Solar power offers Arizona homeowners an excellent way to cut energy costs while embracing renewable energy. Our sunny climate is ideal for solar power production. However, you may not know that parts of a typical solar power system do not perform well in extreme heat. As a result, anyone designing a solar power system for use here must exercise great care. To explain why, here is an overview of how Arizona’s extreme heat affects solar inverters and electrical components.
What Is a Solar Inverter?
When you install solar panels on your roof or property, you cannot plug them straight into your home. That is because solar panels output direct current (DC). Your home, as well as the wider electrical grid, depends on alternating current (AC). A solar inverter is a device that converts DC power from your solar panels into AC power. It also converts power coming from any attached batteries, which also store DC power. To accomplish that, an inverter employs a handful of sensitive electronic components.
Ideal Solar Inverter Operating Temperatures
Different inverter types and brands have different operating specifications. However, most solar inverters operate efficiently at temperatures between 14 degrees and 113 degrees Fahrenheit. Many inverters have active cooling systems and heat sinks to help them stay within that range. Certain types of inverters handle heat better than others. That makes choosing the right inverter types for the Arizona climate essential.
The Effect of Extreme Heat on Solar Inverters
When your solar inverter experiences extreme heat, a few things begin happening. First, many of the materials inside it begin to deteriorate. Wire insulation can become dry and brittle. It can eventually disintegrate. The electronic capacitors inside the inverter suffer stress that can lead to early failure. Soldered connections on the inverter’s circuit boards can weaken or even crack. Any or all those effects can lead to an inverter failure if they continue for long enough.
Extreme heat also reduces the efficiency of the DC to AC conversion process. The culprit is heat-induced resistance. Resistance is the term for the force that impedes the flow of electrons through a substance. As temperatures rise, the resistance of copper and other metal conductors increases. It happens because the heated electrons and molecules that make up the metal move around faster than they otherwise would. The faster they move, the harder it is for the flowing electrons of the electric current to find space to move through the metal. Additionally, collisions between the current and the metal’s electrons generate even more heat. That can increase the frequency of solar overheating issues.
If your solar inverter exceeds its safe operating temperature range, it may enter a de-rate cycle. That refers to a process in which the inverter reduces its power output to lower its temperature. The cycle then lasts as long as the inverter needs to cool itself.
The Effect of Extreme Heat on Solar Panels
You should also know that extreme heat will decrease the power output of your solar panels. Most solar panels come with output ratings determined through laboratory testing. You should know that the laboratory conditions include an environmental temperature of only 77 degrees. To reflect that, solar panel ratings also include something called a temperature coefficient. That tells you how much output loss to expect as temperatures surpass the testing standard.
Most solar panels sold today have temperature coefficients of around -0.3% per degree Celsius. Here, in Arizona, solar panel operating temperatures average about 25 to 45 degrees above the ambient air temperature. On a 103-degree day, your panels may operate at a scorching 148 degrees. At that temperature, your panels could lose approximately 11.8% of their output capacity, even in full sun.
The Effect of Extreme Heat on Solar Electrical Components
The other parts of a typical solar power system can also experience degradation from extreme heat. For example, the wiring that links components together can see its resistance climb in the summer heat. The increase isn’t trivial. It can be as high as .7% of added resistance per degree. The same applies to solar breakers, which serve as critical electrical safety devices. Those can experience increased electrical resistance and even physical degradation from extreme heat.
If your solar power system includes battery storage, heat will affect that, too. Today’s lithium-ion batteries can suffer from accelerated wear in high heat. The heat speeds up the chemical reactions in the battery. Eventually, the added wear can lead to reduced charge capacity and early failure.
Methods of Reducing the Effects of Heat on Your Solar System
Pur Solar and Electrical has expert solar installers who understand how heat affects inverters, panels, and components, and can incorporate some cooling methods into your installation. They incorporate design elements, such as ventilation and the use of any existing shade, to counteract these effects. For example, they may use raised mounts to allow for adequate airflow beneath the panels. They may also install panels on an angle to allow trapped heat to escape more easily. It’s also possible to use strategic placement to keep panels in light shade during periods of peak daytime heat.
Choosing the right installation location can reduce the effects of battery and solar inverter heat in Arizona. Ideally, homes in Arizona should have their inverters and batteries installed indoors. The same applies to solar breakers. As a result, you’ll often find those components installed near a home’s existing electrical panel. Typical installation locations include garages and basements. Either spot keeps the components out of the direct sun. In some cases, it can also let them take advantage of your home’s HVAC.
It’s obviously not possible to avoid running some of your solar system’s wiring outdoors. To avoid problems, it’s necessary to use temperature-rated wire with a UV-resistant jacket. That type of wire resists degradation from solar exposure and high heat. It will still experience added resistance on the hottest days, but providing adequate spacing to increase airflow helps. Often, you can also route cabling beneath your solar panels to keep the wires shaded.
Even with smart system design choices, some energy production loss from high heat is inevitable. Our designers take those factors into account when designing systems for homes here. They can estimate peak expected losses and size up the system to compensate for them. That ensures your system meets your power needs on the hottest days. And on cooler days, it increases your net billing credits, helping your system pay for itself sooner.
Your Local Solar Power Experts
If you are considering investing in solar power in Arizona, you will want to work with an expert. Pur Solar and Electrical has served Camp Verde, AZ, homeowners since 1974. We are one of the oldest solar power installation companies in the country. We handle every aspect of each solar installation in-house. We have a talented team of designers, installers, and maintenance specialists. So, there’s nobody better to entrust for an electrical solar design in AZ. We even offer financing options on approved credit if you need help paying for a solar power installation. To learn more about meeting your electricity needs with solar power in Arizona, contact Pur Solar and Electrical now.
