Grid-Interactive Efficient Buildings Are Easier Than They Sound

Grid-interactive efficient buildings are a big deal with an equally big name.

GEBs, for short, were one of the focal areas in a slate of new building-focused programs announced by the Biden administration earlier this year. Those announcements coincided with the release of a US Department of Energy (DOE) report that sketched out the potential benefits of GEB technologies, which could save more than $100 billion in electric power system costs over the next 20 years. More recently, the DOE awarded $61 million to fund 10 GEB pilot projects across the country.

Meanwhile, electric utilities are taking notice of the ways that GEBs can reduce demands on the grid. Increasingly, utilities are shifting toward rate structures that benefit the grid as well as building owners who employ GEB technologies.

So what is this next big thing in building efficiency with the mouthful of a name? Building managers need not be scared off by the terminology. By and large, GEBs are just a jargony way of describing a package of more familiar measures that together provide energy, cost, and emissions savings. And although GEBs are in some ways the buildings of the future, we have found that building managers can implement many GEB measures today at little to no cost.

What Are GEBs?

Grid-interactive efficient buildings integrate three different energy management technologies and approaches: energy efficiency, distributed energy resources (such as solar panels and battery storage), and demand flexibility.

Whereas energy efficiency measures focus on how much energy a building consumes, demand flexibility refers to a building’s ability to manage when that energy is consumed. Today, demand flexibility mostly revolves around time-of-use pricing for electricity—shifting energy use toward the times when electricity is cheapest. Demand flexibility approaches can be low-tech, such as using a building’s thermal mass to heat or cool spaces at off-peak hours, or high-tech, such as drawing on battery storage to power building operations during peak hours.

The benefits of GEBs include energy cost savings, lower GHG emissions, and resilience to grid disruptions. The energy efficiency and on-site electricity generation of GEBs lead to lower energy consumption and costs, which also reduces overall demands on the electricity system. These measures, as well as the shifting of electricity use with demand flexibility, also help limit costly peaks in demand, which in turn reduces the likelihood of outages and means less need for dirty, fossil-burning “peaker” plants on the grid. Shifting electricity demand toward times of lower utilization or greater supply (for instance, hours when solar energy is abundant) also leads to more efficient use of grid resources, which benefits all customers on the grid.

GEBs Made Easy

Fully interactive GEBs that shift energy use in response to real-time pricing signals or the instantaneous carbon intensity of the grid are the future in most locations, but building managers can already start reaping many of the benefits outlined above. In our recent report Grid-Interactive Efficient Buildings Made Easy, we identified simple, low-cost steps toward GEB readiness that produce immediate cost, energy, and carbon savings.

Our report was written for US General Services Administration (GSA) building managers, but the wide variety of buildings in the GSA portfolio makes the recommendations broadly applicable to a range of commercial properties. As the nation’s largest landlord, the GSA manages almost 10,000 buildings, including offices, courthouses, post offices, and other commercial buildings.

“GSA is a notable leader in climate action and a champion of high-performance buildings,” says RMI’s Cofounder and Chairman Emeritus Amory Lovins. “Grid-interactive efficient buildings play a critical role in supporting GSA’s climate leadership by enabling dynamic load shifting. This cuts operating costs and boosts renewable energy. “

Using What You Have

Building managers can implement many GEB strategies without significant changes to building equipment. These measures range from no-cost measures—changes to the building’s operations without any additional investment in the building’s systems—to low-cost measures that fit within a GSA building manager’s procurement budget (assumed for these purposes to be $50,000).

Examples include “staging” HVAC equipment, or programming heating and cooling systems to turn on in sequence, rather than all at once. This method of shifting when energy is consumed helps limit peaks in demand and reduces the building’s “demand charges,” which are based on a monthly high-water mark of energy use. Building managers can also modify HVAC temperature settings to limit energy use during peak hours in low-traffic spaces, based on observed usage patterns, or in transitional spaces such as hallways.

With efficient, dimmable LED lighting that can be connected to daylight sensors, building managers can program the lighting system to automatically dim during daylight hours. A 2014 study found that lighting in commercial buildings may be dimmed as much as 40 percent in naturally lit areas without affecting the occupants’ comfort, productivity, or safety.

“The beauty of GEBs is that many strategies can be implemented with existing, off-the-shelf technologies that have very compelling financial returns and valuable side benefits, from health and productivity to security and resilience,” Lovins says.

Demand Flexibility Is Key

Building managers are generally familiar with energy efficiency measures, and are increasingly familiar with distributed energy resources such as solar-plus-storage systems. But demand flexibility is a newer concept that offers great potential by better integrating building operations with conditions on the grid.

In the Grid-Interactive Efficient Buildings Made Easy report, we provide a process for gauging the feasibility and impact of demand flexibility measures. The process begins with evaluating the building’s utility rate structure (e.g., a time-of-use rate that incentivizes off-peak energy use), as well as its existing controls and capacity for automation and its daily energy use profile, as shown below.

Depending on the sophistication of the building’s control systems, the building manager may be able to automate many of the demand flexibility processes outlined in the report. Buildings with more basic control systems will require more manual intervention and should be targeted for controls upgrades to enable more demand flexibility.

Benefits from Day One

As the grid gets greener and is increasingly powered by variable energy sources such as solar and wind, when buildings use energy may start to matter more than how much they use. “GEB-ready” buildings will be poised to reap the most benefits as utilities adapt to this new reality by rolling out more granular and real-time pricing structures, and by making available new signals about grid status, such as the real-time carbon intensity of regional electricity supply.

But as our new report explains in depth, the benefits of GEBs are already attainable today. And those benefits—to building owners, the grid, the air quality of local communities, and the climate—will only grow as the power system gets greener.