Solar Energy – Technological Developments and Global Potential

IPCC, in their latest reports, has come up with a stark reality of how close we are to the cliff. If the wealthiest intentions and short-sighted plans to build the riches from fossil fuels prevailed as it has been doing for past decades, by 2025 the world will hit a global rise in temperature by 1.5°C. Just after the latest IPCC results were out, seven new oil and gas projects were approved. With rapidly advancing technology that has the power to reshape the entire world for good, it will be an utter shame if we fail to turn our wheels.

Leveraging the technology to harness the power from natural sources has been accelerating faster than ever – one of the majors being solar energy technology. As reported by IEA, solar energy has the second-highest growth rate when compared to other existing renewable energy technologies and the total power production increased to 821 TWh in 2020. This is a record 23% increase compared to past year and was mainly driven by investment opportunities behind expiring support schemes in China. Out of the total 23% increase, around 75% of the increase was thus driven by China.

The immense potential in solar energy has been expensive to harness in the past but the technical advances have substantially reduced this over the last 30 years. Some solar technologies have proved to be functionally and economically viable in the nations that spend over 1/3^rd of their annual energy for heating purposes.

The recent research at the Chalmers University of Technology has paved a way for efficient long-term storage of solar energy, with a period as long as 18 years. If materialized, this technology has the potential to solve one of the biggest concerns with solar energy – weather dependence. The concept named MOST (Molecular Solar Thermal Energy Storage System) is based on a uniquely designed molecule that converts into an energy-rich isomer when hit by sunlight. This isomer can then be stored for as long as 18 years and when needed, a uniquely designed catalyst releases the stored heat and the molecule regains its original form to be reused again.

Furthermore, scientists from around the globe have come up with alternatives to the widely used material in solar panels – Silicon. The recent research at the University of Toronto’s Faculty of Applied Science and Engineering has experimented with alternative manufacturing element for solar cells. Named Perovskite, this crystal can be mass-manufactured at a lesser energy cost than silicon.

One of the major challenges in the expansion of solar energy is the requirement for land. This is largely being overcome by installing the solar farms offshore. These floating solar farms also solve the heating issues in solar panels, utilizing the cooling effect of water and wind, which in turn increases the overall power production of each panel. One of the biggest floating solar farms in the world, located in Tengeh, Singapore with ten zones of floating solar cells has the potential to offset 32 Kton carbon emissions annually. This is equivalent to removing 7000 cars from the island’s roads. As important as it is to expand the scale of solar energy beyond land, it is equally important to ensure that such farms do not disrupt the flora and fauna of the region.

With an abundance of solar energy, there is no limit to which technology can advance to harness it for global consumption. To visualize the scale of potential the solar energy has, the regions with black discs (radius: 100 km) in the map below, if installed with solar cells with a conversion efficiency of merely 8% can energize the complete world for an entire year. The total power production from the existing sources in the world is less than what can be produced in these six regions – 18 TW.

Certainly, there are challenges to running the globe on solar energy and the biggest is the energy storage. Furthermore, not all the global regions are endowed with an equal amount of sunlight but the very idea of a sustainable future is the Energy Mix from different sources and not solely the one.