Largest U.S. Smart Grid Demo Project Is Set to Roll
- Written by Carl Imhoff
With all system infrastructure in place and utilities finishing up the installation of smart grid asset systems across the Pacific Northwest region, a transactive control system will "go live" this fall, allowing the installed assets to start responding to electric power conditions. Though questions will remain, we believe we are taking a significant step that will move the nation closer to a more efficient, sustainable and resilient power system.
We are in the midst of an impressive transformation of our electric power system. Technological advances are elevating the prospects of a more resilient, sustainable and efficient future power grid. Yet the question remains of how to get us there. What technologies work well? Can we make a business case for a "smarter" grid that can help, for example, integrate renewable energy that is coming online at a tremendous rate? The Pacific Northwest Smart Grid Demonstration Project, or PNW-SGDP, the largest in the nation, is trying to answer some of those questions.
With $178 million in funding from the U.S. Department of Energy and project participants (who are required to match the DOE contribution at 50 percent or more), the PNW-SGDP kicked off its five-year journey in February 2010, when concerted project planning began. Participants include 11 utilities, 5 technology partners and 60,000 consumers across the five states of Idaho, Montana, Oregon, Washington and Wyoming. We set out with five important objectives in mind:
- Quantify smart grid costs and benefits
- Facilitate the integration of renewable resources
- Validate new smart grid technologies and business models
- Advance standards for interoperability and cyber security
- Provide two-way communication between distributed generation, storage and demand assets, and the existing grid infrastructure
At the heart of our efforts is the creation of the project's new transactive control and coordination system. This distributed system will enable responsive assets and energy generation across the five-state region to produce and use electricity more efficiently. The system sends signals that communicate the expected future cost of delivering power to specific locations, allowing loads and distributed energy resources to react to price incentives. The loads and distributed energy resources in turn send a "feedback" signal communicating their energy consumption or supply plans in the future. At locations in the system where the flow of power may be affected these two signals are updated and are used to engage the local responsive assets. We are testing this technology on an array of assets to assess how it will improve future grid efficiency and reliability.
Take for example the problem of electric cars recharging their batteries during peak times of energy demand. Uncoordinated charging can lead to transformers overloading and general strain on the grid. With our new system in place, responsive assets from plug-in hybrid electric vehicles to water heaters can react to the grid's state, as represented in incentive signals, and charge batteries and heat water without straining the balance of generation and load.
The approach taken to transactive control and coordination is to delegate decision-making to each node in the system. The incentive signal informs that decision based upon both global grid conditions and local needs and availability.
For the car-charging example above, imagine a pole-top transformer serving some number of electric vehicles. If the transformer is overloaded, its service life will be reduced. The transformer adjusts the value of the incentive signal based on its current state, weather conditions and feedback from the vehicle chargers about future charging plans. When the transformer changes the future value of the incentive signal based on the charging plans, the plans may change as a result. Because the system is a form of closed loop control, convergence of the give and take between incentive signal changes and charging plans may be assured through careful algorithm design.
Integration of renewable energy provides another example of how the transactive system will work. Right now in the Pacific Northwest, we have about 4,000 megawatts of wind energy in the Bonneville Power Administration's footprint. Over the next couple of years, the amount of wind generation is projected to double. Total regional wind capacity of about 12,000 MW will equal the amount of hydropower generated by the Federal dams along the Columbia and Snake rivers. Our system is capable of incentivizing the consumption of renewable energy, so that the region can benefit from use of its clean natural resources when they are most abundant, and reduce the amount of "spilled" wind power—excess wind-generated electricity that has to be dumped. Perhaps more importantly, the system engages the responsive assets to help balance the intermittent nature of wind energy and allows optimal operation of generation resources such as the hydro system.
This transactive way of managing energy is gaining attention among the wider electricity sector. This January, the IEEE PES Conference on Innovative Smart Grid Technologies featured this approach in plenary and panel sessions entitled "Transactive Energy Techniques." Our project participants are using transactive technologies to engage responsive consumer resources, and other assets in the region to improve overall system efficiency and reliability, and to reduce operating costs for utilities.
In all, these changes can help reduce the need to build costly thermal resources, cut the region's carbon footprint, smooth out peaks in electricity use, help integrate intermittent renewable resources and keep future costs from rising as quickly as they otherwise would.
Our project is a first step towards achieving these objectives. Last April, we successfully connected key system software and hardware components from the project's technology partners: 3TIER, Alstom, IBM, Netezza and Quality Logic with Battelle's Electricity Infrastructure Operations Center (EIOC), and demonstrated communication connectivity to several of our utility partners.
At the same time, our utility partners are transforming the region's grid by installing 80,000 smart grid enabling assets such as smart meters, and 12,000 smart grid-responsive assets, which include water heater load controllers, solar panels, battery storage units and backup generators.
Over the past two years, demo participants have been installing the assets and tools necessary to support this new system. Now, with all system infrastructure in place and utilities finishing up the installation of smart asset systems across the region, we are looking forward to this fall, when our transactive control system will "go live" and allow the installed assets to start responding to electric power system conditions. The data we gather over the next two years of the project from this two-way communication system will help us improve our knowledge of how to operate our power system more efficiently and identify what types of technologies will best suit our region. Starting this fall, status updates will be available on our website.
As we start gathering data and experiences, we will better understand which benefits may be realized and how these could be spread through deployment beyond our current footprint in the Pacific Northwest. The PNW-SGDP will surely not answer all remaining questions, but we are taking a significant step that will move the nation closer to a more efficient, sustainable and resilient power system.