Why Face Solar Panels South
Photovoltaic solar panels produce electricity from light. More light means more electricity. You might have heard that a South-facing garden gets more light than a North-facing garden. Well, its the same for solar panels. Researchers have found that in Ireland, South-facing panels produce the most electricity. So why is South not always the best direction for solar panels?
Utilize Solar Panel Trackers
If your budget allows, consider solar panel tracking systems. They can improve a systems output by ensuring constant, direct exposure to the sun, both during the day and across seasons. Axis trackers generate more electricity by using about the same amount of space as fixed systems.
However, its important to note that solar trackers are expensive. While a standard 4 kW fixed solar panel system costs about $11,400 after incentives, a single-axis tracking system that can produce the same amount of power – such as the Smartflower – is $20,000, or almost double that.
Best Seasonal Angle Of Tilt
A simple way to improve the efficiency of your solar system is to change the angle of tilt depending on the season.
Best angle for winter = latitude + 15°
Best angle for summer = latitude 15°
using these calculations for our Florida and Washington state examples uses the following results:
Florida Optimum winter angle = 27 +15 = 42° Optimum summer angle = 27 15 = 12°
Washington StateOptimum winter angle = 47 +15 = 62° Optimum summer angle =47 -15 = 32°
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If Your School Hospital Or Business Is Planning To Go Solar Make Sure That Your Solar Company Has A Good Plan For Positioning Solar Panels On Your Roof Parking Canopy Or Ground Mount
In the last couple years, installing a solar energy system on site has become more and more popular for homeowners and commercial solar customers like schools and businesses alike.
We know were biased, but our customers tell us they have good reasons to go solar. They save money on their electric bills, which can make a big difference, especially if they use a lot of power. Going solar also elevates an organizations reputation in their community by showing that theyre doing something serious to go green .
Then there are electric cars, coming soon to a garage or parking lot near you.
In the last few months, some of our customers have started thinking of joining the electric vehicle revolution, which seems to be coming now quicker than anybody predicted. Whether youre a small business trying out your first all-electric company car or a school district starting to build a fleet of electric school buses, going solar now will put you in the drivers seat to save even more money when you plug in your first EV. And you can go even deeper green by powering your EVs with clean energy from the sun, instead of mostly dirty energy from the grid.
Our customers also tell us that they did their due diligence before deciding to work with Secure Futures. And thats how it should be. Because if you choose the wrong company to install your solar array, you could be in for unwelcome surprises.
1. Solar Panels Facing South Maximize Solar Energy Production Usually
The Worst Direction For Solar Panels
Now Ive worked out the best direction, along with reasonable directions, I may as well work out the worst direction for each capital.
Below Ive listed the worst direction solar panels can face for each capital which is never very far from 180 degrees due south and what percentage their annual output would be compared to facing the optimal direction. Because the output varies according to the slope of the roof I have assumed it will be 20 degrees, which is a nice round figure between the most common slopes of 15 and 22.5 degrees. The results for both of these roof slopes will be very close to the figures below:
- Adelaide: 184 degrees 74%
About Ronald Brakels
Many years ago now, Ronald Brakels was born in Toowoomba. He first rose to international prominence when his township took up a collection to send him to Japan, which was the furthest they could manage with the money they raised. He became passionately interested in environmental matters upon his return to Australia when the local Mayor met him at the airport and explained it was far too dangerous for him to return to Toowoomba on account of climate change and mutant attack goats. Ronald then moved to a property in the Adelaide Hills where he now lives with his horse, Tonto 23.
Challenging The New York Times: Why Solar Panels Should Face South Not West
Ive always told customers due south is the best orientation for solar electric panels. So why does a recent New York Times article say west is best?
The article doesnt actually say west is best for solar owners, but its implied by the headline, and in todays 140-character world, too many of us dont read past the headline. Allow me to relay what the article does say, while throwing in my two cents.
In North America, south-facing panels are best. They maximize your systems production because were in the Northern Hemisphere and the sun is always to our south. Thats a fact.
The article confirms south is best: captures the most solar energy over the course of the day, which benefits the homeowner. West-facing panels capture more afternoon sun, but less sun overall. Who benefits from that? The utility, because electricity is most expensive later in the day when power demand peaks.
In the course of running this company and helping 450 people benefit from solar, Ive yet to see someone put solar on a roof to help their utility. In fact, most take pleasure in sticking it to the utility by decreasing their dependence on their local monopoly.
In our last customer survey, people said they put solar on their homes and businesses to reduce their electric bills and help the planet. Some also wanted to reduce our countrys reliance on imported and fossil fuels. But helping government-regulated utilities be more profitable? Funny, that one never came up
How Electricity Tariffs Affect The Optimal Solar Panel Orientation
Your panel can have different monetary values, so its important to know about the energy produced by a solar panel. If you are always charged the same kilowatt-hour price, your goal should be getting maximum production from solar panels.
However, many electric companies apply time-of-use tariffs, which change throughout the day. The highest kWh prices are normally billed in the afternoon and evening, since that is when the grid faces maximum consumption. There are many factors that increase operating costs, and this leads to higher tariffs:
- Electric companies must bring more power plants online to meet the peak in consumption, including the plants with high generation costs.
- Since power lines and transformers are carrying a high current, they waste more energy as heat emissions.
- Electrical faults are more likely when the grid is burdened, creating a higher risk of blackouts.
Many power companies apply higher electricity prices at times of peak demand to compensate for their higher operating cost. The high kilowatt-hour price also disincentives consumption in homes and businesses, helping unburden on the grid.
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Does My Roof Need To Face South For A Solar Power System Installation
In a previous blog post I offered some advice on what makes a house suitable for solar. One of the factors was the orientation of the roof to south, which Ill delve deeper into here.
The maximum energy production comes when the suns rays are perpendicular to a solar panel . This is sometimes accomplished by mounting a panel on a tracker. The tracker rotates the panel to continuously face the sun as it moves across the sky from sunrise in the east to sunset in west. Trackers are impractical for houses and rooftops in general but the concept is useful to demonstrate what the maximum production would be.
Now, the practical best case scenario is having the panel permanently fixed to face south. This is because in Canada the sun is always south of us at 12pm, when its intensity is highest.
So, beyond the obvious reasons, why dont we pick up houses and other buildings with cranes to have them face south? The simple answer is that having panels facing directly south isnt required for good production. Thats good, because houses arent built that way see the photo of a neighourhood in Mississauga, Ontario. I see one or maybe two houses that look like they might face directly south.
So how much of an effect does being off-south have? To determine this, we use the concept of azimuth, which is simply the angle that the panels face, relative to south, when looking from above.
Solar Panel Orientation In Cloudy Cities
Additionally, lowering the tilt angle of the panels on your solar roof can also contribute to the total economic benefits east and west-facing solar power systems provide. Panels facing directly east or directly west with a 30° tilt, produce about 20% below peak performance levels. If the tilt is dropped to 15°, production levels at the east and west extremes only decrease by about 15%. While this 5% gain may not seem like a significant difference, this slight change in panel orientation can be enough to save an additional $50-$75 per year even in cloudy cities.
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Can I Still Go Solar If My Roof Doesnt Face South
by Kelly Anderson, on Aug 12, 2020 8:44:00 AM
Making Sure Your Rooftop Is a Good Fit for Solar
Youll often hear the advice that to benefit from solar panels, you need to live somewhere sunny with a south-facing roof. Well discredit the first pointeven cities and states with gloomier weather can produce enough solar energy. In fact, extreme heat can be more harmful than beneficial to solar panels.
But what about your homes orientation? Is it necessary to have a south-facing rooftop? In the past, we suggested south-facing houses are best for solar, but well explain why the answer isnt a clear yes or no below.
Why Do People Say Panels Should Face South?
If the sun rises in the east and sets in the west, why should it matter if your house faces north or south? Well, the sun wont be straight over your home unless you live on the equator. In the northern hemisphere, the sun moves at a slight arch with a southern offset. Therefore, the general practice has been to install solar panels facing south to capture the most sunlight.
What If My House Doesnt Face South?
Even if your panels dont face directly south, your system can still produce large amounts of electricity. If your house is oriented east or west, you will only see a 20-percent decrease in energy produced. Despite this decrease in performance, your panels can still generate enough power to save you hundreds of dollars each year.
Can You Go Solar With A South
Anyone who has looked into installing solar panels in Australia would have quickly learned that north is the best direction for solar panels. If north is not an option, northwest and northeast are generally the next best options, usually followed by due west and due east, depending on the circumstances. But what about south-facing roofs are they a good place for solar panels?
A row of southeast-facing roofs with potentially significant shading from tall backyard trees.
The conventional wisdom says no solar should never be installed on a south-facing roof. Solar panels work best when theyre directly facing the sun, and the sun sheds the most light during the middle of the day, when its to the north of Australia. Interestingly, many solar calculator tools do not have south-facing options.
But as solar PV system prices have come down in recent years, the prospects of installing on a south-facing roof look reasonably good especially if the roof has is also facing slightly to the east or west.
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Solar Panel Tracking Systems
For ground-mounted panels, you might also consider installing a solar panel tracking system. Solar trackers maximize panel efficiency by rotating your panels throughout the day, allowing them to follow the movement of the sun from its rise to its set.
Just how much more efficient can a tracker make your solar panel system? One study showed that on a clear day, the average efficiency of a tracking panel was about 67%, while fixed panels only got about 40% efficiency.
As you consider solar panel tracking systems, you’ll need to decide between a single-axis or a dual-axis system. Single-axis systems only move in one direction, typically north to south. A dual-axis system allows for movement along the north-south axis and the east-west axis.
Dual-axis systems take up more space, and thus are mostly used in commercial settings. They can certainly be effective, enabling your solar panels to reposition in accordance with changing seasons when the sun is higher or lower in the sky, but they typically aren’t necessary for residential use.
Does My House Have To Face South For Solar To Work
The short answer is no. We can install panels on South, East, or West facing roofs. North is the only direction that we dont want to put panels on. Why is that?
Solar panels convert light into DC electricity. The sun doesnt have to be beaming directly on the panels at the perfect angle to work. Panels will even produce some electricity on cloudy days when you dont see an ounce of sunshine.
However, the more direct the sunlight is on the panels, the more electricity theyll produce. This means that placing your panels at the ideal angle will increase the amount of your electric bill that is offset.
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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 Energys National Renewable Energy Laboratory 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, youll need to use an installer network like EnergySage. You can receive free quotes from vetted installers local to you when you register your property on our Solar Marketplace homeowners who get 3 or more quotes can expect to save $5,000 to $10,000 on their solar panel installation.
2. The biggest installers typically dont offer the best price
The bigger isnt 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 by the U.S. government 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 dont overpay for solar.
3. Comparing all your equipment options is just as important
What Should Be The Direction Of Solar Panels On Your Roof
Are you considering switching to solar power for your home? One of the important things you will need to figure out first is which direction should your solar panels face on the roof.
In order for your brand-new solar panels to generate maximum power, you need to determine the best direction for them.
Generally, the professional who comes to install your solar panels will help you pick the perfect direction. However, if you live in the US, you need to follow the rule of thumb your solar panels should be facing the true south direction.
Why? Its quite simple: the more sunlight reaches your panels, the more electricity you will produce. That means lower electricity bills.
Regular South vs. True South
Regular south or also known as magnetic south is what the compass shows you. Thats right a compass doesnt show the true south.
A compass shows the south pole of the geomagnetic field of the earth. The general direction is right but not completely precise. The iron and nickel present in the earths outer core pull the compass needle a little away from true south.
The solar installer professional will calculate the magnetic declination of your location to rectify the compass reading. Another way to determine true south is to look at the shadows in noontime a time when shadows from vertical objects fall from north to south.
What to do if the Roof doesnt face South?
How to Choose the Right Tilt for Your Solar Panels?
One Exception to the Rule
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Real World Solar Panel Production Data
We have lots of real world data to back this up now. With the advent of microinverters, we now have data from many individual sites where there are solar panels with multiple orientations. One of my favorite sites to watch has panels on three roofs south, west, and east. Its also a two story house so there is essentially no shading on the roof from even distant trees or structures.
The residence has had solar panels for almost five years now. What we see at this house is exactly what we would expect. The east and west roofs are within 1% of each other, and both are about 10% less efficient than the south roof.
Here are graphs showing daily energy output on each roof.
East Roof Solar Production
East Roof Solar Production 1.44mWh Lifetime Energy
West Roof Solar Production
West Roof Solar Production 1.43mWh Lifetime Energy
South Roof Solar Production