Hybrid solar cell tackles uneven hotspots to boost thermal and electrical output

Hybrid solar cells with electrical and thermal elements could provide more useful energy with the addition of a vertical mirror, an international team of researchers has found.

Aimed at addressing uneven hotspots on the surface of solar panels to boost electrical and thermal energy output, the team included researchers from Kingston University, the University of Exeter, the Indian Institute of Technology Madras and the Academy of Scientific and Innovative Research, India.

Alongside photovoltaic solar panel systems that convert sunlight to electricity, waste heat can also be collected through hybrid systems to heat water or power air conditioning, helping reduce emissions in hot countries.

To create temperatures that are high enough to be useful, sunlight must be concentrated using parabolic mirrors placed either side of the solar panels. The amount of sunlight hitting the panels can vary, however, creating hotspots that significantly affect overall output and can cause cells to fail.

In the new study, the researchers modelled the performance of a hybrid system with an additional vertical mirror as a ‘homogeniser’ to distribute the concentrated sunlight more evenly. The addition improved electrical output – showing an increase of 12% against the standard compound parabolic concentrator – and thermal performance, which rose 1-2%.

The findings provided an insight into how hybrid systems could make solar energy more cost effective and commercially viable in future, said Kingston University renewable energy expert Dr Hasan Baig.

“The challenge, when optimising a system to harness both types of energy, is you typically only get low grade thermal energy which doesn’t reach the required temperatures,” he said.

“If we’re able to extract more energy out of solar systems, as well as reducing the space needed on rooftops for panels, it could have a real impact on reducing household emissions through the use of clean energy sources, both in the UK and in countries such as India, where air conditioning and refrigeration units are in huge demand.”

The research was published in the Journal of Energy Conservation and Management.

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