In a study by Ryan Miller and the Green Roof Technology, a green roof was constructed for the NY Parks and Rec. Department with both vegetation and solar panels. This particular setup was configured so that the underlying membrane did not need to be pierced when the system was installed and attached. This particular roofing system was also extremely durable as it sustained 90 mph winds from Hurricane Sandy’s landfall. Both the vegetation and solar panels remained in place; the panels did not require any further adjustments either.
Several Mechanisms at Play
The system is usually well ballasted, which is the reason why the roof can be installed without penetrating the membrane beneath. The roofing system also collects and stores rainwater. The stored water contributes through a process called evapotranspiration; overall roof temperatures are greatly reduced.
Evapotranspiration is the process where stored water in the roofing system is evaporated. This process also helps maintain the efficiency of the photovoltaic cells by reducing the temperature of the surface. The reduction in operating temperature also slows the rate of degradation which extends the operating life of the entire roofing system, including the photovoltaic cells.
Power Generation Results
The roofing system was built in the northeast, which has much less sun exposure than Bryan roofing companies experience. With the solar panels angled at 30°, the combined system generated 8.3% more power than a traditional standalone solar panel system.
The total cost of the roofing system was on par with traditional solar roofing systems. The combined system was able to save money due to less mounting equipment used for the solar array. In fact it was estimated that by 2021 the roof will have generated over $359,431 in energy savings ($.20 max kWh).
The federal government also has many programs to support green energy. One green initiative allows a 30% tax concession on business energy investment. In some cases the solar energy can create “Solar Renewable Energy Credits” worth 1 kWh of energy. Those credits can be sold to brokers and investment firms.
Savings do not stop there. In fact, and 25 year roofing system combined with the tax credit incentives, show a payback as within 5 years. Beyond that the roof is generating a consistent revenue stream for the building or homeowner.
A Scalable Option
The roofing system is a scalable as well. Many homeowners feel dissuaded by the installation costs of a solar roofing system. However, a combined system not only saves and generates money for the homeowner; it can be phased in /staged out, on the homeowners build schedule.
Schulte Roofing is a roofing company in Bryan, TX with over 100 years of combined roofing experience. Schulte Roofing has been building green and solar roofs in and around Bryan, TX for over 18 years. To learn more about these combined roofing systems, contact Schulte Roofing today.