Computational methods for assessment of solar energy potential in present and future climates

Climate change has motivated the need to produce energy from non-fossil sources such as solar photovoltaics (PV) and concentrating solar power (CSP). As solar power output depends on both the incident irradiance and the ambient temperature, climate change could affect solar energy production. In the last few years, a handful of studies have investigated the interactions between global climate and solar energy output. The aims of this thesis are to build on this previous work by both introducing a tilted solar collector alignment, such as would be seen in
the real world, and also to include the spectral response of different PV semiconductor materials. A method to mitigate the effects of global temperature increase on solar PV is also explored. These simulations are performed with a number of radiative transfer, heat transfer and energy balance models. It is shown that the solar resource at the end of the 21st Century is expected to differ by more than ±5% compared to today in many regions of the world, and in some places up to ±20%. PV semiconductors with bandgaps in the range of 1.4–1.7 eV perform relatively better in a future climate scenario compared to the commonly-used crystalline silicon (1.1 eV), due to changes in atmospheric absorption characteristics. A further extension to a geoengineering scenario, in which humans deliberately inject aerosols into the atmosphere to lower
global temperatures, shows that tracking PV and CSP energy outputs could decline by up to 15% compared to present-day values. Solar PV output can be increased by up to 6% by passive cooling of solar modules with phase change materials. As solar energy investment decisions are
often made on the long-term annual mean energy output being known to within a few percent, changes in solar resource estimates of this magnitude are of importance.