One of the most beloved sources of power is solar panels. Here in Kenya it has been pushed as the biggest technology that will take care of the last mile power connection in rural homes. Through programmes such as M-KOPA, solar power has been able to penetrate almost every homestead in countries such as Kenya. But solar panels have a very huge drawback – they only work during the day. The solution has always been to include a battery pack in the package so that when the sun is up, the solar panel can charge the battery. But what if the solar panels could work at night too? Here comes the anti-solar panels that aims to achieve just that.
Researchers from the University of California looked at the problem of solar panels working only during the day and asked themselves if they could find a solution to the problem, and what they came up with was anti-solar panels. This is a technology that works in complete reverse of the solar panels. Typically solar panels work by allowing photons from the sun to knock out electrons in a silicon photovoltaic cell, made by doping the top layer of the silicon with phosphorus and the bottom layer with boron, so that the sandwich silicon cell can have an electric energy potential. The potential helps to propel the knocked off electrons from the cell to adjacent cells all the way to collecting plates at the edge of the solar panel, from where the electrons are conducted through wires like any other electric energy.
To reverse this, the researches realized that at night the earth is warmer than the atmosphere, forcing the earth to release heat to the atmosphere – heat that can be captured in an anti-solar system. Capturing this heat (infrared radiation), the researchers proposed that thermoradiative cell can be used instead of the typical solar based photovoltaic cells. When the infrared pass through the thermoradiative cells, electrons can still get knocked off the thermoradiative cells. The efficiency of the anti-solar panels has been projected to be around 25% the efficiency of the current solar panels – which is somewhere around 20%.
An immediate concern anyone reading the proposal by the researchers is whether the anti-solar panels will be able to work hand in hand with solar panels. Details of that hasn’t been provided but it is easy to imagine that probably the anti-solar panels will be integrated with solar panels either by alternated between solar with anti-solar panels same way subpixels in displays such as the AMOLED are arranged; or by making one side of the panel a solar panel and the opposite side an anti-solar panel.
If the technology matures and finds its way to the market, then solar power users will no longer have to worry of not being able to power their homes at night.