What is the difference between demand response and demand flexibility?

Demand response (DR) is the traditional utility-initiated program where buildings curtail loads during specific utility-declared events (typically 10–15 events per year, 2–4 hours each). Demand flexibility is a broader concept encompassing DR plus proactive, automated optimization of loads in response to price signals, forecasts, and grid conditions continuously — not just during utility events. GEBs implement demand flexibility through model predictive control that continuously optimizes the building's load shape, rather than simply responding to infrequent utility curtailment requests. Demand flexibility is considered the next evolution of DR because it provides more grid value (continuous shaping vs. episodic curtailment) and more building value (continuous cost optimization vs. occasional program payments).

How much demand reduction can a typical commercial office building provide?

A well-designed 200,000 sq ft Class A office building can typically provide 20–40% peak demand reduction (100–200 kW) through a combination of: pre-cooling (10–15% reduction), lighting dimming (5–10%), plug load management (3–5%), EV charging throttling (variable, up to 200 kW for a 50-charger garage), and BESS discharge (if installed, 100–500 kW). The actual achievable curtailment depends on building systems, occupancy, outdoor temperature, and comfort constraints. Buildings with high thermal mass (concrete construction), flexible chilled water plants, and substantial EV charging infrastructure achieve the highest flexibility potential. LBNL's commercial buildings DR potential study estimates the national commercial sector could provide 200 GW of flexible demand by 2030.

Does participating in demand response programs require building occupants to be uncomfortable?

Properly designed demand response strategies minimize occupant impacts by using pre-cooling (the building is cooled before the DR event, so occupants experience no temperature increase during the event), raising setpoints by 1–2°F rather than turning off HVAC entirely, and carefully managing event duration and frequency. Research from Lawrence Berkeley National Laboratory found that occupant comfort complaints occur in fewer than 5% of DR events when setpoints are raised by 2°F or less and event duration is under 4 hours. Modern model predictive control algorithms optimize DR responses to maximize load reduction within configurable comfort constraint envelopes (e.g., never allow zone temperature above 76°F or below 70°F), providing reliable performance with predictable occupant experience.

What is OpenADR and do all utilities support it?

OpenADR (Open Automated Demand Response) is the ANSI/CTA-2045 and IEC 62746-10 standard protocol for automated DR signaling between utilities and buildings. OpenADR 2.0b is the most widely deployed version, supported by major US utilities including Pacific Gas & Electric, Southern California Edison, Xcel Energy, Consolidated Edison, and many others. Outside the US, OpenADR 2.0b is deployed in Japan (ECHONET integration), Korea, and parts of Europe. However, not all utilities support OpenADR — some use proprietary APIs or manual phone/email notification systems. Before designing a GEB system around OpenADR, verify with the serving utility that they offer an OpenADR 2.0b VTN and that they have DR programs with automated dispatch. SEPA's Grid Edge Utility Survey tracks utility OpenADR adoption annually.

How does FERC Order 2222 affect commercial building demand flexibility?

FERC Order 2222 (September 2020) requires Independent System Operators (ISOs) and Regional Transmission Organizations (RTOs) to open wholesale electricity markets to aggregations of distributed energy resources (DERs), including building demand response, batteries, EV charging, and rooftop solar. Before Order 2222, individual buildings were generally too small to participate directly in wholesale markets (typical minimum bid size: 100 kW in capacity markets, 1 MW in energy markets). Aggregators can now combine demand flexibility from hundreds of buildings into a single wholesale market bid, allowing even medium-sized commercial buildings to access wholesale market revenue streams (capacity payments, energy market payments, ancillary service payments). Implementation timelines vary by ISO; MISO, PJM, NYISO, and CAISO all have Order 2222 compliance proceedings underway as of 2025.

Engineering·10 min read·October 15, 2025

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Topics covered

grid-interactive efficient buildingsGEBdemand flexibilitydemand responseOpenADRSEPAvirtual power plantthermal masspre-coolingload shiftingbattery energy storageBESSFERC 2222dynamic tariffbuilding grid integration