Over the past decade, the solar installation industry has experienced an average annual growth rate of 24%. A 2021 study by the National Renewable Energy Laboratory (NREL) projected that 40% of all power generation in the U.S. could come from solar by 2035.
Solar’s current trends and forecasts look promising, with photovoltaic (PV) installations playing a major role in solving energy problems like carbon pollution and energy dependence. However, challenges related to solar energy threaten to slow growth and make solar less accessible to homeowners and businesses.
These issues include problems connecting solar to electrical grids, equipment shortages, supply chain delays, a lack of land for commercial solar arrays, and a lack of qualified contractors and laborers to meet installation demands.
Industry stakeholders, governments, manufacturers, and scientists are seeking ways to address these roadblocks and push the development of solar power forward. Here is a closer look at the issues affecting the PV sector and current efforts to solve them.
Technological limitations in photovoltaic efficiency
The U.S. Department of Energy defines solar conversion efficiency as “the percentage of the solar energy shining on a PV device that is converted into usable electricity.” The agency points out that most of the sunlight hitting PV cells gets lost during the conversion process. Light either gets reflected or turned into heat instead of getting converted into electricity.
Recombination is another factor limiting PV efficiency. It happens when charge-carrying electrons encounter defects in the PV material or merge with charge carriers known as “holes,” which do not have electrons. During recombination, the energy turns into light photons or heat instead of producing energy.
Currently, most panels have efficiencies of 17-20%.
Solutions to improve PV efficiency
Researchers have developed new technologies, such as multi-junction PV cells, which increase efficiency to more than 45%. Manufacturing costs, material availability, and other factors need to be addressed before this technology becomes accessible for commercial use.
Another solution is bifacial solar panels, which have cells on their underside to catch light reflected off the ground, roof, or other reflective surfaces. If combined with sun-tracking panels that adjust to maximize solar contact throughout the day, bifacial panels are 30-40% more efficient than their one-sided counterparts.
Solar intermittency and storage challenges
Solar intermittency is the most obvious issue related to PV panel efficiency. The sun is not visible for 24 hours per day except for a short time each year at extreme latitudes. Solar power users need other power sources to use after sunset, and utilities cannot rely on solar alone to provide electricity for their customers.
One solution is to capture extra energy during the daytime and store it. However, storage issues are common. Batteries add to the cost of solar installation. Costs for batteries to cover home energy are $8,500 to $10,000, not including installation and maintenance. These systems may not be enough to cover high energy usage periods, such as heating or cooling the home during extreme temperatures.
Solutions to improve solar reliability
One of the most common solutions for residential and small business customers is net metering. Users keep their utility connections, and their system feeds unused energy back into the grid. The utility company offers credits that the customer can use to cover the cost of electricity from the grid after dark.
Battery technologies are improving, and smart energy management software can help solar users maximize efficiency based on electricity usage patterns. Advances such as more efficient lithium-ion batteries and safer, faster-charging solid-state batteries are on the horizon. These could make storage more efficient and cost-effective and make it possible for more solar users to disconnect from the grid.
Geographic variations in solar intensity
In general, the closer to the equator a location is, the more solar radiation it receives and the more energy PV cells can produce. However, pollution, cloud cover, foliage, elevation, and other factors also play a role in how much solar energy hits PV panels.
In areas with low levels of solar radiation, such as locations in higher latitudes, solar panels may not produce as much energy, making them a less cost-effective option. The same could hold true for areas with lots of cloud cover and rainfall.
Solutions for solar intensity limitations
Solar optimization is one area that has already enjoyed significant advancements. For instance, solar tracking technology allows panels to adjust daily and seasonal changes in the sun’s location. Dual-axis panels rely on software to calculate the ideal angle and tilt based on available sunlight at a given time. Common in utility-scale ground-mounted systems, these systems ensure panels are always in the position to maximize solar radiation exposure.
AI-powered software can also perform an advanced site analysis and use mathematical models to help optimize the placement, location, and angle of panels in a solar array. With these tools, you can design ground-mounted and rooftop systems and calculate yield to ensure maximum exposure to solar energy.
