Increase the Amount of Solar Energy through STPV

Researchers from Massachusetts Institute of Technology has published a paper in the Nature Energy where they have mentioned the efficiency and reliability of the Solar Thermophotovoltaic Device (STPV). This technology ensures that the solar panels can acquire and generate more power that can be used for longer hours.

A typical solar panel requires 40 square meters to ensure that it has the capability to power a home for 24 hours. Because of that, further researches were done to lengthen the hours that it can be used and to improve the performance by acquiring more solar energy. It is a great help, especially due to the abundance of energy coming from the sun.

A normal solar panel has a mechanism where the converted energy from the sunlight is being stored. However, the heat energy is left unused and becomes a waste. With the new technology that was done by the MIT, this heat energy will not be wasted through an additional layer added to the solar panel. This new layer will absorb the heat energy and convert it to light energy. The acquired light energy will reflect to another solar panel for storage.

According to the MIT’s paper:

Solar thermophotovoltaic devices have the potential to enhance the performance of solar energy harvesting by converting broadband sunlight to narrow-band thermal radiation tuned for a photovoltaic cell. A direct comparison of the operation of a photovoltaic with and without a spectral converter is the most critical indicator of the promise of this technology. Here, we demonstrate enhanced device performance through the suppression of 80% of unconvertible photons by pairing a one-dimensional photonic crystal selective emitter with a tandem plasma–interference optical filter. We measured a solar-to-electrical conversion rate of 6.8%, exceeding the performance of the photovoltaic cell alone. The device operates more efficiently while reducing the heat generation rates in the photovoltaic cell by a factor of two at matching output power densities. We determined the theoretical limits, and discuss the implications of surpassing the Shockley–Queisser limit. Improving the performance of an unaltered photovoltaic cell provides an important framework for the design of high-efficiency solar energy converters.

To help you comprehend the technical explanation from their abstract, here’s what MIT has posted on their website:

The basic principle is simple: Instead of dissipating unusable solar energy as heat in the solar cell, all of the energy and heat is first absorbed by an intermediate component, to temperatures that would allow that component to emit thermal radiation. By tuning the materials and configuration of these added layers, it’s possible to emit that radiation in the form of just the right wavelengths of light for the solar cell to capture. This improves the efficiency and reduces the heat generated in the solar cell.

To ensure that the new technology works, the researchers have conducted a test by using a photovoltaic cell with STPV. It was placed under direct sunlight and later on, the sun was blocked to see whether the secondary light emission reflected on the other solar panel.

Because of the success of the new solar panel, MIT is currently planning to make a bigger version. Their vision is to lessen our usage of the fossil fuels.