New Hampshire Solar Savings Calculator: 2026 Updated

New Hampshire Solar Savings Calculator

Calculate New Hampshire solar costs, 2026 federal tax-credit status, statewide net metering, high retail rates, payback period, and 25-year savings.

New Hampshire 2026 rules: No state income tax means no state solar tax credit. The federal Section 25D credit ended for systems placed in service after December 31, 2025. New Hampshire mandates retail-rate net metering for all utilities with monthly rollover and annual true-up. The state has no sales tax. Property tax treatment of solar is a local option adopted by some municipalities.

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Estimates only. Verify utility rates, net metering true-up terms, municipal property tax options, and federal tax status with your utility, installer, and tax professional.

What Is the New Hampshire Solar Savings Calculator?

The New Hampshire Solar Savings Calculator estimates the upfront cost, annual electricity benefits, payback period, and 25-year net savings of a residential solar system. It uses your electricity expenses, proposed system size, installation price, export credit rate, and other financial assumptions to project solar production and determine when accumulated savings may recover the initial cost.

The calculator is designed for homeowners comparing solar installation costs or exploring how electricity prices and utility compensation affect potential savings.

Its model estimates first-year solar production using 1,150 kilowatt-hours (kWh) per kilowatt (kW) of installed capacity. It assumes production declines by 0.5% each year and evaluates financial benefits over a 25-year period.

The calculator also includes editable fields for federal and New Hampshire state credits, upfront rebates, and annual property tax savings. These fields change the estimate mathematically but do not determine eligibility for any particular program.

How the New Hampshire Solar Savings Calculation Works

The calculator combines installation expenses, modeled electricity production, electricity rates, and annual adjustments. The following formulas explain its main calculations.

1. Calculate the Gross Solar System Cost

The gross installation cost is based on the proposed system capacity and the entered installed price per watt.

C_{\text{gross}}=S\times1000\times W

In this formula, C represents the gross cost in dollars, S represents system size in kilowatts, and W represents installed cost per watt. The multiplier of 1,000 converts kilowatts into watts.

For example, an 8 kW system installed at $3.30 per watt has a gross installation cost of:

8\times1000\times3.30=\$26,400

2. Calculate the Net Installation Cost

The calculator subtracts entered federal credits, state credits, and upfront rebates from the gross cost.

C_{\text{net}}=\max\left(0,C_{\text{gross}}-C_{\text{gross}}\frac{F}{100}-C_{\text{gross}}\frac{T}{100}-R\right)

Here, F is the federal credit percentage, T is the state credit percentage, and R is the upfront rebate amount in dollars. Both percentage credits are calculated from the original gross cost.

The formula also prevents the net installation cost from falling below $0, even if the entered deductions exceed the gross cost.

3. Estimate Household Electricity Usage

The calculator estimates annual household electricity consumption from the monthly electric bill and retail electricity rate.

U=\frac{B\times12}{r}

Where U is estimated annual electricity consumption in kWh, B is the monthly electric bill in dollars, and r is the electricity rate in dollars per kWh.

Because the calculation divides by the electricity rate, a positive rate is needed for a meaningful estimate.

4. Estimate Solar Electricity Production

First-year solar production uses a fixed estimate of 1,150 kWh per kW of installed capacity.

P_1=S\times1150

An 8 kW solar system therefore has an estimated first-year production of 9,200 kWh.

The model then reduces electricity production by 0.5% annually.

P_y=1150S(1-0.005)^{y-1}

Here, P represents solar production in kWh, S represents system capacity in kW, and y is the operating year, from 1 through 25.

5. Calculate Self-Used and Exported Solar Electricity

The calculator divides annual solar production among 12 months using fixed seasonal percentages. From January through December, the percentages are 1%, 2%, 4%, 8%, 15%, 19%, 19%, 15%, 8%, 4%, 2%, and 3%.

For each month, self-used electricity is the smaller of the selected self-consumption share and one-twelfth of estimated annual household electricity usage.

H_{y,m}=\min\left(\frac{P_{y,m}h}{100},\frac{U}{12}\right)

In this formula, H is monthly self-used electricity, P is monthly solar production, h is the entered self-consumption percentage, U is estimated annual household usage, and m represents the month.

Remaining solar electricity is counted as exported electricity:

X_{y,m}=\max(0,P_{y,m}-H_{y,m})

The calculator values electricity used at home at the entered retail electricity rate. Electricity exported to the grid receives the separately entered export credit rate.

6. Calculate Annual Solar Savings

Annual modeled savings combine the value of self-used and exported electricity, subtract recurring solar utility fees, and add entered annual property tax savings.

N_y=H_y r_y+X_y e_y-A+Q

Where:

N is the calculated net financial benefit for the year.
H is total self-used solar electricity in kWh.
X is total exported solar electricity in kWh.
r is the retail electricity rate for that year.
e is the export credit rate for that year.
A is the entered annual utility solar fee.
Q is the entered annual property tax savings.

The calculator increases both retail and export credit rates each year using the entered Annual Utility Rate Increase percentage.

r_y=r_1\left(1+\frac{g}{100}\right)^{y-1}

e_y=e_1\left(1+\frac{g}{100}\right)^{y-1}

Here, g is the entered annual rate increase percentage. Annual solar fees and property tax savings stay fixed at their entered dollar amounts.

7. Calculate Payback and 25-Year Net Savings

The calculator adds annual modeled financial benefits over 25 years, then subtracts the net installation cost.

\text{25-Year Net Savings}=\sum_{y=1}^{25}N_y-C_{\text{net}}

The payback period is the first whole year when accumulated financial benefits reach or exceed the net system cost.

If the net installation cost is $0, the calculator displays Immediate. If the modeled savings do not recover the cost during the 25-year period, it displays 25+ Years.

New Hampshire Solar Savings Calculation Example

Consider a hypothetical homeowner using the calculator’s default values.

Calculator Input	Example Value
Monthly Electric Bill	$165
Electricity Rate	$0.270/kWh
System Size	8 kW
Installed Cost per Watt	$3.30
Export Credit	$0.270/kWh
Daytime Self-Consumption	30%
Annual Utility Rate Increase	4%
Annual Utility Solar Fees	$0
Federal Credit	0%
New Hampshire State Credit	0%
Upfront Rebates	$0
Annual Property Tax Savings	$0

Step 1: Calculate the installation cost. An 8 kW system at $3.30 per watt costs $26,400. With no entered credits or rebates, the net cost is also $26,400.

Step 2: Estimate annual household electricity usage.

\frac{165\times12}{0.270}\approx7333.33\text{ kWh}

Step 3: Estimate first-year solar production.

8\times1150=9200\text{ kWh}

Step 4: Calculate first-year self-used and exported solar electricity. With 30% self-consumption, the model assigns 2,760 kWh to household use and 6,440 kWh to electricity exports.

Step 5: Calculate first-year financial benefits. Both self-used and exported electricity have an entered value of $0.270/kWh, with no annual fees or property tax savings.

(2760\times0.270)+(6440\times0.270)=\$2484

Step 6: Project the following 24 years with 4% annual rate growth and 0.5% annual production decline. The calculator sums those yearly benefits and subtracts $26,400 in installation cost.

The calculated results are:

Calculated Result	Estimated Value
Gross System Cost	$26,400
Net Installation Cost	$26,400
Year 1 Production	9,200 kWh
Annual Electricity Usage	7,333 kWh
Calculated First-Year Financial Benefit	$2,484
Payback Period	10 Years
25-Year Net Savings	$70,094
Solar Offset	125%
25-Year CO2 Offset	97.5 tons

The first-year financial benefit in this example is calculated from the underlying model. It is not taken from the interface’s Net Year 1 Savings row, which has a display-label limitation explained below.

These results illustrate the calculator’s assumptions, not guaranteed financial outcomes. Actual system production, utility rates, compensation terms, and installation costs may differ.

How to Use the New Hampshire Solar Savings Calculator

Enter your Monthly Electric Bill. Provide your monthly electricity expense in dollars. The default is $165.
Enter your Electricity Rate. Use the electricity price in dollars per kWh. The default is $0.270/kWh.
Set the System Size. Enter the proposed solar capacity in kW. The default is 8 kW.
Enter Installed Cost per Watt. Provide the proposed installation price per watt. The default is $3.30.
Select your Utility. Choose Eversource NH, Unitil, NHEC (Cooperative), or Municipal or Other.
Enter Export Credit and Daytime Self-Consumption. Specify the export credit in dollars per kWh and the percentage of solar electricity used at home.
Adjust Annual Utility Rate Increase and Solar Fees. Enter the assumed annual electricity rate increase and recurring yearly solar fees.
Review the Battery Storage Checkbox. The checkbox is available, but selecting it does not automatically change system costs, production, self-consumption, or financial results.
Enter applicable incentives. Adjust Direct Federal Credit, New Hampshire State Credit, Upfront Rebates, and annual Property Tax Savings using values you want to include.
Click Calculate Savings. Review the estimated costs, payback period, 25-year net savings, and production results. Use Reset to restore the default inputs and hide the current results.

The monthly bill, electricity rate, system size, and installation cost fields are required. Numeric fields have nonnegative minimum values. Self-consumption and credit percentages range from 0% to 100%, while the annual utility rate increase field ranges from 0% to 50%.

Use a positive electricity rate and keep the other numeric fields filled in. The calculation does not contain a separate safeguard against division by zero or blank optional numeric inputs.

Financial results are displayed in whole U.S. dollars. Energy quantities appear in whole kWh, system size to one decimal place, solar offset as a rounded percentage, and the CO2 offset to one decimal place.

Understanding Your New Hampshire Solar Savings Results

Installation Cost, Payback, and Long-Term Savings

Gross System Cost represents the estimated installation price before incentives. Net Cost represents the remaining amount after entered federal credits, state credits, and upfront rebates.

Payback Period identifies the first whole year when cumulative modeled financial benefits recover the net installation cost. A progress meter compares this period with the 25-year projection.

25-Year Net Savings subtracts the initial net system cost from accumulated modeled financial benefits. A positive result indicates that estimated benefits exceed the installation cost. A negative result means estimated benefits remain below that cost during the projection.

Solar Offset and CO2 Offset

Solar Offset compares first-year solar production with estimated annual household electricity usage.

\text{Solar Offset (\%)}=\frac{\text{Year 1 Solar Production}}{\text{Annual Electricity Usage}}\times100

This percentage can exceed 100% if modeled annual solar production is greater than household electricity consumption. The default example produces approximately 125%.

A solar offset above 100% does not necessarily mean the household will have no electricity charges. Utility fees, export compensation, and differences between electricity production and consumption can affect actual bills.

If estimated annual electricity usage is zero or less, the calculator sets Solar Offset to 0% rather than using that value as the denominator.

The calculator also estimates a 25-year CO2 offset from cumulative solar production using a fixed conversion factor of 0.45 tons per 1,000 kWh.

\text{25-Year CO2 Offset}=\frac{\text{Total 25-Year Solar Production}}{1000}\times0.45

This is a simplified production-based estimate, not a location-specific measurement of actual emissions avoided.

New Hampshire Net Metering and Export Credits

Net metering describes how utilities account for electricity generated by solar panels and sent to the grid.

The calculator’s 2026 informational notes describe statewide retail-rate net metering, monthly rollover of export credits, and annual settlement under utility commission rules. Its utility options include Eversource NH, Unitil, NHEC, and municipal or other utilities.

However, the implemented financial calculation does not separately model monthly rollover or annual credit settlement. It applies the user-entered Export Credit rate to all modeled exported electricity.

The default export credit is $0.270/kWh, equal to the default retail electricity rate. Selecting a different utility does not automatically change either rate or apply a utility-specific compensation arrangement.

To explore different utility terms, manually change the electricity rate, export credit, and recurring solar fees. Verify the actual compensation terms with your utility before relying on the results.

Self-Consumption, Batteries, and Electricity Rate Growth

Daytime self-consumption determines the portion of modeled solar production assigned to household use rather than grid exports.

When the retail electricity rate is higher than the export credit rate, increasing self-consumption generally increases modeled financial benefits. When the two rates are equal, as in the default settings, self-used and exported kWh receive the same monetary value.

The battery storage checkbox does not calculate battery installation costs or charging and discharging behavior. Users can manually change the Daytime Self-Consumption percentage to evaluate different electricity-use assumptions.

The default Annual Utility Rate Increase is 4%. The calculator applies that increase to both retail and export credit rates every year. Solar production simultaneously decreases by 0.5% annually, which gradually reduces the amount of electricity available for household use and exports.

Federal Credits, State Incentives, and Property Taxes

The calculator’s 2026 informational notes state that the residential federal Section 25D credit ended for systems placed in service after December 31, 2025. The Direct Federal Credit field therefore starts at 0%.

The New Hampshire State Credit field also starts at 0%. The calculator describes no state income tax or state sales tax and includes an informational No State Sales Tax badge in its results.

Its notes also describe solar property tax relief as a local option adopted by some municipalities. The Property Tax Savings field starts at $0 per year, rather than assuming a particular homeowner receives a tax benefit.

Entering a nonzero property tax savings amount adds that amount to each year’s modeled benefits. The calculator does not determine eligibility using a home’s assessed value, local tax rate, or municipal rules.

Upfront Rebates also default to $0. Any entered credit or rebate changes the net installation cost mathematically without confirming eligibility for the selected amount.

Important Result-Label Limitations

Some labels in the implemented calculator do not describe the values actually displayed:

Year 1 Self-Use kWh: This row receives the final simulated year’s self-consumption amount, corresponding to year 25 instead of year 1.
Year 1 Export kWh: This row receives the final simulated year’s exported electricity amount rather than the first year’s amount.
Net Year 1 Savings: This row displays the positive portion of the calculated 25-year net savings, or $0 if that long-term result is negative. It does not display the first-year financial benefit.

For example, with the default settings, Net Year 1 Savings displays $70,094, even though the modeled first-year financial benefit is $2,484.

The self-use and export rows display approximately 2,447 kWh and 5,710 kWh, respectively, reflecting year 25 rather than the first year’s 2,760 kWh and 6,440 kWh.

The Retail Net Metering and No State Sales Tax badges are informational labels. They do not verify the selected utility’s tariff or an individual property’s tax treatment.

The model also does not separately calculate financing interest, routine maintenance, equipment replacement, or detailed hourly electricity demand. Actual savings may differ because of installation conditions, taxes, utility policies, and future electricity prices. Review important assumptions with your installer, utility provider, and tax professional when appropriate.

Frequently Asked Questions

How much can solar panels save in New Hampshire?

Potential savings depend on system size, installation cost, electricity rates, export compensation, self-consumption, annual fees, and entered incentives. With the calculator’s default values, the model estimates approximately $70,094 in net savings over 25 years. This is a hypothetical projection based on the calculator’s assumptions, not a guaranteed saving for a New Hampshire household.

How long does solar payback take in New Hampshire?

The calculator determines payback by finding the first whole year when cumulative modeled financial benefits equal or exceed the net installation cost. Its default settings produce a 10-year payback period. Different installation prices, electricity rates, export credits, incentives, or recurring fees can change that result.

Does the New Hampshire solar calculator include a federal tax credit for 2026?

The Direct Federal Credit field defaults to 0%. The calculator’s notes state that the residential Section 25D credit ended for systems placed in service after December 31, 2025. The field remains editable, but the calculator does not assess individual tax eligibility or determine whether a particular solar ownership arrangement qualifies for other incentives.

Does New Hampshire solar net metering credit electricity at the retail rate?

The calculator’s informational notes describe retail-rate net metering with monthly credit rollover and annual settlement. Its mathematical model is simpler: all exported electricity receives the entered Export Credit rate. It does not separately calculate credit rollover or annual true-up. Verify your utility’s current compensation rules before choosing a rate.

Does changing the utility selection affect the estimate?

No. The dropdown lists Eversource NH, Unitil, NHEC (Cooperative), and Municipal or Other, but the implemented calculation does not use that selection to adjust financial results. To evaluate different utility conditions, manually change the electricity rate, export credit rate, and annual utility solar fees.

Does the calculator automatically include property tax savings?

No. Annual Property Tax Savings defaults to $0. The calculator lets users enter an amount, which is added to annual modeled savings throughout the 25-year period. It does not verify whether a municipality offers property tax relief or calculate the actual benefit for an individual home.

Can the 25-year solar savings result be negative?

Yes. A negative result means cumulative modeled financial benefits remain below the net installation cost over 25 years. Higher installation expenses, lower electricity rates, reduced export compensation, or larger annual fees may contribute to a negative estimate. The result reflects the entered assumptions, not a guaranteed financial loss.

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New Hampshire Solar Savings Calculator