Challenge 2

The ORNL Distributed Energy Research Challenge

The existing U.S. power system has served us well…but our 21st Century economy needs a 21st Century grid. The future grid provides a critical platform for U.S. prosperity, competitiveness, and innovation in a global clean energy economy. It must deliver reliable, affordable, and clean electricity to consumers where they want it, when they want it, how they want it. [1]

Introduction

The Grid Modernization Initiative is an aggressive five-year grid modernization strategy for the Department of Energy that aims to help the nation achieve at least three key outcomes within the next ten years:

  • 10% reduction in the societal costs of power outages
  • 33% decrease in cost of reserve margins while maintaining reliability
  • 50% cut in the costs of wind and solar and other direct generation integration

If achieved, these three key outcomes would yield more than $7 billion in annual benefit to the U.S. economy.

Many remote areas lack electricity delivery services that would typically be provided by load serving entities. While some remote communities may be supplied with electricity from a distribution (or village) utility, heavy reliance on fossil fuels for electricity generation has resulted in high costs for electricity, attributed to expenses associated with import/transport of the fuel and storage at the generation site, loss of ecosystem services due to deforestation and increased erosion, and environmental pollution with documented public health impacts [2] [3]. For such remote communities, microgrids that integrate local renewable energy resources (such as wind, micro-hydropower, or solar) to replace or supplement fossil fuel-based generation could offer viable and resilient solutions for electricity cost reduction, while maintaining or improving the reliability of electricity delivery for the region.

Microgrids, which are localized grids that can disconnect from the traditional grid to operate autonomously and help mitigate grid disturbances to strengthen grid resilience, can play an important role in transforming the nation’s electric grid. Microgrids can strengthen grid resilience and help mitigate grid disturbances because they are able to continue operating while the main grid is down, and they can function as a grid resource for faster system response and recovery. Microgrids also support a flexible and efficient electric grid, by enabling the integration of growing deployments of renewable sources of energy such as solar and wind and distributed energy resources such as combined heat and power, energy storage, and demand response. In addition, the use of local, or distributed sources of energy to serve local loads helps reduce energy losses in transmission and distribution, further increasing efficiency of the electric delivery system.

Microgrid demonstrations and deployments have shown the ability of microgrids to provide higher reliability and higher power quality than utility power systems and improved energy utilization. The vast majority of these microgrids are based on AC power, but some manufacturers, power system designers, and researchers are demonstrating and deploying DC power distribution systems for applications where the end-use loads are natively DC, e.g., computers, solid-state lighting, and building networks. These early DC applications may provide higher efficiency, added flexibility, and reduced capital costs over their AC counterparts.

ORNL’s Research Program

In support of the Grid Modernization program Oak Ridge National Laboratory is developing an open framework for Joint Optimization and Control of Networked Microgrids. At the core of this research is a Software-defined Intelligent Grid Research Integration and Development platform (SI-GRID), a network of five fully functioning reconfigurable low-voltage microgrids that 1) comply with relevant standards existing and under development; 2) is extensible by interfacing to grid simulators existing and under development; 3) employs an open data architecture; 4) has a highly instrumented shadow network with high speed data collection, storage and retrieval, to fully monitor operations; 5) generates reference data sets for advanced grid research and 6) can be used to establish/host grid resiliency/cyber-security war game exercises.

The SI-GRID will accelerate the execution and transition of microgrid-related science from the lab into the field, addressing prospection of place-based optimal blends of renewable energy resources to address local demand,  networked microgrid control and optimization, standardization and integration of distributed energy resources, buildings, equipment, appliances, vehicles, renewables, energy storage, as well as protection and cyber-physical security.

An excellent example of a recent energy systems integration demonstration project can be seen here:

The Challenge

Researchers at ORNL have teamed with faculty at the Energy Initiative at Duke University to develop new ways in which the SI-GRID development platform can be used to evaluate the performance and optimization of distributed energy sources for electrical energy conversion and storage attached to a microgrid. This includes characterization of renewable resources at multiple scales, and designing flexible microgrid systems and mesoscale networks of microgrids that can adapt to physiographic and climate constrains to meet the needs of populations in remote, rural and island systems that cannot rely on single energy sources. Furthermore we are interested in simulating the resilience of such systems during extreme events and after extreme events including earthquakes, landslides, floods and severe weather generally.

We invite students to propose creative, but plausible, summer research projects, focusing on one or more of the areas listed below, that would take advantage of the SI-GRID platform:

Dynamic Resource Surveying and Assessment  

Remote terrestrial and ocean environments are often characterized by complex topography which strongly modulates the spatial and temporal distribution of water resources, incoming solar radiation, and winds and clouds that result from the organization of solar radiation by topography and tend to exhibit strong diurnal and seasonal cycles (Fig. 1). For example, fog and weak winds in the early morning hours, clear sky and strong gross-valley winds at mid-day, widespread development of clouds in the mid to late afternoon, strong down valley winds at nighttime. NREL (National Renewable Energy Laboratory, www.nrel.gov) has produced nation-wide assessments of bulk renewable energy resources at coarse spatial and temporal scales.  How would you go about determining the optimal blend of different types of renewable energies (solar, wind, ocean-waves, hydropower, biomass) at the community scale that meets current and evolving demand (economic development plans, population dynamics)? What are the microgrid configurations and regional network architectures that best integrate technology and natural infrastructure platforms (terrain, wetlands, meadows, floodplains) at local and landscape scales? How would you address the challenge of sustainable energy storage and distribution? How would you present or visualize your findings and recommendations?    

Operations and Adaptation

How would you address the question of resource uncertainty associated with changes in weather patterns? What are the opportunities and limitations to microgrid adaptation in response to energy source uncertainty at multiple time-scales and extreme events (e.g. long-lasting drought) and, or technical failure conditional on natural infrastructure (e.g. hillslope landslide; hurricane landfall)? What are the technology alternatives to achieve resilience through microgrid adaptability? How would you go about defining natural infrastructure requirements for local microgrid functionality? What are the obstacles you envision, and how would you address them?    

Regional Scaling of Microgrids Networks

What are the benefits of networking microgrids to regional scale? How would you go about designing a regional network? What are the technological challenges and, or obstacles to networking microgrids from local (e.g. ridge-valley scale; estuary) to regional scales (mountain range, entire island)?

Integrated Renewable Energy Management and Coupled Human-Natural Systems

How do you envision the role of microgrids in sustainable renewable energy management? What are the potential environmental impacts of microgrids and microgrids networks? What are the potential feedbacks on local hydroclimates and ecosystems?  What is the potential role of microgrids at the water-food-energy nexus in remote regions? What are the challenges? How would you present or visualize your findings and recommendations?


References

[1] UNESCO, 2014: The United Nations World Water Development Report.  No 5-2014, 224 pp.

[2] Browne, S., 2012: United Nations Industrial Development Organization: Industrial Solutions for a Sustainable Future. Routlege (Pub.)  184pp.

[3] OECD, 2012: Linking Renewable Energy to Rural Development, OECD Green Growth Studies, OECD  (Pub.)

http://www.nrel.gov/research/publications.html