058 HPM 0415

HPM April 2015

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com RENEWABLEENERGIES Hybrid systems: the best of both worlds There’s been a steady rise in interest in renewable technologies since the launch of the Renewable Heat Incentive, but many off-grid householders are still unsure about replacing their traditional oil-fired boilers. Plumb Center’s Julie McLean says installers have a vital role to play in advising them... According to UK government statistics, four million UK households are not connected to mains gas and instead heat their homes using oil, LPG, coal, wood, or electricity. Homes come in all shapes and sizes, but one thing’s for certain, they all need power and heating. Householders are keen to keep the cost of heating as low as possible, so bills don’t start eating into their disposable income. They could save thousands on energy bills by switching to an alternative heating source, and installers could help them cut the costs. Renewables such as air source heat pumps (ASHPs) can be a viable alternative, but are very much dependent on the weather. Hybrid systems are a great way for homeowners to experience new technologies and the benefits of generating their own energy, while still having the security of their boiler. Efficient renewable heating can supply all the cost-effective heating needed for most of the year. However, when the temperature drops in the depths of winter, it may prove more cost-effective to switch to the back-up of a traditional oil-fired system. SUSTAINABLE ENERGY Hybrid systems provide this happy medium, combining renewables with traditional boilers, so properties can be heated with sustainable energy while the weather permits, and when a cold snap arrives the boiler can kick in. When temperatures are high enough, the renewable half of the system can operate at its highest efficiency, alone, but when it’s chillier, the boiler starts to operate and supports the system, until it has to fully take over if needed. This means the householder has the best of both worlds, and receives the benefits that renewables provide, without losing any comfort. There are three types of hybrid heating systems which are controlled in different ways. Bivalent Alternative Systems are the most basic hybrid. It runs on renewable energy until the temperature drops below a fixed level, at which point the fuel boiler takes over. Once the chill has passed, it is ‘business as usual’ for the hybrid system. Bivalent Parallel Systems do everything that the bivalent alternative system does, but can enable the renewable system and the boiler to run simultaneously, creating more power, or with one subsidising the other. The third is a Tariff-Controlled System, which WWW.HPMMAG.COM Homeowners can save thousands of pounds by switching to an alternative energy source such as hybrids is the most advanced and the most flexible. This system not only takes into account the temperature required and the surrounding temperature, but also the efficiency of the heating sources at the time, as well as how much it would cost to run them. The system ensures that it only ever has to work as hard as it needs to, and always selects the appliance that will save the most money. By making sure that they’re running at the most economical level they can, some systems can deliver up to 35% higher heating efficiencies, as well as major cost savings. As hybrid systems can operate on renewable energy for a large proportion of the year, they can qualify for the Renewable Heat Incentive (RHI). This means that customers get help towards the cost of fitting the system, with the payments that the owner will receive for producing their own energy. However, to work within the RHI, installers must be certified under the Microgeneration Certification Scheme, so training is a must for those who want to branch into hybrid systems. 58 APRIL 2015 HEATING & PLUMBING MONTHLY Hybrids can also reduce bills as under the RHI, renewable technologies earn customers cash per kilowatt hour via the Feed-in Tariff. Because hybrid systems don’t rely on the boiler for much of the year, they increase its operating life and allow it to run more efficiently when it does need to kick in. The Mitsubishi Electric Ecodan ASHP, for example, is a prime candidate for hybrid systems as it has a built-in self-learning hybrid control that decides when it’s most economical to run which appliance. In addition, householders are able to override the system so they can choose what best suits them at the time, making it a very flexible and attractive system. There are clearly many positives to having a hybrid system installed, but many householders are still unaware of the benefits – and in some cases their existence. Government schemes, like the RHI, will help to bring hybrids and renewable technologies to the public eye, but installers can really help educate customers on the benefits of having one installed. enquiry number 145


HPM April 2015
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