Copyright: David Lawson– Property Week 1999Home page
The UK is being left in the shade over development of solar energy. Germans are involved in 5,000 projects testing large scale photovoltaics. Japan has twice that number under way and the US is so far advanced it has been dubbed the 'million-roof programme.' Britain has five.
A deeply inbred conservatism means developers are reluctant to dabble in techniques which add to building cost without hard evidence of better returns. The now-famous sight of a vast curtain wall of cells erected by Akeler on one of its Doxford Park buildings stands in splendid isolation.
Steve Costello of architects Broadway Malayan agrees that energy cost savings alone may not spark demand among occupiers. This can be marginal compared with other spending. But he says that hard evidence is emerging that passive energy management and more natural ventilation leads to an 8% increase in the productivity of every building's major cost - the staff.
Another important factor is also coming from an unexpected direction. Occupiers are realising they can add value through sympathetic branding of their buildings. As awareness grows of environmental issues, they will seek designs which proclaim they are doing their bit.
All the better if it can be integrated as a design feature. Ironically, a business park which failed to persuade planners that its green credentials were sufficient to allow development outside Winchester could provide evidence of how these two factors can be drawn together.
The DTI commissioned a study which took energy-saving one step further on the aborted 85,000 sq ft Morn Hill park by testing what the figures would look like if it had included an overarching photovoltaic roof. The simulation involved a major step forward, as the proposals integrate solar cells into the roof structure .
BM collaborated with engineers Buro Happold to create a cover over the built from a softwood shell and a photovoltaic carrier made of recycled acrylic. ECD made thermal analyses, Shell Solar did photovoltaic calculations and David Langdon & Everest carried out costings.
The results might not be startling in terms of cost savings, which worked out to around 500,000 pounds over 20 years. But Costello said they show how PV can be integrated in a recycled product as a 'status material'. It can be coloured, so an over-roof could be used to create a dramatic impact, or camouflage developments in a green landscape.
'Delivering buildings which are tailored to occupiers' brand values will play an important role in future,' says Costello. 'We are pushing a half-open door.
Original scheme projected cost (7899 sq m B1) £8.44m
(including undercroft parking, site services, infrastructure and low/renewable energy features)
Larger (12,600 sq m) roof with 4994 sq metres PV
£5.9m excluding roof
£1.3m timber shell
£2.0m translucent roof
TOTAL (rounded) £11.8m
PV scheme incorporates a roof 4701sq.m bigger than the buildings.
PV roof cost @ £504/sq metre
Conventional @ £252/sq metre
Extra cost £1.3m
Annual energy generation 400,000kWh
Undiscounted annual cost 15.8p/kWh
Assumes 20yr life but will be muchlonger so costs will be lower