In 2011, commercial and industrial buildings accounted for 40 percent of U.S. energy consumption. In response, Net Zero Energy Building (NZEB) is gaining momentum as design teams and architects strive to achieve higher performance. In fact, the Energy Independence and Security Act of 2007 requires that all federal facilities become net zero by 2030–and all commercial buildings achieve net zero status by 2050.
There are many definitions of “net zero,” though one definition seems to stand out:
“Net zero” indicates that a building has generated at least as much power as it has consumed over a 12-month benchmarking period (which balances out seasonality factors).
In this article, several experts–including Brian Anderson, Founding Partner of Anderson Porter Design, Dru B. Crawley, former Commercial Buildings Team Lead for the Department of Energy and current Director of Building Performance at Bentley Systems, and Blake Bisson, VP of Sales & Marketing at Ekotrope–shed some light on how to achieve net zero in a new or existing building. They also weighed-in on the debate whether net zero is universally attainable or just wishful thinking.
Becoming Net Zero: McCormick’s Case Study
There are two scenarios for net zero projects: retrofitting existing facilities to meet high performance goals, or designing a net zero structure from scratch. Both have different challenges and considerations.
The food conglomerate McCormick recently retrofitted a 363,000 square foot distribution center in Belcamp, Maryland to achieve net zero through a combination of energy efficiency upgrades and the installation of photovoltaic (PV) solar panels on its roof.
Jeff Blankman, McCormick’s Sustainable Manufacturing Manager, says “The most important maneuver in a net zero makeover is to focus on energy efficiency first. You must reduce consumption–making a facility as efficient as possible.”
This chart, provided by Pike Research, demonstrates how a reduction in consumption paired with alternative energy resources like PV panels can create an energy equilibrium–resulting in net zero usage.
Beginning their five-year efficiency project with standard upgrades like efficient lighting, motion sensors and HVAC replacement, the initial goal was to tackle high energy costs. Once he realized their consumption was reduced by 55 percent, they moved forward with the PV installation.
Blankman explains how PV systems produce, capture and redistribute the remaining energy necessary to achieve zero consumption, “On sunny, low-usage days, our building generates more power than it needs. Excess energy returns to the grid and is redistributed to the community. Tonight we’ll be buying power from the electric grid.”
Constellation Energy installed the PVs at McCormick’s facility–at their own expense–as part of a Power Purchase Agreement (PPA). They expected the panels to provide 85 percent of the facility’s energy, but they actually generated 2.2 million kWh and the facility used only 2.1 kWh in the first year. Blankman called the energy surplus a “byproduct” of their energy reduction efforts.
Recommendations For Ground-Up Initiatives
In the case of new building design, the experts offer considerations for design teams and architects to keep in mind throughout the process–from initial conceptualization to the continued oversight once a building is intact.
Integrate planning pre-design. Anderson recommends conducting a thorough pre-design project analysis. “The key is participation by critical stakeholders, board members, the CEO, the banker, as well as the day-to-day management team, designers, and builders.”
Do thorough energy and cost modeling beforehand. Bisson suggests, “Do as much energy and cost modeling in the design process as possible so you can understand all of your alternatives–from a cost and energy standpoint. Energy modeling allows you to better figure out how to reduce cold air, absorb sunlight, and understand insulation.”
Carefully research incentives and funding opportunities. Funding and tax incentives at state and federal levels can save significantly. But, high performance doesn’t necessarily mean a bigger investment. Bisson adds, “You can build an NZEB–with state incentives–at very close to the same cost as traditional construction.”
Expect challenges and ongoing oversight. Crawley says, “It requires a commitment from the building owner and operator to ensure the design intent is carried out. It requires that all energy use in the building be considered. It also takes periodic testing–energy simulation–to ensure performance goals remain on track.”
Reality or Wishful Thinking?
The idea of net zero is an ambitious one. Not all structures can achieve net zero today. Certain buildings–large factories, perhaps–simply use far more energy than they can realistically produce. Crawley notes, “Some buildings will never achieve net zero energy usage–it’s just not possible to reduce their energy use enough so that renewable energy sources can make up the balance.”
Additionally, optimistic consumption forecasts sometimes lead to disappointing results. Building performance relies on too many factors to accurately predict usage patterns–even with state-of-the-art simulation software. Occupant behavior will also heavily impact overall performance.
Things may be changing, though. Energy production and efficiency technologies improve all the time, which shifts the production/use equation. And the cost equation is shifting quickly, too. Prices for renewable energy production systems and energy-saving equipment has been dropping fast. In fact, the Department of Energy forecasts that falling prices for PVs will double U.S. sales of solar panels this year.
Moreover, businesses that lack the capital to invest in energy efficiency upgrades can reach out to Energy Service Companies that provide upgrades with no upfront cost–as well as to energy suppliers offering PPAs for solar installations, as McCormick did.
PPAs are common in states offering solar incentives, allowing smaller companies with less capital the opportunity to finance PV installations. “There are ways to finance efficiency projects–using your monthly energy savings to cover the finance payment,” explains Blankman.
Perhaps the more realistic goal is not making every building net zero, but rather, according to Crawley, developing net zero communities. In this model, a community strives to create an equilibrium of energy usage and consumption. Crawley explains, “The potential over-supply from lower energy-intensity one and two-story buildings can offset higher energy-intensity higher-rise buildings.”
Regardless of whether a net zero is attained, Blankman reminds us that there are many rewards from implementing sustainability initiatives. “Energy efficiency has great paybacks and is a good investment even if net zero is not achieved. It’s an aspirational goal and a vision we should all be thinking toward.”
What’s your take on the net zero movement? Do you think it’s a realistic possibility, or simply aspirational? Share your experience with sustainability initiatives below, or email me at firstname.lastname@example.org.
Thumbnail courtesy of Engineering for Change.