What Is a Solar Energy System?
SOLAR ENERGY SYSTEMS provide homeowners with the opportunity to lower utility energy costs and achieve energy independence by replacing their grid-supplied electricity with self-generated solar power. Solar plus storage systems can even provide backup during long-term outages due to weather, wildfires or line maintenance.
Smart solar systems also allow homeowners to track and monitor their energy production in real-time over the Internet. Enphase energy systems feature this capability, making it simple for homeowners to expand their system over time.
Solar Panels
The large black solar panels that you see on rooftops are made up of solar cells (or photovoltaic cells) that convert sunlight into electricity. SOLAR INVERTER Each individual cell contains silicon semiconductors that absorb and create a flow of electric current when exposed to light. These cells are then connected together into larger units called solar modules, which are then grouped into large arrays that can produce energy for homes and businesses.
Solar power is a clean and renewable resource that can help reduce our dependence on fossil fuels. In fact, the sun provides us with enough energy in one hour to meet our entire global energy needs for a year.
Using sunlight to generate energy can help with our environmental footprint and can lower your electricity bill significantly. A solar system can be connected to the grid or can be self-sufficient with a battery storage solution. Solar energy systems can also benefit communities by providing power to remote areas that may not be connected to the grid and by supplying water in regions with limited access to clean drinking water.
The efficiency of a solar panel depends on the amount of sunlight it receives. The solar irradiance available varies throughout the day and across the year, depending on your location’s latitude. On cloudy days or during the night, your solar system will produce less electricity than needed. Excess solar electricity will be sold to the power grid through a process known as net metering.
Inverters
A solar power system relies on an inverter to take the DC (direct current) from your solar panels and turn it into AC (alternating current). Inverters also increase the voltage, as needed.
Inverters create a clean, continuous sine wave that is ideal for feeding into the electric grid. This is the same type of electricity that you receive from your local municipality or most generators. The inverter also has the ability to produce reactive power, which helps balance out the electricity on the grid.
When a solar panel array is producing at its peak, the inverter must carefully manage the current to prevent “clipping” of the top of the wave. This avoids wasting energy as it gets sent to the battery storage system or the grid. Most solar panels do not produce at their maximum capacity on a regular basis, so it is better to design for the average production.
Inverters are available with built-in transformers that can handle a wide range of DC input voltages, from 6 Volts to 120 volts. For optimum performance, it is important to select a battery with the same DC voltage as your inverter, so that the current can flow both ways. Inverters can also come with battery chargers, allowing them to recharge the batteries directly over DC. Always use appropriately sized fuses and circuit breakers for your inverter and cables. An oversized fuse could result in cables exceeding their ampere capability, creating a fire hazard.
Batteries
Batteries store the electricity that solar panels generate and provide emergency backup power. They are a clean, green alternative to gas generators. Battery systems also take advantage of time-of-use pricing, allowing homeowners to prioritize their stored solar energy during peak usage times, helping reduce their utility bills.
Each battery consists of a number of voltaic cells. The half-cells are separated by and immersed in a conductive electrolyte. The electrolyte allows ions to pass between electrodes, creating the chemical reaction that produces electric current.
Over time, these cells deteriorate and lose their ability to produce sufficient electrical energy to operate devices. When the electrodes’ voltage and current drop to unacceptable levels, the electron tug-of-war between them stops. The batteries’ chemical energy converts to electrical energy at a rate that can no longer meet the load demand.
A battery’s cycle life depends on the type and quality of electrode materials, the chemistry used, and the design. Other factors include the battery’s charge and discharge efficiency, capacity, round-trip efficiency, and storage temperature range.
There are a variety of lead-acid batteries, including the flooded battery, which requires watering and ventilation; the VRLA (valve-regulated lead-acid) gel and absorbed glass Solar Inverter Manufacturer mat (AGM) batteries that have a built-in valve to regulate off-gassing; and the lithium-ion battery, which has excellent charge and discharge efficiency, high capacity, and storage longevity. When combining batteries in series, make sure they have the same voltage level to avoid a short circuit that can damage them and cause a fire.
Controls
A solar charge controller regulates how much energy the PV system charges and discharges a battery. It also controls power to the DC loads connected to the battery. Solar panels convert sunlight into electricity by absorbing electrons from the semiconductor material they are made of. The semiconductor turns these free electrons into an electric current that flows in one direction through metal contacts at the top and bottom of the panel. The panels are designed to withstand harsh weather conditions and are protected with glass and framing.
The battery is designed to hold a charge at all times so that it can supply power when the sun is not shining. The solar charge controller directs a large amount of electricity to the batteries during the day to fill them up quickly. At night, when the battery is full or close to it, the charge controller sends a small amount of power to the batteries in a trickle charge to keep them ready for use.
Concentrated solar power (CSP) systems focus the sun’s heat into a beam that can be used to generate electricity like a conventional utility-scale power plant. They use mirrors and tracking systems to follow the movement of the sun, and they can store thermal energy in oil or molten salt tanks for times when the sun is not shining. CSP requires a substantial initial investment and uses more land and water than other solar technologies, making it a costly option for utilities.