The solar energy striking the Earth at a given moment is more than the entire world’s energy usage in a year. Solar power’s massive energy potential has opened the door to to utility-scale electricity generation all the way down to rooftop power for individual homes. Yet solar panel efficiency and capacity problems have limited solar power from being widely utilized, with most solar panels’ maximum efficiency standing below 23 percent and capacity factors in the low 20s.
Continued innovation in the solar power industry has increased the total energy generation from 585 terawatt hours in 2018 to 720 terawatt hours in 2019, with projections indicating that 1,940 terawatts hours of electricity generation from solar will be reached by 2025. To assist solar panels in pushing their potential, several technologies have been developed to either improve the solar panels efficiency or assist in focusing sunlight into the panel at even stronger rates.
The first innovative solar panel technology are perovskite solar cells. Perovskite cells are made out of a synthetic material with a similar crystalline structure to that used in more most solar panels. Perovskite cells are one-tenth as heavy as standard silicon cells, bendable, and able to be fixed to surfaces that would not be able to handle the weight of standard silicon solar panels. Perovskite cells can also be printed, meaning their production can be rapidly increased. These cells can be affixed to areas not normally suited for solar panels, like bridges or other infrastructure, or by being made into different products like window blinds.
The highest recorded efficiency for perovskite cells peaked at just over 25 percent. Further research and development has focused on insulating perovskite cells from the surrounding environment to protect their efficiency. Being able to pair them with silicon panels may facilitate increased power production upwards of 48 percent. By pairing perovskite cells on top of existing silicon solar panels, the theoretical limit of 33 percent of energy conversion for silicon cells could be bypassed.
Another product that can be utilized alongside existing solar panels are solar paints. These paints can be utilized either directly with solar panels or as a type of solar energy power converter by itself. The paint contains synthetic substances that absorb moisture from the air and separates it into hydrogen and oxygen particles with the help of the titanium oxide in the paint. The hydrogen collected by this process can then be utilized to produce clean energy. Another type of solar paint, photovoltaic paint, utilizes nanoscale semiconductors that can capture light and create an electric current. This paint can also capture blue light from the sun (rays that have a shorter wavelength, but more energy). These paints are able to be sprayed directly onto surfaces or applied by a paintbrush. While only around 5 percent efficient at capturing solar energy, and not yet commercially viable, the potential applications of solar paint –or spin off research– will likely improve
The last innovation in solar panels happens to be the most simplified one: bifacial solar panels. By utilizing PV cells on both sides of a panel, a single panel’s energy capacity and overall efficacy can be increased. Current bifacial solar panels gain anywhere from 5 to 20 percent more power generation than one-sided panels. These types of solar panels depend largely on consistent amounts of sunlight, so are most effective at latitudes greater than 40 degrees, with panels located at latitudes beyond 65 degrees increasing energy production by 71 percent. Bifacial solar panels are usually elevated off of the ground, where the bottom panels can collect reflected light from other surfaces. Ideally, bifacial panels can be integrated into existing infrastructure, so that the existing structure can reflect the light back into the panel, while simultaneously collecting the sun’s rays.
Solar energy today is constantly advancing, with innovations shaving pennies from an already proven source of energy. The largest remaining costs for solar consist of silicon supplies, the lifespan of a single panel, and securing the necessary materials for solar panel production. Finding alternative solar panel materials and further lengthening the lifespan of panels will only drive more investment into the industry. By developing products like larger PV solar cells, paints to absorb and direct sunlight, and double-faced solar panels, the solar industry is well positioned to continue to overcome current efficiency and capacity challenges. And when those hurdles are overcome, energy storage will be the number one renewable innovation challenge.
Written by Roy Mathews, Public Policy Associate
The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization. An innovative think tank, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, energy, infrastructure, innovation, technology, and transportation.