## What is a Solar Calculator

A solar power calculator is a useful tool that helps people design solar power systems, estimate prices, and predict energy savings.

It can quickly calculate different solar energy concerns such as:

- Panel sizing and system pricing
- Power consumption estimates
- Energy output and capacity
- Installation costs
- Electric bill savings
- Return on investment
- Payback periods or break-even points
- Solar financing
- Other solar power design and financial considerations

Our DIY calculator builder lets you easily create any type of solar power calculator you want with no coding at all. You can use all the same equations and formulas you have in Excel and Google Sheets to price solar power packages and jobs. Our calculator builder gives you lots of editing and customization options so you can easily change layouts of our pre-made templates or design a new one from the ground up.

## How to Calculate Solar Power Payback Period

Solar calculators are most often used to help customers understand how a solar power system can lower their electric bills. The calculated savings can then be used to estimate how many years it will take to see a return on investment, or what is known in the solar energy industry as the payback period. ROI is one of the most important considerations people have when deciding on whether or not solar energy is right for them.

A very simple way to calculate the payback period for solar power is to take the total cost of the system and divide it by the estimated annual savings on electricity costs.

**Total System Cost ÷ Average Annual Energy Cost Savings = Payback Period (Years)**

To calculate annual savings just subtract the new average electric bill with the average of the old bill and multiply it by 12 months.

**(Old Electric Bill - New Electric Bill) x 12 months = Annual Energy Cost Savings**

*Example:*

Let’s say a solar power setup costs $10,000 in total after accounting for federal and local incentives. This new solar array is able to cut down the electric bill in half from $200 to $100 a month, which adds up to $1,200 in savings per year.

**($200 - $100) x 12 months = $1,200 in savings per year**

To get the estimated payback period just divide the $10,000 with the estimated energy savings of $1,200 a year.

**$10,000 ÷ $1,200 = 8.33 years**

This sample solar power system will have paid for itself In roughly 8 years and 4 months, and will continue to save you money for many years to come.

## How to Calculate Solar Power System Size

Every solar power system should be properly sized to suit a customer’s specific requirements. Solar power calculators are invaluable tools when it comes to determining how big the solar panel array should be so that it can reliably power essential electrical appliances, especially if the system is off-grid.

There are lots of factors to consider when choosing a solar power system. The more prominent ones include:

- Energy and kWh requirements
- Solar array size
- Number of solar panels required
- Solar panel efficiency
- Battery capacity
- Sun exposure (solar hours per day)
- Roof area (square footage) and angle

It’s hard to take all these specifications and data into consideration all in one go, especially for someone who’s new to solar energy. But a well-designed calculator can make short work of the task and give out estimates and recommendations quickly.

To calculate your energy requirements, check how many watts an electrical appliance consumes. Multiply the wattage by the number of hours it’s used per day and you get a number of watt hours it needs per day.

**Watt Consumption x Hours per Day = Watt Hours per Day**

Add up the watt hour usage for your most important appliances and devices to figure out how many watt hours you’ll need from your solar power system per day.

*Example:*

Let’s get the total energy usage for these appliances.