What museums can learn from carbon footprints

Maurice Davies, 17.05.2010
Once you've got your carbon footprint, the next step is to understand what the numbers mean and use this information to make positive changes
UNDERSTANDING THE NUMBERS

Interpreting the numbers is one place where museums might need the help of an expert. It’s hard, if not impossible, to compare the results of museum carbon footprints because methodologies vary and different types of footprints measure different things.

To make things even more complex, results are sometimes expressed in terms of CO2 and other times in kilowatt-hours.

Furthermore, different figures can’t be easily compared because different types of fuel emit different amounts of CO2. Most strikingly, in standard calculations, electricity is taken to have about three times the CO2 emissions of gas.

As a general guide, carbon footprints are usually measured in tonnes of carbon dioxide equivalent per year - or tCO2e pa.

Total annual emissions are important, but do depend on the size of the museum. The critical figures museum managers should become familiar with are energy use per square metre or energy use per visit.

Interpreting display energy certificates

At their simplest, display energy certificates (DECs) give museums a rating based on an operational energy efficiency ‘score’ based on meter readings: A is good, D is ‘typical’ and G is the worst category. The lower the score, the better the rating. 

As an example, Manchester Art Gallery’s has an energy efficiency score of 213, giving it (like many museums) a G rating. This includes everything with a score of over 150.

In contrast, Tate Modern scored 334 (also giving it a G rating) in 2008-09, while Saffron Walden Museum achieved a score 44 (giving it a B rating).

DECs include a benchmark used for calculating these scores, which takes into account geographical location, the weather during the year and the building’s opening hours.

Another important bit of information DECs provide is energy efficiency in kilowatt-hours per square metre per year (kWh/m2 pa).

Manchester Art Gallery’s DEC shows it uses 590 kWh/m2 pa.

DECs take floor space into account but not volume, so museums with high ceilings do worse than those with low ceilings, says Amanda Wallace, head of asset management and development at Manchester Art Gallery.

It’s worth noting that building efficiency can also be measured in tonnes of CO2 equivalent per square metre per year (kgCO2e/m2 pa).

WHAT MUSEUMS ARE DOING WITH THEIR CARBON FOOTPRINTS

The findings of carbon footprints are particular to each museum but there are some general lessons.

The most important thing is to reduce energy use. For most museums this will be far more effective than trying to obtain energy from renewable sources and certainly better than carbon offsetting.

Lighting is a significant source of carbon emissions – 29 per cent of energy use at the Victoria and Albert Museum's (V&A) main South Kensington building. Manchester and Banbury museums found improving lighting was one of the easiest and most effective ways to reduce energy use.

Air conditioning, especially chilling, is also very energy-intensive. In the short-term, there is scope to save energy by improving the way systems are controlled and improving maintenance. Replacing kit and setting less strict targets for control of temperature and relative humidity could make bigger improvements.

Carbon footprints have made museums aware of possible alternative sources of cooling. For example, Banbury Museum is next to a canal while the V&A sits over a natural aquifer. These (admittedly) long-term projects offer great potential for reducing emissions.

While alternative energy sources are expensive and need a long-term approach, they can be effective. In 2006, the V&A and the Natural History Museum introduced a shared combined heat and power system, which has made the biggest single contribution to the reducing the V&A’s emissions.

Energy management - such as better understanding, analysing and controlling energy use - can bring substantial savings, especially when combined with staff training and raising awareness. Sub-metering can help pinpoint areas of excessive electricity and water use.

Immediate areas to tackle

Carbon-footprinting exercises have also led museums to tackle the following:

· Staff behaviour can make a big difference. After its carbon footprint, Manchester Museum (pictured) commissioned Global Action Plan to train staff as environmental champions.

· Rethinking gallery design can save energy by making more use of natural light or protecting fragile items in buffered showcases.

· Some museums are also exploring the inherent properties of the building; for example, reopening long-sealed ventilation routes that were originally designed to cool using natural airflow. The Whitworth Art Gallery in Manchester is thinking about moving all its storage to the basement, where the conditions are naturally more stable.

· Capital investment to improve things such as lighting and insulation has become available to museums that are part of universities or local authorities. Carbon footprints often give detailed costs and savings for changes making it easy to make the case for investment.

Taking a longer-term approach

Ultimately, carbon footprinting enables museums to take a holistic approach and reduce overall emissions rather than focusing on specific problem areas. Having said that, making little changes makes sense too; for example, installing spray taps to reduce water use and sensors to turn off lights when rooms are unoccupied.

Opinion is divided over whether museums should set targets to reduce their carbon footprint. If it’s able to replace all its lamps with LEDs, then Manchester Museum aims to reduce energy use by 40 per cent by 2012 compared with 2006.

The V&A wants to save 25 per cent of its energy carbon footprint in 2010 compared with 2005. However, Laura Frampton, head of planning at the V&A, admits this target is being reviewed: “We’ve had a large redevelopment, opened up new parts of the building and put more online, so it’s a challenge simply to maintain [energy use] as it is.”

Matt Stephens, area manager at Church Farm Museum in Lincolnshire, says it has resisted setting targets. “You have to be pragmatic and flexible when the opportunities come up rather than setting targets,” he explains.

At Banbury Museum in Oxfordshire, museums services manager Simon Townsend can’t set overall targets because he’s currently unable to control how much energy the air conditioning chiller uses. Instead, he has focused on lighting improvements.

Whatever you do, make sure you tell the world. Banbury Museum works hard to get its energy-saving stories in the press while Manchester Museum is planning an interactive exhibit to show all its energy use in real time.

And remember that it’s vital museums keep up to date with evolving technology. “What might have seemed like a good technology a few years ago might have changed,” says Stevens.

(Image: Manchester Museum, credit Steve Devine)