The Building Blocks of Demand-Side Energy Management

During the Talkstandards’ live Smart Grid event, held at the University of Colorado in Boulder; Professor Gregor Henze spoke on the prospect of aggregated demand-side energy management in large office buildings.

The full presentation made by Dr. Henze can be found here:

Gregor Henze
Professor and Associate Chair
Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder

Gregor P. Henze received his Ph.D. in Civil Engineering from the University of Colorado in 1995 as well as the Diplom-Ingenieur in Mechanical Engineering from the Technical University of Berlin in 1992. From 1996 to 1999, Prof. Henze worked in the energy services industry at Johnson Controls, a manufacturer of building automation systems, where he established a business unit for energy savings performance contracting in Germany. From 2000 until 2008, he joined the University of Nebraska as an assistant and later as an associate professor.

We are seeing the rise of megacities globally and very soon 50% of the world’s population will live in large urban cities. In the US,currently around 75% live in urban centers, but this is expected to increase to over 85% by 2030. Similarly, this number is expected to reach 54% in Asia from just only 37% now – an extra 1.4 billion urban inhabitants. With this rise in urban centers, electric demand will soon far exceed supply, requiring billions of dollars to upgrade transmission and distribution networks.

• Variation of electrical demand is substantial and inefficient
• Demand response happens only a few times a year when the situation is really
• No utilization of forecasts or accounting for building dynamics.
• Electrical demand must be met immediately
• No aggregation of building types or short-term curtailment opportunities.

What is needed from a Smart Grid:
• Automated, online, scalable technologies that continuously integrate
• HVAC operations in commercial buildings with electric grid system

However, promising is the concept of “Elastic buildings” utilizing thermal storage to smooth electric usage across the day through extremely complex and automated electric systems. Exploiting constant pricing and weather predictions it is possible to undertake aggregated demand-side energy management with existing buildings and infrastructure. It will be potentially possible to drive the building community from being a price taker to a market maker and provide storage at a utility scale for renewables.

Issues raised during the presentation:
• Model requires a huge amount of information and is susceptible to the level of precision
• Opt-out is possible even with a participation building.
• Utilities do not take over operation of the building, as they are ill-equipped to do so. Constrains are pre-defined and recommendations possible to reject.
• The owner provides a range of acceptable conditions for the building and those are then optimized for the best price within the range.
• Large commercial buildings already have the required direct digital control automation systems to participate in such a system. Need to focus on a few big consumers who are ready, just need the last bit of communication with the grid.
• While day forward pricing is already available, continuous interaction of signals is very complicated. If the goal is to avoid the few hottest days of the year, that’s complex, but if you want to optimize for a month that’s not as hard.
• For this system to work ideally, it is best if one person owns the building and pays the electric bill. Tenant is responsible for lights but fundamental HVAC is paid for by owner. Just the right amount of complexity is important to distinguish between labs and offices, for example. People are a little more demanding with their work environment than their home environment.