What Type of Roofs Are Best for Solar Panels?

Sometimes, individuals focus on the cost of solar panels rather than the installation site when investing in clean energy. Although most roofs can sustain a renewable energy system, some are better than others.

As the prices of solar power systems decrease and more homes install panels, it’s vital to evaluate the structure of the roof to optimize green energy production.

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    If you are interested in investing in a PV system, you can start by evaluating the compatibility of your roof. Here are the factors you must understand before getting started.

    Roof Shape

    The shape of your roof significantly affects the number of panels it can contain. It also determines the amount of sun exposure the panels may receive.

    Gable, hip, and flat roofs are the most common types that hold PV panels.

    Gable Roofs

    Gable roofs create that conventional pyramid shape many homes have. They contain two flat, rectangular sides that come to a central point. Their uninterrupted geometry allows many solar panels to cover the entire extent of each side.

    The gable roof provides optimal solar panel placement. They score between 22% and 47% on solar receptivity charts. Just about any professional solar installation company can mount panels on a gable rooftop.

    Hip Roofs

    Hip roofs have slopes on four sides, coming together at a singular peak. These structures perform efficiently in extreme weather and high winds. They also contain a perimeter drainage system that keeps water from pooling on the roof.

    Hip rooftops offer optimal sun exposure for every home, no matter what direction it faces. The tapered shape of each side poses an issue for even panel alignment, however. This limits the number of panels a single roof can contain.

    Flat Roofs

    Flat roofs are less common on residential properties and more popular on commercial buildings. These rooftops provide a world of possibilities for solar system installations.

    The direction of the building does not matter when it comes to flat roofs because mounts can position any panel towards the sun. Flat rooftops have the highest solar receptivity rate and provide the largest amounts of solar energy.

    Roof Material

    Professionals also consider the material of your roof when evaluating its compatibility with PV systems. Asphalt shingles are the most common material used on residential rooftops. Their flexibility and durability make them highly compatible with solar panels.

    During installation, professionals drill bolts through the asphalt and attach them to the panel mounting. If the shingle edges are lifting or curling, you should consider replacing your roof before installing panels. A 20-year-old or older roof may also need replacing before installation.

    Tile roofs are not flexible or soft like asphalt shingles. They require professionals to remove the tile when drilling and fastening the mounting structure. Although the installation may be invasive, however, the material provides benefits to the system.

    Tile rooftops are fire-safe, meaning they may protect the PV system from damage during small ignitions. They are also more durable than asphalt and even provide optimal air circulation, cooling a building and reducing energy stress on a solar power system.

    Metal roofs are standard in southern regions due to their reflectivity. They are the most compatible roofing material with PV installations. Their standing seams eliminate the need for drilling, providing easy installation.

    They have a reflective coating that keeps buildings cool, as well. This also reduces the energy stress on a PV system. Metal roofs perform well in high winds, further protecting the solar panels.

    Roof Pitch

    A significant contributing factor to a panel’s sun exposure is the system’s tilt. The angle of a roof combined with the mount structure placement determines the system’s ability to convert sunlight into electricity.

    If a panel lays flat on the ground, its tilt is 0°. If it’s perpendicular to the ground, its tilt is 90°. Depending on the geographical location of your building, the optimal tilt may change. In low-latitude states like Hawaii and Arizona, a 20° tilt is ideal, meaning lower-angled roofs are optimal. In higher-latitude states like Minnesota and Oregon, a 45° tilt is best, meaning steeper roofs are optimal.

    On can typically achieve optimal solar power efficiency between a 20° and 30° angle. If the roof holding a panel has a steeper pitch than 45°, it can compromise a system’s ability to produce sufficient amounts of renewable energy. Any roof with a lower-angled pitch can modify the panel angle with a mount.

    Roof Direction

    When you view a solar-powered home, you may find that one side houses all the panels. The direction the panels face affects their sun exposure and efficiency. In North America, most panels mount to the south-facing side of a roof.

    Solar panels should face true south for maximum sun exposure. The south experiences direct sunlight throughout the day, whereas eastern and western exposures fluctuate. In the southern hemisphere, this rule changes, and panels should face true north.

    Most individuals alter the direction of their panels based on peak energy hours. Society tends to use more electricity in the afternoon and evening after returning from work. We unwind by watching TV, using our stoves for cooking dinner, and illuminating our homes with electric lighting.

    To meet the demands of evening peak energy hours, professionals install panels facing southwest. The sun sets in the west so that west-facing panels can attain high levels of sunlight in the afternoon. If you have a gable roof with east- and west-facing sides, your solar power production may be lower than other panel owners.

    Sources of Shade

    When considering the suitability of your rooftop for a PV solar system, you should evaluate sun obstructors on your property. A single shadow cast on your rooftop could jeopardize the efficiency of the entire system.

    Solar panels rely on consistent sun absorption by each cell. If shade obstructs cells’ light exposure, it could block the energy flow through the entire chain. When trees cast shadows on a rooftop, the PV power output can drop to zero.

    Consider the obstructive features on your property before investing in a solar energy system. Large trees can be taken down or relocated, but buildings or concrete structures may be a more significant threat to the efficiency of your system.

    The Case for Solar Energy

    If you’re looking to invest in solar energy, you may want to evaluate the benefits first.

    Carbon emission reduction is the most significant advantage of solar panel installation. During his first day in office, President Biden signed America back into the Paris Agreement. The agreement is a legally binding international treaty to reduce climate change effects. Participating countries intend to limit Earth’s temperature rise to 2°C below pre-industrial levels or lower.

    The U.S. offers various tax incentives to solar panel customers, hoping to promote a national reliance on renewable energy.

    Society currently relies on greenhouse gas-emitting energy. We fuel our cars, heating and cooling systems, manufacturing industries, and more with fossil fuels. Each device we use and action we take has an independent carbon footprint.

    Carbon emissions cause the enhanced greenhouse effect and alter the global climate. The greenhouse effect is a natural process the planet uses to maintain a life-supporting temperature. It relies on a precise chemical composition in the atmosphere.

    When society emits additional pollutants, we alter the atmosphere’s composition. Greenhouse gases invading the atmosphere trap extra warmth on the planet’s surface. The entrapment of excess heat raises the average global temperature over time.

    Renewable energy offers a sustainable solution to global warming. We can harness non-depletable power sources, like sunlight, to fuel our lives. Fortunately, the accessibility of renewable energy systems increased over the past decade.

    Lower prices, tax incentives, and more efficient technologies prompt individual investments in these systems. As our energy sources change, our roofs must adapt to support the transition.

    How Do Solar Panels Work?

    Before evaluating rooftop compatibility with solar power production, we must understand how the system functions.

    The most common residential and commercial panels are photovoltaic (PV) panels. They contain cells that absorb and convert sunlight. A PV cell produces between 1 and 2 watts of electricity. Their semiconductive material is thin, allowing panels to mount well on roofs.

    A plastic or glass casing holds the cells in place and protects them from outdoor elements. The cells increase power production through their long-chain connections. An accumulation of chains produces a single panel. Multiple panels linked together create a full PV system.

    The entire system includes the panels, mounting unit, direct-current extraction components, an alternating-current battery, and wiring. When a homeowner turns on the lights in their home, a signal is sent to the PV system, allowing solar energy to power the building. PV systems have efficiency rates up to 23% and can power an entire home.

    Individuals mount PV panels on their rooftops to shrink their carbon footprints. Eliminating your reliance on the conventional electricity grid also reduces utility costs. Installing solar panels on your roof increases the value of your property due to an increase in eco-conscious consumers.

    The First Step

    When you evaluate your roof’s compatibility with PV solar panels and decide you’re ready to make the investment, you can start by researching solar companies in your area.

    Finding the right solar company may take time because each company specializes in different roof-type installations. Ensure the company considers your location’s peak energy hours and sunlight obstructors before performing the installation.

    Author bio
    Rose Morrison writes on home improvement topics and is the managing editor of Renovated. She is especially passionate about helping homeowners find ways to be sustainable in their daily lives. Check out her Twitter to see more of her work.

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