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4 Factors That Can Affect Solar Panel Production

By Solar Panel Efficiency - Pick the Most Efficient Solar Panels No Comments

Not all solar panels are created equal. Power ratings, efficiency ratings, and degradation rates are just a few of the qualifications that set solar panels apart from one another. While this is true, there are a variety of other real-world factors that determine how much energy your system will produce throughout the year.

Tilt, orientation, latitude, and climate can have major impacts on a solar system’s performance so if you are planning to offset your electric bill with solar it is important to understand how these factors can impact solar production.

The Tilt of Solar Panels and the Effect on Solar Panel Production

The tilt of your solar panels can have a major impact on the overall output of your system. Ideally, you would want to adjust the tilt of your panels throughout the year because the sun is higher in the summer and lower in the winter. However, systems that track the sun are more expensive and require maintenance because they have moving parts. Every fixed tilt system has an optimal angle where it will make the most out of each season, and, while a few degrees may not make a drastic difference in efficiency in a single year the difference over the lifetime of the system could be much more substantial.

Related reading: How To Choose Solar Panels for Your Home

Can Latitude Affect Solar Panel Production?

Latitude also has a major impact on solar system production. Systems installed at higher latitudes will yield lower production numbers solar-panel-productionthroughout the year due to the tilt of the earth as it spins on its axis. A homeowner going solar in the northeastern United States will require a larger system to offset their bill than a homeowner in the southwest. Unless you are willing to relocate, there is not much you can do to improve your system’s performance when it comes to latitude other than anticipating diminished production and size accordingly.

Solar Panel Placement and the Effect on Production

Where you place modules on your roof can have a major impact on production as well. The best direction to position your modules is south facing, with the second best being west and the third option being east. North facing roofs can provide enough production in some cases to make it worthwhile to install panels, but more often than not north facing azimuths are not recommended. While you cannot control how much roof space is available to each azimuth you can be strategic about how you use your available roof space to optimize the production of your system.

How Does Climate Affect Solar Panel Production?

Climate can also have major impacts on a system’s performance. For example, there is a common misconception that modules will produce less in cold environments. In fact, the opposite is true. Heat is the enemy of efficiency, and cold environments can keep solar systems from overheating and losing efficiency. Furthermore, snow is reflective and concentrates sunlight improving overall irradiance. So as long as you keep the snow from burying your modules, your system will benefit substantially from the cold environment. Understanding how your environment will impact your system from season to season is of paramount importance when designing a solar system to meet your energy requirements.

Knowing what factors affect solar panel production is important to ensure that you get the most savings possible out of your system. If you have any other questions about solar panel production or would like to speak with one of our trusted solar educators, please call (888) 454-9979.

Tesla solar roof

Cost of a Tesla Solar Roof vs Solar Panels

By Tesla Solar Roof: Everything You Need to Know No Comments

There’s no question that the Tesla Solar Roof is among the best looking rooftop solar systems on the market. When it was unveiled in 2016, there seemed to be a collective sense of “Wow, this is what the future of solar looks like.”

But it appears that future is still a ways off. In 2019, Tesla CEO Elon Musk tweeted that he was hoping to manufacture “~1,000 solar roofs/week by the end of this year.” But in the second quarter of 2022, Tesla was deploying about 23 roofs per week.

Much of the slow adoption is due to cost. The Solar Roof was expensive to begin with and the price has been moving in the wrong direction since hitting the market.

So how much does a Tesla Solar Roof cost? In this article, we’ll compare the cost of a Tesla Solar Roof versus the cost of a rooftop solar panels to give you a better sense of your options for going solar.

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How much does a Tesla Solar Roof cost?

The cost of a Tesla Solar Roof has always been somewhat of a moving target. It’s typically around $6 per watt before the solar tax credit is applied, but can vary quite a bit depending on roof, system size, and year.

Tesla recently removed instant quotes from its solar savings calculator, but we crunched the numbers on a Solar Roof sold in 2020 to see what it would look like today.

In 2020, LinkedIn engineer Robby Valles posted his solar contract on Twitter showing a gross cost of $34,067 for a 7.37 kW system, including removal of his existing roofing material. That boils down to $4.62 per watt, which is not an astronomical price, but it’s definitely more expensive than a traditional solar panel system.

But the cost of the Tesla Solar Roof has since gotten more… interesting. First, Tesla introduced a “roof complexity” variable that increased the cost of Solar Roof projects by 30% to 150%. It even sent emails to customers who had already signed Solar Roof contracts asking them to sign a new agreement for a higher price or cancel their order, leading to lawsuits. Recently, it made purchasing a Powerwall battery a requirement to buying a Solar Roof, adding at least $10,500 per battery to each project.

A minimum 30% roof complexity price increase brings Valles’ gross cost to $44,287. With the mandatory Powerwall, Valles’ Solar Roof system would cost at minimum $54,787 today, before claiming the 30% federal solar tax credit.

Let’s see how that compares to a traditional solar panel system.

Tesla Powerwall

At least one Powerwall is required for each Solar Roof project.

Tesla Solar Roof vs solar panels

Alright, let’s say Valles chose the solar panels route instead. How much would his project cost?

According to Wood Mackenzie, the average cost of an 8 kW residential solar system is expected to dip below $3 per watt in 2023. But to be conservative, let’s call it $3.25 per watt.

If Valles’ roof was in good shape, the gross cost of his 7.37 kW system would be $23,942. With a full $9,500 asphalt shingle re-roof, the cost rises to $33,443 and he’s still paying ~$11,000 less for solar panels than a Solar Roof.

And, by going the traditional route, Valles isn’t obligated to buy a Powerwall. However, battery storage can be very beneficial, especially once NEM 3.0 hits California, so let’s include it anyway.

Tesla Solar Roof vs solar panels cost

Tesla Solar Roof Rooftop Solar Panels
Solar system only $44,287 $23,942
Solar with re-roof $44,287 $33,442
Solar with re-roof and Powerwall $54,787 $43,942
30% solar tax credit -$16,436 -$10,332 (does not include re-roof)
Net cost (solar, re-roof, Powerwall) $38,351 $33,610
Net cost, solar only N/A $16,759

Bold = Minimum gross project cost. Figures for example use only and do not represent a binding quote.

Even with a full re-roof and a Powerwall, Valles could save nearly $5,000 by going with traditional solar panels. If his roof was in good shape and he didn’t want a battery (which he didn’t get with his Solar Roof in 2020) he could save over $21,500 by going the traditional solar route.

It’s important to note that the solar tax credit does not apply to traditional roofing work, but does apply to the Solar Roof since the roof itself is considered solar equipment, which helps even out the cost of a Tesla Solar Roof.

Is a Tesla Solar Roof worth it?

Whether a Tesla Solar Roof is worth the extra cost depends on your home, energy goals, and financial situation. At the end of the day, the Solar Roof is a luxury product and an emerging technology, which comes at a premium.

But keep in mind, if you’re in for a penny, you’re in for a pound. The Solar Roof requires at least one $10,500 Powerwall and the price of the solar system varies widely based on the complexity of your roof.

There’s also something to be said about the Solar Roof’s brief and rather erratic track record. Following the price increases (and ensuing lawsuits) in 2021, Tesla delayed and paused Solar Roof installations several times in 2022 due to supply chain issues. In some cases, customers were left with waterproof film protecting their roof for several months.

For some homeowners, have a sexy roof and being on the cutting edge of technology is worth the extra cost and risk of buying a Solar Roof — and there’s nothing wrong with that. However, homeowners looking for a more practical approach to reducing their energy costs and carbon footprint are better served by solar panels.

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Frequently Asked Questions

How much does a Tesla Solar Roof cost?

The cost of a Tesla Solar Roof is typically around $6 per watt, but varies based on your energy consumption, roof, and location. Roof complexity (panes, pitch, and obstructions) can substantially affect the cost of a Solar Roof project.

How long does a Tesla Solar Roof last?

Tesla Solar Roofs have a 25year product warranty for defects in design and materials. It also has a 20-year module warranty that guarantees the output capacity will decline by no more than 0.5% per year.

Does Tesla Solar Roof increase home value?

Going solar in general can increase the property value of a home. The exact figure varies by location and data source. In 2019, Zillow found that, on average, homes with solar panels sold for 4.1% more than comparable homes without them. Kelly Roofing in Naples, Florida has the figure closer to 11%.