The complexity of building energy consumption

By Paolo Gaudiano

Paolo Gaudiano is President and CTO of Icosystem, where he enjoys solving challenging business and technology problems for clients, while striving to ensure that Icosystem continues to be a stimulating, productive and fun company.

Apr 29, 2013 | Smart Cities | 0 comments


Who will you meet?

Cities are innovating, companies are pivoting, and start-ups are growing. Like you, every urban practitioner has a remarkable story of insight and challenge from the past year.

Meet these peers and discuss the future of cities in the new Meeting of the Minds Executive Cohort Program. Replace boring virtual summits with facilitated, online, small-group discussions where you can make real connections with extraordinary, like-minded people.


 

It is estimated that buildings contribute 20-30% of energy use in the United States at an annual cost of over $100B. Buildings also contribute an estimated 35-40% of all US CO2 emissions resulting from building energy consumption. Any effort to decrease building energy consumption can thus have a substantial economic and environmental impact.

Much of the effort invested in building energy efficiency and conservation is focused on analyzing or simulating individual physical systems within a building, to help designers understand, e.g., what savings could result by replacing standard lights with high-efficiency fluorescents, or by using light-colored paint on a building’s roof.  Typical approaches combine simulating the actual physical properties of building systems, and statistical data based on historical usage. However, the complex interactions between building systems and the environment make accurate estimations difficult.

The complexity of this problem increases dramatically when occupant behavior is included. Consider a simple hypothetical example: a building consumes $1M per year in electricity for lighting. Analysis might show that, given current use patterns, installing high-efficiency lighting would cost $1M and result in 50% electricity savings – $500,000 per year – which would lead to break-even in two years. However, suppose that the building owner invests in a campaign to increase awareness, leading to a 25% reduction in how much lighting is used by occupants, or an annual electricity cost of $750,000. The same high-efficiency lighting would now only save $375,000 per year, and would thus take nearly three years to reach break-even.

Even more complex interactions take place when one starts to consider all building systems – such as heating and cooling, appliances and data networks – and other aspects of occupant behavior which impact demand and usage patterns. For instance, improving climate control might encourage occupants to spend more time inside the building, leading to an increase in energy consumption (this is sometimes referred to as the rebound effect).

This type of emergent behavior is a hallmark of complex systems, systems whose overall behavior is determined in sometimes unpredictable ways by the elements of the system interacting with one another and with the environment. We can see examples of human-made complex systems all around us: traffic jams, stock market fluctuations and even sports team performance cannot be predicted even when we know well how each individual is behaving within the system. Similar principles are at work in natural systems, including for examples the flocking behavior of birds, the schooling behavior of fish, of the ability of social insects such as termites to build incredibly complex structures – without the benefit of blueprints and architects.

Traditional analytical techniques are ill-equipped to manage complex systems, whose behavior often exhibits sharp nonlinearities such as tipping points. In recent years, researchers at academic centers such as the Santa Fe Institute, as well as commercial entities such as Icosystem, have successfully studied and managed complex systems using Agent-Based Simulation (ABS), a simulation technique that captures the behavior of systems from the bottom-up. While ABS was initially studied primarily in academic settings, recently ABS has been used to solve a variety of complex business and technology problems in many industry sectors and problem areas.

ABS replicates in software the behavior of individuals, as well as their interactions with the environment and with other individuals. ABS then shows how overall system behavior emerges from these interactions, replicating complex system behaviors that cannot be captured with other analytical techniques and that are often unexpected or counter-intuitive.

Traffic is a classical example of a problem that is best captured with ABS. In particular, traffic jams are an example of an emergent behavior that seems almost paradoxical: each driver is trying to reach his or her destination, and yet traffic jams form even when there are no external factors to cause them. An ABS developed with the NetLogo software can be used to show how simple driver behaviors can lead to traffic jams. In the simulation, drivers accelerate when there is nobody in front of them, and they decelerate when they approach a car ahead. Using these simple rules it is possible to replicate traffic jams that looks surprisingly like traffic jams observed under real conditions.

In the context of building energy efficiency, ABS could be used to understand how occupant behavior impacts energy consumption, by simulating occupants going about their normal daily activities and reacting to their environment, e.g., turning on lights when it gets dark (and sometimes forgetting to turn them off), opening windows or turning on air conditioning when it gets warm, using different types of appliances, and so on. More importantly, an ABS could be used to estimate the impact of various initiatives, including changes to the building itself as well as communications campaigns to encourage energy conservation. This type of quantitative approach could be beneficial in understanding how best to allocate resources to improve energy efficiency.

Discussion

Leave your comment below, or reply to others.

Please note that this comment section is for thoughtful, on-topic discussions. Admin approval is required for all comments. Your comment may be edited if it contains grammatical errors. Low effort, self-promotional, or impolite comments will be deleted.

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *

Read more from MeetingoftheMinds.org

Spotlighting innovations in urban sustainability and connected technology

How Affordable Green Housing Enhances Cities

How Affordable Green Housing Enhances Cities

Housing that is affordable to low-income residents is often substandard and suffering from deferred maintenance, exposing residents to poor air quality and high energy bills. This situation can exacerbate asthma and other respiratory health issues, and siphon scarce dollars from higher value items like more nutritious food, health care, or education. Providing safe, decent, affordable, and healthy housing is one way to address historic inequities in community investment. Engaging with affordable housing and other types of community benefit projects is an important first step toward fully integrating equity into the green building process. In creating a framework for going deeper on equity, our new book, the Blueprint for Affordable Housing (Island Press 2020), starts with the Convention on Human Rights and the fundamental right to housing.  

The Pandemic, Inequality, Housing Affordability, and Urban Land

The Pandemic, Inequality, Housing Affordability, and Urban Land

Since the Great Recession of 2008, the housing wealth gap has expanded to include not just Black and Brown Americans, but younger White Americans as well. Millennials and Generation Z Whites are now joining their Black and Brown peers in facing untenable housing precarity and blocked access to wealth. With wages stuck at 1980 levels and housing prices at least double (in inflation adjusted terms) what they were 40 years ago, many younger Americans, most with college degrees, are giving up on buying a home and even struggle to rent apartments suitable for raising a family.

What makes it hard for policy people and citizens to accept this truth is that we have not seen this problem in a very long time. Back in the 1920s of course, but not really since then. But this is actually an old problem that has come back to haunt us; a problem first articulated by Adam Smith in the 1700s.

Multi-modal Transit and the Public Realm

Multi-modal Transit and the Public Realm

More than ever, urban transit services are in need of sustainable and affordable solutions to better serve all members of our diverse communities, not least among them, those that are traditionally car-dependent. New mobility technologies can be a potential resource for local transit agencies to augment multi-modal connectivity across existing transit infrastructures.

We envision a new decentralized and distributed model that provides multi-modal access through nimble and flexible multi-modal Transit Districts, rather than through traditional, centralized, and often too expensive Multi-modal Transit Hubs. Working in collaboration with existing agencies, new micro-mobility technologies could provide greater and seamless access to existing transit infrastructure, while maximizing the potential of the public realm, creating an experience that many could enjoy beyond just catching the next bus or finding a scooter. So how would we go about it?

The Future of Cities

Mayors, planners, futurists, technologists, executives and advocates — hundreds of urban thought leaders publish on Meeting of the Minds. Sign up below to follow the future of cities.

You have Successfully Subscribed!

Wait! Before You Leave —

Wait! Before You Leave —

Subscribe to receive updates on the Executive Cohort Program!

You have Successfully Subscribed!

Share This