Surface Patterns Boost Solar Energy Efficiency
As the world’s population continues to grow, so does the need for energy — dramatically. The world will need roughly one-third more energy in 2040 than it will in 2020, according to predictions by the U.S. Energy Information Administration.1 Finding viable sources for all that energy will be no small challenge.
Solar energy is one obvious candidate. Enough solar energy strikes the earth in one hour to power the world’s current economy for a year. Solar is not merely renewable, it’s inexhaustible and carbon neutral. In fact, solar may supply 29 percent of the world’s total capacity by 2040, according to one estimate, vs. 1.2 percent of global capacity in 2015, the latest year for which statistics are available.2 & 3
If solar is such an obvious energy solution, what’s holding energy providers back from powering a majority of the world’s energy needs today and tomorrow? One major factor is that to be pervasive, solar panel technology must become dramatically more efficient. Amid widespread commercial and scientific deployments, scientists are gaining insights about how using the right materials in the most efficient patterns will help the world realize adoption ambitions for this important energy source. For example, DuPont™ Solamet® photovoltaic metallization pastes have allowed the conversion efficiencies of mass-produced solar cells to increase by 30 percent over the past 12 years.
A Central Challenge: Efficiency
Achieving a 29 percent level of contribution will require further reduction in the levelized cost of energy derived from photovoltaics. One key driver for this is an increase in the solar conversion efficiency of solar panels.
The key elements of a solar panel’s working photovoltaic cells are negatively and positively “doped” layers within a thin silicon wafer, a metal silver electrode grid on the front (sun facing) side, and an aluminum electrode coating on the rear side. When photons strike the front surface of a cell, they release negative and positive charges at the interface of the doped layers, which flow to opposite sides of the silicon wafer to the silver and aluminum electrodes, respectively, and then out to an external circuit.
The Power of Patterns
Scientists worldwide are engaged in ongoing research to continue to improve conversion efficiency. One method involves changing patterns on the glass that covers the front of a solar panel. That may seem insignificant, but optimizing those patterns can deliver significant efficiency gains.
Architects are working with scientists to integrate some of those patterns into the design of buildings and solar panels for a combination of aesthetics and efficiency. For example, panels that mimic the shape of leaves are now available, with surfaces that improve light harvesting efficiencies, particularly in the near-infrared region.
Multiple Technologies Boost Efficiency
DuPont has played a leading role in the growth and economic viability of solar energy for more than 25 years. On the efficiency front, the newest generation of DuPont™ Solamet® photovoltaic metallization paste, used in the manufacture of solar cells, contributes yet another increase in efficiency.
To improve solar economics and reliability, film-based backsheets made from DuPont™ Tedlar® can extend solar panels’ useful life to more than 30 years, delivering proven performance and lasting value, day after day.
“The efficiency and economic viability of solar systems depend on a large number of factors, and they all add up,” says Randy King, Technology Director, DuPont Electronics and Communications. “Improvements in overall efficiency and levelized costs will take place on multiple fronts, which is why a broad-based research effort is critical.”
Given the consistent pattern of technological improvement and economic growth, the oft-repeated statement that solar energy has a bright future is more accurate than ever.