Category: Solar Farms

The Effect of Shade on Solar Panels

The Effect of Shade on Solar Panels

Just a little shade can affect a solar panel ‘s power output dramatically. Diffuse shade from a “soft” source, like a distant tree branch or cloud can significantly reduce the amount of light reaching a solar panel’s cells. “Hard” sources stop light from reaching solar cells, such as debri or bird dropping sitting on top of the panel. If even one full cell is hard shaded, the voltage of a solar panel drops to half in order to protect itself. If enough cells are hard shaded, the module will not convert any energy and will, in fact, become a significant drain of energy on the entire system over time.

Partial Shading of Cells on a Solar Panel
Partial cell shading that reduce solar panel power by half.

Partial shading of even one cell on a 36-cell solar panel will reduce its power output. Because all cells are connected in a series string, the weakest cell will bring the others down to its reduced power level. Therefore, whether half of one cell is shaded, or half a row of cells is shaded, the power decrease will be the same and proportional to the percentage of area shaded, in this case 50 percent.

When a full cell is shaded, it can use energy produced by the remainder of the cells, and trigger the solar panel to protect itself. The solar panel will route the power around that series string. If even one full cell in a series string is shaded, as seen on the right, it will most likely cause the module to reduce its power level to half of its full available value. If a row of cells at the bottom of a solar panel is fully shaded, the power output may drop to zero. The best way to avoid a drop in output power is to avoid shading whenever possible.

A solar panel affects an array in much the same way a single cell affects a solar panel. In a centralized inverter system, where panels are strung in series, if only one of the solar panels is shaded in an array, the rest of the solar panels’ output diminishes.

When choosing a grid tie solar power system for their home or business, folks often prefer the tried and true technology of a centralized inverter systems. And the price tag on these is pretty good. When you consider the effects of shading, however, it’s easy to understand how microinverter and SolarEdge systems have become so popular.

While using different technologies, both SolarEdge and Microinverter systems allow each solar panel in an array to maximize power output independently, thereby maximizing a system’s power generation. If one solar panel is shaded in either of these systems, the rest of the array’s panels can still operate at full capacity. (SolarEdge provides DC to DC power optimization for each solar panel, while microinverters provide DC to AC optimization at the module level.) Both of these systems allow solar panels to be facing different orientations giving you more design flexibility if part of your installation site is in the shade. A centralized inverter system requires panels to facing the same direction.

Read more about SolarEdge, Enphase Microinverter and Centralized Inverter Systems.


Unirac Teams Up with Kyocera to Power the Masonic Lodge of New Jersey

Unirac Teams Up with Kyocera to Power the Masonic Lodge of New Jersey

Albuquerque, NM – Unirac, Inc., North America’s leading provider of integration hardware for solar power systems, announces that they will be teaming up with Kyocera Solar, Inc. to upgrade the historic Masonic Lodge of New Jersey with a 1.16MW solar installation. Equipped with 5,656 Kyocera KD205 205-watt modules, and framed with Unirac’s innovative ISYS Ground Mount (IGM), the installation is projected to generate approximately 1,600,000 kWh of solar energy a year. That is enough energy to power about 145 homes.

The Masons have owned the Burlington property since the mid 1800s, and come from a long history of being responsible global citizens. The photovoltaic installation affirms the organization’s commitment to preserving the environment, and maximizing the efficiency of their energy usage.

Kyocera‘s solar panels qualify for American Recovery and Reinvestment Act (ARRA), contributing to our nation’s economy. They are highly regarded for their durability and efficiency, and are backed by a solid 20-year warranty.

We expect to see more of these large commercial solar installations in the years to come. The cost of manufacturing solar panels and related components has been steadily dropping, while efficiency standards are improving every year. This fosters a very positive environment for growth in such a dynamic market.



What’s the difference between
1) buying electricity from a utility company that produces electricity from solar or wind, and
2) making your own electricity with a solar or wind power system?

Both scenarios are good for the planet, reducing dependence on dirty, costly fossil fuels. But…

One scenario—buying and installing a solar electric system on your own home—promises that your electricity costs will be capped or eliminated, for the rest of your life. Consider the value of never having to pay another electricity bill, of knowing that you are living within your means. For those of us for whom independence is important, this is a crucial difference.

The other scenario—buying solar- or wind-farmed utility power—while technically good for the planet, will never make your electric bill go away. The initial costs of solar and wind farming are subsidized by federal and state monies AND by utility users. As costs for producing electricity by coal and nuclear continue to grow, utility users will also subsidize these costs. As long as you are buying from the utility company, your rates will always be hinged to the cost of producing electricity by nuclear and fossil fuels.

Now is the time of greatest opportunity for being your own electricity producer. Costs are probably as low as they can go and subsidies are as high as they’ll ever be. If you’re waiting for your utility to do it for you, if you’re waiting for some additional rebate or incentive, you may just miss the boat.