The world of solar energy is in a state of constant and exciting flux. Advancements in technology propel the avalanche of social interest in alternative and sustainable energy and the funding available to support research, development, and implementation of the latest and greatest solar technologies.
Several advancements are here now or coming our way soon.
BUILDING-INTEGRATED SOLAR TECHNOLOGY
Building-integrated photovoltaics or BIPVs, are products and materials that enable solar power generation in roof canopies, facades, windows, terrace floors, curtain walls and skylight systems. The result – renewable energy generation seamlessly incorporated into building designs that reduce the less desirable look of solar panels attached to roofs. BIPVs also eliminate the cost to build and install solar panel racking support systems.
FLOATING SOLAR FARMS
Scientists at the National Renewable Energy Laboratory (NREL) estimate that about 10% percent of American energy requirements could be satisfied using floating solar farms (also referred to as aquavoltaics and floatovoltaics) employed on just one-quarter of the nation's artificial water reservoirs.
This solution saves on land that could be used for other purposes while avoiding some of the environmental consequences of land-based arrays. There are functional benefits to collecting solar energy on water bodies. Notably, installation costs for water-based solar arrays are less, as there is no need to clear and level land and treat the soil. Further, the cooling and cleansing effects of the water can boost solar power production by 10% or more. Solar arrays reduce evaporation rates, and thoughtful design can assist fish growth and other marine life by incorporating solar-powered oxygenators to improved dissolved oxygen levels in the water body and minimize the chance for stagnation and excessive algae growth.
Research continues to find creative and useful ways to apply solar energy generation. Solar fabrics worn as clothing and used as window curtains, deck awnings, pool covers, and shelter canopies become solar power generators.
Presently, thin-film flexible PV panels are laminated or sewn onto fabrics. But researchers will soon announce their next breakthrough – solar fabrics incorporating special photoactive dyes coating thread fibers, transforming each fiber into a miniature solar panel – and solar-power-generating clothing will become a fashionable reality. Although the energy generated from solar fabrics is low, every personal electronic device requiring recharging becomes a target for that energy.
One of the drawbacks for many concerning solar installations is their look – they often detract from the lines of a beautiful home or building. Sistine Solar has developed a product known as solar skins to create whatever look an owner may want for their solar panels.
Solar skins are applied directly to the solar panel and frame. These skins match the roof color and look, allowing the solar panels to blend in with their surroundings. The company claims the solar skin transmits sunlight to the solar panel with very little loss in efficiency and is extremely durable. For commercial applications, solar panels can become advertising signage or works of art.
PHOTOVOLTAIC NOISE BARRIERS
Photovoltaic noise barriers (PVNBs) are an excellent example of creating added benefits from a traditionally single-purpose product.
Traffic noise barriers are deployed throughout North America to reduce highway and road noise for nearby communities. Roughly 3,000 miles of noise barriers are in place in the continental U.S. The U.S. Department of Energy seeks to merge noise reduction with solar generation as Australia and numerous European countries have done. Estimates indicate that transforming America's existing noise barriers into PVNBs could generate sufficient electricity to power 37,000 homes annually.
PEROVSKITE SOLAR CELLS
Perovskite solar cells (PSCs) are made using calcium titanium oxide to replace silicon as the semiconductor commonly used in solar cell production.
PSCs offer several significant advantages for solar power production.
- Compared to silicon solar cells, PSCs are easy to manufacture. Silicon needs to be extremely pure to become a useful PV semiconductor and such refining is expensive. PSCs do not require intense quality control to become a high-performing PV material. As a result, PSC production costs are only about 1/10th that of silicon PV cells.
- PSCs are efficient solar-to-electrical energy converters. In 2009, when Japanese researchers fabricated the first PSC, the material was unstable, and its conversion efficiency was less than 4%. Within a decade, PSCs demonstrate a conversion efficiency of 28%, and the science is still in its infancy – developers expect further performance improvements. Silicon solar cells, on the other hand, represent mature technology, and further gains in efficiency above 25% are unlikely.
- Perovskite is a flexible, lightweight and semi-transparent material – qualities that offer numerous useful applications not available with other PV cell materials. Coatings for windows and painted applications are two prominent possibilities, particularly spray-on solar cells. Current conversion efficiencies for spray-on solar cells are around 11% and improvements will come. Consider the options – solar sprays for vehicles, buildings, rooftops, bridges and other infrastructure – the list is virtually endless.
State-of-the-art PSC technology still has a way to go before it becomes commercially feasible. Aside from their relatively low electrical conversion efficiency, PSCs lack strength and durability. Further, they contain small amounts of lead that pose toxicity concerns for the environment.