1 Design and Construction Of Sustainable Substations P. L. Gogan, Member, IEEE G. D. Wyckoff Abstract—With the advent of Smart Grid era, the discussion has been centered on the ability to predict and intelligently respond to the behavior and actions of all electric power users connected to it – in order to efficiently deliver reliable, economic, and sustainable electricity services. However, the emphasis has been primarily on advanced meter infrastructure (Smart Meters) or self healing circuits. In Europe, one of the goals of the smart grid is to significantly reduce the environmental impact of the whole electricity supply system. In the United States, the work on this goal has been to reduce losses and consumption through voltage optimization. One opportunity to reduce environmental impact is through the development of sustainable substations. This paper explores the opportunity to reduce the environmental impact through the application of existing sustainable concepts used in other industries for the design and construction of substations. Index Terms: design engineering, energy efficiency, environmental management, green design, recycling, sustainable development, substations, waste disposal, waste management I. INTRODUCTION T he process to design and construct substations has not changed in decades. However, the opportunity currently exists to leverage existing commercial Green Building standards in the design and construction of sustainable electrical substations. The advantages of adopting these standards include: • • • • • Reduced environmental impact Wider project acceptance by the public and simplified project permitting A healthier work environment. Reduced construction and operating costs Demonstrate social and environmental responsibility Present-day substation designs already incorporate many design strategies that should be considered environmentally responsible. With the progress that has been made over the last decade in the sustainable building market, many additional opportunities exist by using strategies which have 978-1-4673-1935-5/12/$31.00 ©2012 IEEE been proven successful in other areas of infrastructure. This paper examines the existing sustainable commercial building rating system to determine how future substation designs and construction may benefit from the application of these sustainable building concepts. II. SUSTAINABILITY Sustainability involves the development and application of integrated solutions that are energy efficient, deplete fewer natural resources, generate less waste and provide healthier environments for its employees. The industry standard for measuring sustainability in commercial building is provided by the Leadership in Energy and Environmental Design (LEED®) rating system developed by the US Green Building Council (USGBC). The LEED rating system is a voluntary, consensus-based national rating system for developing high-performance, sustainable buildings. Developed by USGBC, LEED addresses all building types and emphasizes state-of-the-art strategies for sustainable site development, water savings, energy efficiency, materials and resources selection, and indoor environmental quality. The LEED rating system is based on the following five major rating criteria: • • • • • Sustainable Sites Water Efficiency Energy and Atmosphere Materials and Resources Indoor Environmental Quality The rating system is based on a point basis with the lowest level as “certified”, followed by “silver”, “gold”, and “platinum”. A. Sustainable Sites Regarding site selection, innovation is limited due to the limited availability of transmission line right-of-way. The criterion encourages the use of Brownfield site redevelopments versus the use of native land. The LEED criterion does not permit the development of a (substation) 2 project on land that is: • Provincial Agricultural or Forest Land Reserve • Less than 1.5 m above 100 year or 0.9 m above 200 year flood plain • Ecologically sensitive land • Endangered species habitat • Within 30.5 m of wetland • Public parkland without trade of same or better Storm water runoff is a major item of concern for this criterion. Testing has shown that the typical gravel substation is an excellent bio-filter for storm water run off. Experimentation with pervious concrete pavement may also be considered for substation driveways or entrance roads. By capturing storm water and allowing it to seep into the ground, pervious concrete is instrumental in recharging groundwater, reducing storm water runoff, and meeting U.S. Environmental Protection Agency (EPA) storm water regulations and cited as a Best Management Practices (BMPs). If space allows, common detention ponds can be upgraded to a bio-retention basin which naturally treats runoff to avoid contamination of groundwater or surrounding bodies of water. The use of a transformer oil containment designs that contain polymers which allow for water migration but block oil is preferred over a standard concrete containment system. The applications of the above technologies create more efficient land use by eliminating the need for retention ponds, swales, and other storm water management devices. In doing so, they also have the ability to lower overall project costs on a first-cost basis. To take the principal of site selection and design a step further, the compaction of the site layout and leaving area for future use undeveloped until needed can prevent unnecessary disturbance of the area’s natural setting. Implementing these small adjustments in the size of the site footprint can make a huge difference in the impact that that substation causes. Additional points in this criterion are provided for the following features: • • Minimize the Heat Island effect of the site and / or the control house roof through the use of lightcolored materials (selection of white gravel would qualify) or infrared reflective coating on building roofs. Minimize Light Pollution by only lighting areas as required for safety and comfort. Do not exceed 80% of the lighting power densities for exterior areas and 50% for building facades and landscape features as defined in American Society of Heating, Refrigerating and Air- Conditioning Engineers (ASHRAE) Standard 90.1. B. Water Efficiency In general, substations do not typically utilize water. However, points are available for the selection of water efficient (drought-tolerant or native plant) landscaping including “no mow” type grass. Depending on geographical location, it could be possible to implement a rainwater collection system to be used for landscape irrigation. If the control house requires restroom facilities, low-flow plumbing fixtures and/or a gray water reuse system would be beneficial. C. Energy and Atmosphere The electricity sector is the single largest user of electricity. In the United States, it is estimated that 1.15 TWh can be saved by 2030 through the implementation of efficiency measures to reduce substation auxiliary losses Error! Reference source not found.. Credits are available for optimizing the energy efficiency for new or existing buildings. New substations shall be designed to reduce energy consumption by 25% below Model National Energy Code for Buildings (MNECB) reference case reduce the design energy cost by 18% relative to ASHRAE standard 90.1 reference case. Installation of meters to monitor auxiliary power usage has the distinct advantage to be able to compare energy consumption on new substation designs vs. existing. Due to the fact that most substations are unmanned and had little need for heat or cooling, substation control houses were initially designed with little or no insulation. Energy usage by the utility was most often not metered or tracked. The advent of microprocessor relays and prefabricated control houses resulted in the need to provide cooling for the electronics. The initial prefabricated control house designs evolved from “walk-in” refrigeration designs. The manufacturers of the current prefabricated control houses have the ability to accommodate insulation system ratings of R30 for the ceiling, R26 for the walls, and R19 for the floors without structural modifications. The application of an economizer in HVAC units, which bring in cooler outside air when there is a call for cooling in lieu of running the compressor, bring additional energy savings. The use of set back thermometers and occupancy sensors can provide additional energy savings. The occupancy sensors can also be integrated into the lighting design. Consideration of timers or sensors for outdoor lights should also be considered to prevent light being left on. On a typical control house design, the control house is positively pressured to remove the hydrogen produced during charging. However, if the battery room was separated from the rest of the control house, it would allow for separate temperature thresholds and optimize the use of the HVAC system as a whole. 3 Additional points are available for: • • Enhanced Refrigerant Management Zero use of CFCbased refrigerants in new base building HVAC systems. Renewable Power - Supply at least 5% of the building's total energy use (expressed as a fraction of annual energy cost) through the use of on-site renewable energy systems. The lack of trees, available land and the ability to connect to the metering system is an ideal application for siting small to large solar and/or wind installations. D. Materials and Resources Substations are typically designed to recycle as much as soil as possible on the site. In addition, the utilization of coal fly ash in the design of concrete structures and foundations can provide additional points and cost savings. Additional points can be applied through the use of certified (Forest Stewardship Council Principles and Criteria) wood in the concrete forms during construction and the use of local materials (eg. steel within 500 miles). The overall percentage of recycled content can be increased by pushing material suppliers to increase the availability of products with higher recyclables. Many construction waste management plans have been created to manage this waste stream. The objective of these plans include ensuring as much waste as possible avoids a landfill and also optimizing the ever-increasing economic benefits to recycling. A valuable aspect of typical substation design is that most of the materials either already possess a high recycled content, or have the potential to do so. Ensuring that the structural steel and/or crushed rock used in the design possesses a high recycled content is an easy way to ensure a higher overall recycled content of the substation. F. Other Environmental Non-LEED Considerations Some of the items to consider in creating or applying a new LEED type standard specific only to electrical substations may include the following criteria: • • • Non-ozone depleting materials (e.g. SF6 gas) in the electrical equipment or monitoring systems that would detect and alarms leaks of 1% per year (EPA Best Practice). The use of vegetable based vs. mineral insulating oils in electrical equipment or the ability to monitor and correct leaks. The incorporation of plug-in hybrid electric vehicles. With the ability to recharge at a substation, a plug-in hybrid substation maintenance truck may be a good application. III. CONCLUSION Although the US Green Building Council’s Leadership in Energy and Environmental Design rating system is designed for manned commercial buildings, this paper demonstrates the ability to utilize LEED design techniques in substation design and construction to reduce the overall costs and the impact on the environment. The sustainably designed substation model also allows companies to showcase to their stakeholders their commitment to social and environmental responsibility. Through this showcase, opportunities can arise to educate the public on the environmentally sustainable strategies used in the design. It allows customers to directly see all the different ways that a sustainably designed substation. These results will assist utilities in obtaining project acceptance by the public and simplified project permitting. IV. REFERENCES E. Indoor Environmental Quality The economizer provides outdoor air delivery so that the system can meet the air change effectiveness greater than 0.9, per ASHRAE standard 129-1997. An occupancy sensor / control system could be added to supplement the HVAC system. Additional points are available for: • Prohibition of smoking in the building – a typical substation industry practice due to the possible presence of hydrogen from battery charging • Low emitting materials (adhesives, sealants, paints, coatings, etc.) in the construction of the building. • CO2 Monitoring • Natural lighting. Technical Reports: [1] EPRI “The Power to Reduce CO2 Emissions”, Transmission System Efficiency, Program document 1020142, December 2010, Efficient Transmission and Distribution Systems for a Low-Carbon Future (Program 172) Papers Presented at Conferences: [2] EPRI Green Transmission Efficiency Initiative workshops (project 1019531) Standards: Leadership in Energy and Environmental Design (LEED) for New Construction, US Green Building Council 4 V. BIOGRAPHY Mr. Gogan holds a Bachelor of Science degree in Electrical Engineering and a Masters of Business Administration degree both from Marquette University. He is a registered Professional Engineer in Wisconsin and Illinois. In Mr. Gogan’s current position at We Energies, he manages a staff of 50 engineers, and technicians performing design, testing, and asset management of electrical systems for We Energies electric distribution system. Prior to his current position, Mr. Gogan managed the Substation Engineering and Construction & Maintenance groups with the responsibility for the engineering, construction and maintenance of these facilities. In total, he has twenty five years of experience in the design, maintenance, operation and construction of electric distribution, transmission and generation facilities. Mr. Gogan has also served as Chairman of the Midwest Energy Association Substation Committee and as a member of the Marquette University College of Engineering Industry Advisory Board. Mr. Gogan is an author of several IEEE electric distribution standards. Mr. Wyckoff holds a Bachelors of Science degree in Civil/Environmental Engineering from Oklahoma State University. Mr. Wyckoff is a civil/structural design engineer at Burns & McDonnell. In this position, he is responsible for the development of loads, structural analysis, and design of foundations, structural steel, and other structural elements for a project. Mr. Wyckoff’s experience includes structural design for a variety of facilities including structural steel and reinforced concrete supports for electric utility substation equipment. Mr. Wyckoff has also served on the Board of Directors for the Missouri Society of Professional Engineers and in various roles for the Kansas City Chapter of the United States Green Building Council. Mr. Wyckoff is a LEED Accredited Professional through the United States Green Building Council (USGBC).
