One of the fundamental components of a solar energy system is the solar panel array. If you are considering harnessing solar power for your home or business, understanding what a solar panel array is can help you make an informed decision. What is a Solar Panel Array? Essentially, a solar panel array is a collection of multiple solar panels that work together to capture sunlight and convert it into electrical energy.
It can be thought of as a “team” of solar panels, synergizing to produce more energy than a single panel could alone. Solar panel arrays come in various sizes, ranging from small installations on residential rooftops (with about 10 to 30 solar panels, generating 3 to 10 kilowatts (kW) of power) to large installations in solar power plants (which may consist of thousands to hundreds of thousands of panels, generating 1 megawatt (MW) to hundreds of megawatts (MW) of power). The arrangement of solar panel arrays is designed to maximize sunlight utilization. These arrays can be fixed in place or equipped with tracking systems that adjust their position throughout the day to follow the sun’s path, thereby increasing efficiency. Electrical Characteristics of Solar Panel Arrays There are several key electrical characteristics that determine the performance and efficiency of solar panel arrays. Voltage (V): The voltage of a solar panel array depends on the number of panels connected in series. Each individual panel has a rated voltage (typically between 18-40 volts), and when panels are connected in series, their voltages add up. Array Voltage: The total voltage of the array is the sum of the voltages of all series-connected panels. For example, if each panel has a voltage of 30V and there are 10 series-connected panels, the array voltage is 300V. Current (I): The capacity of a solar panel array depends on the number of panels connected in parallel. Each panel has a rated current (typically between 5-10 amperes). When solar panels are connected in parallel, their currents add up while the voltage remains constant. Array Current: For instance, if each panel has a current of 5 amperes and there are 5 panels connected in parallel, the total current is 25 amperes. Power (W): The output power of a solar panel array is the product of the array voltage and current (P = V x I). The unit is watts (W) or kilowatts (kW). Array Power: Under optimal conditions, each solar panel can generate 250W to 400W of power.Therefore, an array consisting of 20 solar panels, each capable of generating 300W of power, can generate approximately 6,000W (or 6kW) of power.
Each solar panel and solar cell array has a specific point called the maximum power point (MPP), which is the combination of voltage and current at which the panel or array generates maximum power. MPP changes according to sunlight intensity and temperature. Maximum power voltage (Vmp): The voltage at which the array generates maximum power. Maximum power current (Imp): The current at which the array generates maximum power. Open-circuit voltage (Voc): This open-circuit voltage is the voltage across the array when no load is connected, meaning the circuit is open and no current flows. The total open-circuit voltage of the array will be the sum of the voltages of all panels connected in series. Short-circuit current (Isc): This short-circuit current is the current flowing when the array output is short-circuited (i.e., no load and current flows freely). The maximum short-circuit current of an ISC solar cell array is the sum of the short-circuit currents of all parallel solar panels. It represents the maximum current that a solar cell array can generate under ideal sunlight conditions. Temperature coefficient: Solar panels have a temperature coefficient that describes how the performance of a solar cell array changes with temperature. Generally, as temperature rises, the efficiency of solar panels decreases. For example, if the temperature coefficient of a panel is -0.4%/°C, the power output will decrease by 0.4% for every degree increase in temperature. Maximum system voltage: This maximum system voltage is the highest voltage that the system (including the array and inverter) can safely handle. This is an important characteristic to ensure the safety and correct design of a solar energy system. Connecting solar cell arrays: Series and parallel configurations There are mainly two configurations: series and parallel. Each configuration has its own advantages and impacts on voltage and current output. 1. Series connection: In a series configuration, solar panels are connected one after another. This means that the positive terminal of one panel is connected to the negative terminal of the next panel. The main feature of this setting is that the voltages of the panels add up while the current remains constant. For example, if you connect three 300-watt panels in series and the voltage output of each panel is 36 volts, the total voltage will be 108 volts (36V + 36V + 36V). This higher voltage is beneficial for reducing losses over long distances. 2. Parallel connection: In a parallel configuration, the positive terminals of all panels are connected together and the negative terminals are also connected together.In this configuration, the current of each panel adds up while the voltage remains constant. For instance, when connecting three 300-watt panels, each with a voltage of 36 volts, the total voltage remains at 36 volts, but the current will triple, assuming each panel produces 8 amperes. This setup is ideal if you wish to increase the total current output without increasing the voltage. Calculating the voltage of a solar panel array: To calculate the voltage of a solar panel array, simply apply the connection method of your choice: For series: Total Voltage = Voltage of Panel 1 + Voltage of Panel 2 + Voltage of Panel 3 + … For parallel: Total Voltage = Voltage of any single panel (as it remains constant). Solar panel array dimensions: Residential-scale and utility-scale solar panel arrays have different sizes and configurations, primarily divided into residential systems and utility-scale systems. Residential solar panel arrays: Residential solar panel arrays are designed for home installation. Their capacity typically ranges from 3 kilowatts to 10 kilowatts. System capacity: A common size for residential setups is around 5 kilowatts, which can meet the electricity needs of an average household. Number of panels: Given that most solar panels generate between 250 and 400 watts, a 5-kilowatt system would require approximately 15 to 20 panels. Utility-scale solar panel arrays: Utility-grade solar panel arrays are larger in scale and designed to power the electrical grid. These systems range in capacity from several hundred kilowatts to several megawatts (MW). System capacity: A typical utility-scale project has a capacity of 1 megawatt, sufficient to power hundreds of homes. Number of panels: To achieve a power output of 1 MW, depending on the wattage of solar panels, approximately 2,500 to 4,000 solar panels are needed. For example, using 400-watt solar panels, about 2,500 panels would be required. Residential battery arrays are suitable for individual homes, while utility-scale battery arrays can provide electricity on a larger scale, making a significant contribution to the power grid. Where can solar panels be installed? Roofs are the most common option. Homes and businesses with suitable roof space can easily install solar panels. Even flat roofs are viable, as long as the installation brackets allow the solar panels to be tilted, thus better capturing sunlight. If roof space is limited, ground-mounted systems are a great alternative.
These are highly suitable for large open areas such as courtyards or farms. Some even combine solar energy with agriculture, known as agrivoltaics, where solar panels are placed above crops or pastures. Another option is solar carports. They provide shade for parked vehicles and generate electricity. They are often found in commercial parking lots or public spaces. Solar pergolas are similar, but they are placed above walkways or open spaces.
They can be considered as energy-generating shade structures, usually located in parks or campuses. For large-scale power generation, solar farms utilize vast land areas to produce a significant amount of electricity, typically situated in remote areas with abundant sunlight. For more mobile setups, solar panels for boats or RVs provide energy while on the move, especially in remote areas. Below is a summary of the typical costs involved in residential solar installations. Name Estimated Cost Solar Panels (15-20 pieces) $3,000 – $10,000 Inverter $1,000 – $3,000 Installation Hardware $500 – $1,500 Electrical Components $300 – $800 Installation Labor $1,000 – $3,000 Permits and Fees $100 – $500 Estimated Total Cost $6,000 – $20,000 Solar Panels: Generally, more efficient solar panels cost more but provide greater energy output. Inverters: The type of inverter you choose—string, micro-inverters, or power optimizers—affects the overall cost. Installation Hardware: This includes racks and brackets used to secure the panels to the roof or ground. Electrical Components: This includes wiring, connectors, and any other necessary components required for the electrical system. Installation Labor: Labor costs can vary significantly depending on the complexity of the installation and local contractor rates. It is recommended to obtain multiple solar quotes to ensure fair pricing. Permits and Fees: These costs are usually minimal but may vary due to local regulations. Can solar panels be added to an existing array? Yes, more solar panels can be added to an existing solar array. Before adding panels, you need to ensure they match the voltage and current ratings of the current panels. If the number of panels you add exceeds what the inverter can handle, it will need to be upgraded to avoid overload. Planning Your Solar Panel Array 1. Assess Your Energy Needs: Reviewing your utility bills will help you determine how much electricity you need, which will guide the size of your solar panels.2. Site Assessment: Identify areas with minimal shading, optimal sunlight exposure, and sufficient space to accommodate the required number of panels.
3. Determine System Type: Decide whether you want a grid-tied system, connected to the utility grid, or an off-grid system that relies entirely on solar power. This choice will affect the components you need, such as batteries and inverters.
4. Select High-Quality Components: Look for well-known brands with good warranty and efficiency ratings. At Hilden, we offer a range of high-quality solar panels and inverters designed to meet various energy needs. Our team is dedicated to helping you find the perfect components for your solar array, and we provide free consultation to guide you through the planning process.