Building Resilience – Six Lessons from Superstorm Sandy
By Clay Nesler
Superstorm Sandy forced many people to abandon the homes, offices, schools, churches and stores in their community for extended periods of time and seek refuge. This extreme event placed a tragic burden on those affected and was a test on how well these buildings were designed and operated. The results were mixed. As we reflect on how well our buildings and energy systems met the challenge and how we can do better moving forward, we should consider three overall objectives of building resilience: 1) minimizing damage to critical infrastructure during the event, 2) maintaining operational integrity and critical services immediately following the event and 3) returning the building to normal, safe operating conditions as soon as possible. The following are six lessons that should help guide the redesign and rebuilding of our buildings, cities and energy infrastructure to be more resilient.
1. Reduce the initial damage to building systems and infrastructure
Major electrical and mechanical equipment used to provide critical services should be installed in locations unlikely to be flooded. This can be accomplished by installing equipment above ground level or providing underground storm water holding areas or diversion paths. Burying electrical lines underground is another practice to increase reliability and robustness. These practices need to make their way into building codes as they are much more practical and cost-effective to implement during initial construction or reconstruction.
2. Improve the reliability of emergency back-up systems
Anecdotal estimates suggest that up to half of NYC building’s emergency back-up generators failed to start when they were needed. This was caused by lack of maintenance and regular full-load testing. Many generators ran out of fuel in a day or less as they were unable to receive supplemental fuel deliveries. The conventional practice of storing one day’s worth of fuel supply on-site needs to be reconsidered, given the increasing likelihood of severe storm events in the future.
3. Have buildings support limited critical services for extended periods of time
After Hurricane Sandy, most grid connected solar PV systems were not operational because of safety systems installed to protect utility workers and grid integrity on restart. This was a surprise to many business and homeowners who had invested in solar PV systems expecting their buildings to be powered at least during daylight hours. Availability of even a limited amount of renewable energy, such as solar or micro-wind, combined with energy storage and a secure grid disconnect mechanism would allow buildings to provide critical services over extended periods of time.
4. Designate and upgrade select buildings to provide critical community services
With so many people displaced from their homes and workplaces, designated locations should be established in each community to provide critical services such as shelter, food, water, electricity and communications. Renewable energy with energy storage or micro-generation with on-site fuel supplies could meet the critical needs of the community at schools, community centers, churches and other designated locations.
5. Use passive design principles to increase building resilience
Passive approaches to providing electrical power, such as renewable energy, and passive building designs can increase building resiliency. Passive design principles including building envelope, natural ventilation, shading and water capture and storage allows buildings to provide adequate comfort and water without requiring a significant energy supply. When severe storms or other events are accompanied with excessively hot or cold weather, providing comfortable and safe environments using minimal energy resources is highly desirable. An additional benefit is that buildings designed using passive principles will be significantly more energy efficient and have a lower environmental impact during normal day-to-day operation.
6. Use distributed generation and micro-grids to increase community resilience
Dependence on a centralized electrical grid is a definite liability given the extended time that is sometimes required for utilities to bring entire communities back on-line after a severe storm event. In Hurricane Sandy, large numbers of overhead power lines were down over an extended distance making repair crew logistics challenging. The use of micro-grids, which allow decentralized energy distribution at a community scale, supported by distributed energy generation are a potential solution. At a community scale, the application of district heating, cooling and energy plants and renewable energy generation is more scalable, cost effective and resilient than their use in individual building applications. Water treatment and other critical services can also be more cost-effectively provided within a community-scale micro-grid. The U.S. Department of Defense is at the leading edge of designing and installing micro-grids to maintain operational integrity and improve resilience and can set an example for cities, communities and campuses to follow.
Many of us involved in designing and operating the built environment have been promoting the environmental, economic and social benefits of more efficient and sustainable buildings for decades. There have also been strong voices in the sustainable energy industry calling for the greater use of renewable energy, distributed generation and district energy systems as a more cost effective, and environmentally sound, approach to meeting future energy needs. As we have learned in Hurricane Sandy, many of the same design and operational principles that lead to greater sustainability can also lead to greater resilience. As if improving efficiency, reducing costs, creating jobs and protecting the environment weren’t enough, we can now add increasing resilience to the list of benefits resulting from more sustainable buildings and energy systems.
This article first appeared as a blog on the USGBC web site.