Determining the True Cost of Solar: A Comprehensive Guide to Installing Solar Panels – Solar panel cost can be calculated in terms of cost per kilowatt-hour (kWh) or cost per square foot. For homes, it is possible to use a calculator to determine the cost of installing solar panels based on the size of the system and location. The life cycle of solar panels is typically around 25-30 years, during which time they will convert sunlight into electricity with a certain efficiency or conversion rate. Solar panels can be used for both commercial and industrial purposes, and the power output of a panel is measured in watts. A good performance solar panel will have a high conversion rate and be able to generate a large amount of power. To calculate the ratio of solar panels needed for a particular application, you can divide the desired power output by the power output of a single panel. While it is not possible for solar panels to be 100% efficient, some panels are able to achieve efficiency rates of around 20-25%.

Use this solar panel calculator to calculate your need

The decision to switch to solar energy is a big one, and it’s natural to have questions about the cost of solar panels and the overall price of installing a solar energy system. In this article, we’ll provide a comprehensive guide to help you understand the true cost of solar and make an informed decision about whether solar power is right for you.

First, it’s important to understand that the cost of solar panels has decreased significantly over the past decade. According to the U.S. Department of Energy, the average cost of solar panels was around $7 per watt in 2010. As of 2021, the average cost is around $2.80 per watt, and some companies offer panels for as low as $1.50 per watt. This decrease in cost is due in part to advances in solar panel technology and an increase in the number of solar panel manufacturers.

So, what does this mean in terms of the overall cost of installing a solar energy system? The size of the system you need will depend on your energy usage and the size of your home or business. As a general rule, a 5-kilowatt (kW) solar energy system will cost around $14,000-$16,000 after tax credits. This price includes the cost of solar panels, inverters, mounting equipment, and any other necessary components. It’s worth noting that the cost of installing a solar energy system can vary depending on your location and the complexity of the installation.

In addition to the upfront cost of installing a solar energy system, there are also ongoing maintenance costs to consider. Solar panels require very little maintenance, but it’s a good idea to have them inspected and cleaned every few years to ensure they are operating at their best. You may also need to replace your inverter at some point, which can cost around $1,000-$2,000.

Now, let’s talk about the financial benefits of switching to solar. One of the main advantages of solar energy is that it can significantly reduce or even eliminate your monthly electricity bills. The amount of money you save will depend on the size of your solar energy system and your energy usage, but on average, homeowners can save around $30-$50 per month by switching to solar. This means that the cost of a solar energy system can be recouped in as little as 5-10 years.

In addition to the financial benefits, there are also environmental benefits to consider. Solar energy is a clean, renewable energy source that does not produce any greenhouse gas emissions. By switching to solar, you can help reduce your carbon footprint and do your part to combat climate change.

So, is solar energy right for you? It’s a good idea to do your research and consider your financial and environmental goals before making a decision. Here are a few things to consider:

  • Your energy usage: The size of the solar energy system you need will depend on your energy usage. It’s a good idea to take a look at your energy bills to get a sense of how much power you use on a monthly basis.
  • The size of your roof: Solar panels need to be installed on a flat or slightly sloped surface, and you’ll need enough space to accommodate the number of panels you need.
  • Your location: The amount of sunlight your area receives will affect the performance of your solar panels. It’s a good idea to check the solar resource map for your state to get a sense of the average solar insolation in your area.
  • Your budget: The cost of solar panels and installation can vary depending on the size of the system and the complexity of the installation. It’s a good idea to get quotes from multiple companies to find the best price.

How Many Solar Panels Do I Need?

When considering the installation of solar panels, one common question is “how many solar panels do I need?” The answer to this question depends on various factors, including the energy usage of the home or business, the surface area available for panel installation, the orientation of the roof or property, and the location. To determine the energy usage of a home, it is advisable to review the total energy consumption from the previous twelve months as reflected on utility bills. The average electricity consumption for a residential customer in the United States was 10,649 kWh in 2019, or approximately 877 kWh per month. It is also important to consider the number of peak hours of sunlight that the location typically receives, as this can impact the number of panels needed to generate a sufficient amount of power.

There are several factors that can impact the efficiency of solar panels, which determines how well they can convert sunlight into energy. The design of the panel is one factor, with more efficient panels often lacking gridlines and having a higher quality construction that is resistant to corrosion and cracking. The average output efficiency for residential solar panels is between 150-370 watts, with an average wattage per square foot of 15 watts. The cost of solar panels can range from $0.65 to over $2 per watt, with an average 6 kW system costing around $12,000, not including installation costs which can add an additional $5,000-$10,000. The price of solar panel installation can vary based on location, with warmer climates generally requiring more panels but having a lower cost, and colder climates requiring fewer panels but having a higher cost. However, tax credits and incentives can help offset the cost of installation and provide ongoing savings.

Determining the Number of Solar Panels Needed to Power a Home

When determining the amount of solar energy required to power a home, it is important to consider the size of the residence. The average energy consumption for a home can vary based on the size of the dwelling, with a 1500 sqft home typically using around 633 kWh per month, while a 3000 sqft home may use approximately 1185 kWh per month. On average, a homeowner may need to install between 28-34 solar panels to offset their electricity usage. The chart below provides an estimate of the number of panels that may be needed based on the size of the home.

Home SizeAvg Energy Consumption/Month (kWh)Recommended Amount of Panels
1500 ft263314-17
2000 ft296719-25
2500 ft2102324-30
3000 ft2118527-30


To determine the number of solar panels needed for a specific solar energy system, divide the desired system size by the wattage of each panel. For example, if you want to install a 4 kW system, you would divide 4,000 watts by the wattage of the panels, which is typically around 320 watts. This would give you a result of 12.5 panels, which you would round up to 13 panels. It is also possible to calculate the number of panels needed on a per appliance basis. To do this, divide the average annual wattage of the appliance by the wattage of the solar panels. For example, a 600 kWh refrigerator would require approximately two panels (600 / 320).

In conclusion, the cost of solar panels has significantly decreased in recent years, making it a more affordable and viable option for many homeowners and businesses. While there is an upfront cost to install a solar energy system, the financial and environmental benefits make it a worthwhile investment. By doing your research and considering your energy usage, budget, location, and other factors, you can make an informed decision about whether solar power is right for you.