A pioneering PV office in the UK
by the CADDET UK National Team

The first office building in the UK to incorporate building-integrated PV has been completed at the Doxford International Business Park in north-east England. With a cell area of 532 m2, the PV facade of the Doxford Solar Office is the largest constructed in Europe to date. The office building was designed and built in 15 months.

The PV facade

 

Building design

The main feature of the building is the 66 m long south-facing PV faćade which, in section, is inclined at 60° to the horizontal. The main entrance to the building is at the faćade's mid point. Located behind the faćade is a central atrium which has

three-storey wings on either side, containing office space, and a central core to the north (see artist's impression opposite). An internal 'street' runs immediately behind the faćade at ground level.

There are 352 PV modules (incorporating over 400,000 PV cells) integrated into the building's faćade, which also incorporates conventional glazing. Cables connect the modules with plant rooms where the power is converted from direct

to alternating current. It is anticipated that the PV installation will meet up to 30% of the building's annual power needs, and at times when the cells produce more electricity than the building can utilise, such as in the summer months, the surplus will be exported to the UK's national grid.

Development

About £4.5 million was spent on developing and constructing the Doxford Solar Office (where £ is the UK pound); the developers, Akeler Developments, won a European Regional Development Funding grant of £1.35 million towards the incorporation of PV and other low-energy features into the building. The building was designed in accordance with passive solar principles to minimise its energy requirement.

The low-energy measures include generous ceiling heights, which encourage daylighting and cross-ventilation, a well-insulated and well-sealed building envelope to minimise winter heat losses, and the provision of effective and responsive environmental controls. The building design includes an energy strategy which fully integrates the PV installation with the low-energy aspects. Detailed studies were carried out at the design stage to ensure that occupant comfort is not compromised by the inclusion of PV.

Doxford Solar Office

 

Performance

The 73 kW (peak) array will provide an estimated 55,100 kWh/year of electricity. The energy consumption target for the building, when occupied by a tenant with conventional power requirements, is 85 kWh/m2/year compared with that of a well-designed air-conditioned conventional office, which would consume 250 kWh/m2/year. Taken together, the PV and passive solar design elements of the building yield an annual saving of £55,000 and an annual reduction in carbon dioxide emissions of 375,600 kg. Monitoring is being carried out as part of a two-year project funded under the UK Department of Trade and Industry's New & Renewable Energy Programme. This will include monitoring the performance of the PV installation, the amount of energy the building consumes and occupant comfort.

For more information contact the CADDET UK National Team in Oxfordshire.

The CADDET Renewable Energy Newsletter is a quarterly magazine published by the CADDET Centre for Renewable Energy at ETSU, UK.

The articles published in the Newsletter reflect the opinions of the authors. They do not necessarily reflect the official view of CADDET.

Enquiries concerning the Newsletter should be addressed to Pauline Toole , Editor, CADDET Centre for Renewable Energy, ETSU, Harwell, Oxfordshire OX11 0RA, United Kingdom. Tel: +44 1235 432968, Fax: +44 1235 433595.