Solar Panel Energy & Savings Calculator
Estimate your potential solar energy production, electricity savings, and simple payback period with this calculator. Understand how much energy your solar system could generate and how quickly it might pay for itself.
Enter your average daily electricity consumption in kilowatt-hours (kWh). You can find this on your electricity bill.
Input the average number of peak sun hours per day for your location. This is the equivalent number of hours per day when solar irradiance averages 1,000 watts per square meter. This value varies significantly by geographic location and time of year.
Enter the desired or planned size of your solar panel system in kilowatts (kW). This is the DC rating of your panels.
This factor accounts for various losses in a real-world solar system, including inverter efficiency, wiring losses, temperature effects, shading, and dirt on panels. A common range is 70-85%.
Enter your current electricity rate per kilowatt-hour ($/kWh). This can be found on your utility bill.
Input the total estimated cost of your solar panel system, including equipment, installation, and any applicable taxes, before incentives.
Understanding Your Solar Potential
Going solar is a significant investment that can lead to substantial long-term savings and environmental benefits. This calculator helps you get a preliminary estimate of how much energy your system could produce and what your financial returns might look like.
How Solar Energy Works
Solar panels convert sunlight into direct current (DC) electricity. An inverter then converts this DC electricity into alternating current (AC) electricity, which is what your home appliances use. Any excess electricity generated can often be sent back to the grid, potentially earning you credits through net metering programs.
Key Inputs Explained:
- Average Daily Electricity Usage (kWh): This is crucial for determining how large a system you need to offset your consumption. A higher usage means you'll need a larger system to cover your needs.
- Average Daily Peak Sun Hours (hours): This is perhaps the most critical factor for energy production. It represents the intensity and duration of sunlight your panels receive. Locations with more peak sun hours will generate more electricity from the same size system. You can find this data for your specific location from resources like the National Renewable Energy Laboratory (NREL) or local solar installers.
- Solar System Size (kW): This refers to the total DC power rating of all the solar panels in your system. For example, a 6 kW system might consist of 20 panels, each rated at 300 watts (20 * 0.3 kW = 6 kW).
- System Derate Factor (%): No solar system operates at 100% efficiency due to various losses. This factor accounts for these real-world inefficiencies. It includes losses from the inverter converting DC to AC, wiring resistance, temperature effects (panels are less efficient when hot), shading, and even dust or dirt on the panels. A typical derate factor ranges from 70% to 85%.
- Current Electricity Rate ($/kWh): Your current cost of electricity directly impacts your potential savings. The higher your rate, the more you save by generating your own power.
- Total Installed System Cost ($): This is the upfront investment for your solar system. It includes the cost of panels, inverters, mounting hardware, labor for installation, permitting fees, and any other associated costs. Remember that this calculator does not account for federal, state, or local incentives, which can significantly reduce your net cost.
Understanding the Outputs:
- Estimated Daily/Annual Solar Production: This tells you how much electricity your system is expected to generate on a daily and annual basis. This is a direct measure of your system's energy output.
- Estimated Annual Electricity Savings: This is the financial benefit you could expect each year by generating your own electricity instead of buying it from the utility company.
- Percentage of Daily Usage Offset: This indicates what portion of your daily electricity needs your solar system is projected to cover. A 100% offset means your system is designed to produce as much electricity as you consume.
- Simple Payback Period: This is the number of years it would take for your accumulated annual savings to equal the initial cost of your solar system. It's a basic measure of financial return, not accounting for the time value of money or system degradation over time.
This calculator provides estimates and should be used for informational purposes only. For precise figures and a detailed assessment, it's always best to consult with a professional solar installer who can evaluate your specific property, energy needs, and local regulations.