Showing the way to renewable energy
The ground-source heat pump in this plant room serving the village store extracts heat from the ground via six boreholes in the adjacent car park.
A small village in North Yorkshire is a working model of the effective application of renewable-energy technologies.Renewable energy is moving on from the stage of being talked about to the need for action to start. That is the perspective of Stewart Purchase, managing director of Viessmann in the UK, which has been in the business of renewable energy for over 10 years. In that time, Viessmann products have been installed in nearly 10 000 installations in the UK — delivering the benefits of renewable energy to homes, schools, swimming pools, offices and a host of other types of buildings. Engineering expertise
In exploiting renewable energy, engineering expertise comes to the fore. ‘Systems have to be designed, installed and commissioned,’ explains Stewart Purchase. ‘Now we have reached the hard part, and there is no “silver bullet”. ‘Saving the environment is not all negative and switch off everything. In the H&V industry, we have the knowledge, the technical expertise and experience to bring about significant changes in the use of energy in homes, commercial and public buildings.’ A wide range of renewable-energy technologies is available, and a fine example of their use in appropriate circumstances is provided by Botton Village in the heart of the North Yorkshire Moors. The village extends over 650 areas at the head of a dale Run by Camphill Trust, Botton Village is a community of around 330 adults and children, about 140 of which have learning difficulties. They all live in extended families of varying sizes in about 30 houses. There is also a range of community and working buildings such as a dairy, village hall, workshops and village shop. The village has been growing and developing since 1955 and the story of its energy needs and how they have been provided is a microcosm of the wider world. Energy has to be transported into this isolated community, and power cuts can last for up to a week at a time.
Among renewable-energy technologies being used in Martins House is a wood-pellet burner and flat-plate solar thermal collectors.
Various forms of energy have been used over the years, including coal, heavy oil and kerosene. Gas, stored centrally as LPG, is also part of the energy mix. Mike Gilbert, an architect who has worked with Camphill Trust at Botton Village for many years, says, ‘Gas seemed like a good idea 10 years ago, but with rising fuel prices it is time to move off LPG to alternative and renewable sources of energy, while leaving the LPG systems in place as backup and support.’ Wind energy is a non-starter at Botton. The site is sheltered, and the average annual wind speed is just 3.2 m/s. At Serra de Outes in northern Spain, where there are several large wind farms, the average annual wind speed is 19.2 m/s. Options
The renewable-energy options at Botton are solar energy, ground and air-source heat pumps and wood. The geology at Botton is well suited to ground-source heat pumps. It is easy to sink boreholes into the underlying shale, which is quite wet — adding to the efficiency of heat pumps. Wood is also in plentiful supply. 150 acres of woodland is being developed, and timber for fuel is being recovered from the workshops. In developing its use of renewable energy, the village has been working with Vitotec Solutions and County Heating for some eight years. Vitotec develops the designs, which are then installed by County Heating, which has become the preferred M&E contractor. A range of projects have been completed, based on equipment supplied by Viessmann UK. The village store, for example has its heating and hot-water requirements served by a 26 kW heat pump that extracts heat from the ground via six 60 m-deep U-tube boreholes in the adjacent car park. This energy source is combined with 5 m2 of flat-plate solar thermal collectors. Space heating is delivered by a low-temperature underfloor system embedded in the wooden floors. The village store installation also includes a 500 litre indirect stainless-steel cylinder and a 200 litre stainless-steel buffer vessel. The underfloor heating is controlled by Vitrotronic 050 controllers. A Vitodens 300 LPG condensing boiler with an output of 44 kW and weather-compensation control provides support and backup. Viessmann solar collectors serve several other buildings. The creamery, for example has 10 m2 installed on its roof. They are controlled by a Vitosolic 200 controller and generate domestic hot water that is used for wash-down in the food-preparation area. High Farm uses 5 m2 of Vitosol 100 flat-plate solar collectors to generate high-temperature hot water for use in the milking parlour when washing down. Illustrating the application of wood burning in the ongoing project at Martins House. The plan is to install a 26 kW Vitolig 300 wood-pellet burner and 7 m2 of Vitosol 100 flat-plate solar thermal collectors. Hot water will be stored in Vitosol twin-coil stainless-steel cylinders. The energy demand will be reduced by Vitovent 300 heat-recovery ventilation units in bathrooms. Boilers burning logs are used to heat some buildings. Because of the operating characteristics of these boilers the heating systems they serve are integrated with a heat accumulator storing 4 t of water at up to 98°C. This large volume of hot water enables heating to be provided when the log-burning boiler is turned off. Domestic hot water, as well as space heating via underfloor heating circuits with a flow temperature of 40 to 45°C can be supplied. Systems approach
The key to the steady introduction of alternative energy at Botton Village has been a systems approach, with installations specifically designed to meet the special requirements of each project. John Brett of Vitotec Solutions, which designed the systems and worked with County Heating on their installation, stresses the importance of developing integrated solutions using a wide range of components. He has seven years of experience with applying Viessmann products, and stresses that one of the keys to a successful installation that effectively maximises the benefits of renewable energy is control.