Power output (W) is an important factor to consider when comparing solar panel options. You may hear your solar installer say, “it’s a 300 Watt panel” or “the panel I am recommending is has a wattage of 400.” Or, when you are reading a quote from a solar installer, you might see numbers like 300W, 320W, or 375W next to the name of the panel. They are all referring to a solar panel’s wattage, capacity and power output.
How Much Energy Does A Solar Panel Produce?
For the sake of example, if you are getting 5 hours of direct sunlight per day in a sunny in Singapore you can calculate your solar panel output this way: 5 hours x 300 watts (an example wattage of a premium solar panel) = 1,500 watts-hours, or roughly 1.5 kilowatt-hours (kwh). Thus, the output for each solar panel in your array would produce around 540-560 kWh of energy per year.
All solar panels are rated by the amount of DC (direct current) power they produce under standard test conditions. Solar panel output is expressed in units of watts (W) and represents the panel’s theoretical power production under ideal sunlight and temperature conditions. Most home solar panels on the market today have power output ratings ranging from 300 to 450 watts, with higher power ratings generally considered preferable to lower power ratings. The total wattage of your solar panels plays a significant part in the overall cost of your solar energy system.
What Can You Power With A Single Solar Panel?
In the example above, the solar panel is producing 1.5 kWh per day, which ends up being about 45 kWh per month. That’s enough energy to power some small appliances without too much issue, but if you want to cover the energy used by your property’s climate control systems or large cooking appliances, you’ll need more solar panels.
Why Does Solar Panel Output Matter? How To Calculate Panel Wattage
Power output is an important metric for your home or commercial solar panel system. When you buy or install a solar photovoltaic (PV) energy system, the price you pay is typically based on the total power output of the solar panels in the system (expressed in watts or kilowatts).
Solar panel wattage represents a solar panel’s theoretical power production under ideal sunlight and temperature conditions. Wattage is calculated by multiplying volts x amps where volts represents the amount of force of the electricity and amperes (amps) refers to the aggregate amount of energy used. The financial savings you derive from the solar system is a result of the electric energy that it generates over time (expressed in kilowatt-hours).
Size vs. Quantity: Typical Solar Panel Ratings & Capacity
Power output on its own is not a complete indicator of a panel’s quality and performance characteristics. For some panels, their high power output rating is due to their larger physical size rather than their higher efficiency or technological superiority.
For example, if two solar panels both have 15% efficiency ratings, but one has a power output rating of 300 watts and the other is rated at 350 watts, it means that the 350-watt panel is about 20% physically larger than the 300-watt panel. That’s why Solar Era and other industry experts view panel efficiency as being a more indicative criterion of solar panel performance strength than solar capacity alone.
In practical terms, a solar panel system with a total rated capacity of 5kW (kilowatts) could be made up of either 17 300-Watt panels or 14 350-Watt panels. Both systems will generate the same amount of power in the same geographic location. Though a 5kW system may produce 6,000 kilowatt-hours (kWh) of electricity every year in Boston, that same system will produce 8,000 kWh every year in Los Angeles because of the amount of sun each location gets each year.
The electricity generated by a solar PV system is governed by its rated power output, but it’s also dependent on other factors such as panel efficiency and temperature sensitivity, as well as the degree of shading that the system experiences and the tilt angle and azimuth of the roof on which it’s installed. As a general rule of thumb, it makes prudent financial sense to install a solar system with as much power output as you can afford (or that your roof will accommodate). That will ensure you maximize your savings and speed up the payback period of your solar energy system.
Three Tips for Solar Shoppers
1. Homeowners who get multiple quotes save 10% or more.
As with any big ticket purchase, shopping for a solar panel installation takes a lot of research and consideration, including a thorough review of the companies in your area. A recent report by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) recommended that consumers compare as many solar options as possible to avoid paying inflated prices offered by the large installers in the solar industry.
To find the smaller contractors that typically offer lower prices, we will advise you can receive free quotes from Solar Era.
2. The biggest installers typically don’t offer the best price
The bigger isn’t always better mantra is one of the main reasons we strongly encourage homeowners to consider all of their solar options, not just the brands large enough to pay for the most advertising. A recent report in Singapore found that large installers are $2,000 to $5,000 more expensive than small solar companies. If you have offers from some of the big installers in solar, make sure you compare those bids with quotes from local installers to ensure you don’t overpay for solar.
3. Comparing all your equipment options is just as important
National-scale installers don’t just offer higher prices – they also tend to have fewer solar equipment options, which can have a significant impact on your system’s electricity production. By collecting a diverse array of solar bids, you can compare costs and savings based on the different equipment packages available to you.
There are multiple variables to consider when seeking out the best solar panels on the market. While certain panels will have higher efficiency ratings than others, investing in top-of-the-line solar equipment doesn’t always result in higher savings. The only way to find the “sweet spot” for your property is to evaluate quotes with varying equipment and financing offers.
For any homeowner in the early stage of shopping for solar that would just like a ballpark estimate for an installation, you can contact us to know about your upfront cost and long-term savings estimates based on your location and roof type.