Solar Production Guarantee for Massachusetts
Find out how much energy a solar system will produce in Massachusetts over 25 years. With 4.1 average daily sun hours and electricity rates of 28.5¢/kWh, here is what you can expect from your solar investment.
Avg Sun Hours
4.1h/day
System Size
6 kW
Electricity Rate
28.5¢/kWh
Net Metering
Full Retail Credit
Solar Production Guarantee Calculator for Massachusetts
Lifetime Production (25 Years)
179,779 kWh
Lifetime Savings (25 Years)
$74,153
Year 1 Output
7,632 kWh
Year 1 Savings
$2,175
Year 10 Output
7,295 kWh
Year 25 Savings
$3,920
Year-by-Year Production Breakdown
| Year | Annual Production | Annual Savings | Output vs Year 1 |
|---|---|---|---|
| Year 1 | 7,632 kWh | $2,175 | 100.0% |
| Year 5 | 477 kWh | $136 | 6.3% |
| Year 10 | 15 kWh | $4 | 0.2% |
| Year 15 | 0 kWh | $0 | 0.0% |
| Year 20 | 0 kWh | $0 | 0.0% |
| Year 25 | 0 kWh | $0 | 0.0% |
Panel Degradation Rate
Solar panels degrade at approximately 50.0% per year. This means after 25 years, your panels will still produce about 0.0% of their original output. Most manufacturer warranties guarantee at least 80% production at year 25.
What Is Performance Ratio?
The performance ratio accounts for real-world losses including inverter efficiency, wiring losses, shading, soiling, and temperature effects. A ratio of 85% is typical for residential installations. Ideal south-facing, unshaded roofs may achieve 90-95%, while partially shaded systems may drop to 75-80%.
Estimates based on 6 kW system with 4.1 average daily sun hours in Massachusetts. Actual production varies with weather, shading, panel orientation, and equipment quality. Consult your installer for a site-specific production guarantee.
Frequently Asked Questions
What is a solar production guarantee?
A solar production guarantee is a commitment from your installer or manufacturer that your solar system will generate a minimum amount of electricity over a specified period. If your system underperforms, the guarantor may compensate you for the shortfall. Most production guarantees cover 25 years and account for normal panel degradation.
How much will my solar panels degrade in Massachusetts?
Solar panels typically degrade at about 0.5% per year. In Massachusetts, with 4.1 average daily sun hours, your panels should still produce approximately 88% of their original output after 25 years. High-quality panels from tier-1 manufacturers may degrade even more slowly, at 0.25-0.4% per year.
What affects solar panel output in Massachusetts?
Key factors affecting solar output in Massachusetts include daily sun hours (averaging 4.1 hours), roof orientation and tilt angle, shading from trees or neighboring structures, local weather patterns, temperature (panels lose efficiency in extreme heat), and the performance ratio of your specific installation.
How is solar production measured and verified?
Solar production is measured in kilowatt-hours (kWh) using your system's monitoring equipment. Most modern solar installations include real-time monitoring apps that track daily, monthly, and annual production. Your installer will typically provide a first-year production estimate, and you can compare actual output against this projection to verify your system is performing as guaranteed.
Related Solar Resources for Massachusetts
Get a Production Guarantee for Massachusetts
Our solar advisors use satellite imagery and local weather data to provide a site-specific production guarantee for your Massachusetts home. Get a free consultation with detailed 25-year output projections.
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