Solar Array Performance & Cost Estimator
Use this calculator to estimate the potential energy production, system size, and cost of a solar panel array based on your specific inputs. Understand how many panels you might need, how much energy they could generate, and the potential savings on your electricity bill.
This is the average number of hours per day that your location receives direct sunlight equivalent to 1000 W/m². You can find this data for your specific location online (e.g., PVWatts calculator).
The peak power output of a single solar panel under standard test conditions (STC). Common panels range from 300Wp to 500Wp.
The total number of solar panels you plan to install in your array.
Accounts for real-world losses due to temperature, shading, dust, wiring, inverter efficiency, etc. Typically ranges from 75% to 85% (enter 80 for 80%).
Your average daily electricity usage. You can find this on your electricity bill by dividing your monthly kWh by the number of days in the billing cycle.
The average cost to install solar per watt of peak power. This includes panels, inverter, mounting, labor, and permits. Varies by region and system size.
The price you pay for electricity from your utility company, including all charges. Found on your electricity bill.
Understanding Your Solar Array Calculations
A solar array calculator helps you project the performance and financial aspects of a photovoltaic (PV) system. By inputting key variables, you can get a realistic estimate of how much energy your system will produce, its approximate cost, and the potential impact on your electricity bills.
Key Input Factors Explained:
- Average Daily Peak Sun Hours: This isn't just the number of hours the sun is visible. It's a measure of the intensity of sunlight, averaged over a day, that is equivalent to full sun (1000 watts per square meter). Locations closer to the equator or with less cloud cover generally have higher peak sun hours. This is a critical factor in determining energy production.
- Individual Solar Panel Wattage (Wp): This is the rated power output of a single panel under ideal laboratory conditions. Higher wattage panels can produce more electricity per panel, potentially reducing the number of panels needed for a given energy target.
- Number of Solar Panels: The total count of panels in your proposed system. This directly influences the total peak power of your array.
- System Derating Factor: Solar panels rarely operate at their peak rated power in real-world conditions. This factor accounts for various losses, including temperature effects (panels produce less power when hot), dust and dirt accumulation, shading, wiring losses, and inverter efficiency. A typical derating factor is between 75% and 85%.
- Average Daily Household Energy Consumption (kWh/day): Knowing your daily energy usage is essential to determine if your proposed solar array will meet your needs. Your electricity bill is the best source for this information.
- Estimated Installation Cost per Watt ($/Wp): This is a common metric for estimating the total cost of a solar system. It includes the cost of panels, inverters, mounting hardware, labor, permits, and other soft costs. Prices vary significantly based on location, system size, and installer.
- Current Electricity Price ($/kWh): Your current utility rate is crucial for calculating potential financial savings. This rate can vary based on time of day (time-of-use rates) or consumption tiers, so using an average blended rate from your bill is often best for initial estimates.
Interpreting Your Results:
- Total Array Peak Power (kWp): This is the sum of the peak power of all your panels. It represents the maximum power your system can generate under ideal conditions.
- Estimated Daily Energy Production (kWh/day): This is the most important output for understanding how much electricity your system will actually generate on an average day, taking into account all the real-world factors.
- Estimated Annual Energy Production (kWh/year): Simply the daily production multiplied by 365 days, giving you a yearly estimate of your system's output.
- Percentage of Energy Needs Met (%): This tells you what proportion of your average daily electricity consumption your solar array is expected to cover. A value of 100% means your system is designed to produce as much as you consume on average.
- Estimated System Installation Cost ($): A rough estimate of the total upfront cost for your solar system, based on the cost per watt. Remember this is an estimate and actual quotes will vary.
- Estimated Annual Electricity Savings ($/year): This is the projected monetary value of the electricity your system produces, based on your current electricity price. This figure helps you understand the financial benefit of going solar.
This calculator provides a valuable starting point for your solar journey. For precise figures and a detailed proposal, it's always recommended to consult with professional solar installers who can assess your specific site conditions and energy needs.