How Much Solar Power Do We Need
One of the most common questions we get is: How much solar power do I need? The answer is pretty complex, and frankly, most people approach it from the wrong angle when they start to look into solar. If you want to run through calculations yourself to determine the size of the solar power system you should get for your specific circumstances, youll want to figure out the main constraints on the project and use those restrictions as the starting point for the design. You can approach the project from two angles:
1) How much money youre prepared to spend.
2) How much electricity your household uses.
Take into consideration other sizing factors and common stumbling blocks that may impact how to size a solar system:1) Local levels of sun exposure
2) Orientation of the array 3) Plans for future expansion
Before you begin to size a solar system, follow these steps to determine your homes average electricity consumption and PV needs:
1. Calculate Your kWh Usage
1) Gather the kilowatt-hours usage from your electric bill. We will assume it is quarterly. Look at how many kWhs you have used in the previous 4 quarters. The information will be on your billlook for usage over time and add up the last 4 quarters. That is how many kWhs of electricity you use per year. Lets imagine you use 6250 kWh per year.2) Figure your daily kWh usage. Divide your by 365. That is your daily usage. In this example it comes out as 17kWhs per day.
2. Look Up Your Peak Sun Hours
Complete Guide For Solar Power Alberta 2021
Congratulations! Youve found the ultimate guide for going solar in Alberta!
Alberta is currently ranked the #3 province in the country for installing a solar power system, scoring as one of the best provinces for sunlight levels, cash rebates, and installation costs.
This page contains all relevant information about installing solar in Alberta including utility policies, system financing, solar incentives, and natural factors
This guide is sponsored by Solar YYC, a residential and commercial solar developer serving all of Alberta. to visit their website and to get a free cost estimate.
The guide begins by answering the two most common questions about solar systems, then it explores each solar ranking factor.
You can read from top to bottom, or skip to your preferred section by clicking on it below:
|3. System Costs|
How Much Output Do You Get From Solar Panels
How much power do solar panels produce? is a question we often receive from consumers. In our experience, they could be asking about either of the following two things:
- Solar panel power output rating: This is the output capacity of an individual solar panel, measured in watts. It varies from model to model.
- Solar panel production at a specific place : The energy production of an individual solar panel over a time period, installed in a specific place .
These are both crucial things to know for anyone interested in, or already using, solar power. The good news is that both of these concepts are closely related, and relatively easy to understand.
Once you understand solar panel output, we can move on to asking the big question: How much electricity will solar panels produce on my house, and how many modules do I need to cover my electricity bill?
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Is Residential Solar Right For You
Now that you know solar panels can work even when the sun isn’t directly shining and that there are ways to store your energy for times your panels aren’t producing electricity, you may be more interested in installing your own system.
You can get started with a free, no-obligation quote from a top solar company in your area by filling out the 30-second form below.
Are All Solar Panels Equally Efficient When There Is No Sunlight
The answer is, No. All the solar panels perform best when there is an optimum level of sunlight. It means when the condition is not too hot or cold.
In regions like Europe and North America, summer is the ideal season for the best sunlight. However, as discussed earlier, solar panels work during the winter as well, even at a lower efficiency.
The ability of solar panels to capture sunlight depends on their size and power.
Smaller solar panels will take more time to capture and generate solar energy. This is why to work efficiently, the installation of a larger number of units is required.
On the other hand, bigger solar panels are needed in fewer numbers to capture the same amount of sunlight and produce electricity.
The efficiency of solar panels also depends on the type of solar panels. For example, three types of solar panels, amorphous, polycrystalline, monocrystalline, have different efficiency.
Amorphous solar panels need very little light to produce solar energy and can work even in shaded locations. However, these panels are quite inefficient compared to mono- and polycrystalline panels and need in more numbers to deliver the same energy.
Polycrystalline solar panels are more efficient than amorphous panels and can work well in changeable weather conditions. Though the level of efficiency of these panels much lower than polycrystalline panels.
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Snow Doesn’t Stick To Panels For Long
In order to maximize sun exposure, solar arrays are mounted at an angle. Combine this steep angle with the slick glass surface of the solar panels, and you have an object that snow just cant stick to for long.
Arrays have one more thing that really makes it hard for snow to hang around. Heat.
The dark silicone cells of solar panels are designed to absorb heat from sunlight. Once any portion of a panel is exposed to the sun, a small amount of heat spreads throughout the panel and melts the snow. You see this same effect with a blacktop driveway, once a hole in the snow becomes exposed to the sun, it quickly grows. Once a bit of your array is clear and absorbing sunlight, the rest will follow.
Thanks to array design and installation, snow on panels rarely lasts for more than a few days. Youll even see solar panels completely snow free while the rest of the roof is still covered in snow.
Putting It All Together
With those variables in mind, we can roughly estimate the number of solar panels for home that you’ll need. In this example, we’ll use the average annual energy consumption, solar panel wattage and hours of sunlight that we mentioned earlier.
Let’s say that your property receives four hours of sunshine each day, and you’re purchasing 325-watt solar panels. In that case, each panel can generate 1,300 watt-hours per day . Assuming that your energy usage is in line with the average of 29 kWh per day, you’d need 23 325-watt panels to create enough electricity for your home.
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How Much Power Does A Solar Panel Produce Over A Month Or A Year
When we measure a solar panels output over time, we use the unit kilowatt hours . It is equivalent to 1000 watts of continuous power production over 1 hour.
Now lets look at:
- What is the solar panel output of different modules based on their wattage rating
- How many solar panels would be needed to power a 6 kW solar panel system
Solar panel output by power output rating
|SunPower Maxeon 3|
*Based on an average of 4 peak sun hours per day and average month length of 30.4375 days. Expect power output to vary over the year due to day-to-day changes in weather and seasonal changes in climates.
The above table is useful in helping you get an idea of how many solar panels you need to reach a desired power output. It allows us to answer the following questions:
How Do Solar Panels Generate Electricity
PV solar panels generate direct current electricity. With DC electricity, electrons flow in one direction around a circuit. This example shows a battery powering a light bulb. The electrons move from the negative side of the battery, through the lamp, and return to the positive side of the battery.
With AC electricity, electrons are pushed and pulled, periodically reversing direction, much like the cylinder of a car’s engine. Generators create AC electricity when a coil of wire is spun next to a magnet. Many different energy sources can “turn the handle” of this generator, such as gas or diesel fuel, hydroelectricity, nuclear, coal, wind, or solar.
AC electricity was chosen for the U.S. electrical power grid, primarily because it is less expensive to transmit over long distances. However, solar panels create DC electricity. How do we get DC electricity into the AC grid? We use an inverter.
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Innovative Technologies That Have Made Solar Cells Work In Cloudy Weather
Scientists at the University of British Columbia have developed a sustainable and economical method to make solar cells using a specific type of bacteria that can convert light into energy!
These bacteria-powered solar cells can even work during the overcast weather.
Initial experiments have shown that the solar cells can work efficiently both in dim and bright light. Also, these cells can generate a current, which is stronger than any similar event recorded in the past.
This unique technology is ideal for implementing in regions like Northern Europe and Canada, where cloudy and colder weather is common. Other environments, including deep-sea, and mines, could also be considered for implementation.
This innovation may have taken a great stride toward wider adoption of solar power in areas like British Columbia where cloudy skies are common.
Another innovative technology has been developed by scientists in China. They have created graphene-coated solar panels that can produce electricity from raindrops.
To make these solar panels, Chinese scientists have applied a thin layer of graphene to enable the panels to produce power from rain.
Raindrops have natural elements like salt, which splits into forms of ions, which are ammonium, calcium, and sodium. The ions, along with graphene and water, make a suitable combination for generating electricity.
The thin layers that scientists use have a variance between them, and this variance is strong enough to generate electricity.
Can Artificial Light Power A Solar Panel
The short answer is yes, artificial light can power a solar panel.
Depending on the wattage, the number of bulbs, and distance the solar panel is from the light source will determine how strong a charge the solar panel receives, and how much wattage the solar panel will then be able to produce for powering other objects.
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Storing Solar Energy To Use On Cloudy Days And At Night
During hours of peak sunlight, your solar panels may actually generate more power than you need. This surplus power can be used to provide extra electricity on cloudy days or at night.
But how do you store this energy for future use? There are a couple of options to consider:
You can store surplus energy in a solar battery.
When you add a solar battery to your residential solar installation, any excess electricity can be collected and used during hours of suboptimal sun exposure, including nighttime hours and during exceptionally cloudy weather.
Batteries may allow you to run your solar PV system all day long, though there are some drawbacks of battery storage to be aware of:
- It’s one more thing you need to install.
- It adds to the total cost of your solar system.
- Batteries will take up a bit of space.
- You will likely need multiple batteries if you want electricity for more than a handful of hours. For example, Tesla solar installations require two Powerwall batteries if your system is over 13 kilowatts.
You can use a net metering program.
Net metering programs enable you to transmit any excess power your system produces into your municipal electric grid, receiving credits from your utility company. Those credits can be cashed in to offset any electrical costs you incur on overcast days or at night when you cannot power your home with solar energy alone.
Finding The Right Light For Any Weather
Outdoor solar lights are a great addition to the outside of your home, and its good to keep in mind that different times of year can have different effects on how well they will perform.
Remember that solar lights work best in direct sunlight, so cloudy weather can diminish how well they perform. Depending on where you live and the amount of sunlight you get throughout the year, you may choose to either store your lights for some part of the year, or strategically place them so that they receive the maximum amount of sunlight possible.
In extremely cold temperatures, your solar lights may actually work more efficiently, but not in extremely hot ones. Most solar lights are engineered to withstand a wide range of temperatures, so there is no one rule of thumb regarding when to take them inside for storage according to temperature.
However, other extreme weather conditions, such as severe rain or heavy snow may risk breaking the glass or diminishing the lights ability to absorb sunlight. Make sure to consult the information included with the solar light you purchase to find out about its individual capacity.
No matter what the weather brings, outdoor decorative or landscape solar lights are a great addition to the outside of your home, and Outdoor Solar Store has all the info to get you started.
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How To Get Started With A Solar Battery
Getting started with a solar battery bank is as simple as getting started with the rest of a solar energy system. Heres a step by step guide:
How Many Solar Panels Do You Need For 1000 Kwh Per Month
A family with several siblings can easily reach a monthly consumption of 1,000 kWh. In places with expensive electricity, this results in monthly electric bills of over $200. However, solar power is an effective solution to reduce energy expenses.
As explained above, the number of panels needed to reach 1,000 kWh per month changes depending on local sunshine and panel wattage. To simplify calculations, solar radiation is specified in peak sun-hours per day. Weather scientists calculate this value by measuring the total sunshine in a location and converting it to equivalent hours of peak sunshine.
- Peak sun hours should not be confused with daylight hours
- Since sunlight is moderate in the early morning and late afternoon, these hours do not count as complete peak sun hours
- You may find a site that gets 12 hours of average daylight, and 6 peak sun hours per day
There are many online databases that provide peak sun hours based on site coordinates, including the Atmospheric Science Data Center from NASA. Once you know the peak sun hours, estimating the number of solar panels needed for 1,000 kWh is simple.
- The first step is calculating the kilowatts needed. You must simply divide the average daily kWh by the peak sun hours
- Assuming a 30-day month, an electricity generation of 1,000 kWh is equivalent to 33.33 kWh per day
- If the site gets 6 peak sun hours per day, you need 5.56 kilowatts
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Can Solar Lights Charge Through Windows
Built-in batteries are dissimilar. Lithium-ion ones are beneficial. They are lightweight, compact, and long-lasting. These storage media have not less than 1,000 recharging cycles. They are energy-dense and heat-resistant. The batteries withstand temperatures up to 100° F.
Do you live in a region with a hot climate? In Texas or Florida, extremely hot days happen in August and July. Will the best solar landscape lights operate when the temperatures exceed 104°? The batteries recharge, losing about 10% of their life. The same happens in winter, at below-freezing temperatures. Battery capacity and energy conversion rate matters.
Charging Your Solar Batteries On Cloudy Days
First off, I want to reiterate that even on cloudy days, solar panels do collect some charge.
It wont be as strong as on bright, sunny days, but theres still solar energy being sent down to earth from the sun.
That being said, the best way to charge solar batteries or lights on cloudy days is with the use of an amorphous solar panel rather than the more popular polycrystalline or monocrystalline panels.
Amorphous panels arent as efficient as poly and monocrystalline panels, but they gather more light energy from cloudy skies because of their nature.
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