China is at it yet again. This nation always looks to make advances when it comes to clean energy, and this latest development very much falls in line with attempts at decarbonization and lowering emissions. Should this latest development prove to be a success, it will be another energy system from China that the world will do well to copy.
How solar power is being adapted to fit the needs of the Chinese people
China has an array of exciting renewable energy projects on the go. From solar panel arrays in the ocean to extensive hydro plants in the mountains. Now they are looking to turn buildings into power stations. Regular buildings in the city are being fitted with something that could see entire neighborhoods generate their own power, silently and cleanly.
China has a large population, and so space has become an issue. Finding enough open land for solar and wind farms is challenging, and rooftop space is also an issue in the more urban areas. This means that more enterprising techniques need to be resorted to when planning the installation of large-scale solar arrays.
How China is looking to make more space for solar power
Buildings can be enormous structures that occupy a lot of space. So why not use an aspect of these in looking to generate clean energy? Take, for instance, the windows of a building. Usually, buildings are adorned with a lot of glass windows, which are perfect to use as solar panels, provided you have the right technology, and China does.
A breakthrough has been made with a new coating. An invisible layer is applied to normal window glass, which then turns that window into a solar panel that still functions as a window. It will still allow most of the light inside, but a portion of this light is funneled towards photovoltaic strips on the edges of the window, which can generate energy.
How these transparent solar window panels work
This project is still in its early phases, being tested rigorously in lab settings, but reports indicate that the invisible coating maintains over 60 percent of visible transparency while ensuring natural color is still evident. The coating transforms regular glass windows into solar panels that can produce electricity, which will do wonders for the grid and lowering emissions.
The device can reach an energy efficiency level of around the mid-teens in percentage. Researchers at Nanjing University are spearheading this project, and so far, things are going well. They are calling this coating a colorless, unidirectional solar concentrator (CUSC). A few select neighborhoods have been used for pilot testing.
There are cholesteric liquid crystal (CLC) multilayers embedded in the coating that is then used to coat regular glass windows. These layers bend parts of the sunlight and direct this towards the edges of a windowpane. At which point, photovoltaic strips trap this concentrated sunlight. Only one polarization is captured, which allows more than half of the light to pass through the window.
What could these solar-powered windows mean for the future of China’s energy supply?
Windows with this coating applied have achieved 18 percent conversion efficiency when under full-spectrum lighting. This is high for this kind of solar technology, and it does this while still allowing 64.2% of visible light to pass through the window.
This approach also reduces the number of solar cells needed, and much less photovoltaic material is needed for these solar-powered windows, which could dramatically alter energy production in large cities.
Scaling this will take time, and the coating will have to withstand harsh weather conditions and cleaning. Refinements are being skillfully made to its performance with enhancements around polarization, but should this work and be scaled to be used in cities, solar power, and the way we approach it may never be the same again.