Compare the total 25-year cost of solar vs staying on the grid. See exactly how much you save by going solar today.
Solar vs Grid Cost Calculator
How to Use the Solar vs Grid Cost Calculator
The Solar vs Grid Cost Calculator on Solar Estimator Pro helps you make an informed financial decision by comparing the long-term costs of staying connected to the electrical grid versus investing in a solar energy system. Follow these simple steps to get your personalized comparison:
- Enter Your Current Monthly Electric Bill: Start by inputting your average monthly electricity bill in dollars. You can find this information on any recent utility bill from your local electric company. If your bills vary seasonally, calculate an average by adding up 12 months of bills and dividing by 12.
- Enter Your Solar System Cost After Incentives: Input the total cost of your proposed solar system after accounting for all applicable incentives. This includes federal tax credits, state rebates, utility rebates, and any other financial incentives you qualify for. This number represents what you would actually pay out of pocket after all discounts and credits are applied.
- Select the Annual Electricity Rate Increase: Choose the percentage rate at which you expect utility electricity rates to increase each year. This accounts for inflation and rising energy demand. The calculator provides common options, but you can also enter a custom percentage based on your local utility’s historical rate increases.
- Choose Your Solar Coverage Percentage: Select what percentage of your current electricity bill you want solar to cover. Your options include 80%, 90%, 100%, or 110% with surplus for net metering. The 110% option is ideal if your system will generate more electricity than you use, allowing you to send excess power back to the grid for credits.
- Click Compare Solar vs Grid: Once you’ve entered all the required information, click the “Compare Solar vs Grid” button to generate your comprehensive 25-year cost comparison analysis.
How the 25-Year Comparison Works
The Solar vs Grid Cost Calculator uses a 25-year analysis period because this is the typical warranty period for most residential solar panels. During this timeframe, the calculator computes detailed financial projections for both scenarios: remaining on the grid and investing in solar energy.
Grid Cost Calculation: The calculator takes your current monthly electric bill and compounds it with the annual electricity rate increase you selected. This compounding effect is crucial because it demonstrates how utility costs grow exponentially over time rather than linearly. For example, if your current bill is $150 per month and rates increase by 3% annually, your bill in year five will be significantly higher than $150. The calculator sums all 25 years of projected grid bills to show the total you would pay if you never installed solar.
Solar Cost Calculation: Your total solar cost includes two primary components. First is the upfront system investment after incentives—the amount you entered at the beginning. Second is any remaining grid costs for the portion of your electricity bill that solar doesn’t cover. For instance, if you selected 80% solar coverage, you’ll still pay for the remaining 20% of your electricity consumption from the grid. The calculator applies the same rate increase projections to this remaining portion over 25 years and adds it to your upfront system cost.
Break-Even Analysis: One of the most valuable features of this calculator is the identification of your break-even year—the exact point in time when your cumulative savings from solar exceed the upfront investment cost. Before the break-even year, you’re investing in your system. After the break-even year, every dollar of electricity production represents pure savings. This year provides critical context for your financial decision-making.
Understanding Your Solar vs Grid Results
Once the calculator completes your analysis, you’ll receive four key metrics that paint a complete financial picture of your solar investment decision:
- Grid Cost Over 25 Years: This is the total amount of money you would pay to your electric utility company if you never installed solar and remained fully connected to the grid. This number represents your baseline scenario and includes all projected rate increases over the 25-year period. This is often the largest number in your results and demonstrates the escalating burden of electricity costs over time.
- Solar Cost Over 25 Years: This represents your total investment when choosing solar. It combines your upfront system cost (after incentives) with any remaining grid electricity charges for the portion not covered by your solar panels over the full 25 years. Even if you choose 100% solar coverage, this number may include small grid charges for backup power during cloudy days or maintenance periods.
- Your Savings with Solar Over 25 Years: This is the difference between your grid cost and your solar cost—essentially the money you keep in your pocket by choosing solar instead of staying on the grid. This figure represents your return on investment and is the primary metric for evaluating whether solar makes financial sense for your household.
- Break-Even Year: This crucial metric shows you exactly which year your solar investment pays for itself through electricity savings. Before this year, the grid is technically cheaper from a cumulative perspective. After this year, solar becomes the more economical choice. This helps you understand the payback timeline for your investment.
- Grid Bill in Year 25: This projection shows what your monthly electricity bill would be in 2049 (or 25 years from now) if you stay on the grid. This eye-opening figure demonstrates the dramatic impact of compounding rate increases and illustrates why solar becomes increasingly valuable over time. It also shows the monthly amount you would eliminate with solar.
Frequently Asked Questions
What is the average annual electricity rate increase in the United States?
The average annual electricity rate increase across the United States is approximately 2.5% to 3.5% per year, though this varies significantly by region and utility company. Some states experience rate increases exceeding 4% annually, while others average closer to 2%. Historical data shows an average increase of about 2.8% nationally. When using the calculator, you can research your specific utility company’s historical rate increases or use the national average if local data isn’t readily available. Your utility company typically publishes rate change information on their website or in annual reports.
How does net metering affect the solar vs grid comparison?
Net metering allows solar customers who generate more electricity than they use to send excess power back to the grid in exchange for bill credits. This is why the calculator offers a 110% solar coverage option. With net metering, your solar system can offset not only your daytime usage but also your nighttime and cloudy-day consumption through accumulated credits. This dramatically improves your financial results by maximizing the electricity value generated by your solar panels. However, net metering policies vary by state and utility company. Some states have reduced net metering rates, while others have eliminated the program entirely. Before selecting 110% coverage, verify that your utility company offers net metering and understand the credit rates they provide.
What happens to my savings after the 25-year solar panel warranty expires?
The 25-year warranty is merely the manufacturer’s guarantee on panel degradation and defects—it doesn’t mean your panels stop producing electricity or providing savings after 25 years. Most quality solar panels continue generating electricity at 80-90% of their original capacity well beyond 25 years. After year 25, your savings actually increase dramatically because you’ve already paid for your system, meaning nearly all electricity generation becomes pure savings with minimal additional costs. The calculator conservatively uses 25 years for comparison purposes, but your actual long-term financial benefits extend far beyond this timeframe, making solar an even more attractive long-term investment than the 25-year analysis suggests.