The Sustainable Solar Roof Installer - Best Practices Make Perfect

February 12, 2013

Strong financing incentives and reputable installers are contributing to a boon in solar installations.

Solar energy systems are quickly becoming a value-added opportunity for the construction industry. Implementing solar systems is attractive for building owners as it allows them to lock in their electricity rates, ideally at a lower cost than what they would be paying to their utility company.

In recent years, residential and commercial installations of photovoltaic (PV) solar systems have exploded. Since the beginning of 2010, the average cost of a PV solar system has dropped by more than 46%, with the average price of a solar panel declining by 51%. These, coupled with innovative financing models that have defrayed nearly all-upfront costs, has allowed thousands of home and business owners to take advantage of this technology. The significant decrease in cost, and readily available financing, has helped the number of solar installations double in 2010 and double again in 2011.

The U.S now has more than 5,700 MW of installed solar electric capacity – enough to power more than 940,000 American households. As this number grows, the demand for solar-skilled contractors will increase. It is imperative for the continued growth of the solar industry that contractors understand the key challenges involved in PV panel solar installation.

Ensuring building integrity

The roof is critical to the health of any building. How that roof is treated during a solar installation is vital to a successful project. While many view solar installation as primarily an electrical job; ensuring roof integrity is just as important.

Careful solar installers will be knowledgeable about roof penetrations and take care to minimize them. The rule to remember is … If you penetrate the roofing materials, you must flash and waterproof to code to avoid voiding the roofing warranty.

Depending on the type of roof shingles, there are also special mounting brackets that attach to the roof with a minimal amount of roof penetration. Mounting solar panels will, of course, require a certain amount of roof penetration. Effective solar installers will know how to properly use correct flashing and sealants to maintain roof integrity.

Maximizing the installation

There are several roof considerations to be addressed before the installation. The two most important are: 1) a southern facing roof; and 2) making sure the roof is at an appropriate angle. Solar panels need to face south and be mounted at an angle between 10 and 20 degrees. The lack of either requirement never completely limits a building from being eligible for solar panels, but it will limit some roof types from solar installations.

Flat roofs by themselves can’t provide the proper panel angle, but can provide good starting points with the right equipment. For a flat roof, the panels need to be installed on a frame, which can be directed and angled to maximize the solar arrays’ exposure to the sun. The same is true for Mansard-style roofs since they also feature relatively large spaces.

Unfortunately, if the roof faces north, the customer should be advised to look elsewhere for the installation. Directionally, the panel’s placement does not have to perfect. Southeast and southwest are not huge obstacles to overcome, but panels installed on a roof that faces in a northerly direction will not provide a sufficient return on investment.

Always remember that the amount of electricity solar panels can produce is directly proportional to the amount of exposure to the sun that they receive. It should go without saying, but shady rooftops, blocked from sunlight by large trees or buildings, are poor candidates for solar because the amount of sunlight they receive won’t generate enough power to provide a good return on investment.

Choosing the best equipment

The PPA model of solar places a premium on equipment selection because it changes going solar from a simple product choice into an investment decision. As a result, the companies that finance these projects value reliable solar panels, because those are the ones that provide the best return on their investment.

Solar manufacturers understand these concerns. That is why they have worked with racking component makers to develop easy solar mounting solutions. These combined panel and mounting solutions minimize the amount of time an installer needs to be on the roof as well as the amount of equipment they will need to bring with them. This increases rooftop safety and profitability, as installations can be completed more quickly.

Entering the Solar market

With proper training, solar panel installations are simple for an experienced hand familiar with roof care, electrical maintenance and local permitting processes. There are a number of workforce development organizations that work to train workers in solar and match them with employers. These include the Interstate Renewable Energy Council, SolarTech and GRID Alternatives.

As sustainable construction practices become more integrated into the mainstream, businesses with the most experience will thrive and those lagging behind will suffer. A great solar installation is just like any other construction project, it takes experience, skill and copious attention to detail.

To read the full story, click here to download the Spring 2013 issue of Sustainable Construction.

Antelope Valley School District

Antelope Valley School District, like most in California, is facing major budget issues. The executive team and school board made quick, informed decisions to build what is currently the largest school solar project under construction in the nation.

The district’s deputy superintendent championed the project and made sure there was no disruption to regular school activities during installation at the multiple sites.

Antelope Valley is ideal for a large solar system. The sun provides the power and the wind helps keep the inverters cool, which keeps the system running at the high end of its rated efficiency.

In total, the installed systems are expected to meet 80% of the total electricity needs of the schools. PsomasFMG developed the project and sold the PPA to GCL Solar, which in turn brought in Wells Fargo Bank as the tax equity partner.

Customer: Antelope Valley School District

Type of Customer: The union high school district includes eight public high schools, one trade school and two continuation high schools in the cities of Palmdale and Lancaster and their immediate suburbs.

Location: Los Angeles County, California

Type: Roof- and ground-mounted

Size: 9.6 MW

Product: Trina Solar TSM-PA05 230W Modules

Number of Modules: 40,000

Completion Date: February 2011

Emissions Savings: The system reduces C02 emissions by more than 14 million pounds per year. This is equivalent to 17 million miles of driving or planting 1440 acres of trees. Over 25 years the emissions reduction is more than 358 million pounds of CO2, which is equivalent to 429 million miles of driving and planting 36,000 acres of trees.

Cost Savings: $2 million/year for the next 20 years. The system is being paid for though a power purchasing agreement.

Job Creation: From the start of the project, about 85 jobs were created.

Implementation Highlights: The 9.6 MW system is the largest school solar system in the United States. Students at all the high schools were active on social media, talking about the solar systems being installed on their campuses. The installation also serves as an important teaching aide the students could observe outside their classroom.

PsomasFMG and GCL established a Raleigh Wright Solar Scholarship Fund for top AVUHSD students, funding $80,000 in scholarships over the next four years.

Meridian Center Business Park

This unique project, comprised of 25 separate "mini-systems," has been installed on four adjacent buildings in the Meridian Center Business Park in Eatontown, New Jersey. It is currently the largest solar system in Monmouth County. The project saves the equivalent of 1,386 barrels of oil annually. More than 30 people were employed during the time of the installation.

With the success of the project, the owners of the Meridian Center Business Park have developed their own energy consulting firm, Anova Energy Solutions. Anova has a solar project development pipeline for projects up to 2.4 MW in capacity and has already developed more than 5 MW in projects.

System Owner: Meridian Solar Partners LLC

Customer: Meridian Center Business Park

Type of Customer: Four-building business park

Location: Eatontown, New Jersey

Type: Roof-mounted

Size: 728 kW

Product: Trina Solar TSM 235 Modules

Number of Modules: 3,119

Completion Date: October 2010

Emissions Savings: Carbon Dioxide (CO2) 1,314,300 lbs./year; Sulfur Dioxide (SO2) 5,933 lbs./year; Nitrogen Dioxide (NO2) 1,950 lbs./year. This is equal to: Car Travel: 67,000 gallons of gasoline; Planted Trees: 127 acres of pine forest preserved; Barrels of Oil: 1,386 barrels of oil conserved

Cost Savings: The system is saving about $120,000 per year in energy bills, accounting for nearly 50% of the complex’s energy use. (This is the total actual savings, which is shared between the system owner and the customer.)

Implementation Highlights:

The project began in 2009 due to high energy rates. The building owners changed the lighting and HVAC systems, and are now one of the more energy efficiency business parks in the state. Initially, they believed that a solar system would be too expensive. But upon analysis, the principals realized that the energy cost-savings, along with federal and state incentives, made the system installation a great investment. Since then, the business park has spun off a PPA company that is involved in an additional 5MW of projects.