a-Si PVT-ORC · A novel amorphous silicon cell-based solar cogeneration system using the coupled thermal storage/organic Rankine cycle as an alternative to battery

A novel amorphous silicon cell-based solar cogeneration system using the coupled thermal storage/organic Rankine cycle as an alternative to battery

The organic Rankine cycle (ORC) is a technology for low-grade heat to power conversion. Solar thermal power generation is one field of application for the ORC. Solar ORC can be driven by vacuum-tube or low-concentration solar collectors, and is applicable in the regions without rich direct radiation resource. Photovoltaic/thermal(PV/T) technology is another way to utilize solar energy. A PV/T module can provide more energy than a sole PV module. The heat captured from the PV/T module helps to accelerate the return on investment. Notably, cooperation of the two technologies will be beneficial. To achieve this, a PV/T collector can be operated at a higher temperature, at which heat collected and stored can be used to drive the ORC when required. Combination of low-cost thermal storage and ORC will be a more economical and environmentally-friendly alternative to battery. Water is an ideal working fluid for thermal storage in the temperature range below 150°C. The a-Si PVT-ORC system has the potential to be more cost-effective than sole PVT or solar ORC systems. Compared with the c-Si PVT system, it has additional power output (WORC) but more initial investment on ORC and heat storage. The cost of water storage shall be small. The ORC working at about 120°C is already commercialized in the fields of geothermal power generation and waste heat recovery, and the payback period is expected to be less than 5 years. The a-Si PVT-ORC system has an overall electrical efficiency close to that of c-Si PVT at 75°C, which is about 12.8% as shown subsequently. Particularly, it is resilient via thermal storage, and expensive battery is eliminated or greatly reduced. Compared with a sole solar ORC system, the a-Si PVT-ORC system has the integrated PVT collector to provide heat for the ORC, and this will make solar ORC more cost-effective regarding the highly increased solar power efficiency. The project aims to investigate a medium temperature photovoltaic/thermal (PVT) system incorporated with the coupled thermal storage/organic Rankine cycle (ORC) as a novel alternative to battery. The overall scientific objectives are: (1) Experiments of a-Si cell performance and its stability at the temperature up to 150°C. (2) Prototype development of a-Si PVT collector for medium-high temperature application. (3) Feasibility demonstration of fast prototyping of small scale turbine by 3D printing technology. (4) Modelling of a-Si cell, PVT collector, ORC, and the whole system. (5) Economic and environmental assessment of the a-Si PVT-ORC system. Through the development of the project, it is concluded that the a-Si PV/T system is technically feasible and promising especially in tri-generation applications.

Data: CORDIS, © European Union