Wednesday, 11 September 2013


Isaac Newton, Charles Darwin and Stephen Hawking are among the greatest minds that have studied and worked at the University of Cambridge. Within its walls, the electron was discovered, the structure of DNA was mapped and the atom was split. But world-leading scientific research comes with a hefty carbon footprint.

The university – which attracts the largest amount of investment for academic research in the UK – generated 77,604 tonnes of CO2 in 2010, and has an annual electricity bill of more than £10 million.

So how can the university use its most prized asset – its collective brainpower – to put teaching and research on a more sustainable footing? The problem is not unique to Cambridge. According to the Higher Education Funding Council for England (HEFCE), in 2005 the sector emitted 5.4 million tonnes of CO2.

Research-intensive universities, known collectively as the Russell Group, represented 15 of the 18 highest emitting higher education institutions in England, Cambridge coming in fourth after Manchester, Imperial College London and Southampton.

Coming Up With A Plan

In 2010, HEFCE published its carbon reduction target and strategy for colleges and universities in England. The strategy sets overarching carbon reduction targets; requires institutions to set their own targets and develop carbon management plans; and provides financial incentives by linking capital funding with performance against CO2 reduction plans.

Updated the same year, Cambridge’s carbon management plan committed the university to reducing energy-related CO2emissions by 34% by 2020 against a 2005 baseline. Based on previous years’ figures, the university is expected to generate 104,861 tonnes of CO2by 2020, so meeting its target will require a reduction of 61,324 tonnes.

Alongside meeting targets and saving money, there are other reasons for cutting carbon, says professor Jeremy Sanders, pro-vice-chancellor for institutional affairs: “Environment and energy are important from at least two perspectives. The first is purely financial. The university’s electricity bill is more than £10 million a year and if we don’t do anything it will carry on increasing.

“Second, there’s the question of leadership and our impact on the environment. The university has world-class research in energy, from fundamental physics and chemistry to applied engineering. We have a wonderful range of expertise in the research area; the question is, how do we apply that expertise in our own buildings?”

To harness that knowhow, in 2010 the university launched its energy and carbon reduction project (ECRP). With an annual budget of £2 million, the project is taking a scientific approach to cutting CO2 by using five university departments as carbon reduction experiments.

“The pilots have been chosen for their different patterns of energy use, the idea being to test ways of reducing energy consumption in those departments,” Sanders explains.

Once identified, the best behavioural and technological ways of cutting energy use will be rolled out across the university. “That might mean more efficient pumps or computer cooling systems, but also everybody being more careful about turning off lights and computers. All those things contribute,” he adds.

Piloting Change

While the university is made up of more than 150 departments, faculties and schools spread over 300 buildings and covering more than 500,000m2 of floor space, around 70% of the university’s carbon emissions come from just 30 buildings.

Between them, the five pilot departments – engineering, chemistry, plant sciences, the Gurdon Institute and the university library – accounted for 23% of Cambridge’s total carbon emissions in 2010.
The pilots are addressing a wide range of issues. The library – which houses one of the greatest collections of books and manuscripts in the world – has the fourth largest carbon footprint in the university, and is examining the energy required to achieve the environmental control needed to preserve books and artefacts. Meanwhile, the chemistry department, which has an annual electricity bill of around £1 million, is focusing on fume cupboards.

“Chemistry uses 10% of the university’s electricity and a lot is down to the fume cupboards,” confirms the university’s environmental officer, Joanna Simpson. “The cupboards use air that’s been heated to push fumes out and the air then has to be heated again, so we’re heating air to expel it from the building.

“There are 350 fume cupboards in one building, so that’s one reason the department was picked as a pilot. Lots of other departments also have fume cupboards, so if we can work out how to reduce energy use in the chemistry department, we can retrofit it in other departments and learn lessons for designing new laboratories.”

Lighting The Way

Like fume cupboards, plant growth chambers are a piece of carbon-intensive equipment used widely across the university. Providing the light that plants need to grow and powering chillers to remove the excess heat the lighting generates, makes the building housing the plant sciences department one of the most carbon-intensive in the university – and plant growth chambers are the biggest energy-related challenge the department faces.

As part of the ECRP, the plant sciences department is looking at the feasibility of replacing its 2,880 fluorescent tubes with lower-energy LED lighting. But while installing low-energy lighting in offices is a quick win, using them to grow plants is far less simple because of the spectrum of light they emit and the heat they generate.

The trial’s aim is to work out whether LED lighting could provide plant growth, flowering and seed production, as well as photosynthetic performance similar to traditional fluorescent lighting. If successful, the project could transform how plants are grown indoors at Cambridge and further afield.

Across the university, IT equipment is one of the largest and most ubiquitous electricity users, and one where changes could net significant carbon savings. The engineering department is the largest in the university, with 1,500 students and 600 full-time equivalent staff spread over seven buildings. Around 50% of its baseload relates to IT. For its part of the ECRP, the department is examining how heating, lighting and ventilation are provided, centralising and updating key services.

“One example is our computer rooms,” says David Green, superintendent of the engineering workshops. “We’ve moved from having several small computer rooms with two or three racks of servers to two much larger facilities, and then we’ve made them as efficient as possible. We’re particularly proud of the work we’ve done to improve the energy efficiency of the cooling in the server rooms.”

By using evaporative cooling (which cools and circulates air through water evaporation), the engineering department is saving hundreds of tonnes of carbon and £75,000 a year on its electricity bills – payback on the investment is expected in just five years. The improvements also make a major difference to the department’s performance under the university’s energy incentivisation scheme.

The scheme consists of targets, fines and rebates designed to encourage individual departments to cut electricity use, even though bills are paid centrally. “At the end of 2008/09 when the scheme came in, we got a bill for £35,000 because we’d exceeded our energy use target. Our computer room has reversed that in one hit,” Green explains.

Engineering is also putting its own research into practice in the shape of an “energy roof”. The £1 million project will generate up to 61,188kWh a year and, instead of commercially available photovoltaic (PV) units, it uses panels developed at Cambridge that incorporate a microinverter and thin-film technology.

“We’re putting PV onto one of our roofs, which will put energy back into the grid using technologies developed in this department. We’re proud of that,” Green says. “It means we can compare and contrast, and push the boundaries a bit.”

To be continued...

— Source: Nature GeoScience, National Geographic, BBC Science.

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