes and hot water. Central heating systems, as we have known them, are changing dramatically and new solutions are needed.

Hybrid heating systems are an example of a ‘new’, efficient way to heat our homes and businesses. Particularly for off-grid homes. Hybrid products are abundant in today's marketplace: phones, cars and household products. Whilst the world waits for the next product combination, the heating industry is delivering its own impressive fusion of energy sources- the hybrid heating system.

Hybrids - or bivalent systems -as they are sometimes known, are those that provide heat, water or energy from both a renewable source and a traditional one. By combining technologies consumers can take advantages of each heating system’s best characteristics and minimise the modifications needed to use renewables in an existing home.

A traditional condensing boiler is electronically interlocked with an air source heat pump so that the controller decides when to use the heat pump and when to use the boiler to ensure that the heat demand is always met and the most efficient energy source employed.

They can be fitted into both new and existing buildings and can meet the heating as well as the cooling demand- should it be necessary in the UK!

Hybrids have great potential for the homeowner who is off the gas grid. Hybrids compliment LPG and Oil and whilst maximising efficiencies. Some properties that are off grid and have a high heat load would require a three-phase heat pump to satisfy the demand which is not always practical. The installation of a hybrid that only requires a single phase supply offers a solution.

The government’s Renewable Heat Incentive scheme pays 7.63 pence per kWh for each unit of renewable heat produced from an air-to-water heat pump, and 19.64 pence per kWh for ground source heat pumps.

The smart controls of the hybrid can adapt to gradual improvements of the energy performance of a building, steadily increasing the heat pump’s share of the heat load. They can also integrate with weather compensation technology, making the system even ‘smarter’.

Behind the scenes, so to speak; HHIC is currently working with members, alongside the Building Research Establishment, BRE, to enable hybrid products to be listed in ‘Standard Assessment Procedure’, SAP, which is the government approved system for assessing the energy rating for a new home. A SAP Rating is a way of comparing energy performance of different homes. It results in a figure between 1 and 100+ (100 representing zero energy cost and anything over means you are exporting energy). The higher the SAP rating, the lower the fuel costs and the lower the associated emissions of carbon dioxide.

Government are currently evaluating the hybrid heating system to fully understand its potential and when the route for them to be more easily listed in SAP is complete they will then have the opportunity to show their full potential.

The European Heating Industry (EHI) Expert Group on hybrids has prepared a position paper to introduce the hybrid heat pump technology and its benefits to Brussels-based policy-makers. It is part of a broader effort by EHI to ‘educate’ policy-makers about the wide range of heating technologies available.