B&ES backing renewables ‘lab'

Although many renewable technologies have been around for years, we still don’t know how to make them work properly in an urban environment, according to a leading academic.

Professor Tony Day of London South Bank University believes the main thrust of research should be focused on getting renewables to work where they can have the biggest impact – in cities.

“There is still a lot of theoretical thinking out there and much of what we know is based on applying certain technologies in an ideal environment,” he told a recent briefing session for B&ES members.

“The critical task now is to see if they can be applied successfully in cities and which are the right solutions for each application.”

Facility
LSBU has recently completed the construction of a £3m research and teaching facility CEREB (Centre for Efficient and Renewable Energy in Buildings), which was partly funded by B&ES.

This was designed to showcase various renewable and low carbon technologies, but also to produce practical working information of use to contractors as well as academics. B&ES members now have special, privileged access to the Centre and to the data it is producing.The Centre sits on top of the new eight-storey K2 building that forms the centrepiece of the university’s campus redevelopment project.

CEREB acts as the energy centre for the rest of the building and it emits 55 per cent less CO2 than the standard required by the 2006 Building Regulations.“We are helping to put London in the vanguard of renewable technology development,” said Professor Day. “For us, London is the laboratory. We are now able to get a real insight into how these technologies perform in an urban setting. That is incredibly valuable as it is in urban areas where the greatest potential for energy and carbon savings lies.”

Damaged
Troubleshooting practical problems is a key element of the CEREB project. For example, the Centre has 19 high efficiency evacuated tube solar collectors, but they did not work properly at first because they had been damaged during installation.

Unfortunately, nobody picked up on this because the boilers just topped up the hot water supply to the rest of the building.

The B&ES head of sustainability David Frise, who recently visited the Centre, said these were the lessons our sector needed to learn.“We must start to build up a picture of how these installations work in practice and see things from the user’s perspective,” he said.

“The problem with CEREB’s solar array illustrates how service teams in buildings need to be trained to monitor systems properly. As there was plenty of hot water, nobody in the building complained, but a proper inspection of the system would have shown that all the hot water was coming from the boilers and the solar array was offline despite it being the middle of summer.”

Urban wind
Another lesson learned by CEREB since it opened this summer is that vertical axis wind turbines do not work in cities. “Don’t install them,” Professor Day told the B&ES delegation. “They might be ok for a windy hillside, but not here.”

CEREB is also trialling absorption chillers, which it says work well and so they are now looking at using excess heat from the (now working) solar thermal array to drive the absorption process to get summer cooling from solar heat.

It is also showcasing solar fibre optics where natural daylight is directed into the centre through the light fittings. This is another practical application suitable for an ordinary city building where window sizes are often restricted and central areas have, therefore, to be continually lit by artificial means. With the CEREB solution, as daylight fades the artificial lighting comes on gradually to provide a smooth transition, but also in an energy efficient way.

Heat pumps
Reverse cycle ground source heat pumps (GSHP) provide renewable heat in winter and cooling in summer from the 173 piles built into the K2 building’s foundations to a depth of 23 metres.

Professor Day said the Centre’s experience showed that GSHP technology is ideal for cities so long as it is planned in when the foundations are being laid.Phase change material is built into the fabric of CEREB to help regulate the internal temperature by storing excess heat when the occupied space is in danger of overheating and then releasing it again when the rooms cool down.

Students
A series of PhD and MSc students are being dedicated to projects based at CEREB to investigate specific technical issues, including the long-term performance of the solar and heat pump technologies, which will benefit the wider building services industry.

Within its building services engineering department, LSBU also has 18 Knowledge Transfer Partnership students, who are seconded from industry firms to work on specific, practical projects. This is an exceptionally high number and reflects the importance the university places on industry links and the practical nature of the work researchers carry out.

The B&ES sponsorship money has been dedicated to creating the Workplace Footprint Tracker system. This is a web-based software system that gives a complete picture of energy consumption in all parts of the building allowing researchers to closely measure and analyse data in a real-time environment.This leading edge information tool can zero in on different zones of the building and feedback directly to individual occupants about energy consumption patterns in their part of the building.

Wasted
The availability of such instant and specific information is expected to radically change users’ behaviour patterns and cut consumption by 30 per cent.“Our research shows that it takes three months to ‘lock in’ changes in usage behaviour by providing detailed information about how energy is being wasted,” says Professor Day.

“Floor by floor power analysis creates a level of competition between departments to cut the most.”Ultimately, the software will be able to provide weekly Display Energy Certificates (DECs) so engineering staff can continually fine tune the energy performance of the building to further reduce carbon emissions.

“It is the practical nature of CEREB that is so exciting,” says Mr Frise. “B&ES members are crying out for ‘real’ data and practical experience so they can properly gauge the likely long-term performance of some of the carbon saving solutions they are considering.

"This is a hugely valuable resource and B&ES is delighted that it has had a hand in its development via the M&E Sustainability initiative. We fully intend to keep up our involvement so that members can have access to all of this extremely valuable intelligence being gathered by Professor Day and his team.

”B&ES members have special access to the Centre either remotely to gain valuable insight into the performance of the technologies and techniques studied, or to hold events and training courses at the facility.

To find out more visit the CEREB website.