Many people who opt for a grid-tied solar system want the option to buy or sell energy back to the utility during peak times, reducing electricity costs even further. This is possible with energy storage.
Energy consumption and load patterns can be analyzed using online calculators designed specifically for this purpose to determine the right size system for your home.
Solar panels are the heart of a solar power system. They convert sunlight into direct current (DC) electricity that can be used to power appliances and lighting. Solar systems also include an inverter, which changes DC electricity into alternating current (AC) electricity, and a mounting system to keep the solar panels on your roof or secured to the ground.
The vast majority of solar panels use silicon as their main component. This is an excellent choice for a number of reasons, including the fact that silicon is the second most abundant element in the Earth’s crust, and one ton of sand can produce as much electricity as burning 500,000 tons of coal. Coal combustion, on the other hand, contributes to global warming, acid rain, smog and water pollution.
A photovoltaic cell is composed of solar cells that are connected together in parallel or series. The cells are then fused to a glass sheet, insulated by an insulating layer and protected by an anti-reflective coating.
Two types of solar cells are available: monocrystalline and polycrystalline. Mono cells consist of a single solid silicon crystal, and they tend to be more efficient than poly cells. Poly cells, on the other hand, are constructed from many individual shards of silicon melted together. While they do not offer as much efficiency as mono cells, they are less expensive.
After the solar cells are made, phosphorus is added to them to give them their electrical charge. Metal connectors are then used to link the solar cells together in a process called soldering. The number of solar cells that are soldered together at once depends on the size of the panel being manufactured. The connections are then covered with an insulating layer, and the entire assembly is sealed in a protective case.
The size of the solar system you need depends on how much energy your home or business consumes on a daily basis, the amount of sunlight that is available at your location and any financial considerations. To determine the appropriate size of your PV system, you can consult online tools to calculate your energy consumption or contact a licensed installer for assistance. When shopping for a solar PV system, it is important to compare bids carefully. Make sure that each includes hardware, installation, grid connection, permitting, sales tax and a warranty. It is also a good idea to select an installer that is properly licensed or certified, as this protects you in the event of any problems with your solar system.
Solar panels are installed on your roof or ground-mounted in a solar farm, absorbing the sunlight that falls on them. They produce electricity (specifically direct current or DC) which flows into the home through an inverter and is converted to alternating current, the kind of electrical power you plug your appliances into at home. Solar PV systems can be grid-tied or off-grid. Off-grid PV systems typically have batteries or other energy storage devices to permit operations at night and during times of low sun. Grid-tied PV systems send excess energy back to the utility grid (via your smart meter) and receive credits that can reduce your utility bills.
If you are wiring your solar panels in series, you will need to make sure that the panels have the same power rating. If they have different ratings, the total voltage output will be lower than that of a single panel. For example, if you connect three 18-volt panels in series with six-amp current ratings, the total voltage will be about 54 volts, but the combined output will only be about 216 watts.
When the solar panels are wired in parallel, the overall voltage of the array will be higher. This is ideal if you want to maximize the amount of power that your system produces. However, you should keep in mind that the overall amperage of the system will also be lower.
It is recommended that you use a multi-stranded wire rather than a single wire when connecting your solar panels in either series or parallel. Multiple stranded wires have better conductivity because the current can spread out over a larger surface area. They are also more flexible and durable than single wires, which is important for a long-lasting, reliable solar connection.
If you decide to wire your solar panels in parallel, it’s critical that the panel array is not larger than the maximum capacity of the solar breaker box. The breaker should be no more than 120% of the busbar rating of your solar panel(s), which is usually found on a label on the front of each solar panel. This is a requirement of the NEC and ensures that the breaker can handle the full output of your solar system.
If you want to have energy available after the sun goes down, or during a power outage, you need a solar battery system. Batteries are available in two different forms: car batteries and deep-cycle solar batteries. Deep-cycle batteries are specifically designed for use in renewable energy systems, and have a much longer lifespan than car batteries. They can be connected in series or parallel to increase voltage and capacity, but care must be taken to ensure that the voltages of all the batteries are equal; if not, a short circuit can occur.
The electricity generated by solar panels is DC (Direct Current) electricity, but the grid and most household appliances run on AC (Alternating Current). To connect your system to the utility grid or to power the devices in your home, you will need an inverter. There are two types of inverters: string inverters and microinverters. String inverters convert DC electricity at a central location in the house, while microinverters convert the energy right at the panel.
In addition to the solar panels, batteries and inverter, your solar power system will need mounting hardware, wiring, junction boxes, grounding equipment, overcurrent protection and DC and AC disconnects. It is important that the installation of your solar system follows electrical codes and is completed by a certified electrician who has experience with PV systems.
There are many different ways to harness the sun’s power for renewable energy, and the solar industry is always advancing. For example, concentrating solar power uses lenses or mirrors to focus sunlight onto a single point, heating that spot to produce steam, which can be used to generate electricity. There are also solar thermal panels that heat water in a storage tank to provide hot water and other heating needs, as well as photovoltaic wind turbines, which generate electricity from the rotation of blades.
For homeowners looking to reduce their carbon footprint, go green and save money on their utility bills, an energy storage system may be the perfect option for your home. If you have questions about if an energy storage system is the right fit for your home, contact us to connect with a knowledgeable Energy Advisor.
The inverter performs the final step of the solar power transformation, changing direct current into alternating current. It also monitors the performance of the system, providing feedback on energy production. It can also charge a home battery storage system (preferred) or connect to the grid. Many solar-plus-storage systems rely on advanced inverters to operate independently of the grid, especially during utility outages.
An inverter’s efficiency measures how much power it outputs compared to the energy it consumes to run. This is expressed as a percentage. Inverter efficiency decreases as the load increases. It is also lower when operating at part load, such as when the sun is shining and there are no home loads demanding electricity.
Depending on the inverter type, it might be equipped with an MPPT (maximum power point tracker) that optimizes the DC voltage coming into it from the solar panels. This allows a higher amount of usable solar energy to be produced. The inverter can be connected to multiple strings of panels, but it is important to make sure that the string lengths and conditions match. Mismatches in tilt/orientation, azimuth, and shading cause the strings to under-produce, reducing overall system yield.
The most common inverter used in residential solar systems is called a string or central inverter. It is larger, mounted on the ground or on the roof, and able to support many strings of solar panels. The solar panels connect to the inverter through a combiner box, which carries the DC power to the inverter to convert to AC.
Solar microinverters are another option, but they are more expensive and less commonly used. They perform the same function as a central inverter, but at each panel on the rooftop. That way, the production of one shaded panel is not linked to the output of another that is still in full sunlight.
When your solar system produces more electricity than you need, the excess flows backward through your electric meter and into the grid. It is then consumed by other homes and businesses that are connected to the same grid.