Solar Energy Options: Some Cool Products!

Solar Trees, which first came into being in the late 1990s in east Europe, are essentially photovoltaic panels mounted high on the branches springing off a central trunk-like pole, crafted sculpturally to mimic the aesthetics of a tree. While they look good, their main advantage is that many solar panels can be mounted on minimum floor/ ground area i.e. more solar energy harnessed per unit area in an aesthetically pleasing structure. Early models were complementary to rooftop solar installations and helped in creating awareness regarding the advantages of switching to solar energy. Later, industrial designer Ross Lovegrove adapted them into beautiful artworks that harnessed solar energy during day and used it to power the LEDs fixed within to light up the outdoors at night. The east European Strawberry Energy company created the Strawberry Tree, a public charging station which used the harnessed solar energy for charging mobile devices. In India, the CSIR has created Solar Trees intended for installation in villages, which can generate 3 -7 Kw of electricity on an area of 4 sq. ft. More aesthetic models of the same are being developed for installation in parks and public spaces. The solar trees have also been mimicked in the mini and made available commercially for indoor use to charge batteries and devices!

Of course, the most spectacular solar trees are the 18 super trees which can be found in the Gardens by the Bay in Singapore (cover image). Towering to a height of 50 m., these super trees are not just solar harnesses, but are also vertical gardens, rain-water harvesting devices and air vents for the surrounding conservatories, in addition to being awe-inspiring spectacles that attract observers from around the world!

The idea of using readily available glass surfaces like windows as photovoltaic panels to harness solar energy has been a dream many researchers have pursued. If windows become enabled to collect solar energy that can be converted as required, the ease of installation and compliance with aesthetic would make the switch to solar energy a lot easier and attractive. Well, researchers at the University of Minnesota and University of Milano-Bicocca have developed a technology to embed nanoparticles capable of collecting and trapping useful sunlight frequencies in luminescent solar concentrators (LSCs). This trapped solar energy is then passed on to tiny photovoltaic cells in the window edges to convert to electricity. The development of this technology would essentially increase the usable surface area of a building for harnessing the sun’s energy and make our windows a source of more than just natural light.

Traditional or commonly used solar panels, being made up of a silicon photovoltaic cell array, are rigid and need to be mounted on large flat areas, preferably roof tops, making the surface area available for harnessing a limitation. Research in the direction of surpassing this shortcoming has led to the innovation of thin film solar cells made with CIGS technology which are flexible and can be mounted on a variety of surfaces, like exterior walls and windows. Sunflare, the Los Angeles based solar technology firm has already developed Solar Wall Paper, a thin and flexible sheet of solar cells that can be ‘stuck’ on to any surface like the top of a vehicle or the surface of a wall. Furthermore, a couple of Korean universities are developing flex sheet solar cells which will be no thicker than a micrometre, and can be used by wrapping them around any object like a table, a book or even a pencil!  

Researchers have been pursuing the idea of reducing the cost and increasing the efficiency of production of PV panels by the method of spraying the photovoltaic film of chemicals on to panels as they move on a conveyor belt. This not only reduces time and cost of production but also becomes adaptable to different types of surfaces. But, the next and more exciting phase of this research is the development of a chemical mix which can be sprayed on to any surface to make it photovoltaic. This game changing new material called Perovskite could be sprayed on to any surface like your garden deck or your car’s exterior to convert that into a solar energy harnesser!

Solar power generation and usage crossed the 1% threshold at the end of 2015, making it a record smashing milestone in clean energy and renewables. The innovations in solar tech are flowing over the brim, just waiting to be consumed by customers who hold the key to a clean, green world. Soon we could see every little surface around us become capable of harnessing the sun’s bounty, the primary source of all the world’s energy, summarily diffusing the distinction between natural and artificial light and heat!