how many solar watts do i need

How many solar watts do I need In 2024 ?

How many solar watts do I need?” is a critical question that requires careful consideration to ensure that you install the right size solar panel system that meets your energy needs and saves you money on electricity bills.

Installing solar panels in houses has become a cultural phenomenon as many people are eager to shift to a sustainable and eco-friendly lifestyle. But most of us need to know how many solar watts we need.

While we need to consider various factors while determining the number of solar watts required to power a home or business, the method is quite simple. So, let’s get into the details:

Determine the electricity consumption

The amount of electricity you are consuming right now is essential in determining how many solar watts you need. It is because everyone has different needs. For example, my office does not use that much electricity, but my house’s requirements are high.

So, to determine how much electricity you consume, analyze the average usage of your power bill. Search for “Kilowatt Hours (or kWh) Used” or a similar term, then take note of the duration displayed (usually 30 days).

determine electricity consumption

If your analysis doesn’t list the kilowatt hours consumed, look for the beginning and ending meter readings and deduct the earlier lesson from the current one.

To determine your solar demands, use your daily energy consumption as your goal average. If you wish to meet most of your electricity needs, that is the kilowatt-hours your solar system must produce.

The fact that solar panels don’t function at their highest level of efficiency every single day must be noted. For instance, weather changes may momentarily lower your system’s effectiveness. Experts advise adding a 25% “cushion” to your intended daily average to ensure you can produce all the renewable energy you need.

Determine the typical price of solar panels per watt

Since the market is full of different kinds of solar panel brands, the exact price of the solar panel is not available.

However, as per my experience, high-end solar panels typically range in price from $0.65 per watt to more than $2 per watt. In other words, depending on the area, a typical 6 kW system can cost up to $12,000. Installation fees are not included, which may add another $5,000 to $10,000.

Generally, PV systems are more expensive yet require fewer panels in warmer climes, and the reverse is true in colder climates. Thankfully, tax breaks and incentives can reduce the cost of installing solar panels and offer further savings over their lifespan. If you are interested, here I am providing the best options for 400W solar panels in 2024.

Determine the number of sunny days in your area

The amount of energy your home solar system will likely produce will directly depend on when the sun is strongest in your area. For instance, Phoenix residents can anticipate more peak solar hours than Seattle residents. A Seattle homeowner can still go solar, which means they would require more panels.

sunny days

So, determining the number of sunny days in your area is also crucial when determining how many solar watts you need. Hopefully, information on sunlight is available per state and for large cities from the Renewable Resource Data Center. You can check on the area easily.

Determine the elements that influence the solar panels’ output efficiency

The quality of the solar panel is important in this situation. The market is filled with a wide variety of solar panel models.

So, it’s challenging to generalize which solar panels are best for anyone, including me. Additionally, it is challenging to determine how many we will need for our home because of the significant variations in quality and efficiency.

The main takeaway is that the more effective the solar panels are, the fewer you will need to have installed on your roof to generate the same amount of electricity because they can produce more power.

Determine what kind of solar electricity you will require.

Examine previous utility bills to figure out your home’s typical energy usage. The number of solar panels you require can be determined by calculating your household’s hourly energy needs by the area’s peak sunlight hours and then dividing the result by the wattage of each panel.

To define a range, use examples of low-wattage (150 W) and high-wattage (370 W) systems (for instance, 17–42 panels to produce 11,000 kWh annually). If you are planning to install a 200W solar panel system, then you should know how much energy can a 200W solar panel produce.

Calculations – how many solar watts do I need?

It’s important to understand that a home’s power use is based on something other than its square footage before we go on to the examples. The number of inhabitants and their energy usage patterns have a significantly greater impact.

Nonetheless, I have outlined the examples in these terms to make it easier for folks wondering, “How much solar electricity do I need?” regarding square footage.

Example 1: How many solar panels will I need for a home that is 2500 square feet?

Assume that a 2500-square-foot residence with five occupants uses an average of 1000 kWh per month or 12,000 kWh annually.

You will require the following number of solar panels: Solar Panels = 12000 / 1.6 / 600 = 12.50 or 13 solar panels. This is based on a panel wattage of 600 and a production ratio of 1.6.

Example 2: How many solar panels are needed for a 1500-square-foot home?

Assume that there are four individuals living in our 1,500-square-foot house and that they all utilize energy daily. If so, the anticipated usage would be 1,232 kWh monthly or 14,784 kWh annually.

Again, using a 400W panel and a 1.2 production ratio, we can solve for the number of solar panels using the formula: Solar Panels = 14,784 / 1.2 / 400 = 30.80, or 31 solar panels.


Solar Panels kWh Calculator

Based on your typical monthly kWh use and the city closest to your home, you may use this calculator to rapidly calculate how many solar panels you’ll need. The latter enables you to estimate your location-specific exposure to sunshine more accurately.

electricity consumption

Solar Panel Square Footage Calculator

As an alternative, calculate your solar panel requirements using the area of your roof. This is helpful if you want to put solar panels on a new home but have yet to keep track of your monthly power use.

Nevertheless, no calculator will perform this task for you directly, as there is no connection between consumption and square footage.

But there is a workaround. Based on the inhabitants’ energy usage patterns and the number of people living there, you can use the calculator below to get the expected monthly kWh usage:

solar panel square footage calculator

Enter it into the solar panel kWh calculator above once you have the projected monthly kWh use.


Frequently Asked Questions:-

  • How many solar panels are needed to power a whole house?

For a typical home to completely balance utility costs with solar, 17 and 21 solar panels are required. A few important elements, including your location and the characteristics of each panel, determine the number of solar panels you require.

  • Can a house be operated entirely on solar energy?

An entire house might be powered solely by solar energy. However, the cost and time required to disconnect from the grid entirely are significant. Your need for solar panels will increase as your energy needs increase.

  • How much do solar panels typically cost?

After accounting for the federal solar tax credit, the average cost of a solar panel installation in 2024 will be between $16,870 and $23,170, with a typical solar installation costing about $20,020. In 2024, the average solar panels cost per watt ($/W) will be $2.86.

  • Do solar panels fit on any roof?

The best orientation for a solar panel is true south, which will provide the most power. The efficiency of a roof facing east, west, or south is reduced by about 15% compared to a roof facing south, whereas roofs facing southwest and southeast are also thought to be quite efficient.

  • Why aren’t solar panels used everywhere?

To produce electricity directly from sunlight, solar panels use pricey semiconductor material. The construction and upkeep of semiconductor factories are expensive, and they require “clean” working environments. Approximately 22% of solar cells are efficient. The remainder of the sun’s energy that enters the panel is lost as heat.

  • What is the solar panel’s lifespan?

Photovoltaic or PV panels, another name for solar panels, are designed to last over 25 years. Many solar panels installed as early as the 1980s are still working at their predicted capacity.

[Video Credit – Two Bit da Vinci]


Ultimately, it’s not as hard to figure out how many solar watts you need for your house or company as it may appear. All you need to do is determine your electricity usage’s magnitude and preferences. I hope you are now fit to determine how many solar watts you need. So, let’s conclude this article here.

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Ray is an avid reader and writer with over 25 years of experience serving various domestic and multinational private and public energy companies in the USA.

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