Sustainable technology at Harper Adams

Posted 8 June 2006

Harper Adams University College has shown commitment to alternative energy by embarking on a number of projects to install sustainable technology systems.

Across the Shropshire-based campus, experts have erected the Bioenergy Development Centre – which houses the world’s first Combined Heat and Power (CHP) generator. The system incorporates an indirectly fired micro-air turbine and uses air rather than steam to power.

Scientists at the 700 acre estate campus are also set to open a new student hall of residence in September – generating electricity for the accommodation from sunlight. Photovoltaics will be integrated into the building and the electricity can be stored in a battery or used on the national grid.

The two recent modifications follow construction of the Bamford Library – completed in September 2003. Within the 2,600m² building, mechanical ventilation systems have been kept to a minimum by the use of a natural ventilation system.

Dr Andrea Humphries, Sustainable Technologies Manager at Harper Adams, commented on the developments: “Through collaboration with regional and national organisations Harper Adams University College provides an excellent vehicle for researching, demonstrating and promoting sustainable systems. Visitors, staff and students have shown immense enthusiasm for the installations, with several students completing dissertations centred around these technologies.”

Harper Adams is firmly committed to sustainable initiatives and have worked directly with experts and contracting companies to ensure the successful outcome of project undertaken.

The BG100 biomass generator, developed by Stafford-based company Talbott’s Heating Ltd after 10 years of research and development, began testing in December 2005 at Harper Adams.

The Combined Heat and Power (CHP) generator is the first system in the world to incorporate an indirectly fired micro-air turbine and uses air rather than steam to power. The generator is capable of producing 100kW of renewable electricity and between 150kW and 250kW of heat from the combustion of biomass.

It has an estimated biomass requirement of 2.5 tonnes a day and can be fuelled by forestry and agricultural residues, wood chips and pellets, and energy crops such as miscanthus and short rotation coppice. It can generate enough energy to provide 25% of Harper Adams’ electrical demand and could provide 50% of heat needed for the students’ union building, the conference building, students’ union bar and two student halls of residence.

Installation of the generator led to Harper Adams receiving the Green Gown Award for renewable technologies and sustainable design. The university college aims to be at the core of future energy development and provide a springboard for the delivery of rural community benefits.

The objective is to demonstrate a fully vertically integrated on-farm CHP system which includes the production, harvesting and utilisation of a range of biomass energy sources and the subsequent distribution of the thermal energy generated through an on-site heat network. This will create an exemplar reference system that identifies the positive attributes of this approach and the disadvantages that need to be addressed. The technology provides an opportunity to the agricultural community for diversification revenues and added value energy producers by selling green power to the grid.

It is estimated the annual Carbon Dioxide savings will be 600 tonnes assuming an operation time of 8000 hours a year. The generator is fuelled by the biomass and hot air from the combustion chamber enters a heat exchange system, which is a network of tubes. Clean air on the other side of the tubes is superheated to 800°C. As the air is heated it expands and the pressure increases. The superheated air is fired through the turbine before returning to the combustion chamber. Renewable heat from the generator is captured in a water jacket placed around the flue. The generator is designed for rural and urban settings and is ideal for installation on farms, large estates and public buildings.

Similarly, Harper Adams has embarked on a project in partnership with the DTI Major Photovoltaic Demonstration Programme, to install a 10 kWp photovoltaic SolarTile array on a new student hall of residence. The scheme encourages good quality investment to lead to a level of market activity which can be self-sustaining within 10 years.

Photovoltaics (PV), or solar cells, are semiconductor devices that convert sunlight into direct current electricity. Groups of these cells are electrically configured into modules and arrays, the electricity can be stored in a battery or used on the national grid. Advantages of the PVs are that they create no noise and no emissions, and they require minimal maintenance because there are no moving parts. The product, which was developed by Southampton University, is building mounted, which means the tile integrates with the surrounding roof tiles to produce an unobtrusive and aesthetically pleasing system with a long functional life.

The new accommodation, which will house 150 students, is central to the college and provides an ideal location for promotion of photovoltaic systems to students, staff and visitors. Once the new system is in place, monitoring and display information will be used to raise awareness of the amount of electricity and the Carbon savings the system produces. 
The main features of the SolarTile array are that it generates electricity from sunlight, even in cloudy conditions. It is anticipated the performance of the photovoltaics will be as follows:
·        Estimated kWh per annum: 8,624 kWh
·        Estimated electricity cost saving: £366.52 annually
·        Estimated revenue from Renewable Obligation Certificates: £360 annually
·        Estimated Carbon Dioxide saving per year: 3,700 kg

The Solartile represents an optimal design for a PV tile (shingle) which can be integrated into most types of tiled roofs. It can be manufactured in a variety of textured materials allowing a harmonious blend with surrounding tiles.

Harper Adams University College has also worked with specialists to construct the 2,600m²  Bamford Library – completed in September 2003. Mechanical ventilation systems have been kept to a minimum by the use of a natural ventilation system. The system is computer controlled, and in response to remote sensing of C02 and temperature within the building, and the temperature and wind-speed outside, the windows and roof vents open automatically to provide fresh air. The first floor vents can be seen above the wooden louvres at roof level. The ground floor is vented via the two glazed 'chimneys' on the first floor.

A large amount of concrete remains exposed on the ground floor ceiling of the building to act as a thermal mass. This stores heat in the winter, which is gradually released to complement the mechanical heating system. In the summer, the ventilation windows open to allow cooler night air to be 'stored' in the concrete and released during the daytime.

The building uses a number of systems to reduce electricity use. The lighting is operated by passive-infra red (PIR) detectors that respond to movement to switch on and switch off automatically. If a shelving area is dark then moves along it and the lights will come on. There are very few light switches in the side rooms, as these too are controlled by this system. The lighting also responds to light levels outside the building. If it is bright outside, the system will dim internal lights to reduce power use. 

The toilets are connected to a rainwater harvesting system. Rainwater is collected from the roof and stored in a large underground tank. When rainwater is available, it is pumped to the lavatory system.  In dry periods, the system is bypassed and the normal water supply is used. Whilst the ground floor of the building is of typical construction, the first floor has a wooden frame. The contractors involved in this element were Greenoak Construction, who were shortlisted in 2002 for the Stirling Prize (the RIBA's premier award) for their 'Gridshell' building at the Weald and Downland Open Air Museum in Sussex . We have been told that this is probably one of the most significant buildings in the UK with a softwood frame since the 19th century, so it is somewhat unique. The large slits down the side of the columns are deliberate, as they have been provided to allow for natural expansion and contraction in the wood. 

The building has more than open access desktop computers (flat screen technology was used to reduce heat gain), and a wireless local area network has been installed to allow users to access the College network. This is in addition to the new computer rooms provided in the Engineering Design Centre, which have the latest computer assisted design (CAD) software packages. A new café is located at the rear of the building as a further resource for our students and staff.

Certain areas of the building have received the generous support of sponsors.  JCB funded the Engineering Design Centre. The Parker Bequest funded the Exhibition Hall area (Mr Parker was an Oxfordshire landowner who left a generous bequest to the College). The Frank Parkinson Agricultural Trust funded two rooms - an IT training room and a group study room on the first floor of the building. The Higher Education Funding Council for England provided nearly £3/4 million in grant assistance towards the project.  We are grateful to them all.

Conclusively, all three projects form part of wider sustainable initiatives at Harper Adams which aims to reduce carbon emissions and produce renewable energy to protect the university college from price fluctuations as well as providing a secure energy supply.