The first detailed global assessment of the electricity generation potential of rooftop solar photovoltaics (PV) technology has been conducted by researchers at MaREI, the SFI Research Centre for Energy, Climate and Marine in University College Cork (UCC), in collaboration with international research partners. The findings are published in Nature Communications.
Owing to improved deployment capability and reduced costs, rooftop solar Photovoltaics (PV) technology, such as roof mounted solar panels used in home, commercial and industrial buildings, is currently the fastest deployable electricty generation technology and is projected to supply 25–49% of global electricity needs by 2050. Despite these predictions, a global assessment of the technology's electricity generation potential and the associated costs remains a challenge.
The research team including lead author Siddharth Joshi, together with UCC colleagues Professor Brian Ó Gallachóir, Dr Paul Holloway and colleagues at Imperial College London, Columbia University, and Ahmedabad University, assessed the electricity generation potential of rooftop solar PV globally and the associated costs. The authors mapped 130 million km2 of global land surface area to identify 0.2 million km2 of rooftop area using a novel Machine Learning algorithm. This rooftop area was then analysed to quantify the global electricity generation potential of rooftop solar PV.
The authors found that a global potential of 27 petawatt-hour per year can be attained at a cost of between US$ 40–280 per megawatt-hour with the greatest electricity generation potential in Asia, North America and Europe. They indicate that the lowest cost for attaining the potential energy is in India (US$66 per megawatt-hour) and China (US$68 per megawatt-hour), while the UK and USA are among the most costly countries. The authors suggest that the electricity generation potential of rooftop solar panels exceeded the global yearly aggregated energy consumption in 2018. However, its future potential will depend on the development and cost of storage solutions for the generated energy.