January 1, 2012

EPRI Bridges Industry R&D Gaps

By Arshad Mansoor, Electric Power Research Institute

Energy Efficiency (End-to-End)

Energy efficiency is widely acknowledged as a resource to help maintain reliable and affordable electric service, reduce emissions, and save resources. Efficiency goals are mandated in 24 states and are under consideration in others. The continued development and adoption of energy efficient technologies and best practices is essential to realizing these goals. Utility energy efficiency activities have focused on incentives to end-use customers to adopt relatively mature technologies, most notably compact-fluorescent lamps. However, realizing the resource potential of energy efficiency requires the development and availability of a wider variety of efficient end-use technologies in homes, buildings, and industrial facilities.

Realizing the full potential of energy efficiency also requires a more holistic view upstream of the end-use realm, including power generation and delivery. Improvements in the efficiency of auxiliary loads in power plants and in techniques to reduce T&D energy losses can yield significant energy savings within acceptable costs, but also require validation through extensive assessment, testing, and demonstration.

EPRI is conducting a multi-year energy efficiency demonstration project focused on six “hyper-efficient” electricity utilization technologies. These technologies may have the potential to reduce electric energy consumption in residential and commercial applications by up to 40% for each application. If fully deployed, these technologies could reduce the demand for electric energy between 10% and 20%. The six “hyper-efficient” technologies being demonstrated are:

• Variable refrigerant flow air conditioning (with and without ice storage)
• Heat pump water heating
• Ductless residential heat pumps and air conditioners
• Hyper-efficient residential appliances
• Data center energy efficiency
• Light-emitting diode street and area lighting

Improve Efficiency in Generation and Delivery. Energy efficiency can help meet the challenges of maintaining reliable and affordable electric service, managing energy resources, and reducing carbon emissions. While many utilities are encouraged by their regulators to engage in end-use energy efficiency programs, few consider options to reduce energy losses along the electricity value chain. In many cases, the efficiency gains that could be realized through measures to reduce T&D losses or reduce electricity consumption at power plants can be significant.

Recent EPRI analyses indicate that approximately 11% of electricity produced is consumed in the production and delivery of electricity itself by energizing auxiliary devices such as pumps, material handlers, and environmental controls, and through T&D losses. Based on 2010 estimates of electricity generation, this represents 450.7 billion kilowatt-hours of U.S. electricity generated, making the electric sector the second-largest electric-consuming industry.

The application of new technologies may have the potential to reduce electricity use in electric utilities by 10% to 15%. Even a 10% reduction is enough electricity to power 3.9 million homes. EPRI has identified technology options and changes in operating methods that can improve overall efficiency.

In power production, duty-cycle or capacity factor is the key driver that influences internal power use relative to unit output. In coal-fired power plants, the average internal power use across the sample used in EPRI’s analysis was 7.6%. In nuclear power plants, the average was 4.1%. Opportunities to reduce electricity use in power production may include advances in control systems for auxiliary power devices and the use of adjustable-speed drive (ASD) mechanisms. In addition, ASD installations often reduce CO₂ emissions.

Electricity losses in power delivery total approximately 6.3%. In the distribution system, the use of efficient transformers, improved voltage control, phase balancing, and balancing of reactive power needs could substantially reduce electricity use. In the transmission system, opportunities include extra-high-voltage overlays, and transformer and line efficiency. In addition, there are a couple of other “discoveries” worth highlighting:

• Newer power plants are not necessarily more efficient than older plants, due principally to environmental requirements.
• Non-baseload operating plants have a particularly high potential for improvement by the application of ASDs on motors.

Other EPRI research shows that shifting loads from peak to off-peak hours provides significant improvement by reducing load flows on the T&D system during peak periods when losses are exacerbated, while also reducing cycling operation for selected generation units. Use of alternative energy sources close to load centers to supply energy requirements during peak periods also can significantly reduce T&D losses during the most challenging periods of operation.

Given the intensity of energy consumption in the industry’s own physical infrastructure, efficiency measures undertaken at a finite number of power plants or in the power delivery grid can potentially yield energy savings and carbon emission reductions more cost-effectively than traditional end-use programs targeted at buildings, residential users, and other industries.

Improve Data Center Energy Efficiency. Typical data center power delivery designs use alternating current (AC) power, typically distributed within the facility at 480V AC. This power goes through several conversions from AC to DC and back again. The power losses due to the use of inefficient power conversion devices from both outside and within equipment result in a large loss of useful electrical power. They also directly increase the energy required to remove the heat produced. Though estimates and actual measurements vary, the power utilization by information technology (IT) loads can sometimes be 50% or less of the total input power consumption.

Duke Energy and EPRI are working together in a demonstration project that focuses on DC conversion at the data center (or facility) level. The approach will convert the facility’s 480V AC into 380V DC and deliver it to the equipment racks via a 380V DC bus. The very best AC equipment can be deployed to improve power distribution efficiency, but that approach only squeezes some of the losses out of each component. The DC approach eliminates those losses completely, through the removal of the less-efficient AC components.

DC power distribution is an alternative approach to a conventional data center AC power scheme. Most data center server racks are not currently powered using DC, but the servers and storage arrays can operate with either AC or DC. Typical servers and storage arrays inherently convert an AC power source to DC within each power supply, which adds an additional power conversion loss. Using the DC powering approach, extra power conversion steps are eliminated, lowering losses, increasing reliability, reducing cooling needs and square footage requirements for data centers, and simplifying power supplies.

Testing of a DC power system at a Duke Energy data center in Charlotte, N.C., has revealed preliminary results that the system uses 15% less energy than a typical double-conversion UPS AC power system.

Smart Grid

The “smart grid” concept combines information and communications technologies with the electricity grid to increase performance and provide new capabilities.

Increasing use of variable generation and controllable loads, combined with an aging infrastructure, is a scenario where conveying actionable information to and from interactive markets, or monitoring asset health, will require greater use of information and communication technologies. Each utility will create its own smart grid through investments made in back office systems, communications networks, and intelligent electric devices.

Smart grid functional requirements, interoperability, and cyber security standards are still evolving, and premature technology obsolescence could strand some investments as transitional technologies need to be replaced before their expected end of life.

This strategic issue requires a holistic vision with end-to-end system considerations including transmission, distribution, and end use.

Launch “Protect the Grid” Initiative. The increasing interconnectedness, automation, and communication capabilities of the power grid pose several significant cyber security, resiliency, and privacy challenges. Security threats to the grid could come from deliberate attacks by terrorists and hackers as well as inadvertent user errors and equipment failures. Additionally, the dramatic increase in the granularity of data about end-user behavior raises several new privacy concerns. To achieve a secure and resilient grid, advances must be made in assessing and monitoring risk, architectures to support end-to-end security, legacy systems security, approaches for managing incidents, and technology to support privacy.

EPRI has launched the Security and Privacy Initiative, a collaborative effort to investigate cyber security standards, business processes, and technologies that can address these issues. This project, which will expand to become the Cyber Security and Privacy Program in 2012, also will develop technologies, best practices, and controls on data privacy.

EPRI also has partnered with the DOE to conduct cyber security research and analysis to support the National Electric Sector Cyber Security Organization. As part of this three-year public/private partnership, EPRI will determine how to mitigate risks from impending threats, harmonize cyber security requirements, and assess cyber security standards and technologies.

Assessing and monitoring the cyber security posture for energy delivery systems is vital to understanding and managing cyber security risk. As part of its R&D, EPRI is working with advanced metering infrastructure (AMI) vendors and utilities to identify a set of alerts and alarms that can be standardized to enhance AMI security event monitoring. The EPRI program in 2012 will continue this effort and also focus on network security management architectures for T&D systems. These activities will support the long-term objective of enhanced situational awareness across the domains of the power delivery system.

Increasing the security of next-generation energy delivery systems will require a combination of new security architectures, tools, and procedures that provide end-to-end security and support defense-in-depth features. The EPRI program will address this need by developing protective measures, such as key management, high-assurance architectures, and security testing tools to validate the level of protection. The program also will focus on reducing the security risk of legacy systems through the development of risk mitigation strategies, transition strategies, and the assessment of substation security solutions.

5. Low exposure. An EPRI researcher takes data on radio-frequency exposure from smart meters. These meters are typically part of a wireless mesh network consisting of approximately 500 to 750 home meters connected through a “cell relay” meter to local utility via a cellular wireless wide area network. The cell relay meter operates at a nominal power level of 1 watt. Courtesy: EPRI

Although efforts to prevent and detect cyber incidents are important for the protection of control systems, they do not prepare for the eventuality of a cyber incident. Energy delivery systems also must be resilient to cyber incidents and continue to perform critical functions while under duress and during the recovery process. EPRI’s R&D is addressing part of this issue by developing guidelines and best practices for responding to cyber incidents on AMI systems. In the future, the EPRI program will support resiliency for the grid by focusing on decision support tools for responding to cyber incidents, as well as tools and techniques to support cyber security forensics.

Make the Smart Grid Interoperable. Interoperability is the ability of two devices or systems to exchange information and use that information to perform their functions. The vision of the smart grid is that millions of devices in different domains and with different owners will be able to exchange information. This exchange of information needs to happen with minimal integration cost and difficulty.

The lack of mature, uniform standards to enable interoperability among systems has been cited by utilities and regulators as a reason for not moving forward with smart grid applications such as AMI. Investments in proprietary systems risk long-term vendor lock-in and costly “fork-lift” upgrades to fully take advantage of new smart grid applications.

The key to interoperability is standards. The use of standards to integrate complex systems and components dramatically reduces both implementation and operational costs. But for devices and systems to communicate easily, they must speak the same language. Standards abound in the utility space, but they have different, sometimes overlapping domains. Some standards are mature and others are emerging.

Both technical and implementation gaps need to be addressed simultaneously. Existing technical standards for smart grid applications are incomplete and have not been broadly adopted by utilities, vendors, and third-party device manufacturers. Some existing standards need to be harmonized, and reference architectures and interface standards that will enable interoperability between equipment from different vendors will need to be developed. In addition, many of the existing standards do not address cyber security or device management uniformly.

Achieving interoperability is a huge undertaking that involves the active involvement of all stakeholders, including the federal government, standards development organizations, and user groups. All of these activities need to be coordinated and harmonized to enable data and information to be shared with the people and individuals who need it.