Improving the Resilience of Buildings and Energy Systems
By Clay Nesler
In April 2013, with the devastation of Superstorm Sandy still top of mind, the Johnson Controls Institute for Building Efficiency surveyed over 600 energy and facility executives across North America on their current practices and future plans to improve the resiliency of their buildings and energy systems. Many articles in the aftermath of Sandy have offered advice to building professionals on improving resiliency. Apparently the message is getting out, as the survey indicates that about half of the organizations have made or plan to make significant improvements in how their buildings and energy systems are designed and will operate in the future.
Resilient Building Operations
Operation practices can have a significant impact on the resiliency of buildings and energy systems. Two types of building systems failures figured prominently in Superstorm Sandy: backup generator failures and flood damage to electrical/mechanical system.
During Sandy, an unacceptably large number of emergency generators failed to start after grid outages due to lack of maintenance and regular full-load testing. Additionally, many generators ran out of fuel in a day or less as the owners were unable to receive supplemental fuel deliveries. The conventional practice of storing one day’s fuel on site needs to be reconsidered, given the increasing likelihood of severe storms in the future.
Electrical system failures were also prevalent because, by standard practice, the systems were located in the basements. To improve resilience, critical electrical and mechanical equipment should be installed above ground level or otherwise protected from flooding. Above–ground locations may be more practical and cost-effective to implement during initial construction, but given flooding risks in many regions, relocation of equipment in existing buildings should be considered during reconstruction and renovation projects.
Resilient Building Design
The impact of building design on resilience goes well beyond equipment location. Buildings should be designed to provide critical services such as shelter, food, water, electricity and communications during and after extreme weather events. Buildings such as schools churches and community centers, with limited distributed generation and energy storage capacity, could meet the critical needs of their communities.
The Global Green USA ”Solar for Sandy” project is a great example of a community center designed for resiliency. Located in the New York City Parks’ Red Hook Recreation Center in Brooklyn, the facility is a safe, well-lit and centrally located gathering point with resilient heating, cooling and ventilation systems, communications services, cell phone and laptop charging stations, energy efficient lighting, and refrigeration for food and emergency medicine.
Passive design principles including an efficient building envelope, natural ventilation, shading and water capture and storage allow buildings to provide adequate comfort and water without requiring a significant energy supply. When severe storms or other events are accompanied by extremely hot or cold weather, comfortable and safe environments that use minimal energy are highly desirable.
Resilient Distributed Energy Systems
After Sandy, most grid-connected solar photovoltaic (PV) systems were not operational because of safety systems installed to protect the grid and utility workers from electrical surge and shock on restart. 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.
Given the long times sometimes required for utilities to bring entire communities back online after a severe storm, dependence on a centralized electrical grid can be a liability. In Superstorm Sandy, large numbers of overhead power lines were down over an expansive area, making repair crew logistics challenging. Microgrids, which allow decentralized energy distribution at a community scale – supported by distributed energy generation – are a potential solution.
In August, the Hurricane Sandy Rebuilding Strategy was released by U.S. Housing and Urban Development Secretary Shaun Donovan. Recommendation #14 focuses on the potential of distributed generation and microgrids to improve community resilience: “The new approach would define policies and technical requirements for how to incorporate smart grid technology, microgrids, building controls, and distributed generation, including CHP, with two-way flow networks into the grid…This approach would allow building controls to provide a minimal level of service such as basic lights and refrigeration during emergencies.”
New York University, Princeton University, the College of New Jersey and Stony Brook University all stayed online during Superstorm Sandy because of combined heat and power systems installed primarily for economic reasons. Co-op City in the Bronx, South Oaks Hospital in Long Island and Danbury Hospital in Connecticut similarly benefitted from having on-site CHP systems. New York, New Jersey and Connecticut are all planning microgrid installations to protect their communities’ critical infrastructure.
The U.S. Department of Defense is at the leading edge of designing and installing microgrids to maintain operational integrity and improve resilience and can set an example for cities, communities and campuses to follow. The U.S. Army Net Zero Initiative seeks to pilot technologies at 10 installations each that provide net zero energy, net zero water and net zero waste. Ft. Bliss in Texas, one of the net zero pilot installations, has implemented PV solar, solar thermal and solar cooling, along with lighting and HVAC improvements. While the Department of Defense may be taking the lead, many more organizations are planning to adopt distributed generation, microgrids and net zero energy strategies in the future.
Lack of financing is undoubtedly a barrier to investment in improving building efficiency and resilience for many organizations, public and private. For these organizations, the Department of Defense provides a case study in resiliency financing.
Defense and other federal government departments are using energy savings performance contracts (ESPCs) to fund many of their energy efficiency, renewable energy, and energy security projects. With ESPCs, the government can finance energy infrastructure capital projects with the energy cost savings from lower utility bills. At Ft. Bliss, for example, ESPCs and energy services agreements (ESAs) were used to make the energy efficiency and renewable energy infrastructure improvements, funded by energy cost savings over time.
ESPCs are also a popular financing solution for other public sector organizations including schools, universities, hospitals and municipalities. Schools in particular could leverage ESPC-type financing for resilience improvements. With the addition of limited solar PV and electrical storage, a transfer switch and properly zoned electrical and mechanical equipment, a local K-12 school can be transformed into a temporary community shelter, providing critical services in times of severe weather and other emergencies.
Federal, state and local governments should consider directing grants and incentives for resiliency improvements to schools and other community organizations using ESPCs and other ESAs. In this way, the energy cost savings can help fund the incremental investments in distributed generation, energy storage, microgrids and control technologies, maximizing the benefit from limited public funds.
ESPCs have the added advantage of being able to capture cost savings and incentives from utility and other energy providers for energy peak shaving, demand response, and grid regulation services. These incentives help justify the incremental investment in energy storage systems.
It is encouraging to see that half of the surveyed organizations were planning to make investments to improve the resiliency of their buildings. Cost-effective ways should also be found to help all organizations and communities make these needed investments. Financial solutions such as ESPCs can help by converting wasted energy costs into energy infrastructure investments, making buildings and energy systems more efficient, more sustainable and more resilient.