Size Vs Quantity: Typical Solar Panel Ratings And Capacity
Power output on its own is not a complete indicator of a panels 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 percent efficiency ratings, but one has a power output rating of 250 watts and the other is rated at 300 watts, it means that the 300-watt panel is about 20 percent physically larger than the 250-watt panel. Thats why EnergySage 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 could be made up of either 20 250-Watt panels or 16 300-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 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.
Find out more about average prices for solar across the country for 3kW,4kW, 5kW, 6kW, 7kW, 8 kW and 10kW solar systems. The EnergySage Solar Marketplace makes it easy for you to compare your savings from solar panels with various power output ratings.
The Fifth One Is How Efficient Are Your Panels
Different solar panel systems will yield different amounts of electricity, and how much you get out is measured by the efficiency.
This number can vary between manufacturers and models but its important to note that more expensive doesnt always mean better although many new solar technologies have been coming on the market recently which makes this less of a factor.
Canadas Best And Worst For Solar Energy
- The best provinces for producing solar energy in Canada are all located on the prairies: Alberta, Manitoba, and Saskatchewan.
This is because these provinces have relatively sunny weather all year around.
- The worst province for producing solar energy in Canada Newfoundland and Labrador, while the worst territory is the Yukon.
This is primarily because of high annual cloud cover in Newfoundland and Labrador, and a combination of high latitude and cloudy weather in the Yukon.
- The best place in Canada for producing solar power is Torquay, Saskatchewan , while the worst place is at the small research base located in Eureka, Nunavut .
- The best month for producing solar energy in Canada is April when days are mid-length and skies are clear. The worst month for producing solar energy in Canada is December when days are short.
You May Like: How Much To Add Solar Panels To House
How Many Solar Panels Do I Need For My Business
The number of solar panels that you require to fit the power needs of your business will be dependent on varying factors.
First, you will need to know how much power you use per day or month. That is based on the equipment and appliances you have in your business.
Each device requires different amounts of hours. Therefore, you have to add the power needs of all of them to determine how much power you need.
For example, if your business uses an average of 25,000 kWh of electricity per year, it is logical to say that you need around 70 kWh per day . The next step is to know how much electricity an average solar panel produces.
For example, the standard panels produce an average of 1- 1.5 kWh per day. If you take 1.5kWh as the average, then you will require at least 47 panels.
The calculations would be like this / 1.5kWh per day = 47 panels.
Therefore, the larger the business, the more the power needed and hence, more solar panels to cover the electricity needs.
Also, due to varying factors like sunlight and the efficiency of the solar panels, businesses in some areas may require more solar panels than others.
The difference can occur even though both companies need the same amount of power.
What Is The Photovoltaic Effect
The word literally means light voltage. Abbreviated PV effect, its the scientific reason why solar power exists at all.
Basically, the PV effect refers to the conversion of sunlight into electrical energy in the form of direct current electricity.
The photovoltaic effect is only possible because some materials possess a photoelectric effect. In other words, certain materials absorb light energy , which, in turn, knocks off energized electrons that initially move in a randomized fashion within it.
The material in which the PV effect occurs in practically all home solar panels today is impure silicon. As a semiconductor, silicon is purposely made impure to enable it to act more like an electrical conductor. This is important so that electrical energy can be produced and then transported inside your home to power it up.
Doping with a few boron and phosphorus atoms, each in separate silicon wafers, is all thats needed to increase silicons ability to conduct electricity.
Silicon containing boron atoms is called P-type, which lacks electrons for complete bonding with silicon atoms.
When phosphorus atoms are added, its called N-type silicon. There are extra electrons in the N-type silicon that arent involved with silicon bonding. These electrons move freely through the silicon crystal.
When two layers of silicon, one N-type and one P-type, are stacked on top of one another in every solar cell located in a solar panel, a P-N junction forms between them in each solar cell.
Also Check: Do Solar Attic Fans Work At Night
Myth #: I Will Store The Excess Energy I Generate In Batteries
FACT: Nearly all modern solar panel systems are grid tied which means theyre connected to the conventional electricity grid. Your system generates power during the day and excess is fed back into the grid through a system callednet metering. When this happens, your meter spins backwards and your utility company credits you for that power. At night or on overcast days, youll use grid power, but you dont generally get charged for it because of all the credit youve generated. This grid tied method tends to be the most convenient for homeowners. Home Battery Energy Storage Systems are an additional option to store and manage your excess electricity and power your home during blackouts.
How To Understand All The Numbers And Symbols
Figuring out how much power youre going to get from your solar panel is actually a lot simpler than you might think.
Solar panels measure the power they collect from the sun in Watts . Typically, domestic solar panels produce a power output of between 250 and 400 Watts. Kilowatt is just another name for 1,000 Watts. We measure the energy a solar panel produces in Kilowatt Hours . So if you have a 250 W solar panel that gets the equivalent of four hours of direct sunlight a day, it produces 1 kWh of energy .
And then if you multiply your average daily power output by 365 , then you have your annual solar power output. In the example I used above, the yearly energy production would be 365 kWh.
Heres that calculation again:
Solar Panel Power in Kilowatts x Average Sunlight Hours Per Day x 365 = Annual Power in Kilowatt Hours
And thats it for the math.
The problem I have with all of this is that these numbers dont mean much to me until I translate them into actual energy usage. Why dont we take a look at what these Kilowatt Hours of energy mean to you and your electricity bill?
Recommended Reading: What Is The Best Solar System
Will Solar Panels Operate In Rain And Snow
While the rain itself will not affect the panels, the rain clouds will most likely reduce your output.
On the other hand, the occasional rainstorm may be beneficial to the output of your Solar Panels since it is a no-fuss, secure way to clean your panels.
Continuous rainstorms prevent a layer of dirt or dust from covering the panels and blocking the light, potentially reducing output.
Although it’s not yet a widely available option, scientists are working on a new type of Solar Panel that can generate power even when it is raining.
These solar cells, known as hybrid solar panels, collect energy from both the sun and rain.
When rain falls on the panels, the force of the impact is converted into electricity.
When it’s sunny, they function similarly to traditional Solar Panels .
Snow, as opposed to rain, which does not accumulate on the panels and block light, will affect production in addition to cloud coverage.
After all, whatever prevents the sun from shining on your panels prevents the panels from producing electricity.
Even heavy snowfalls, depending on the weather after the snowstorm and the tilt of your panel, will melt and slide right off your panels in no time.
Even though solar energy relies on the sun, it is still an excellent choice for many residences, businesses, and farms in cloudy, rainy, or snowy areas.
Additional Components To The System
If youre looking to install additional components while installing the solar panels, this will increase your cost of equipment but can decrease the installation costs. Whether youre planning to install a solar battery storage system or additional features like pigeon proofing your panels, it is best to club them with installing the panels, so that you can decrease the installation cost.
Also Check: How To Heal Solar Plexus Chakra
How Much Power Do Solar Panels Produce
Solar panels are designed to take photons and turn them around into usable electricity for commercial properties and households. Making the decision to switch to solar energy requires thorough research and understanding. If you are curious about solar panels, you are likely wondering how much power solar panels actually produce.
Myth #: My Solar Panels Wont Work In The Cold Winter Weather
FACT: Solar panels produce power based on the amount of sunlight the panels are exposed to, so they are unaffected by temperature. In fact, you might be surprised to know that solar PV panels actually work better in colder weather as opposed to extremely hot temperatures.
Those sunny, yet cold days in winter could generate comparable amounts of solar energy to a hot, summer day. Although you wont be producing as much solar power as you do during the summer months, your system is designed so that you can draw on the electricity credits you generated during the summer.
Although this might seem counter-intuitive, consider that solar panels on a rooftop in cool, foggy San Francisco produce only one percent less electricity than one in nearby Sacramento, where its sunny and hot. Solar works great all over North America. Germany, the #1 world producer of solar electricity, is equal to Alaska in solar resources.
Youll be amazed at how much clean, renewable energy is available every day. In fact, solar radiation as a source of clean, renewable power is abundant throughout the Bay area and all of California. The San Francisco Bay Area counties receive 5-5.5 Kwh/m2/day and our state has the ability to generate a whopping 128 million megawatt hours per year. That gives California the nations highest solar resource potential rating.
You May Like: Can You Add More Solar Panels To An Existing System
What Factors Change How Much Solar Panels Produce
We all wish that solar panels always performed at their peak projections, but there are 5 common variables that contribute to the efficiency level of all residential solar systems.
Sunlight:
The biggest factor for determining how much electricity a solar panel produces is the amount of sunlight it receives. Depending on the state you live in, there will be an average number of sunny days to expect.
One way that solar companies guarantee maximum sunlight is by placing panels on southern facing roofs. Throughout the course of the day, the sun will constantly shine on the southern facing roof. If you dont have a roof that faces south, a couple extra panels on eastern or western facing roofs can produce the same amount of power.
Any shading on your roof by trees will also cause a large drop in overall efficiency. Luckily, trees can be removed, and many states have solar easement laws that allow homeowners to remove any objects on their or neighbors properties that block sun from their roof.
Weather:
All in all, cloudy weather usually decreases panel efficiency by only 10% to 20%. Surprisingly enough, homeowners in states with cloudy weather often save more by going solar because electricity costs more in these states. So, dont let those clouds deter you from choosing to go solar!
Roof Angle:
Temperature:
Surface Maintenance:
Five: Figure Out How Many Solar Panels You Need
Now all you have to do is divide this number by how many hours in a day there are and how much wattage your system produces, and voila! You know how big of a system that you need on top of your roof.
If the number is more than how many panels you have, dont worry this doesnt necessarily mean that the system will be too small to work for your house.
You can use a combination of tracking how much sunlight falls on it throughout the day and adjusting its orientation as needed to ensure that it captures enough energy.
Read Also: Can Solar Panels Work On A Cloudy Day
Solar Power For The Home: Benefits
A significant benefit to PV installation is a lower energy bill, but the magnitude of this benefit depends on the amount of solar energy that can be produced given the available conditions and the way in which utilities charge for electricity.
The first consideration is the solar irradiation levels available in the home’s geographical location. When it comes to using solar panels, being closer to the equator is generally better, but other factors must be considered. The National Renewable Energy Laboratory produces maps for the U.S. showing solar irradiation levels the tools on its website provide detailed solar information for specific locations within the U.S.
Similar maps and data are available in other countries as well, often from government environmental agencies or renewable energy organizations. Equally important is the home’s orientation for rooftop arrays, a south-facing roof without trees or other objects obstructing sunlight maximizes the available solar energy. If this is not available, panels can be mounted on external supports and installed away from the house, incurring additional costs for the extra hardware and cables.
The final benefit is the potential effect on a home’s value due to the addition of a solar array. In general, it is reasonable to assume that solar panels would raise the value of most homes.
How Net Metering Works
Let us assume that you are gone in a vacation with your family. The solar system still generates energy when youre gone but since you are not using it, its being automatically sent back to the grid and you get credits for it. As a result, your electricity bill will decrease according to how many credits you have.
Knowing the answers to the above questions will give you a good understanding of the number of panels needed to achieve your daily energy production goals and will allow to calculate in a realistic range solar panels needed for your home.
Don’t Miss: What Can You Run Off A 100 Watt Solar Panel
How Much Kwh Does A Solar Panel Produce
The amount of energy generated by any solar panel depends heavily on the irradiance for the panels location measured in kilowatt-hours per square meter per day .
For convenience, its also known as the locations Peak-Sun-Hours and can be used as a quick estimated of a solar panel arrays output per day or year measured in kWh.
Its an important number. For example, the energy output for a solar panel in Arizona with of 7.5peak-sun-hours/day is very different from Indiana with 3/day!
See the table below to see solar panel outputs compared across US states:
What Is The Average Wattage Of Solar Panels
The power rating of solar panels is commonly misunderstood. All panels are tested under equivalent laboratory conditions, and the resulting wattage becomes their rated power. However, the operating conditions in actual projects differ from the ideal lab scenario, and energy production also varies.
Solar panels with 60 cells normally have a wattage in the range of 250 to 350 watts. Some 72-cell panels go above 400 watts, since they have 12 additional solar cells producing electricity.
The controlled laboratory conditions for panel wattage tests differ from those found in most project sites. However, the power rating gives an idea of how solar panels compare with each other. A 360-watt panel will tend to produce around 20% more energy than a 300-watt panel, even if they dont operate at their rated wattage in actual projects.
Based on the efficiency of the average solar panel, you can expect to convert between 15% and 20% of sunshine into electricity. However, some of the most efficient solar panels available go above 22%.
Recommended Reading: Can You Use Pine Sol On Stainless Steel
Can You Increase A Solar Panels Output Or Efficiency
Theres no way to increase the solar panel output and efficiency a solar panel was designed to achieve.
What you can do is make sure that the solar panels are performing as efficiently as possible this is achieved by performing routine cleaning. Dust, debris, and snow can lower the efficiency of the panels, so youll want to keep them clean.
How Do We Measure The Efficiency Of A Solar Panel
The efficiency in solar panels means the amount of solar energy converted into electricity, from the energy absorbed from the sunlight. It is crucial to understand that not all the sunlight absorbed, is converted into solar electricity. Even if you buy the best solar panels out there, you still rely on the quality of the sun and irradiance in your area.
Traditionally, the solar panels used to have an efficiency level of between 6% and 10%.
Due to the advancement in solar panel technology, the panels have been improved. Now they can reach an efficiency level of even 30% or more.
When measuring the efficiency of a solar panel, you should use a deviancy of + or -2% since the ratings are not 100%.
Calculation of Solar panel efficiency can be as follows:
Efficiency = * 100
Where
Power Rating is the rating indicated on the panel and,
Surface stands for the surface area of the panel
For example, if the power rating is 350 watts, and the surface area of the panel is 1800 square meters, then the efficiency will be:
Efficiency = 350/1800* 100 = 19.44%
Efficiency is just one way to determine how a solar panel performs. You can likely refer to capacity factor in addition to efficiency. See more related renewable energy definitions in our dictionary.
Here is a video to help you understand capacity factor.
How to Calculate kWh
When calculating the kWh of a solar panel, you need to know the exact number of hours you get direct sunlight and multiply by the power rating of the panel.
Don’t Miss: When Is The Best Time To Install Solar Panels
