KJ Tait were engaged by CBRE and the British Library to provide consultancy support on a new solar thermal installation for the British Library, St Pancras, London. This is one of the largest solar thermal installations in the UK.
The project was funded through Salix grant funding. KJ Tait’s role included reviewing the high level proposals and validating the solar thermal proposals in relation to building summer heating demand.
The Library is ideally suited for a solar thermal heating installation as the building has a high year round heating load with a high heat load in summer months due to the need for humidity control of book storage areas. The heat is required to reheat air following dehumidification.
The solar thermal array was designed to cater for peak summer heating and hot water load and the solar thermal can provide heat up to 75oC.
The solar thermal installation was provided by Naked Energy and they were supported on the project by Convert Energy who had responsibility for installation, specialist design and setting to work.
The solar thermal system has been designed to deliver up to 170kW from the combined heat and PV panels and up to 340kW from solar thermal panels. Naked Energy estimated that the solar thermal installation will deliver 326,598kWh/year in gas savings and 14,23kWh/year in electrical savings as one array on the roof is a combined PV and solar thermal collector.
The system design includes a 15m3 buffer vessel to store heated water for use out of sunlight hours and to store excess heat generated by the solar thermal system.
The project was complex to deliver due to the heating plant being located in the sub-basement and remote from the solar thermal dropping pipes.
As the building is listed, we could not include a heat dump to discharge excessive heat on the roof as would be usual. The heat dump is located in the basement plantroom and the existing flues used to discharge this heat to atmosphere.
Integrating the solar thermal controls with the building controls required detailed design works to ensure the heat used was effectively distributed and on sunny days in spring and in the summer months can support the full heating requirement of the library.
This project was completed in August 2023 and is currently being gradually brought on line.