Solar Panel Efficiency Which PV Brands Bring Top Power?

Who makes the world’s most efficient residential solar panels? The panels listed here have earned the right to be considered when homeowners are looking for a system to provide the best savings over the years. Remember that solar technology is moving quickly and striving for higher efficiency with each new panel created, so manufacturers regularly discontinue solar panels and release new,
more efficient panels to take their place. This chart will help get you started
understanding available solar panel efficiencies from a variety
of manufacturers:

Understanding Solar Panel Efficiency

Solar panel efficiency can make an enormous difference in the savings realized on monthly utility bills over the long run. The efficiency of solar panels is based on the ability to convert sunlight into electricity. If the same amount of sunlight shines for the same duration on two different panels, the one with the highest efficiency will produce the most electricity.

Though solar panel efficiency is rising quickly, some companies still do claim efficiency numbers that are garnered only under strictly controlled test conditions – which is not what homeowners get when they install a system. In the real world, efficiency depends upon the type and brand of solar panel being used, as well as on-site considerations. Getting the maximum efficiency from your solar panel depends on several factors:

What can homeowners reasonably expect?

“On the high side at around 22.1 percent and on the low about 14 percent,” MacLeod said. “I almost never see a panel produce to its full efficiency rating in field conditions. There are usually as much as 20 percent in losses.”

To ensure solar panels are top-notch in terms of efficiency, it’s time to do some homework. This guide is designed to help homeowners understand how efficiency works, how to choose the best solar panels for the job and learn how to compare solar panels to find the ones that work best for a particular environment.

Solar Panel vs. Solar Cell Efficiency

Solar panels are only as efficient as the solar cells inside them – but why doesn’t the higher solar cell efficiency translate into higher solar panel efficiency? One of the top reasons is simply how those cells are used in the panel space.

“Look at the cell layout on the panel face,” MacLeod said. “Some manufacturers make more efficient use of the available area on the front and back of the panel. More cells, less cells, types of cells – all determine efficiency.”

Manufacturers are getting smarter about configuring solar panels, just as the industry is getting better about producing higher-efficiency cells for those panels.

“Eight years ago we were using panels that were 12 percent efficient, now we are up to 22 percent. Pretty good so far,” MacLeod said. “All the manufacturers are competing against each other for the efficiency prize.”

Another issue with higher-efficiency solar panels is the prohibitive cost.

“There are cells out there that are as high as 44.5 percent efficient but will take a lot of time before they come to market,” MacLeod said. “Pathfinder on Mars used cells that were 44 percent efficient but cost over a million dollars.”

“Efficiency will continue to increase as Multi Layered Cells and Gallium Arsenide cells enter the market,” he said. “Panel wattage is on the increase as well. Ten years ago it was 185 watt panels, now its 300s, 315s, 345s, 360s and on.”

What Affects Solar Panel Efficiency?

Though the technology that makes up the panel itself has a strong impact on efficiency, the site where the solar panels are installed also has a hand in the amount of power created. In some areas of the country, solar panels will be more efficient simply because of a more conducive environment. But efficiency can vary dramatically from one neighborhood to the next or even from one home to another on the same street, based on site considerations. The following are the biggest factors in solar efficiency outside of the panel itself.

Solar Panel Tracking Systems

With so many issues concerning the tilt and orientation of solar panels, some homeowners might be curious about tracking systems. These systems do just what it sounds like: they track the path of the sun by moving the solar panels to achieve the best solar coverage possible.

It sounds like a good idea: it would allow homeowners to capture as much of the sun’s rays as possible. But MacLeod has some misgivings.

“Trackers are mostly used for ground mounted systems,” he said. “They are ideal for areas like New Mexico and Nevada where the irradiance factors are the highest. They also have motors and moving parts that can fail in extreme environmental conditions of the northeast. As the cost comes down on trackers, then I might give more positive consideration to using them.”

As solar panels become more affordable, the costs of trackers will continue to drop in order to compete the in the market. But besides the cost, there are a few other downsides to consider.

• Weight limitations

  Solar trackers might be very heavy, depending upon the size of the array, which doesn’t make them a viable option for many roof-mounted systems.

• Extra maintenance

  They are made of moving parts, which can lead to more maintenance requirements and opportunities for the system breaking down.

• Shorter warranty

  The warranty might be troublesome as well: companies routinely offer anywhere from two to 10 years under warranty, while inverter and panel warranties typically start at 10 years and go up to 25 years or more.