Solar energy is one of the fastest-growing forms of energy in the country. You can see it on neighbor’s rooftops or in acres of fields, but how did solar energy begin? Where is the technology headed?
Using power from the sun is an ancient practice, but harnessing solar power in the form of photovoltaics to produce electricity is a relatively recent discovery.
Throughout the 1800s, various scientists worked to improve the basic photovoltaic cell that created the basis for modern photovoltaics.
At a basic level, when semiconductors are exposed to light, they can emit electrons that create an electric current. The first solar cells used selenium to create the “photovoltaic effect,” which is the generation of electricity from light exposure.
Today, we use silicon.
Although photovoltaic technology was developed in the 1800s, it took more than a century to become more commonplace. The Space Age in the 1950s and 1960s saw a slight increase in production of solar photovoltaics to power spacecrafts. An oil shortage in the 1970s brought more awareness to alternative energies.
Throughout the last century, solar cells’ efficiency has improved. The first solar cells had an efficiency—the amount of energy from sunlight converted to electricity—of about 4% in the late 1800s, advancing to approximately 11% in the 1950s. Modern solar cells have an efficiency of around 15% to 20%.
With solar energy becoming more mainstream, other emerging technologies beyond the traditional solar photovoltaic cell could play a role in coming decades. Other forms are also in use.
One is concentrating solar power technology, which uses thousands of mirrors to concentrate solar energy onto traditional steam turbines or engines to generate electricity. This type of technology requires about 500 acres of land to be cost effective.
Another existing type of solar technology is solar heating and cooling, which collects thermal energy to be directly used for water and space heating and cooling across many applications. This includes most solar water heaters.
Several forms of experimental solar technology are relatively less developed, such as floating solar arrays, also called floating photovoltaics. This technology uses solar panels fixed on top of a buoyant structure in a body of water.
Most FPV arrays are located on inland bodies of water, like lakes or reservoirs, because the calmer waters allow for easier installation and less degradation of the technology over time. The water helps cool down the solar panel, which increases the efficiency of electricity generation.
While not all environmental effects are known, in certain habitats, having FPV can provide shade to reduce evaporation and the growth of algae blooms. Another benefit of FPV is freeing up valuable land for other uses and reducing the need to remove forests for large solar arrays.
While there may be potential to expand FPV into the open ocean, installation and maintenance costs for these projects are higher.
Another relatively new form of solar technology is printable solar cells—photovoltaic cells that are paper-thin and can be used almost anywhere.
Instead of using silicon like in conventional photovoltaic cells, these printable cells break down organic semiconductor polymers into “solar ink” on a plastic film, which can then generate electricity from light.
Although the technology has been proven to work, there are still some major issues to solve before the technology can be commercialized.
The printable solar cells last only six months and have an efficiency of 10%.
Researchers are working to solve those challenges. Once brought to market, the printable cells would be flexible and portable enough to be placed on the sides of buildings and various other applications.
As newer forms of solar technology develop and become commercially available, many more kinds of solar technology are likely to emerge.
Solar technology has come a long way in the past century. The sun is just starting to rise on the age of solar.