Academic researchers are developing technology and methodology that may boost the viability of solar power as a sustainable, prosperous energy source. Adoption of solar as a key energy source has been slowed by such barriers as energy storage, efficient design and public acceptance.

Calcium-ion batteries

Once photovoltaic cells generate and invert current to usable energy, it must be stored. Lithium-ion batteries and storage cells are the first order of energy storage. But lithium can be scarce and expensive. Researchers at Rensselaer Polytechnic Institute (RPI) are developing alternative storage capacity using calcium ions.

The cells are generally larger—which isn’t always desirable—but the size does have a higher charge density from the calcium ions. In an article on RPI’s website, Nikhil Koratkar, professor of mechanical, aerospace and nuclear engineering, wrote: "The vast majority of rechargeable battery products are based on lithium-ion technology, which is the gold standard in terms of performance. However, the Achilles’ heel for lithium-ion technology is cost. Lithium is a limited resource on the planet, and its price has increased drastically in recent years. We are working on an inexpensive, abundant, safe, and sustainable battery chemistry that uses calcium ions in an aqueous, waterbased electrolyte."

The evolution of perovskite

Using perovskite compounds in the materials used for making solar panels is a significant advancement. The compounds can be easily deposited onto a wide variety of surfaces, including those that are textured or flexible.

"Perovskite" refers to a unique type of crystalline structure rather than to a specific element (such as silicon). Perovskite semiconductors used in solar cells are advantageous because they tolerate defects in structure and can perform in rigorous environments. The silicons conventionally used in solar panels must be from pure materials to perform sufficiently, while perovskites perform well in the presence of impurities and other imperfections.

This all means that solar panels designed and fabricated with perovskites are more durable and still provide the desired output in conditions that would otherwise inhibit the panel’s performance with other materials.

Although such materials are in early development, this discovery could change the possibilities for fabricating solar panels.

Reducing panels' footprints

Another challenge is reducing the footprint made by solar farms. Adjusting the arrangement of panels so more energy can be produced in a smaller area of land could be one possible solution.

In a research paper—" Land Requirements for Utility-Scale PV: An Empirical Update on Power and Energy Density"— published in the March 2022 IEEE Journal of Photovoltaics, researchers Mark Bolinger and Greta Bolinger wrote, "The rapid deployment of large numbers of utility-scale photovoltaic (PV) plants in the United States, combined with heightened expectations of future deployment, has raised concerns about land requirements and associated land-use impacts."

They found that tilting the panels resulted in a greater density in megawatts per acre. They compared a tilted panel arrangement to a tracking plant, whereby panels automatically follow the position of the sun. This maximizes the output by ensuring panels continuously receive direct sunlight for the greatest exposure year-round.

Fixed-tilt and tracking panels increased the output of electricity. According to the researchers, "We find that the median power density increased by 52% for fixedtilt plants and 43% for tracking plants from 2011 to 2019, while the median energy density increased by 33% for fixed-tilt and 25% for tracking plants over the same period. Those relying on the earlier benchmarks published nearly a decade ago are, thus, significantly overstating the land requirements of utility-scale PV."

It seems that panel arrangement and mapping facilitate the best use of space for the greatest energy density from panels on a solar farm, space or solar panel array. This area will prove prosperous and help fine-tune the way energy is extracted from panels in the future.

As sustainable energy continues to pick up speed and researchers gain much momentum and funding to advance sustainable energy such as solar and its storage, we can expect an optimistic outlook on solar technology now and into the future.