Project overviewThe original house was significantly extended and refurbished throughout. GreenAct designed and installed room heating and hot water systems, based on ground-source heating and solar thermal power. We installed a solar PV system to provide cost-free electrical energy.

Customer requirementsThe client wanted the house to remain off the gas grid and to generate its own electrical energy to provide power for the heat pump. They also saw the benefits of using solar thermal panels to provide domestic hot water for most of the year.

Our challenge was to design and install these systems, so that they worked together and maximized the use of renewable energy.

What we didDue to its low operating costs and high coefficient of performance, GreenAct installed a Viessmann three-phase Vitocal 300-G ground source heat pump system. The heat pump supplies warm water to 19 under-floor heating circuits throughout the property, whilst a Vitocell 200-litre buffer cylinder ensures there is always a reserve available to cope with any sudden demand for heat.

At very low outdoor temperatures, the heat pump is supported by an auxiliary in-line electric heater. For the majority of the year, this also helps the heat pump operate at its peak efficiency. It works hand-in hand with weather-compensated controls, which tailor the output of the heat pump to the outdoor temperature, reducing the waste of redundant heat and the associated cost to the homeowner.

Location Sector

Rugby Domestic refurbishment

www.greenact.co.uk

three renewable technologiesworking together

case study

Avondale

“Avondale” was amongst the first properties in the UK to fully adopt renewable energy across a range of technologies. Its goal was to reduce C02 emissions and energy costs to a low level, for our client and his family in their retirement.

Waverley House, 70 Binswood Avenue, Leamington Spa CV32 5RY

Contact us08455 33 32 31 hello@greenact.co.uk

GreenAct spent a great deal of time in guiding me through various stages of installation and resolving any interactive issues that arose alongside the ongoing building works.

www.greenact.co.uk

Small plant room for all renewable technologies

On sunny days, the integrated control system suppresses the heat pump and instead collects energy from Viessmann Vitosol 200-F solar panels on the roof. This ensures hot water is always generated by the source with the lowest cost. At other times, the heat pump is brought on-line to top up the 300 litre cylinder which stores the home’s hot water.

Electricity is produced on-site by a 2.25 kWp (ie. peak power) solar PV system, to which a second array has since been added as more roof space became available. The harvested energy is fed back to the heat pump to further reduce its cost of operation, or back into the mains grid at times of surplus.

Benefits & outcomesThe heating system is now harvesting 25,720 kWh of free energy from the ground. Solar PV panels are also generating over 3,200 kWh of free electricity, with the solar thermal and solar PV systems working together to reduce C02 production by 3 tonnes per year.

Compared to an oil-fired boiler, the installed system is costing 45 percent less to run, the equivalent of £972 per year. Without any incentive payments, the installation costs would be recouped in around 20 years, but with support from the domestic Renewable Heat Incentive scheme the installation reaches break-even in under 5 years.

Our client already receives Feed in Tariff incentive payments for the two solar PV arrays, and the government’s Renewable Heat Premium Payment has already paid £1,250 towards the heat pump and £300 for the solar hot water installation.

We provided end-to-end support for this ambitious project - from feasibility assessment, through to design and installation.

It was one of the first hybrid energy systems we did, after the Company was formed. While this became ‘the norm’ over subsequent years, it was innovative at the time and was “finalist” in 3 separate national awards.