Reducing the College’s carbon footprint is an important objective for us. We are already generating energy from renewable sources – with a biomass district heating system and air source heat pump on campus – and are putting in place measures to improve energy efficiency on an ongoing basis. This is an area in which all members of the College community can help – be it as simple as not leaving lights on unnecessarily.

Biomass District Heating System

The library, Garner Block, Sir Emrys Jones Centre, Parkinson Lecture Theatre and support services/sports building, are heated via a biomass district heating system. This system was installed in 2011 at the same time as new teaching and support services facilities were being built. These new facilities needed heating, whilst the existing oil-fired systems serving the other buildings were also in need of replacement as they were old and inefficient. This provided the College with an opportunity to consider new approaches to heating a substantial part of the campus, and in the process, to make significant carbon savings.

Following consideration of a range of different options, the decision was taken to install a biomass district heating system and this is now in operation. Water is heated by the boiler and is then fed through highly-insulated underground pipes to each of the buildings on the system. The boiler is fuelled by woodchip and it is expected that using this system will reduce the College’s carbon footprint by over 100 t/CO2 a year. The College was also fortunate to benefit from a capital grant to support the installation of the biomass system from the South West Regional Development Agency through the South West Bioheat Programme which was delivered by Regen SW.

Biomass boiler systems are considered to be ‘carbon neutral’ because carbon that is released when the woodchip is burnt in the boiler is offset by carbon that has been locked-up or ‘sequestered’ in the trees when they are growing. In order to maintain this carbon balance, it is important that woodchip is not transported too far and comes from sustainable sources. This was therefore an important consideration for the College when considering where to source the woodchip from. The supply of woodchip for the College’s boiler comes from a supplier committed to using local sustainable sources and with a depot located in Gloucestershire.

More details can be found in the Regen SW / RAC biomass district heating system case-study.

Air Source Heat Pump

An air source heat pump is also used for heating and hot water in the sports pavilion. The pavilion is located some distance from the other College buildings and therefore could not easily be connected to a district heating system. Air source heat pumps are considered to be a renewable energy technology because they work by extracting heat from the outside air (even when the outside temperature is very low). Energy from the air is transferred through a heat exchanger and into a compressor. This works on the same principles as a refrigerator, and concentrates the input into higher temperature heat which can then be used for heating and hot water. Although it still requires some electricity to operate the system, because the electricity that is put into the system is added to by the heat energy from the outside air, less electricity is required to obtain the same amount of heat output than would be the case with an entirely electricity-based system.

Anaerobic Digester at Kemble Farms

Through an agreement with Kemble Farms Ltd., students at the College have educational access to Kemble Farm’s slurry and energy crops-fed anaerobic digester. This is operated alongside their 750 cow dairy unit located half a mile from the College campus and provides an informative example to students of how renewable energy can be integrated into a farming business. The plant generates heat and electricity (some of which is used locally with the majority being exported to the National Grid) as well as producing digestate which is put back on the land as fertiliser.

Energy Efficiency

Whilst the College is committed to generating a significant proportion of its energy from renewable sources, reducing energy wastage is also an important priority. This is, firstly, to help reduce the College’s carbon footprint, and secondly, to cut energy expenditure, particularly at a time when energy costs are increasing. We have already taken a number of steps to improve our energy efficiency, and we are engaged in an ongoing process of identifying, and making, further cost-effective, energy efficiency improvements.

Some of the energy efficiency measures that are already in place at the College include the following:

• Students are encouraged to take responsibility from their own energy use, through individual metering of electricity use in their rooms on campus
• The new teaching facilities incorporate a range of energy efficiency measures including movement sensitive low energy lighting and passive solar design.
• New virtualised IT servers have recently been installed, which have reduced the electricity requirement for the College servers from 35 amps to around 7 amps.