Author: Steve Oman
According to the Minnesota Sustainable Building 2030 program, projects starting design between 2010 and 2015 must reduce EUI (energy-use intensity) by 60 percent compared to an average building in 2003; projects starting design between 2015 and 2020 must reduce EUI by 70 percent; projects starting design between 2020 and 2025 must reduce by 80 percent; and projects starting design between 2025 and 2030 must reduce EUI by 90 percent.
Since the beginning of this year, IPS Solar is hearing from more Architectural and Construction firms interested to learn how to integrate solar into their sustainable building design. This seems to be driven by the decrease in EUI from 70% to 80% staring in 2020. ”We can’t get to 80% without integrating solar” is becoming a popular refrain.
While SB is mandated for State of Minnesota funded buildings only, the standard can be readily applied to other multi-family and commercial/industrial buildings as well.
Because SB2030 requires the use of onsite solar, and rooftops offer the most available unobstructed square footage, rooftop solar is often seen as the go-to solution. In many cases this is true. There are a number of issues that can make or break a rooftop solar system that should be taken into consideration early on in the design process, including:
As the building height gets taller, physical attachment of the solar array to the roof may be required instead of a ballasted system
Parapets around the building edge can increase the snow load, adding to the total dead load on the roof
Locations of rooftop penetrations, including RTU’s, power vents and drains should be positioned so as to minimize interference with the best solar array layouts.
A representative solar layout on a 5 story multi-family development might look something like this:
In the past, solar was often restricted to offsetting electrical usage in the “common areas” of the building, including heated parking, elevators, lounges, fitness areas, and meeting rooms. With the advent of distributed control systems enabling monitoring of individual unit usage instead of individual meters for every unit, it is now possible for solar to offset a much larger percentage of the total electrical load in the building. For a building with significant usable square footage, this can be the difference between whether a 40 kilowatt or 240-kilowatt solar array ends up on the roof.
One final thought – since the payback criteria for SB2030 is a relatively long 15 years, other onsite solar options that can help meet SB2030, such as solar carports and urban solar awnings, are now affordable too. Solar carports can be cost effective for a small number of parking spots or in an even more expansive configuration. And a smart solar management system can be integrated with EV charging stations to reduce demand charges.
A spin-off of the traditional solar carport structure, the urban solar awning has a power density approximately 2.5x – 3x that of a rooftop solar installations A 100kW solar awning takes less than 1/8 of an acre (20′ x 240′) and can be ideally located along the property line, in lieu of a berm/landscaping, or even alongside a parking structure as an aesthetic upgrade!
Pollinator-friendly plantings and native turf grass also provide a favorable environment for bees and help absorb water run-off.
Today there are more solar options than ever to help Architects and Developers meet SB2030. IPS Solar is committed to providing innovative, cost-effective solutions that help make integrating solar into SB2030 a reality.
Solar Carports provide another viable option to meet SB2030