Our approach is to firstly to assess requirements based on location, lifestyle, building fabric and local resources. Because we maintain accreditations to design and install systems utilising all the main renewable technologies we are in a position to recommend those technologies that offer the best fit for any project.
For example, we would not advise installing a heat pump in a building with an existing high temperature heat distribution system, unless the heat losses had been substantially reduced by improving its insulation and airtightness. A biomass boiler would probably be better suited.
We will often use technologies in combination. For example, a heat pump will operate most efficiently at a low flow temperatures, ideally between 35 and 40°C. Its efficiency will drop, i.e. it will use more electricity, when it generates hot water at a higher temperature, typically 55°C. Combining a solar thermal collector with a heat pump will improve the overall efficiency (seasonal performance factor) for the heat pump by minimising the extent to which it is required to generate hot water at elevated temperatures.
PV systems will typically benefit from having a solar switch installed. This device works by sensing when you are generating more electricity that you are using onsite and then it diverts electricity to a demand in the house such as switching on the immersion element in your hot water cylinder. This can provide a substantial amount of your domestic hot water in the non-heating season.
Biomass encompasses a broad spectrum ranging from a small wood stove burning logs heating a single room to a large commercial boiler burning either woodchip, logs or pellets distributing heat to multiple buildings. We design and install systems across this entire range including wood and pellet stoves, boiler stoves, wood gasification log boilers, woodchip and pellet boilers.
Our key design objective is to maximise the effective solar thermal contribution by sizing the collector area to achieve at least 70% domestic hot water (DHW) solar fraction, where possible. To achieve this we typically specify a hot water storage cylinder with two solar coils. Heat from the solar collector is firstly directed to the upper coil. Once the upper part of the cylinder reaches its target temperature, the controller diverts heat to the lower coil to complete charging of the remainder of the cylinder.
Whenever we install a heat pump we are concerned to ensure that it will meet the expectations of the owner, particularly the operating costs. In comparison to a conventional boiler a heat pump needs to operate at a relatively low flow temperature to achieve the efficiency claimed by the manufacturer. Whilst most heat pumps can achieve temperatures of 55 to 60°C required to heat domestic hot water, they do so at the cost of lower efficiency (= higher cost).
Our experience of with installation photovoltaic arrays is wide ranging including residential, commercial and industrial buildings, and also ground and flat roof mounted systems. Our installations include extremely sensitive locations such as listed buildings, including a Grade 1 listed Church. We have also installed off-grid systems, building integrated systems (BIPV) and photovoltaic thermal (PVT) systems.