Go Solar! Save Money! Be Green!
Sounds great right? Going solar can be a wonderful addition to a home and can mean fantastic reductions to your carbon footprint and your electric bill. But when you add solar to your home what exactly is getting added? What is this rooftop system made up of?
Today we wanted to share a little bit about the components that make up a typical solar installation. Knowledge helps you make better decisions for your home, be that purchasing a new system, expanding an existing system, or even looking to purchase a home with panels already on the rooftop.
Rooftop solar can be broken down into a few parts. There are panels, inverters, a mounting system, and optionally, battery backup.
Solar panels
There are two types of photovoltaic (PV) panels: monocrystalline solar panels and polycrystalline solar panels.
Monocrystalline solar panels, also called “single cell”, are unique because they are made from a very pure silicone. According to AlternativeEnergy.org “monocrystalline solar cells are the most efficient of all; efficiencies are documented at upwards of 20%”. The drawback to these cells is that they are expensive to produce, and that cost is forwarded to the consumer.
Polycrystalline solar cells, also known as polysilicon and multi silicon cells, were the first solar cells ever introduced to the industry in 1981. Polycrystalline cells are processed differently than monocrystalline cells. The silicone is melted and poured into a square mold. These cells are much more affordable but polycrystalline solar systems operate at a 13-16% efficiency. One other drawback of polycrystalline is that it has a lower heat tolerance than monocrystalline which means they do not perform as efficiently in high temperatures.
Check out our YouTube video for tips on what to look for when choosing the right solar panel for your home.
Inverters
Inverters convert direct current (DC) electricity generated by your solar panels into usable alternating current (AC) electricity. Given the complex power electronics and software contained within, inverters are vital to the success of your solar power system. You have three major choices on the market today.
- String inverters offer centralized DC to AC conversion, easier system maintenance, no electronics on the roof, and lower installation costs. They are known for their durability and reliability and usually have a 7-to-12-year warranty. String inverter systems only offer string-level monitoring, and if there is a production issue or outage anywhere in the string, the entire string is affected.
- Inverters + power optimizers. With centralized DC to AC conversion, the power output of each panel is optimized independently, providing both system and panel level monitoring. Future system size increases may require an additional central inverter. If any panel in the system is damaged, all panels in the system are offline.
- Microinverters are widely accepted in the industry as the most efficient and most reliable inverters. Unlike string inverters or a centralized inverter, if one panel is damaged, the rest continue to operate uninterrupted. Power output of each panel is optimized independently, and the system size can be expanded easily in the future. Microinverters typically have a 25-year warranty.
In this YouTube video we dive a little deeper into the comparison between the microinverters and the centralized inverters.
The mounting hardware
Mounting will vary depending on your roof type. Whatever mounting system is used should meet code requirements for your municipality. Railing, and clips are the most used
mounting systems. Railing requires roof penetration and must be properly sealed to prevent leaks in the future. Properly installed mounting systems do not harm your roof and a reputable installer will warranty the labor done to seal and secure the panels.
When selecting the mounting brackets make sure that your installer is installing according to your local building codes. Plans will not be approved and stamped by your municipality if they are not up to local building codes.
In some regions the mounting method must account for snow loads on your roof, and in others the local codes call for wind load calculations. You should choose an installer that has the resources to create custom structural and electrical plans to suit your roof and region. This will ensure that the building codes will be respected, and your plans will pass through the municipality with as few delays as possible.
There are several major manufacturers of components for mounting. Unirac and Ironridge are common in south Florida installations. Make sure your installer is using all components from the same manufacturer to make sure your manufacturer’s warranty is not compromised. All components should be weather resistant and colored to match your panels and roof type where possible.
Fun Fact: Standing seam metal roofs requite no penetrations! Your installer uses S-5 clamps. This is a safe, installation that is approved by some of the toughest municipalities in the nation!
Add on Battery Storage
When adding batteries to a system you must take into consideration your existing components. DO you have microinverters, string inverters, or a centralized inverter?
With so many battery options on the market it is important to understand how you would connect to your solar installation. Connections are established through A/C power coupling, or direct D/C connections. Your existing system type will determine how the connections must be made.
Once you understand your system you can determine the best solution for your home. We have always recommended an A/C couple solution over the direct D/C connection to ensure efficiency and safety. All battery systems should support monitoring software for your usage to ensure that your batteries stay charged and ready for an emergency.
We hope you find this information helpful and if you have any questions you can contact us at www.cbsolar.miami
Till the next time let the sun power your lifestyle!