Solar Roofs

Solar roofs integrate solar panels directly into the structure of a building’s roof, and can be a a seamless and aesthetically pleasing way to harness solar energy. In the right conditions, they can be a sustainable solution for reducing electricity costs and minimizing environmental impact.

A rooftop solar power system, also known as a rooftop PV system, is a photovoltaic system where electricity-generating solar panels are mounted on a rooftop. As of 2022, roughly 25 million households relied on rooftop solar power system worldwide, and rooftop PV systems were also present on many other building types, such as shopping centres and office buildings. One example of a country at the forefront of this development is Australia, where the climate favor solar power and many isolated farms benefit greatly from on-site electricity generation.

Compared to large-scale commercial “solar farms”, rooftop PV systems tend to be small, and they are often only intended to produce electricity for use within the building, although having the system connected to the grid is also quite common.

In many jurisdictions, getting permission for a rooftop PV system is much easier than being approved for a solar farm.

solar roof shingles

Components

The basic components of a rooftop PV system are photovoltaic modules, cables, solar inverters, and various electrical accessories. The system also need to be mounted or attached somehow, depending on which type of system it is.

Capacity

A rooftop PV system for a single-family house will usually have a capacity within the 5-20 kW range. For larger systems placed on commercial buildings, it is not unusual to have a capacity of up to 1 MW, and very large roofs, e.g. on industrial buildings, can produce in the 1-10 MW range.

Rooftop solar power in Ohio

Solar power in Ohio has increased a lot compared to 15 years ago, through a combination of solar roofs and other types of solar power installations.

In Ohio, any electricity customer that generates up to 25 kW is permitted to use net metering, and the kilowatt hour surplus will be rolled over each month. Surplus will be paid for once a year upon request. This has made it more appealing for ordinary households to install solar roofs.

Several hospitals in Ohio have rooftop solar power, but for them, two meters are required if they want to sell surplus electricity. One meter is for generation and the other for utility supplied electricity. For this configuration, there is no upper limit.

One notable example of solar power in Ohio that is not a separate solar farm is Euclid´s City Hall and Library, where Ohio Cooperative Solar is leasing the rooftops and have installed solar panels on them.

Types of solar roofs

  1. Solar Shingles
    • Description: Also known as photovoltaic shingles, these are designed to look like traditional roofing materials while generating electricity.
    • Advantages: Blend seamlessly with the roof, often more aesthetically pleasing than traditional solar panels.
    • Examples: Tesla Solar Roof, CertainTeed Apollo II.
  2. Building-Integrated Photovoltaics (BIPV)
    • Description: These systems incorporate solar panels into the building materials, such as roof tiles or facade elements.
    • Advantages: Provide dual functionality by serving as both a building material and a solar energy generator.
    • Examples: Solar tiles, solar facades.
  3. Traditional Solar Panels
    • Description: Not integrated into the roof. These panels are mounted on top of existing roofing materials.
    • Advantages: Often more efficient and cost-effective, with well-established technology and installation methods.
    • Examples: Standard photovoltaic panels from companies like SunPower, LG, and Panasonic.

Benefits of solar roofs

  1. Cost Savings
    • Reduced Electricity Bills: Generate your own electricity and reduce reliance on grid power.
    • Incentives and Rebates: In some parts of the world, you may benefit from government incentives, tax credits, and rebates that lower the initial investment.
  2. Environmental Impact
    • Renewable Energy: Solar roofs produce clean energy, reducing greenhouse gas emissions and dependence on fossil fuels.
    • Sustainability: Contribute to sustainable building practices and energy-efficient home design.
  3. Aesthetics and Property Value
    • Seamless Integration: Solar shingles and BIPV systems offer a more aesthetically pleasing alternative to traditional panels.
    • Increased Property Value: Homes with solar installations can have higher property values and appeal to environmentally conscious buyers.
  4. Energy Independence
    • Grid Independence: Generate your own electricity and reduce vulnerability to grid outages.
    • Battery Storage: Combine with battery storage solutions to store excess energy for use during non-sunny periods.

Considerations for Installation

  1. Initial Cost
    • Upfront Investment: Solar roofs can have a higher upfront cost compared to traditional roofs, but this can be offset by long-term savings and incentives.
  2. Roof Suitability
    • Roof Condition: Ensure your roof is in good condition before installation. Roof repairs or replacements may be necessary.
    • Sun Exposure: Optimal solar energy production requires good sun exposure. Shading from trees or buildings can reduce efficiency.
  3. Maintenance
    • Durability: Solar shingles and panels are designed to be durable and withstand harsh weather conditions.
    • Cleaning: Regular cleaning may be necessary to maintain efficiency, especially in areas with high dust or pollen.
  4. Local Regulations and Incentives
    • Permits and Codes: Check local building codes and permit requirements for solar installations.
    • Incentives: Research available federal, state, and local incentives to reduce installation costs.

Examples of well-known companies

  1. Tesla Solar Roof
    • Innovative Design: Integrates solar cells into roof tiles for a sleek, modern look.
    • Durability: Made of tempered glass, designed to be more durable than traditional roofing materials.
  2. CertainTeed
    • Apollo II Solar Shingles: Combine the benefits of solar power with the aesthetics of traditional roofing.
    • Versatility: Can be installed as part of a new roof or integrated into an existing roof.
  3. SunTegra
    • Solar Shingles and Tiles: Offer integrated solar solutions that blend with traditional roofing materials.
    • Efficiency: Focus on delivering high efficiency and reliability.

Conclusion

Solar roofs represent a significant advancement in sustainable building technology, offering a blend of efficiency, aesthetics, and environmental benefits.

While the initial investment can be substantial, the long-term savings, coupled with available incentives, make it an attractive option for homeowners seeking to reduce their carbon footprint and achieve energy independence.

Whether through solar shingles, BIPV systems, or traditional panels, solar roofs are paving the way for a greener future.