From efforts that mimic nature like leaves and trees, to arrays that float on water or in space, there has been a wide range of solar energy innovations in 2016. From tiny solar applications of nanotechnologies to massive space-based arrays, the growth of solar power is being fueled by market forces, including increasing efficiency and decreasing cost.
The number of possible innovative applications is virtually limitless. To address the problem of intermittency, we need solar storage systems and systems that work at night. We need solar powered airports, solar powered airplanes and drones capable of staying in the air indefinitely. While some of these innovations may sound like science fiction, they are in fact current day realities.
Solar technologies continue to evolve in terms of decreasing costs, increased performance, and greater functionality. With new efficiency records being set almost every week, this is an exciting time for solar energy. There is every reason to believe that the price of solar will keep declining as we see even more innovation. Conventional crystalline silicon solar cells still rule, but thin-film solar cells are catching up. There are also entirely new solar technologies that are on the cusp of commercial scale production.
Declining costs are key to the widespread adoption of solar power. In 2016, solar became the least expensive form of energy generation in the world and prices are expected to fall another 59 percent in the next decade.
Earlier this year, researchers developed a system that set an all-time solar efficiency record. The record-setting cell has a conversion efficiency of 34.5 percent compared to less than 20 percent for the average solar panel. This takes us two-thirds of the way to the theoretical maximum efficiency for solar cells. According to one report, the 35 percent conversion rate was not expected until 2050.
Researchers have developed bionic leaves that mimic photosynthesis. In this process, solar electricity is used to split water into oxygen and hydrogen, microbes then feed on the hydrogen and convert CO2 in the air into alcohol fuels.
An Indian institute has created a solar tree to harvest energy from the sun. The self-cleaning “Solar Power Tree” can harness maximum solar energy and minimize land use. A 5 kW Solar Power Tree takes up only four feet, whereas an equivalent conventional solar array would occupy 400 sq. ft. The tree also gets one hour more sun per day, translating to 10-15 percent more power. Future trees can be made even more efficient by incorporating rotating panels that align with the movement of the sun.
A spherical sun-tracking solar energy-generating glass globe called Betaray, concentrates light up to 10,000 times. Its solar harvesting capabilities are 35 percent more efficient than conventional dual-axis photovoltaic designs. It can be used for cloudy days; it can even be used to generate power from moonlight.
Floating solar photovoltaic arrays also called floatovoltaics, are able to cover drought-stricken lakes to both generate power and conserve water by reducing evaporation. floatovoltaic projects are now being built all around the world including Australia, Brazil, China, England, India, Japan, South Korea, and California.
A transportable carpet-like solar panel has been developed called the Roll-Array. It generates 10 times more power than other transportable solar panels on the market today. The system comes with batteries and inverters that are attached to the base of the panels.
A new generation of an all-weather solar panel is composed of thin-film solar laid over a sheet of graphene. By incorporating graphene, solar panels are able to harvest energy from the sun and generate electricity from the rain. Such solar panels have already been built by a team of scientists in Qingdao, China.
Nanotechnology (aka nanotech) is one of the most promising solar developments. This involves dimensions and tolerances of less than 100 nanometers. A technology called thermophotovoltaics broke through the upper limit of silicon solar cell efficiency this year. The key to breaking the record is trapping heat from the sun before it reaches the solar cell. The heat is then emitted in the form of thermal radiation, which is tuned to wavelengths that can be assimilated by the solar cell. This carbon nanotube solar cell has the potential for high-efficiency solar conversion even on cloudy days.
A new kind of nanoscale rectenna (half antenna and half rectifier) can convert solar and infrared into electricity. This technique uses carbon nanotubes to generate solar power with 40 percent broad spectrum efficiency at a one-tenth of the cost of conventional solar cells. Researchers have already created nanocones that increased solar cell efficiency by 15 percent. Scientists have also fabricated nanomaterial that can even make solar panels work in the dark.
Thin light and transparent
A completely transparent ultrathin solar panel has been developed that can absorb only the invisible parts of the solar spectrum—ultraviolet and infrared radiation. Such solar cells could be incorporated into any existing glass or plastic surface from smartphones to skyscrapers.
Researchers have also created the thinnest and lightest photovoltaic cells ever in 2016. This ultrathin solar cell is so light, it can sit on a soap bubble. Practical applications include fabric, paper, and glass. These cells are about 1.3 microns thick or one-eighth the thickness of the average human hair. They weigh only 0.01 lbs. per square yard (3.6 grams per square meter) or one twentieth of the weight of a piece of paper. Conventional silicon-based solar modules produce about 6.8 watts per lb. (15 watts per kilogram). This new solar cell produces 2,720 watts per lb. (6 watts per gram), or about 400 times as much as conventional solar panels. The manufacturing of these cells also has a much smaller environmental footprint than conventional solar panels. Because of its light weight, these cells may be ideal for aerospace applications.
The final frontier
There is an unlimited new frontier for solar beyond earth’s atmosphere. Harvesting the sun’s energy from space may be the most promising application of solar energy. Space enables solar to overcome the biggest obstacles hindering terrestrial arrays. The first is the problem of intermittency, the second is storage and the third is scale. They would also last for centuries.
Zero gravity makes massive solar arrays possible. As an uninterrupted supply, it will not need to be stored and it can be continuously beamed down to earth via satellite using microwave technology. In fact, the final frontier is such an ideal environment for solar that some predict there will be an energy race in space. This technology could be a game-changer by providing unlimited supplies of inexpensive emissions-free power to people all around the world.
Researchers in the U.S., China, Japan, the UAE and elsewhere believe that space-based solar is technically feasible and they are currently testing the concept. There are already space based solar projects in the pipeline including a solar power satellite from Solaren, which has signed an agreement with Pacific Gas and Electric in San Francisco.
The Space Solar Power Initiative (SSPI) has developed a system of lightweight space based tiles which can convert solar energy to radio waves and beam power back to Earth. These “multifunctional tiles” can be used to build the largest space structure every constructed.
We have entered the age of the Anthropocene, a time defined by human destruction of the planet, but solar energy is leading the way out of the mess we have made with innovative energy innovations. Historians will look back on this period as the golden age of solar power.
Richard Matthews is a consultant, eco-entrepreneur, green investor and author of numerous articles on sustainable positioning, eco-economics and enviro-politics. He is the owner of The Green Market Oracle, a leading sustainable business site and one of the Web’s most comprehensive resources on the business of the environment. Find The Green Market on Facebook and follow The Green Market’s twitter feed.
Image credit: wikimedia