Most of the sunlight absorbed by photovoltaic (PV) cells is emitted as thermal energy and only a small proportion is converted into electricity. The thermal energy increases the operating temperature of the PV cell and this increased temperature reduces the electrical power output significantly (by 4 % for each 10 C rise in operating temperature). The effect is reduced in free standing PV systems by maximising the air convection around the modules.
In building integrated PV the situation is more difficult due to restricted airflow around the modules. The additional heat generated by the PV system can lead to increased building cooling loads, especially during the summer months when cooling loads are already at a maximum. The main thrust of this project is to investigate and develop effective methods of extracting this heat to improve the electrical power output.
The primary objectives of this project are to investigate effective methods of increasing the heat transfer from PV to the surrounding air in building integrated situations; and to develop a PV module with improved heat transfer characteristics.
This will be achieved by addressing the following issues:
- modelling PV module behaviour and the heat transfer mechanisms from module to the surrounding medium;
- methods of integrating PV with various aspects of the building services; - examining module fabrication processes to identify effective methods of building in improved heat transfer capabilities;
- developing and testing prototype cladding elements with improved heat transfer capabilities;
- examining the effects of the improved PV performance on overall building performance;
- whether the improvements in electrical efficiency and reduced cooling loads offset the costs of effective heat extraction.
The main achievements arising from the successful implementation of this project would be the construction of experimentally tested prototype elements for increasing the heat loss from PV in building elements and the development of an experimentally validated model of the dynamic thermal behaviour of PV in a building element.
The proposal is pre-competitive in nature and will result in the construction of a number of prototype PV modules specifically for building integrated applications. It is anticipated that the most promising prototype elements will be taken forward for more detailed product development by PV manufacturers with the assistance of the whole project team.
Funding SchemeCSC - Cost-sharing contracts
21020 Ispra - Varese
RG27 0PR Hook Eversley,hants