Flat Roof Solar Panel: 11 Pros & Cons (What To Watch For During Installation)

For those interested in how this technology might serve as a viable renewable energy alternative to power their flat-roof home, RV, or other property types, this article will provide a step-by-step overview of the pros and cons of flat roof solar panel installation, as well as tips and tricks for prospective installers.

As a means of reducing individual carbon footprint, solar panels are the renewable energy source that keeps on giving. They take the edge off carbon emissions, lower dependence on non-renewable energy, and lower energy costs for households and businesses.

Using a flat roof solar panel system has become popular as an emergent technology within the solar panel movement for their tendency to blend in with the environment and construction architecture.¹

What Is a Flat Roof Solar Panel & Solar Shingles?

Flat roof solar panels are solar panels built on flat roofs rather than roofs with a slant. This means that in order to maximize sunlight exposure, the panels must be mounted on frames.

They expand the surface area of a flat roof to power the home, allowing the benefits of solar energy conversion to be reaped by users across a variety of home setups and property types.²

As with most investments, there are two sides to the coin.

To start with the positives: flat roof solar installation boasts reduced overall costs, greater self-sufficiency, and even the possibility for buyers to see a return on their investment. This system provides safety from external shocks, both natural and economic.

In an increasingly unstable world, that’s got to count for something. It’s also a clean energy source that produces little to no carbon emissions during operation, reducing greenhouse gas emissions for the betterment of future generations and the health of the planet.

However, that doesn’t mean there isn’t an eco-cost to solar panels. The mining, manufacturing and disposal of the panels (and the battery systems) is emission intensive.

Though these upsides are promising, potential buyers should be aware of the caveats. Switching to solar often incurs high initial costs, and the subsequent building process can be troubled by limited or compromised space, installation challenges, reduced effectiveness in certain climates, and potential roof damage.

Those hoping to increase their home energy effectiveness should note that flat-roof solar panel performance is more easily compromised by debris buildup (dirt, grime, and all the natural elements) than a traditional slanted-roof setup, and thus requires a greater degree of maintenance and inspection to see a true return on investment.

Flat Roof Solar Panels: Pros and Cons of Solar Panels on My Roof

Flat roof solar panels offer several advantages and some downsides. Prospective buyers should be mindful of the following arguments for both sides of the coin.

Pros of Solar Panels on Flat Roof:

You can see below a list of the positive sides of having solar panels on a flat roof.

1. Increased Energy Efficiency

One of the primary benefits is that they can increase the energy efficiency of a building, significantly reducing their reliance on grid electricity.

The generated electricity can power a host of devices, even stuff like HVAC systems, reducing the need for electricity from the grid.³

2. Reduce Energy Costs

For buyers daunted by the upfront cost of flat roof solar panels, it may be instructive to think of home energy costs in the long term (mileage varies, buyer beware).

The initial installation costs can be high, but the panels can last two to three decades, so the cost savings can end up being substantial.

Solar electricity can supplement or even supplant the costs of the grid, saving homeowners the need to pay future utility bills.⁴

3. Greenhouse Gas Reduction

Flat roof solar panels are a clean energy source. What that means is that they don’t emit carbon dioxide or other gasses when used, reducing greenhouse gas emissions. The reduction of a building or house’s carbon footprint, however small, benefits worldwide efforts to fix climate change.

In Australia, this is already happening, with coal power plants shutting down, and new solar farms springing up, not only in Australia but many other countries around the world.

Individuals can mobilize this change by choosing how to install solar panels on roof (flat or otherwise). Also, flat-roof solar panels can decrease fossil fuel use and thus decrease dependence on non-renewable energy.⁵

However, the emissions aren’t zero. There is a carbon footprint for solar panels and the batteries the system uses to store electricity.

The mining of the materials is especially carbon intensive, and so is the proper disposal. Moreover, when placed on the ground, the eco damage can be significant.

Solar panels aren’t a magic solution, but when installed on existing structure, like flat roof solar panels, they can decrease emissions from coal and fossil fuel generators.

4. Make Some Bucks From Sunshine

With net metering options, homeowners can reduce their utility costs by transferring surplus energy to the main power grid.

Surplus electricity can be sold back to the grid. In some cases, this can offset the cost of the initial installation and some experts now suggest that costs are overall close to conventional pitched roofs when compared with the cost over the entire lifetime of use.⁶

However, you will need a certified electrician from the power company to perform the connection.

5. Minimum Maintenance

Flat roof solar panels require regular maintenance or lubrication, but not much more than occasional cleaning to keep the panels operating at peak effectiveness.^6,7

Cons of Flat Roof Solar Panels

Regardless of the positives of flat roof solar panels, there are also potential downsides for interested buyers to consider.

6. Higher Upfront Investment

A big downside of flat roof solar panels is their very high initial installation costs.^8,9 Users must be equipped to put down a considerable sum of money with hopes of getting back a return over 2-3 decades. That’s never an easy sell.

This renders solar panel installation outside the budget of many buyers, especially for those who have smaller budgets or those who can’t get financing to cover installation.

Given the present financing climate in the U.S., where interest rates are skyrocketing, this option may prove to be less viable in the short run.¹⁰

The solar tax credits available to homeowners can help reduce these high upfront costs.

7. Less Effective in Certain Climates

Solar panels work optimally in sunny climes with clear skies and few obstructions.

When there are areas that have a lot of cloudy or overcast weather, the panels may not generate enough electricity.⁸ Think of places that rain a lot and stay cloudy, like Seattle or London.

8. Limited Space

Some prospective buyers may be challenged by issues of scale, as sometimes the roof is too small to have a meaningful solar installation.

Buyers must also take into account t shading from surrounding structures, or from the building itself.⁹

If a building has limited roof space, it may be difficult to install enough panels to create the right amount of electricity, and that would lead to a reduction in cost savings or even a situation where it just isn’t viable.

9. Installation Difficulties

Problems may crop up out of nowhere, especially when the buildings have complex roof designs or limited access.

If one needs to climb up with climbing gear or use special machinery, the overall cost of installation increases.¹² The type of solar panels chosen can also add to the complexity of the issue.

Existing structures on the roof, such as drains, parapets, vents, curbs, exhaust fans, and other structures built on the roof add further annoyance to the task. It may be advisable to consult an expert for these considerations.¹³

10. Damaging the Roof

Solar panels can create damage to the roof itself. The weight of the panels and the installation process can deteriorate the roof membrane, leading to leaks and other problems.

Roofs are one of the most precious parts of a house, so it’s understandable when homeowners are concerned with keeping them in top condition.

11. Finding the Right Man for the Job

Some installers do not install flat roof solar panels, so it is good to check with the local installers ahead of any purchase decisions.

This may vary depending on location and how skilled the local installers are, or if they are available at all.

Choosing the Right Flat Roof Materials

There is a wide range of flat roof materials to choose from when planning your flat roof solar panels installation.

Solar Panel for Flat Roof: Options

Solar panels for flat roofs come in different types, the most common types being:

Crystalline Silicon Panels

Known as the most common type, these panels are made from silicon wafers and are highly efficient. Two types of crystalline silicon panels exist: monocrystalline and polycrystalline.

Monocrystalline panels are made from a single silicon crystal, while polycrystalline panels are made from multiple. The former is more efficient than the latter, but they are also more costly.

Thin-Film Panels

Thin-film panels are made from a layer of photovoltaic material, framed by a base material.

Such panels are flexible and light, which makes them ideal for flat roofs that won’t tolerate much weight. On the flip side, the panels are less efficient.

However, innovation has allowed this type of panel to be employed on flat roof solar systems.

Building-Integrated Photovoltaics (BIPV)

With building-integrated photovoltaics (BIPV), the panels are integrated into the building’s design like solar shingles or solar tiles.

BIPV panels can be a good option for flat roofs, as they can blend seamlessly into the building’s design while generating electricity, perhaps even contributing to the structural strength of the roof.

The flip side for them is they are more expensive.

CSP & OPV

CSPs (Concentrated Solar Panels) use mirrors or lenses to direct the sunlight into a small area, which then heats the fluid to create electricity.

That seems wasteful but CSP panels can be a good option where space is an issue, as they require less space. On the flip side, CSP panels tend to be pricey and may require specialized gizmos and professionals for setting them up.

Organic photovoltaics, or OPVs, are made from organic materials. OPV panels are lightweight and flexible, but also less efficient than crystalline silicon panels and may degrade more quickly over time. One wonders how plants are so much more efficient with sunlight.

Cost Analysis

Many buyers wonder just how much solar panels cost, and the answer often depends on a range of factors. The cost of installing solar panels on a flat roof can differ based on the type of solar panel, the size of the system, and the complexity of the installation.

Theoretically, users will be saddled with a large cost upfront that will provide greater returns over decades. These costs upfront are substantial, as they include the cost of the solar panels themselves, the cost of installation, and any needed electrical upgrades.

The amount spent on solar panels can vary, with crystalline silicon panel costs generally ranging higher than thin-film panels.

The upside is that they play a role in reducing or even eliminating the building’s electricity costs. Additionally, there may be incentives and tax credits for installing solar panels.

The return on investment (ROI) varies. It’s good to know that some solar panel systems will pay for themselves within a decade. But that may not be the typical buyer’s use case. Mileage varies, so buyer beware!

Maintenance Costs

Maintenance costs are low but not zero, as they require little upkeep beyond occasional cleaning and inspections. It is still good to factor in the cost of any repairs or replacements over the lifetime. To know more, read how much do solar panels cost.

Finance

In 2023, with the dark clouds of a recession looming overhead, there are few easy financing options and many potential buyers may hesitate. Some options are leasing, power purchase agreements, loans, and lines of credit.

Prospective buyers also may do well to consider that investing in a solar panel system may help to hold capital in a useful productive asset (i.e. solar), rather than rely on cash value with inflation. That’s a serious consideration in today’s high inflation times.

Thankfully, many states offer solar incentives, which include financing options for homeowners and businesses.

Installing Solar Panels on Roof: How It’s Done? (Rooftop Solar Panel)

Because the installation of solar panels on a flat roof is often a complicated and labor-intensive pursuit, the best advice is to leave it to the professionals.

The process involves several steps, such as site assessment, design and engineering, permitting, and installation. For buyers who might be up to the challenge of DIY installation, keep in mind the following tips and tricks:

Assessing, Engineering & Permit

Assessing the site is crucial to the process of getting solar panels up and running smoothly. To ensure the viability of installing solar panels, prospective buyers and helping professionals must consider the roof’s orientation, shading, size, and pitch (angle) of the roof.

To be sure that the solar panel system can be accommodated, it’s essential that the building’s electrical systems must be thoroughly assessed.

After the site inspection, users should draw from their findings to determine the optimal configuration, type of solar panel, and system size for future engineering. By taking time to complete thorough drawings and calculations, the engineers make sure all local and national codes and standards are met.

Right before flat roof solar panels are installed, the appropriate permits must be obtained from the local government. This requires buyers to submit detailed designs and documents for inspection and approval to the local building department. A happy bureaucrat and plenty of red tapes can be expected.

Installation (Finally!)

Once permits are complete, homeowners can expect to finally begin the installation process.

If the buyer isn’t exhausted by now, there are a bunch of steps involved, including mounting hardware, attaching the solar panels to the mounting gear, and wiring the solar panels to the electrical system.

Flat roofs may require custom mounting hardware, which can add complexity and cost, and possibly a headache (buyer beware!).

How It’s Done?

Installation starts with finding the right place for mounting hardware. The mounting hardware includes brackets that are attached using screws or some other means. These could then be put together using rails or frames, with the solar panels getting attached to the frame.

Then, finally, after the mounting hardware is in properly, solar panels are attached to the hardware using clamps or clips. These panels are usually built in rows, with each row consisting of several panels. They are then wired together using cables.

The final thing one needs to complete is creating the connection to the electrical system. It is complicated and would involve the installation of an inverter, which converts the DC power generated by the solar panels into AC power. The inverter is typically located near the electrical panel.

Sustaining the System

Once the solar panel system is installed, it needs minimal maintenance beyond occasional cleaning and inspections.

In the best-case scenario, flat-roof homeowners can enjoy their newfound insurance against grid outages!

What Are Some Basic Things To Consider Before Installing Solar Panels on a Flat Roof? Can You Put Solar Panels on a Flat Roof?

Even optimistic buyers in the solar panel market must face the fact that solar panels present different challenges for a flat roof when compared to pitched or sloped ones. To begin with, tilted roofs are easier to keep clean with either rain or sprayed water.

An upwards tilt is mandatory to get any kind of efficiency, as otherwise, they wouldn’t get enough sunlight.

Severe storms, heavy rains, and wind load also require both roofing and solar panels to have some degree of tilt to be durable, depending on the installation type – whether free-standing or fixed racking and also depending on the type of building – whether it be a wooden roof or a concrete building.

Because of the reasons mentioned above, a minimum of 10 degrees of tilt is needed, although 20-50 degrees is preferable. Generally speaking, it’s not possible to get the power capacity from the same surface area with a flat roof, because of shading from solar panels or parapet walls, which in turn needs spacing, which ultimately means fewer square feet to play with. Still, better than no solar panels at all.

What Kind of Return Can You Expect From Your Flat Roof Solar Panels?

It depends. A host of circumstances, ranging from local electricity costs, location, climate, local or federal incentives, and the ability to sell electricity to the grid all affect the cost, efficiency, and financial benefits of going solar.

Be wary of general figures, as they will vary widely, particularly from solar roof panel companies that are less scrupulous and tend to give highly unrealistic estimates. This has been a source of a number of scandals in recent years, with negative returns for some buyers.

To learn more about the power produced by a solar panel to better assess the return buyers can expect from their flat roof solar panel, here’s an article on how much power does a solar panel produce.

Frames for Solar Panels: What Are They?

Frames for solar panels provide structural rigidity.

They can also help with issues like heat dissipation and electrical safety. In case of wind or a storm, the frames make sure the panels don’t break off or bend in a way that damages them.

How Much Do Solar Panels Weigh?

While not an MMA weigh-in, weight does matter because of the structural integrity of the roof. Some roofs are just not designed for heavy loads placed above them, especially when there is a storm.

There is no one answer to how much solar panels weigh, as it all depends on type, size, and manufacturer.

However, generally speaking, residential panels range from 33 to 50 pounds (15 to 23 kg) and commercial panels are larger and can weigh more, ranging between 50 to 70 pounds (23 to 32 kg).

How About Solar Panel Systems on Aliexpress?

Users looking at systems in the $10-$20 range, should note that these are used mostly camping, and won’t have the capacity to handle more substantial household energy needs. A $20 setup with 3-4 LED bulbs might be better suited to act in case of an emergency grid outage.

In the $50-$500 range, buyers can expect to find a range of products better equipped to use for an RV setup, or even a small cabin in the woods, depending on bandwidth.

Closer to $1000 and above, certain offerings could be worth using in a very small house without major energy needs, provided that conditions for installation and the lump sum of upkeep costs are ideal for the buyer.

Are There Any Major Safety Considerations?

For those wondering about the safety of flat roof solar mounting, it’s definitely much safer for the people installing it.¹²

Complications may arise from angling the panels, such as the need for solar panel stands, which in

How To Become a Solar Photovoltaic Installer

In most cases, a solar installer needs at least a high school diploma or equivalent and on-the-job training for about a year to become a professional installer.^18,20

Solar energy is a rapidly growing industry, so a career in this sector may prove to be lucrative. Robots probably won’t take over solar panel installation jobs anytime soon!

What About Solar Panels on Membrane Roof?

For this setup, the installer needs to make sure when installing on a membrane roof that the membrane is thick and solid enough to withstand the installation, from a structural and load-bearing point of view.

This is especially true for single-ply membrane roofs.¹³

Do Solar Panels Work on Cloudy Days?

To those wondering, “Do solar panels work on cloudy days?”

Solar panels are less effective when it’s cloudy. Yet, this doesn’t mean they won’t work entirely. The key to the answer is “How cloudy?” For more info here’s an article on what does a solar panel do?

How To Connect Solar Panel To Battery

Storing solar energy is not as simple as knowing how to connect solar panel to battery.

The answer to this depends on the specific type of solar panels and battery system. Very simple solar panels can directly connect to a small solar battery or even a spare power bank.

This is actually a favorite combination for backpackers and road trip enthusiasts who own a small panel that connects to charge a cellphone or power bank, and perhaps a small LED lamp with its own small battery.

More high-end systems need the solar panel to be connected to a charge controller, which is then linked to a battery. It’s not rocket science, rather it’s basically three subsystems with the controller as the middle subsystem.

Many systems utilize an inverter to get the right kind of electricity. You can learn more about such systems by reading this article about design of solar panel.

Nature’s Karma: Benefits of Flat Roof Solar Panels

Putting together a solar panel system on a flat roof has various environmental advantages. It is a sustainable energy source that, unlike some others, does not generate greenhouse gases or pollutants during operation, such as traditional fossil fuels.

As a result, at least locally, the use of solar energy can help limit climate change and improve air quality, allowing users to consciously channel their buying power toward making a difference in their community

Greenhouse Gas Emissions

Solar panels do not emit greenhouse gases.¹⁴ Owners of such wondrous systems can reduce their carbon footprint and contribute to the global effort to reduce greenhouse gas emissions.^15,16

Reduced Energy Consumption & Water Usage

Solar panels installed on a flat roof can become less reliant on traditional fossil fuel-generated electricity, which can be expensive and prone to price volatility, by harvesting their own electricity.

Coal power plants require a lot of water to generate electricity. When substituted with solar, this water can be saved.

Breathe Better

Fossil fuel use emits pollutants into the atmosphere such as sulfur dioxide, nitrogen oxides, carbon dioxide, and particulate matter. These contaminants have been linked to respiratory issues, heart disease, and other health issues.

Less Land Needed

Solar panels can be put on existing structures like buildings, allowing users to optimize the property they already own. This definitely leaves more room for nature and biodiversity.

Recycling of Flat Roof Solar Panel

At the end of their life cycle, solar panels can be recycled to recover stuff like glass and silicon, which can then be reused to make more solar panels or other electronics.

Recycling reduces waste and conserves natural resources.^16,17

It’s great that solar panels have grown in popularity in recent years, and their installation on flat roofs provides a chance to harvest electricity in a limited space. In this article, the benefits and drawbacks of flat roof solar panels, the various types of solar panels available for flat roofs, the cost of installing solar panels on a flat roof, and the environmental benefits have all been discussed.

The upside of flat roof solar panels is clear: buyers generate their own electricity and reduce their reliance on the grid. Also, their carbon footprint solar panels are smaller, while also helping to reduce greenhouse gases.

Flat roof solar panels can also help to reduce land use and preserve the natural habitat.

On the flip side, the initial cost of installation, the necessity for ongoing maintenance, and the possibility of panel shading or obstruction exist.

The National Renewable Energy Laboratory (NREL) predicts that solar will account for 45% of all power generation in the US by 2050,^13,20 with decreasing costs and increasing efficiency.

In short, the flat-roof solar panel is an increasingly attractive option.

Frequently Asked Questions About Flat Roof Solar Panel