Do solar panels have limits?

When the incoming radiation comes only from an area of the sky the size of the Sun, the efficiency limit drops to 68.7%. Not all of the sunlight that reaches a photovoltaic cell is converted to electricity. In fact, most of it is lost. Multiple factors in solar cell design influence the limitation of a cell's ability to convert the sunlight it receives.

Designing with these factors in mind is how greater efficiencies can be achieved. The conversion efficiency of a photovoltaic (PV) cell, or solar cell, is the percentage of solar energy that falls on a photovoltaic device and that is converted into usable electricity. Enphase is a leader in solar microinverters, and this most recent microinverter can mitigate many of the limitations of a solar PV system, especially inefficiency and power during outages. Almost all of the solar panels currently in operation use traditional single-layer silicon cells, which have proven their resistance to weathering for decades.

The reason, says Marc Baldo, professor of electrical engineering and computer science at MIT, is that these highly efficient multilayer solar cells are too complex and expensive to produce like solar panels. That way, if one panel underperforms, all other panels will be able to operate at maximum efficiency. The first perovskite solar cells were only produced a decade ago, but since then they have recorded the fastest efficiency gains of any type of solar cell to date. The silicon needed for solar cells is rare in nature, so most materials for solar cells have to be manufactured.

Even under small-scale laboratory conditions, the world's best single-junction solar cells, such as those found in most solar panels, still maximally capture 29 percent of the Sun's energy. With individual microinverters, you can ensure that each of your solar panels operates at maximum efficiency. More importantly, they allow each of their solar panels to work independently of the others at their maximum efficiency. Traditional photovoltaic solar panels can be expensive, especially those that are more efficient, lighter, and less bulky.

Installers need to find flat roof spaces to place their solar panels, and that's one of the reasons solar installations can be expensive. For example, some of your solar panels could be covered in snow and operate at a lower efficiency that day. To really get more solar energy on the power grid, it's necessary to figure out how to reach the Shockley-Queisser limit with silicon-based single-junction solar cells, which are comparatively easy and cheap to produce. In fact, this solution can keep your solar panels up and running during a power outage without the need for a backup solar battery.