Industrial Innovation and the Smart Grid
By Danielle Merfeld
Realization of the smart grid depends on technology development, standards development and policy development. Technical innovation is key but will not yield all possible rewards unless standards are harmonized and national policy is consistently geared to produce all the social benefits desired.
We are in the midst of great change. One area where we are experiencing this is in the increased demand for power generation, as a billion people climb out of poverty and join the middle class. It is expected that over the next 15 years there will be 4 terawatts added to the 16 TW of global electrical capacity that exists today. However, only 4 percent of this additional capacity will be built in the United States. Roughly half of the new capacity will be added in China and India, opening the opportunity for leapfrog technology where new ideas are not constrained by existing infrastructure. The resilience of our energy systems will also be critical as we expect that more than 12,000 natural disasters to occur around the world within the next 15 years, according to Munich Re.
The culture within GE is to embrace the fact that the world is changing very fast; though challenges are cropping up every day, so are novel solutions. A key focus at the company is the electric power system and, in particular, the three critical areas where innovation is required to realize the smart grid of the future: technology development, standards development and policy development.
In terms of technology development, one obvious set of challenges has to do with the introduction of renewables into the grid. Traditional controls and system protection are no longer suitable when power is generated non-centrally and flows bi-directionally. Solar and wind generation assets are tied into transmission lines as well as the distribution grid. Therefore, in certain circumstances parts of the distribution grid could see power flow moving in the opposite direction than is typical (that is, flowing away from a home that is generating more energy than it is consuming). But distribution controls and protection traditionally take advantage of and are designed only for unidirectional power flow.
Other challenges created by distributed renewable generation are voltage regulation and voltage control. Unintended consequences include open circuit over-voltage due to unintentional islanding, protection ratings not matched to fault currents, and stress on voltage regulation equipment.
Another category of technical challenges lies in the manual nature of our service of the grid. The lack of appropriate levels of distribution automation deployed on the grid leads to longer than necessary outage times experienced for customers, especially those on un-faulted (healthy) sections of the grid.
Outage times are a critical metric for every utility: SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index) are two well-known indices for assessing utility performance, as well as potential penalties. To address those costly problems, existing FDIR (Fault Detection, Isolation, and Restoration) methods can include automated systems that are able to rapidly restore service to customers faster than might otherwise be possible. Clearly much depends on the severity of the event. But further protection can be had from distributing intelligence further downstream than is typical today, empowering local decision making and control, and closing the loop on software applications such as FDIR.
Another longer-term solution is to reduce the losses and better manage the demand, through active optimization of voltage and reactive power—controlling voltage manages demand and controlling reactive power manages losses. There are two relevant approaches : Coordinated Volt Var Control (CVVC), where the logic is substation based; and Integrated Volt Var Control (IVVC), which is a centralized approach, tying multiple substations together. The latter is more detailed but more difficult to implement by comparison with CVVC, which provides quick implementation and allows a utility to implement and realize benefits quickly. The optimal end state is a hybrid architecture, utilizing CVVC most of the time except where a system view across multiple substations is needed, triggering IVVC to kick in . That is the most robust and effective solution.
A final example of where industrial innovation can really drive smart grid technology forward is Demand Optimization. GE’s approach is based on our GE Grid IQ software services platform, a software backbone that enables demand response implementation, optimal use of load resources for peak management and grid operation support. These kinds of services enable consumers to better manage consumption and cost.
None of the innovative smart grid technologies will work well with each other if they are not compatible at every level. Proprietary standards will hinder their adoption, and therefore GE is engaged in helping to enable these innovations by making sure that they mesh well.
It is an active participant, for example, in the Smart Grid Interoperability Panel (SGIP), an industry group established to ensure that the standards that govern the components of a smart grid solution are interoperable with each other. Standards are included into the SGIP Catalog of Standards once they are reviewed for compatibility with architecture, cyber security, guidelines and so on, and are voted on by members.
As SGIP Board Chair John McDonald has stated: “The mission of SGIP is not to develop standards but to do something far more important—to coordinate standards to assure that both existing and new standards are utilized correctly. The devices and systems in an integrated solution, or the components, must be compliant with the relevant standards and be tested for interoperability to assure the electric system operates seamlessly.” In addition to the panel’s role in shaping standards, they continue to educate industry stakeholders and the public as a whole that interoperability is vital if we are to have a seamless, safe, cost effective and reliable energy system.
Policy also is essential to successful smart grid development. In contrast to some other industries, electric power has not been deregulated in a consistent manner in the United States, which has led to limited competition and a slow pace of innovation. The policy variation that exists across regions has led to a variety of rate structures and regulatory bodies making it very difficult to build scale and succeed in timely development.
There are clear demonstrations of how regulation has been used to incentivize innovation in the renewables space in both China and Europe. These examples should provide some context for how governments can drive progress. Ancillary benefits such as social advantages must be clearly articulated, so incentives are tailored to achieve all the desired values.
The AC electric grid has been identified as the most significant engineering feat of the last century. The future of the electric grid can be equally impressive as we make moves to incorporate new advances in power generation, supply and service. These important innovations coming from industrial research activities and product development are poised to provide resilient, sustainable and affordable power to people across the globe.
Thomas Edison, GE’s founder, is reputed to have said, “I find out what the world needs, then I proceed to invent it.” In that spirit, GE continues to innovate with the challenges enumerated above in mind. To address issues of bi-directional power flows in distribution systems that incorporate renewable generation, GE has devised a transfer-trip wireless communication system that disconnects the remote distributed generation source to allow for a safe line repair following a line fault. Alternately, GE has also developed capabilities within its own converters and inverters to sense this fault and disengage automatically without the need for a wireless signaling system.
GE also developed a control system to manage a set of complex energy resources such as those found on a microgrid. We have customers—including the U.S. military—in need of this solution today. This system is called the U90 Microgrid controller and it features optimal dispatch, supervisory controls and islanding/ tie-line controls. It is expected that the demand for more local control will increase as customers increase their breadth of power generation solutions on site. In general, we advocate for more local control to improve grid health.
There are several other tools and solutions to help manage the effects of the ever-higher penetration of renewables on the grid. One set of solutions focuses on the optimal dispatch of reserves by leveraging production forecasting and intelligent unit commitment. To compensate for variability we have developed fast-responding power plants (FlexEfficiency 60) and cost-effective energy storage (Durathon Battery). To leverage the full capabilities of renewables, GE has pioneered the development of robust controls and management of renewable sources, to stay connected longer and appear more like conventional generation to the grid.
GE has been a part of the development of our global electrical infrastructure for over 130 years, and today our power technology generates a quarter of the world's daily electricity. However, we also have a deep appreciation for change and look forward to playing our part in the development of the modern smart grid through the development of advanced technology, support for comprehensive standards and backing of smart policy.
Danielle Merfeld, an IEEE member, is is Technology Director, Electrical Technologies & Systems at GE Global Research in Niskayuna, N.Y. She leads a global team of over 500 scientists and engineers, responsible for advanced technology development in the areas of semiconductor devices and packaging, controls, power electronics and power conversion, distributed across GE’s four global research facilities. Previously, Merfeld was General Manager of Solar Technologies at GE Energy. She initially joined GE Global Research in 1999, upon earning a bachelor’s degree in electrical engineering at the University of Notre Dame and a Ph.D. in electrical engineering at Northwestern University. Her article is an adaptation of a talk she delivered at IEEE’s Innovative Smart Grid Technology conference in Washington, D.C., in January.