Understanding DIY Solar Panel Efficiency Ratings Posted on 6 May 09:00

Solar Panel Efficiency Ratings

The DIY solar panel efficiency rating measures how much of the sunlight hitting the panel is actually converted into usable electricity. This is an extremely important factor in determining the right photovoltaic system for you.

Higher is better when it comes to efficiency, but how much does it really matter?

Comparing Solar Panel Efficiency

Under laboratory conditions, scientists have created solar cells — the key components of a photovoltaic panel — that are 46 percent efficient.

Unfortunately, these high-efficiency solar cells are currently so expensive that they are only used in space applications. The most efficient commercially available solar panel has a 36.7 percent efficiency rating; however, this model is not used in residential applications.

So don’t expect efficiency ratings like those for your solar power system.

The highest-rated model produced for rooftop solar today is just over 22 percent, but most residential photovoltaic panels clock in at somewhere between 14 and 20 percent efficiency.

Although that may sound dire, it’s actually completely normal for professionally installed as well as DIY solar kit systems. Here’s why.

Factors that Can Affect DIY Solar Panel Efficiency

Although technology has progressed significantly, solar efficiency ratings still aren’t an exact science.

Many factors can affect how well PV panels convert light. Orienting your panels to face south is usually ideal; though an east- or west-facing installation can work just as well in most cases.

If you aren’t careful in your DIY solar panel planning and installation, however, your system efficiency may be reduced.

The pitch or tilt of your roof may also have an effect, as the panels need to be angled properly to absorb the optimal amount of energy from the sun.

Of course, shade can decrease your efficiency, particularly if you have a string inverter. With this type of inverter, shade on one solar panel can reduce the energy production of the entire array. If you have micro-inverters, however, shade will not have a system-wide effect.

Weather can also influence the efficiency of your photovoltaic panels.

Cloudy skies can — but not always — result in a drop in energy output. Also, some PV panels are less efficient in hotter climates. But mounting the photovoltaic panels in a way that provides air flow between the panel and the roof can help resolve this issue easily.

Should You Wait for Solar Panel Efficiency to Improve?

Experts anticipate that costs will come down for ultra-high-efficiency panels, but they are still at the top of the price scale. So, given the current market, should you wait for efficiency to improve before investing in a DIY solar kit or custom photovoltaic system?

The answer is a resounding NO!

A higher efficiency rating doesn’t necessarily mean that a particular model is a superior choice. In choosing your DIY solar panels, you must consider a variety of other factors, including the wattage, the space available on your roof and the warranty details.

So, while you should certainly look at efficiency, it shouldn’t be your main consideration. And every day you wait before investing in a DIY solar kit or custom photovoltaic system is a day you don’t save money by leveraging the power of the sun.

Besides, if you wait around in anticipation of a more efficient technology that may be decades in coming, you are likely to lose out on the 30 percent federal tax credit as well as myriad local and state-based incentive programs available today.

At Solar GOODs, your DIY solar superstore, we understand that you have lots of questions about alternative energy systems. Visit our site today to learn more about the significant financial and energy independence that a DIY solar panel kit can provide.