Easy Guide to Understanding Residential Solar
Residential Solar Intro
Purchasing and installing a solar array can be intimidating. It is a significant investment made in a complex electrical system. However, understanding the benefits both from the community and individual perspectives can be made easier by understanding the solar industry lingo. Defining the common terminology used in regards to solar panels and how they function can ease worries and allow homeowners to begin seeing the unequivocal value of going solar. This post outlines some of these commonly used terms that homeowners often find are unfamiliar to them. These terms are the key that can unlock the language of solar, and help homeowners better understand how solar interacts with both the home and the greater community.
Key Solar Terms
- Distributed generation: Distributed generation is also referred to as on-site generation or decentralized generation. It refers to generating usable electricity on-site as compared to transmitting energy from a large, centralized facility, such as a coal-fired power plant, over the electric grid. Currently, most of the United States is powered by energy generated in centralized sources that then transmit the power over long distances. There are many downsides to this, one being that about 6% of generated power is lost during the transmission process, mostly as a result of the long distances that the power must travel. Additionally, when the grid goes down, all of those reliant on it will be without power. Solar is one of the most prominent examples of distributed generation. There are many benefits of distributed generation including increasing energy efficiency, improving grid resiliency, and decreasing pollution from carbon. Another key benefit, and perhaps the most significant, of distributed generation through rooftop solar is lessening the demand on the grid. In a centralized system, when one area or community demands above and beyond the capabilities of the local central producer, perhaps during an extreme heat event, the grid operators must turn on emergency power plants or purchase energy from elsewhere to meet demand. This can lead to skyrocketing prices, or even worse, outages. Distributed generation can help ease the burden on the grid operators, and make this problem more manageable.
- Net metering: Net metering, is a way of billing that credits the owners of solar arrays for the electricity they added to the grid. During the day when the solar array is producing energy from the sun, it will likely generate more electricity than the home uses. For homes that are net-metered, the electricity meter will run backward to provide credit for times when there is bad weather, during the nighttime, or any time when the electricity used exceeds what the system is producing. At the end of the billing period, homeowners are only billed for their “net” energy use, which can allow the bill to be $0! The process of net metering truly gives homeowners control over their energy and, most importantly, their electricity bills. In a world where electricity bills are always rising, solar energy allows homeowners to own their energy and avoid these rising costs. The process to obtain net metering varies depending on the state, city, and utility rules. These different entities can also refer to net metering as interconnection or net billing. For example, in Cincinnati, Ohio with Duke Energy, a homeowner could be receiving different credits than a homeowner just north in Columbus, Ohio with AEP. It is important to work with a knowledgeable installer who understands these differences. Homeowners prefer working with in-house, dedicated Project Managers to handle all of the net metering, making the transition to solar hassle-free.
- The Grid: Electricity that is generated at power plants arrives to consumers through a complex network commonly referred to as the grid. This complex system is made up of electricity substations, transformers, and power lines that deliver electricity to homeowners. In the United States, there are hundreds of thousands of miles of high-voltage power lines and millions of miles of low-voltage power lines that make up the electricity grid.
- Grid-tied system: This is a solar array that is still interconnected with the grid, pulling power when the home needs it and sending excess power back instead of storing it. This does not mean that backup is not available, a system can still be tied to the grid and set up to produce power during an outage with a backup system. This just means that the solar array works based on a bidirectional meter, so when the homeowner is consuming energy, their meter runs forward and when their solar array is producing energy, it runs backward. It runs backward because the solar array is creating electricity and feeding it back into the electrical meter at the home, all while the utility company credits them for it. At night, the home is being powered from the grid, but during the day when the panels are producing from the sun, excess energy is being put back into the grid and the utility company is purchasing it through Net Metering. A grid-tied system ensures that the homeowner will still have energy even during bad weather and nighttime. The best part and the beauty of solar energy is that if the home produces energy in their billing cycle to cover all the electricity they used in that cycle, then energy bills can be as low as $0!
- Photovoltaic (PV) cells: PV cells are an active system composed of small panels faced with a semiconducting material that, when hit with sunlight, generates a direct current, transforming sunlight into electricity. PV cells can be used in a wide range of climates and they can operate in every region of the United States. It is important to select an installation partner that has access to panels with high efficiency at strong warranties and does not use whatever is collecting dust in the warehouse.
- Inverter, microinverter, and optimizer: After the PV cells capture sunlight and turn it into energy, that energy gets sent to the inverter. The inverter takes the energy, which is in the form of DC energy, and changes it into AC energy. This is necessary because most homes use AC energy. So basically, the inverter changes the energy created by the PV cells into a form that can be used by homes.
- Solar PV arrays with microinverters have a small inverter installed next to each individual panel. This allows the microinverters to change the DC energy into AC energy right on the roof. Microinverters at each panel provide performance benefits, especially for complex systems.
- Power optimizers are located next to each solar panel. They “condition” the DC electricity by fixing the voltage of the electricity at which point they send it to the inverter. The main point of optimizers is that they help to improve the efficiency of the solar panel system, especially if the roof is very complicated. Optimizers are not used with microinverters.
- It is crucial to make sure before signing up with a solar installation partner that you ask questions about the design. Was this done by a NABCEP (North American Board of Certified Energy Practitioners) certified designer, or did a salesperson throw it together? Installation companies approach projects in a wide variety of ways, so it is important to pick the right one who won’t waste time with ill-prepared designs upfront. In just Ohio, for example, between Cincinnati, Columbus, and Cleveland, there are dozens of partners who can approach projects from full turn-key to delivering just a DIY kit.
An average homeowner will never become an expert on electrical systems or grid integrity. This guide is meant to help sort through the many options available to homeowners, and to help pick the right expert. Solar Is Freedom is dedicated to a no-nonsense, NABCEP certified design upfront that will save hours of guesswork and sets clear expectations from the beginning. This has resulted in hundreds of satisfied reviews. Homeowners can reach out today to see the difference.