Solar Shingle

A solar shingle is a photovoltaic (PV) module designed to look and be installed like a conventional roofing shingle or tile. Rather than mounting panels on racks above an existing roof, the solar units themselves form part of the weather-shedding roof covering, usually mixed with matching non-solar shingles or tiles. Solar shingles and solar tiles are the most common form of building-integrated photovoltaics (BIPV).

History

Solar shingles became commercially available in about 2005. Dow's POWERHOUSE Solar System went on sale in Colorado in October 2011; a later version was licensed to RGS Energy from 2017 until RGS filed for bankruptcy in 2020. In October 2016 Tesla, together with SolarCity, announced the Solar Roof. In January 2022 GAF announced a solar shingle product. A Dutch company developed and patented a ceramic solar roof tile in 2013.

Technology

• Cells: most current products use monocrystalline or polycrystalline silicon cells; some early products used thin-film CIGS cells.
• Formats: rigid shingle-sized panels, semi-rigid silicon designs and flexible thin-film units.
• Size and output: many shingle products measure about 12 by 86 in (305 by 2,185 mm), with a 5 by 86 in (127 by 2,185 mm) exposed strip, and some reach up to 100 W DC per unit.

Cost

Installed costs have been reported at about US$3.80-9.00 per watt, depending on manufacturer, technology and system size, generally higher than conventional rack-mounted panels, though the gap has narrowed. Part of the cost is offset because the solar units replace ordinary roofing material.

Performance considerations

• Because they sit close to the roof deck with little air flow, integrated modules run hotter than rack-mounted panels, and higher temperatures reduce output and can shorten life.
• Output depends on roof orientation, pitch and shading.
• Building codes require the assembly to meet both roofing (fire, wind, water) and electrical safety requirements.

Terminology

Systems retrofitted onto finished roofs are usually called building-applied photovoltaics (BAPV), while BIPV replaces part of the building envelope.