Renewable Energy Installer April 2015 | Page 25

Knowledge: Heat pumps Going to ground Kensa Heat Pumps explore the diverse opportunities for micro heat networks using ground source heat pumps espite the current dip in oil prices helping to ease the pressure on home heating a little, interest in district heating continues to gain momentum, not least because of the recent popularity of district biomass systems. However, with biomass RHI tariffs now starting to degress and with the inherent drawbacks and inefficiencies of conventional central plant district heating systems, micro district ground source heat networks can provide a more compelling solution for landlords or housing developers looking to heat multiple buildings, especially those in rural, off gas grid areas. With the domestic RHI unavailable for new build developers and structured in a way that fails to present a compelling case for social landlords in the retro fit sector, the opportunity for larger scale residential projects increasingly lies with district heating solutions and the existing non domestic phase of the RHI. Significantly for the residential sector, the non domestic RHI also covers district heating installations, both for existing buildings and – unlike the domestic RHI – new build. This opens up significant opportunities for renewable heat installers to promote solutions to residential developers, social housing providers and private landlords by considering a district heating approach. And with significantly more appealing non domestic RHI tariff rates for ground source heat pumps now in place, the economics of the solution make interesting reading. Under Kensa’s innovative micro district approach, individual GSHPs are installed in each dwelling - giving each occupier complete control over their own heating and hot water system and responsibility for their own bill. Multiple heat pumps are then linked to a communal ground array, which enables the system to qualify as district heating under the RHI, generating 20 years of income under the non domestic RHI stream. Crucially, unlike district biomass systems, there is no need for a plant room, no heat losses through the district distribution pipework and no need to apportion bills between residents. And of course, there D The opportunity for larger scale residential projects increasingly lies with district heating solutions is no need for fuel storage and logistical management of fuel deliveries; or expensive regular maintenance to enable the system to continue to operate efficiently. And importantly for the retro-fit sector, district ground source systems are also recognised as a measure able to attract ECO funding, so particularly where electric heating is being displaced, landlords can benefit from an attractive capital subsidy in addition to the long term RHI payments. Opportunity knocks: Unlike its biomass counterparts, district GSHP networks have the advantages of no plant rooms or distribution pipes and associated heat loss, argues Kensa Heat Pumps Westward Housing has already pioneered this approach for the replacement of electric heating systems at a sheltered housing scheme in Holsworthy, Devon and is the first housing association scheme in the UK to be retrofitted with a Kensa ground source heat network, receiving support funding through a combination of the ECO and a Ready for Retrofit grant. The scheme, which is designated for elderly residents, has seen 17 flats retrofitted with GSHPs, with great success and praise from the residents regarding the real savings they are making on their electricity bills since the GSHPs have been installed. With significantly more appealing non domestic RHI tariff rates for GSHPs now in place and this route available as an option for both existing buildings and – unlike the domestic RHI – new build, the opportunity for small district ground source heat pump systems is one that MCS installers can now consider as a really attractive option whenever the opportunity to heat multiple buildings arises. www.renewableenergyinstaller.co.uk | 25