Bacon's Rebellion

Making Net-Zero Energy Affordable

Kelly Vaughn explains how exterior sun shades adjust the sunlight and energy admitted into the Rocky Mountain Institute headquarters building.

The new Rocky Mountain Institute headquarters building in Basalt, Colo., demonstrates how to drive net energy consumption down to zero at a cost that offers a four-year payback.

by James A. Bacon

When the Rocky Mountain Institute (RMI) decided to build a new headquarters building in Basalt, Colo., it had its own high standards to uphold. The free-market, environmental think tank had set a goal of transforming four billion square feet of building space into smart, energy-efficient structures, enough to reduce energy consumption over five years by 398 trillion BTUs and prevent emissions of 50 million metric tons of CO2 — the equivalent of decommissioning 17 coal-fired power plants.

Doubling as a meeting center where legendary co-founder Amory Lovins could convene with Fortune 500 executives visiting nearby Aspen, the new facility had to push the envelope for passive, integrative design. But it also had to show that investing in energy efficiency made economic sense. There wasn’t much point in demonstrating cutting-edge approaches that were too expensive to replicate.

When the 15,610-square-foot Innovation Center opened in December 2015, it was one of only 200 buildings constructed to net-zero energy standards, meaning that it produced more energy than it consumed on an annual basis. But it was more than an ideological fashion statement. Although achieving net-zero and a design life of more than 100 years added an incremental cost of 10.8%, RMI will recoup that sum, primarily through energy savings, in just under four years.

I gained an interest in energy-efficient buildings when my wife worked at Richmond-based Tridium, developer of a software platform for smart buildings. Buildings account for about 60% of the electricity generated around the world, and energy constitutes a major expense of property ownership. A whole industry has grown up around using technology to wring electricity savings from HVAC and lighting. But the RMI Innovation Center went beyond tweaking its HVAC system — it dispensed with it altogether. Instead of paying for heaters, coolers and ducts, RMI invested in solar energy, sensors, insulation and passive design.

Exterior shot of the Innovation Center. Photo credit: Rocky Mountain Institute

During my visit to Aspen earlier this month, I took a side trip to Basalt a few miles away to check out RMI’s Innovation Center myself. I wanted to see what state-of-the-art energy efficiency looked like and gauge what potential might exist for cutting electricity consumption and CO2 emissions by redesigning the built community. RMI was kind enough to assign Kelly Vaughn, a marketing manager with RMI’s communications team, to give my friend and me a tour.

The building sports many of the features one might expect from an energy efficient building — big windows with a southern exposure to the sun, shades to control sunlight entering the building, and solar panels to generate electricity on-site. Less visibly, the building is so tightly insulated that the Passive House Institute declared it to be one of the most air-tight buildings it ever measured. Heat is stored in concrete floor slabs and other thermal masses such as walls.

Also invisible, more than 120 submeters track temperature, humidity, CO2, lighting and other critical variables that feed into the building’s brain. “The building is so smart,” says Vaughn, “that it saves us from making stupid decisions. You don’t just walk up to the thermostat. The building makes critical decisions based on outdoor temperatures projected out to the next day.”

Most office lighting comes from outside, although RMI does use LED lights as backup.

The building generates solar electricity, some of which it stores in a 30 kW lithium ion battery system. The batteries provide a buffer for periods of peak demand, such as the coldest hours of the coldest days of the year. The storage allows the building to keep peak demand under 50kW, which places it in a lower commercial rate class with its local electric co-op.

Perhaps RMI’s greatest innovation is to re-think the 68º-to-72º temperature zone maintained in most office buildings by taking an innovative approach to delivering thermal comfort. “We’ve thought beyond what temperatures we need to maintain in a building and expanded our ideas about how to deliver comfort on an individual level, allowing us to expand our temperature bandwidth from 67º to 82º,” says Vaughn. 

Studies have shown that six factors, not just temperature, affect a person’s comfort in an office building. These include humidity, air movement, metabolic levels and clothing. RMI has designed the office to give people more control over their micro-environments — overhead fans, and even chairs with built-in seat heaters, like those found in automobiles, and fans that blow air on the back. An office-hoteling arrangement also allows employees to switch to work stations in warmer or cooler parts of the building. Says Vaughn: “This is something a lot of green buildings ignore.” (For details on how RMI re-defines thermal comfort, click here.)

Perhaps the most remarkable thing about the Innovation Center is how unremarkable the technology is. Most of it is off-the-shelf.  The key to making the building energy efficient, says Vaughn, was adopting the right project management strategy. RMI brought together architects, engineers, contractors subcontractors and other stakeholders early in the process to get their interests aligned. The Integrated Project Delivery approach gave everyone a stake in the outcome. (RMI shares its contract, as seen here.)

Bacon’s bottom line: RMI has demonstrated that it’s possible to design a net-zero energy building at a reasonable price — there is no need to pay a big premium to be green.

I don’t see the Basalt design translating directly to Virginia, though. The Old Dominion is more humid than Colorado, and Virginians would be loath to give up their trees, which would interfere with RMI’s approach to passive solar heating. Design features would have to be adjusted accordingly.

A bigger problem is that it may be difficult to retrofit existing building stock with heated floors, large, southern-facing windows and other design features incorporated into RMI’s from-the-ground-up construction. HVAC systems will be with us for decades, if not centuries, in existing buildings.

But no one said it would be easy changing the world. If nothing else, RMI has shown what is possible.

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