Science – Solar energy success

The most successful technologies for reducing carbon emissions, which cause the increasing climate disasters, are solar followed by wind and electric vehicles. The ongoing reductions in cost for installed solar panels ensures the increased level of residential solar is certain to continue for the future. The increasing number of installed domestic solar systems in NZ reflects the desire of the local community to join this trend. Transpower forecasts solar power in NZ to increase to 535 megawatts (MW) by 2030.

The financial case for installing residential solar seems sound as it has a series of advantages. Firstly, the fact that an installed solar system providing power for an electric vehicle can eliminate the increasing cost of petrol fuel needed for combustion cars. Secondly, the fact that an installed solar system adds significant capital value to the residential property, is another advantage. This increase in capital value may even offset the installed cost of the solar system. Finally, the reduction in residential energy bills.

Another factor promoting the global growth in solar energy is the ongoing technical improvements in the development of solar panels. These improvements so far are based on innovative developments in silicon materials systems. These include monocrystalline panels (24.4% efficiency), polycrystalline solar panels (19.9% efficiency), flexible thin-film solar panels (18.9% efficiency) and bifacial solar panels, which can generate 11% to 23% more energy than the single-sided panels.

The typical lifetime of solar panels is 25 years, which makes the initial investment in a solar system worthwhile. Components of solar panels can be recycled, including aluminum, plastics and glass, which makes the technology more sustainable. The US Environmental Protection Agency proposes that the recycling of solar panels represents a major opportunity to recover valuable materials and create jobs. It has been demonstrated in research that recycled silicon from end-of-life photo voltaic (PV) panels can be processed in an environmentally friendly way to produce high-value nano-silicon.

Another advantage of solar energy is its capacity to be upscaled from solar residential panels to massive solar farms, which can supply green energy to cities and regions. Of the four largest solar farms in the world last year, one was in India, two were in China and one was in Egypt. Currently, the largest solar farm in the world is the Golmud Solar Park in China. The largest solar farm last year was the Bhadia Solar Park in India. Bhadia Park occupies an area of 56 square kilometers, with an installed capacity of 2243MW.

Some solar farms float on water systems (floatovoltaics), which makes the panels more efficient. The largest floating solar farm is one in Dezhuo, China, that has a 320MW capacity and is connected to a 100MW wind farm. Further rapid growth in solar energy worldwide seems assured and the growth in NZ is just beginning.