Solar Panel Calculator: Cost and Savings

SolarJerry Lee

In today's world, where sustainability and renewable energy are gaining significant momentum, solar power has emerged as a popular and environmentally friendly alternative. With advancements in technology and increasing affordability, many homeowners and businesses are turning to solar panels to harness the power of the sun. However, navigating the complexities of solar energy can be overwhelming, particularly when it comes to determining the number of panels, and understanding the cost implications. In this comprehensive guide to solar panels calculators, we will delve into each of these crucial aspects, equipping you with the knowledge and tools to make informed decisions about your solar journey. Read on to explore more.


How Many Solar Panels Do I Need?

Let's take a general American family as an example and go through the solar panel calculation process to determine the solar panel size they should choose.

1. Determine average daily energy consumption:

According to the U.S. Energy Information Administration, the average American household consumes around 900 kWh of electricity per month. So, the average daily energy consumption would be approximately 900 kWh / 30 days = 30 kWh.

2. Calculate required system size:

The average peak sun hours in the United States can vary depending on the location. As a rough estimate, let's consider an average of 4 peak sun hours per day. Below is the solar panels kwh calculator:

System Size (in kW) = Average Daily Energy Consumption (in kWh) / Average Peak Sun Hours

System Size = 30 kWh / 4 hours = 7.5 kW

3. Determine the number of solar panels:

The number of solar panels needed will depend on the power rating of the panels chosen. Let's assume we select 300-watt panels for this example.

Number of Panels = System Size (in kW) / Power Rating per Panel (in kW)

Number of Panels = 7.5 kW / 0.3 kW = 25 panels

In this example, a general American family would need approximately 25 solar panels with a power rating of 300 watts each to meet their average daily energy consumption of 30 kWh.

How to Calculate the Total Solar Panel Size?


To determine the size of 25 solar panels, you would need to consider the dimensions of the specific solar panels you plan to use. Solar panel sizes can vary, but a common size for residential panels is around 65 inches by 39 inches (165 cm by 99 cm).

Assuming you plan to arrange the panels in a 5x5 configuration (5 panels per row and 5 rows), the total size of solar panels would be:

5 panels x 69 inches (width) = 345 inches (total width per row)

5 panels x 39 inches (width) = 195 inches (total height per column)

So, the total size of solar panels would be approximately:

345 inches (width) x 195 inches (height) = 67,275 square inches

To convert this to square feet, divide by 144:

38,025 square inches ÷ 144 = 467 square feet

Therefore, according to the solar panel size calculator, you would need a roof area of more than 467 square feet to accommodate 25 solar panels arranged in a 5x5 configuration.

It's important to note that higher-efficiency solar panels produce more electricity per square foot. If you have limited installation space, opting for more efficient panels can help maximize your energy production. However, keep in mind that higher-efficiency panels often come at a higher cost.

Solar Panel Installation Cost Factors


Once you have determined the number of solar panels you require, the next step is to consider the cost associated with them. The price of solar panels is influenced by various factors, which include the type of panel, its size, location and the expenses involved in the installation. Let's explore each of these factors in more detail to gain a clearer understanding of their impact on cost:

Solar Panel Types

The type of solar panel chosen is an essential factor. Efficiency, life expectancy, and design are critical considerations. Higher efficiency and longer life expectancy panels may have a higher upfront cost but could be more cost-effective in the long run. The design of the panels also affects the space they occupy and their flexibility in attaching to different structures.

The three major types of solar panels are monocrystalline, polycrystalline, and thin film. Monocrystalline panels, made of high-purity silicon, offer top performance in a compact size, costing around $1 to $1.50 per watt and lasting up to 40 years. Polycrystalline panels, made of melted and molded silicon, are slightly less energy efficient but occupy a similar amount of space. They cost $0.70 to $1 per watt and have a lifespan of 25 to 30 years. Thin film panels are the most flexible option, suitable for various shapes and angles. They cost between $1 and $1.50 per watt but have a shorter lifespan of 10 to 20 years.

Size and Number

The number of panels required also impacts the overall cost. Most homes typically need around 20 to 25 panels for full power, but this can vary from 15 to 34 depending on the energy goals and available space. Higher-efficiency panels, like Anker solar panels with a conversion efficiency of 23%, can maximize energy production in limited installation spaces, but they may come at a higher cost.


Location is another influential factor. Areas with less sunlight or cloudy climates may incur higher costs due to factors like labor expenses and local incentives. The cost of living also varies from state to state, with some states having more competitive prices for solar panel installation.

Installation and Labor Expenses

Labor costs are a significant component of the total installation cost. Hiring an experienced professional is crucial, with an average budget of $0.50 per watt for labor. However, this estimate does not include permits or additional technology costs.

In summary, solar panel installation costs range from $2.50 to $3.50 per watt, encompassing material costs, labor expenses, and other factors. For a general American home, they need power of 7500W, so the estimated cost for the solar panel installation would range between $18,750 and $26,250.

How Much Electricity Bills Will Solar Panels Save? And When They Pay It Off?

To provide a rough estimate, let's assume an average cost of $3 per watt for the solar panel installation and consider the lower end of the range mentioned earlier.

7500 watts * $3 per watt = $22,500 (estimated cost)

Suppose the household's average monthly electricity bill prior to installing solar panels was $150. With solar panels, this bill could be significantly reduced or even eliminated, depending on the factors mentioned earlier. Let's conservatively estimate a 50% reduction in monthly electricity expenses, resulting in $75 in savings per month.

To calculate the payback period, divide the estimated cost of the installation by the monthly savings:

$22,500 / $75 per month = 300 months

Therefore, based on these estimates, it would take approximately 300 months (or 25 years) to recoup the initial investment in solar panels through electricity bill savings. It's important to note that this solar panels calculation is a simplified estimate and does not consider factors such as inflation, changes in electricity rates, maintenance costs, or potential incentives or tax credits that could shorten the payback period.

Final Thoughts

Investing in solar panels is a significant decision that can have long-term financial and environmental benefits. When choosing the right solar panel size, consider your energy requirements and available roof space. Calculate the number of panels needed based on your monthly electricity consumption and don’t forget the solar panel output calculator. Understand the cost factors involved, such as panel types, efficiency, size, and installation expenses. Additionally, evaluate the potential savings on electricity bills and the payback period to assess the financial feasibility. By considering these factors comprehensively, you can make an informed decision that aligns with your energy goals and budget.