Three D’s supporting decarbonization | Climate Week


Decarbonization of the built environment – residential structures, commercial real estate, and infrastructure – is essential to avoid the most severe impacts of climate change. There is increasing alignment that this critical objective requires an unprecedented combination of energy demand management, energy efficiency, and carbon-free energy supply. It is also true that the built environment cannot meet this challenge alone. Let’s consider the “three D’s” at the intersection between the built environment and energy supply.

#1 | Dependencies

The first “D” is Dependency: Buildings depend on energy infrastructure, critically, their supporting electricity grids. Although frequently treated as separate sectors of the economy, buildings and grids are intimately connected. In the United States, approximately 78% of electricity generation is consumed by residential and commercial buildings (US Environmental Protection Agency). Rather than being separate, it is most accurate to say that buildings are the grid’s majority owner and stakeholder. The grid must get cleaner and more responsive to enable building sector decarbonization. Fortunately, these changes will enable the built environment to create billions of dollars of value for utilities through the provision of energy savings, capacity, avoided transmission, and a variety of ancillary services.

Aggregate value of grid-interactive buildings for US electricity utilities across different adoption scenarios (U.S. Department of Energy, National Roadmap for Grid Interactive Buildings)

Learn more about the opportunities and challenges associated with grid dependencies from Jim Landau (who has been leading participation for five GRESB entities over the last 10 years) and his colleague Giuls Kunkel, who tackle this topic in “Greening the Grid:  A Tipping Point in U.S. Renewable Energy Production.”

#2 | Data

Understanding and managing buildings in light of these dependencies requires data. Frankly, the building sector has been engaged in a decades-long struggle to get timely and actionable data from utilities. This remains a generational challenge; however, there are real signs of progress. Today, public and private entities are making energy supply dramatically more transparent. Asset owners and managers can quickly access information about the source and emissions intensity of electricity supplies over a range of time scales.

Electricity Map data illustrating the carbon intensity of energy production over a 24-hour period ending at 9 AM on September 15, 2023. During this period, the PJM Interconnection covering Washington, DC and other Midatlantic had an emissions intensity of 367 grams of GHG per kWh. The supply was 40% carbon-free and 6% renewable.

These granular data allow owners and managers to understand important patterns of daily, seasonal, and annual variation in emissions rates. This can inform facility management and capital planning.

(a) 24-hour average 329 gm/kWh

(b) 12-month average 266 gm/kWh

Electricity Map comparison of emissions intensity for the (a) 24-hours ending September 15, 2023 at 9 AM compared to (b) the 12-month average. The 12-month average emissions rate would underestimate daily emissions by 24%. This is an illustrative day.

Learn more about the emerging information ecosystem:

#3 | Ducks

Inspection of these new data sources quickly leads to the third D: Ducks! The rapid growth of intermittent renewable resources means that grid conditions, including carbon intensity, often vary dramatically over short periods of time and across geographic divisions. Consequently, national-average emissions statistics and annual aggregate consumption are becoming less relevant to conditions at any given location and point of time. This is reflected in the famous “duck” curves that illustrate daily cycles in energy supply and demand, often with carbon intensity reaching a minimum during midday and peaking in the early evening. This means that the emissions associated with an activity – making toast, charging a car, or heating water – may vary by several multiples depending on the time and location of the action. This creates real opportunities and challenges. We have the opportunity to shift the time and location of loads to reduce emissions. We have the challenge that the prevailing paradigm of annual aggregated energy and emissions reporting will inevitably become obsolete.

The U.S. Energy Information Agency illustrated the strengthening of California’s “duck curve” between 2015 and 2023. The “belly” of the duck represents periods of high solar generation. The “head” of the duck represents peak demand, often supplied by relatively carbon-intense electricity.

Learn more about “ducks”:


The “three D’s” are just the beginning of a larger conversation about the changing nature of interactions between the built environment and the energy system. One thing is clear: Companies that design, build, and operate the built environment will need to break from the traditional paradigm of passive consumption of energy services. Meeting their decarbonization goals will require understanding the nature of building-grid dependencies, obtaining relevant, actionable data, and managing dynamic conditions to reduce emissions and support the changing grid. Yes, these are new, perhaps unfamiliar issues for built environment stakeholders, but we will navigate this together and achieve our shared goals of a rapid, clean energy transition.

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Explore Industry Insights about electricity and energy supply:

Chris Pyke

Chief Innovation Officer, GRESB

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