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E1.3 Renewable Energy Systems

Requirement

Install renewable systems in new facilities that have an annual energy production of at least 1.2 W/ft² of roof area for single story buildings and 2.0 W/ft² of roof area for other buildings.[1]

Applicability

All businesses that are constructing or modernizing buildings for their own use shall meet this requirement. Construction projects that are not within the scope of Standard 90.1-2013 are exempt from this requirement. 

Documentation

Projects that trigger this requirement shall be identified in the AA Report. For each project details of the system installed or designed to meet the requirement shall be referenced[2].

Resources

Pless S., M. Deru, P. Torcellini, and S. Hayter, Procedure for Measuring and Reporting the Performance of Photovoltaic Systems in Buildings, NREL/TP-550,38603, October 2005.   

Test Method for Photovoltaic Module Power Rating FSEC Standard 202-10 January 2010  See http://www.fsec.ucf.edu/en/publications/pdf/standards/FSECstd_202-10.pdf

Notes

[1]       This requirement is consistent with ASHRAE Standard 189.1 Section 7.3.2, but is converted to W/ft², instead of Wh/ft², as expressed in the standard. The former is a power requirement, while the latter is an energy requirement that is more complicated to implement, since it depends on the local weather conditions, the azimuth and tilt of the collectors, shading and other factors. Standard 189.1 requires 20 kWh/m² (1.86 kWh/ft²) for single story buildings and 32 kWh/m² (2.97 kWh/ft²) for other buildings. PV systems generally produce between 1,200 and 1,800 kWh/kW of capacity.  A value of 1,500 kWh/kW is assumed here for the conversion. This translates to 1.2 W/ft² for single story buildings and 2.0 W/ft² for other buildings. Modern PV panels have a STC (Standard Test Condition) rating of about 20 W/ft² of collector area (360 W / 17.65 ft²) so meeting this requirement using this typical product would require only about 6 ft² of solar collector for each 100 ft² of roof area for single story buildings and about 10 ft² of collector area for each 100 ft² of roof area for other buildings.

    Standard test conditions (STC) for terrestrial solar power modules. To compare the performance of different solar power modules uniform operating data have been defined as standard test conditions (STC). These conditions define performance at an incident sunlight of 1000 W/m², a cell temperature of 25°C (77°F) and an AM of 1.5 (AM = Air Mass). The air mass determines the radiation impact and the spectral combination of the light arriving on the earth's surface.

[2]       Referencing a requirement means that a link is provided in the AA Report where the AIE or others can go to get more details of the complying PV or wind system.