SITU Studio has teamed up with Brooklyn Solar Works to develop the residential Solar Canopy – a modular rooftop structure that incorporates PV solar panels affixed to a lightweight, adjustable aluminum frame. Solar Canopy offers significant cost savings for homeowners — from federal and state tax credits, to an NYC tax abatement — Gaelen McKee President of BSW believes “now is the absolute best time to go solar.” According to US Green Buildings Council, buildings and homes in the US currently account for 60% of our country’s total electricity usage.  Switching to solar provides alternative power sources that decrease our dependency on fossil fuels and increase our use of renewable energy.

15_0607_brooklyn solar works_rendering_rk_forblogRendering of Solar Canopy

The Solar Canopy project is an exciting opportunity for us to work closely with our friends at Brooklyn Solar Works in the design and fabrication of the first prototype. Solar Canopy has the potential to be both replicable and customizable depending on roof size and structure as well as the particular solar capacities of the location. Ben Duarte, project manager at SITU Fabrication will walk us through the design process.

The first step is to survey the existing rooftop. In our collaboration with BSW we’re looking at applications at residential properties in existing Brooklyn neighborhoods and therefore must account for adjacent structures, foliage, roof penetrations and roof access – all of which play a role in the location and size of Solar Canopy. In addition, the Department of Buildings (DOB) requires a 6’ wide path of travel to the nearest stairway in compliance with the fire code, as well as a 9’ firefighter clearance height. We like to think of this as a 6’ wide x 9’ high volume that provides the minimum height and width for occupiable space beneath the canopy.

Elevation drawing showing the minimum 9′ height requirement

The second design factor and major consideration is the material size and shape of the structure. Attachment to an existing roof structure presents certain limitations and unknown variables, so careful attention must be paid to the location of anchor points and any perforations into the existing building envelope. With these factors in mind, SITU set about designing a canopy that contains both fixed – replicable, standard components – while also offering site specific adjustments. Aluminum was chosen for its lightweight properties, a revision from the original proposal of using steel tubes and speedrail fittings.

Exploded axonometric of one pre-fabricated truss and rails.

Pre-fabricated aluminum metal trusses serve as beams to support the rails upon which the solar panels are attached, offering maximum ease of maintenance. The feet sleeve into the legs allowing height adjustability – up to 18 inches. The feet also have a cleft end with a central pivot hole that can be attached anywhere on the roofing rails. The panels come in standard sizes which determined the overall size and shape of the Solar Canopy structure – roof applications vary from 15 to 35 PV panels per canopy and have the capacity to supply most typical household electricity usage.

After nearly a year in development, the engineers of record calculated the weight of the structure on the roof, including maximum wind and snow loads. The canopy structure was approved and sent off to the DOB where it is currently waiting on city approval.

The first installation is set to be completed in a few weeks– check back for a project update!