How Much Energy is produced by Solar Panels?

When evaluating solar panel alternatives, power output, or wattage, is a critical component to consider. You could hear your solar installer remark, "it's a 255 Watt panel" or "the panel I'm suggesting has a solar panel wattage of 300." You might also see figures like 245W, 300W, or 345W next to the name of the panel while reading a quote from a solar installation. The wattage, capacity, and power output of a solar panel are all mentioned.

Although many factors can influence the amount of energy a solar panel can generate, a standard single solar panel in the U. S. can produce roughly 2 kWh per day, saving an average of $0.36 on power bills every day.

Now, $0.36 may not sound like much, but it is only the energy savings from one panel over the course of one day. Installing a full solar panel system, on the other hand, would save you around $132 per month (or more!).

But what really influences how much power a solar panel will generate, and how can you calculate the amount of electricity produced by a single solar panel? 

Which factors determine the power output of solar panels?

Before determining how much energy a solar panel can produce, it's critical to understand the two primary factors that influence its power output: cell efficiency and solar panel size.

Let's look at each aspect independently to have a better understanding of them.

Efficiency and output of solar panels

Most silicon-based solar cells can now convert roughly 20% of the sunlight that strikes them into useable solar energy, allowing panels to reach 400 watts of electricity. Because more efficiency equals more energy, high-efficiency solar panels will typically create more power for your home.

The number of solar cells and the size of the solar panel

To make things easier, solar panels are classified into two sizes: 60-cell solar panels and 72-cell solar panels. 60-cell solar panels are typically 5.4 feet tall by 3.25 feet wide and have an output of 270 to 300 watts. 72-cell solar panels, on the other hand, are bigger due to an extra row of cells, and their typical output ranges between 350 and 400 watts. 72-cell panels are typically seen on bigger structures and in commercial solar projects, rather than on private dwellings.

The average energy a solar panel produces

Under conventional test settings, all solar panels are assessed by the amount of DC (direct current) electricity they produce. Solar panel output is calculated in watts (W) and indicates the theoretical power produced by the panel under perfect sunshine and temperature conditions. The majority of household solar panels on the market today have power output ratings ranging from 250 to 400 watts, with greater power ratings being preferred over lower power ratings. Solar pricing is commonly defined in dollars per watt ($/W), and the total wattage of your solar panels has a significant role in the overall cost of your solar system.

If you are getting 5 hours of direct sun per day, in a state like California, you can calculate your solar panel output this way: 5 hours x 290 watts (an example wattage of a premium solar panel) = 1,450 watts-hours, or around 1.5 kilowatt-hours (kWh). As a result, the output for each solar panel in your array would be around 500-550 kWh of electricity each year.

What can a single solar panel provide power to?

In the above example, the solar panel generates 1.5 kWh each day, resulting in around 45 kWh per month. That should be enough energy to power a few small appliances, but if you want to cover the energy needed by your home's climate control systems or major culinary equipment, you'll need to install more solar panels. To further understand how much solar energy your specific property requires, see our post on how many solar panels you need for your home.

How much electricity can a solar panel system generate?

Knowing how much electricity a single solar panel generates is useful, but how much solar power can your roof produce? Let's run the numbers:

Consider our previous scenario, in which you receive an average of five hours of direct sun each day (the amount of sunlight received in most locations of California) and use solar panels rated at 290W. Assuming you put 30 of all those premium solar panels on your roof, which results in an 8,700 watt, or 8.7 kW, solar panel system.

Multiply the five direct sun hours by 8.7 kW to get an estimate of 43.5 kWh of energy generated per day. Finally, multiplying 43.5 by 365 days in a year yields roughly 15,800 kWh of energy generated in a full calendar year by a 30 premium rooftop array, 290 W solar panels. Given that the yearly average for electrical power in the United States is roughly 10,600 kWh that should be more than enough to power your home using solar.

This estimate for most solar shoppers is probably higher than you would expect, and this is because of the estimate for sunlight hours that we have given.

Why is the output of solar panels important? Calculating the wattage of a panel

The power output of your residential or business solar panel system is an essential factor to consider. When you purchase or install a solar photovoltaic (PV) energy system, the price you have to pay is usually determined by the system's solar panel output (expressed in watts or kilowatts).

The theoretical power output of a solar panel under optimal sunshine and temperature settings is represented as solar panel wattage. Wattage is computed by multiplying volts by amps, where volts indicate the amount of force applied by the electricity and amperes (amps) reflect the total amount of energy utilized. Open-circuit voltage and system voltage may be less of a concern for grid-connected systems. However, for individuals who live off-grid or desire to use battery storage, it is an essential component of your PV system. The financial benefits you receive from your solar system are the results of the electric energy that it creates over time (expressed in kilowatt-hours).

It's Time for You to Lower Your Bills and Your Carbon Footprint

Most of the time, installing solar panels is enough to cover your monthly power needs. Installing for instance a 6 kW solar system can save you between $90 and $100 every month - but it depends on a lot of factors.

At Forme Solar, we will ensure that you have the right amount and kind of solar panels to maximize your rooftop's solar power production.  With a personalized solar solution, you can rest easy. Our solutions are tailored to your home's structure, lifestyle, energy, and financial goals.

We have the skills and resources to optimize the performance of your solar systems. We'll walk you through the whole process, from contract through installation and maintenance. And we will be here to help and advise you for many years to come.