Grid-Tied Solar System Calculator

Enter your **Monthly Electricity Usage**, **Electricity Rate**, **Available Roof Space**, and a few panel specs like **Solar Panel Wattage** and **System Efficiency** to find your **Recommended System Size** — plus how many panels you'll need, your **Annual Energy Production**, and exactly how much you could shave off your electricity bill with **Estimated Annual Savings**.

kWh

Average monthly kWh from your electric bill

$/kWh

Rate you pay per kWh in dollars

sq ft

Solar-efficient roof area facing south

hours/day

Average daily peak sun hours for your location

%

Overall system efficiency including inverter losses

Results

Recommended System Size

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Number of Panels

--

Annual Energy Production

--

Annual Energy Offset

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Estimated Annual Savings

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Roof Space Utilization

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Energy Production vs Usage

Frequently Asked Questions

How accurate is this grid-tied solar calculator?

This calculator provides estimates based on typical system parameters. Actual results may vary based on shading, roof orientation, local weather patterns, and specific equipment used. For precise calculations, consult with a solar installer.

What is the average peak sun hour range in my area?

Peak sun hours vary by geographic location, typically ranging from 3-7 hours per day. Southern states generally receive 5-7 peak sun hours, while northern states receive 3-5 hours. Check solar irradiance maps for your specific location.

How much roof space do I need for a solar system?

Typically, you need about 100-200 square feet of roof space per kW of solar capacity. A standard residential system (5-10 kW) requires 500-2000 square feet of unshaded, south-facing roof area.

What factors affect grid-tied solar system efficiency?

System efficiency depends on panel quality, inverter efficiency, shading, temperature, roof angle, and maintenance. Modern systems typically achieve 80-90% overall efficiency when accounting for all losses.

Can a grid-tied system completely eliminate my electric bill?

Yes, if your system produces enough energy to offset your usage. However, you'll still pay connection fees and may have seasonal variations. Net metering policies vary by utility company and location.

What happens to excess solar energy in a grid-tied system?

Excess energy is fed back into the grid through net metering. You receive credits for this energy, which can offset future electricity usage when your panels aren't producing enough power.

How long do grid-tied solar systems last?

Solar panels typically come with 25-year warranties and can last 30+ years. Inverters usually last 10-15 years. Most systems pay for themselves in 6-10 years through energy savings.

Do I need batteries with a grid-tied solar system?

No, grid-tied systems don't require batteries. The electrical grid acts as your storage system. However, adding batteries provides backup power during outages but increases system cost and complexity.

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