New Solar PV technologies will revolutionise power production!
The Solar photovoltaics (PV) market has been growing for the last two decades and it shows no sign of slowing down anytime soon as renewable power production is increasing and new storage technologies are rapidly developing. At 2018, the solar PV market created 3.36 million jobs worldwide for researchers, utilities, installers and commercial businesses with 153 billion dollar worth of new investments in 2017. However in most cases, the product to be installed is usually a 1.6m2 opaque and rigid silicon solar cell, leaving little room for product designers to make changes and a very small room for energy yield optimisation. In fact, the final solar panel is basically the same even though there are small differences in efficiency and costs.
But the winds of change are blowing strongly.
Over the last few years the technology has improved a lot at research levels and the attention has shifted towards new classes of materials. A first wave of optimism emerged after the introduction of high efficiency and flexible technologies like Cadmium Tellurium (CdTe) and CIGS, with CdTe owning 5% of the market, as it performs better at higher temperatures. However, the wave died out as Cadmium was banned in Europe and CIGS failed to achieve high efficiencies for module sized solar panels until few months ago.
Recently, a new wave of optimism has taken over the market with the rise of perovskites, a family of materials already known for their ferro-, pyro- and piezoelectric properties. Recent improvements in this technology forecast the first production line to be operative by the end of 2020.
Their photogeneration properties were discovered only ten years ago, and nowadays they hold the 3rd position for the highest efficiency solar cell at research level following GaAs and monocrystalline silicon. In fact, perovskite production process requires low temperatures and can be performed in a single day, not weeks as required for other technologies. Following the development of perovskites, many new insights in the quantum world of light absorption became invaluable for other technologies to overcome their limitations. This research boost permitted other technologies to further improve their record efficiencies as it happened for organic solar cells, quantum dots and CIGS.
But most important, perovskites can be easily modified and tuned to adapt to the end-use requirements. Therefore solar panels can now appear almost invisible to the untrained eye, be frameless, integrated in solar windows and other electronics devices. The newly discovered materials can also be used for photoelectrochemical cells for the production of clean solar fuels like hydrogen. Additionally, a breakthrough in organic solar cells permitted a MIT spin-off called Ubiquitous Energy, to develop fully transparent solar cells that harvest the Infrared radiation while letting the visible light pass through.
Moreover, the NREL institute of research has recently demonstrated a thermochromic solar cell made with perovskites. First of its kind, the cell is fully transparent at low temperatures, while it turns opaque when heated up over a certain temperature and achieves 11.3% efficiency.
The development of such technology would permit generation during the sunny days while it would let light pass through during the night. Moreover, its use in skyscrapers would maintain low temperatures during the day transforming the radiative heat of the sun directly into electricity.
The time has come to drastically change our point of view on solar panels as black rigid panels and embrace a new wave of flexible, coloured, semi-transparent and phase-shifting solar cells. New possible shapes and even more complex structures are on the way to the market. New engineers positions will be opened to cope with the necessary optimisation of customizable products. Additionally, product designers will land in the scene to develop new and fashionable designs.
The time has come for solar to be cool again!
By Jacopo Sala
Published 6th June 2019