Fishing for Wind in High Water

The Bonneville Power Administration (Bonneville) is the custodian of the Pacific Northwest’s federal power supply and the manager of dams on the Columbia River. Bonneville is required by law to encourage the development of renewable energy in its service area, including a sizeable and growing fleet of wind power generators, while at the same time providing federal power to residential customers and protecting endangered fish species. It is Bonneville’s responsibility to balance these interests, and new policies to meet the needs of renewable energy integration are increasingly necessary. The latest chapter of this balancing act was the publication of Interim Environmental Redispatch and Negative Pricing Policies Record of Decision, and the widely divergent comments filed in response.

Heavy Flow and Strong Winds

The Federal Columbia River Power System (FCRPS), including the Pacific Northwest’s hydroelectric dams, are operated in order to produce electricity, control floods, provide water for municipal uses and irrigation, and protect the river’s fish populations. In order to protect fish populations, Bonneville is required to manage the amount of water that is run through dam generators, spilled over the top of dams, and maintained in reservoirs. For the past two weeks, with water flow at its annual peak, Bonneville has struggled to maintain its obligation to protect juvenile fish populations by keeping Total Dissolved Gas (TDG) levels within Clean Water Act and Endangered Species Act limits. In response to this high flow of water, Bonneville made arrangements to run more water through its generators, which creates less bubbles of air and TDG than spilling water over the dams. Like most actions from this agency, this is controversial. Some fish advocates are strong proponents of increasing the amount of water spilled, believing that the benefits to fish outweigh the risks associated with gas bubbles.

As a Balancing Area Authority (BAA), Bonneville is required to maintain a balance between total electric demand (load) and total electric generation on its system. Bonneville does this by utilizing the flexibility of the FCRPS to quickly increase or decrease its output based upon the needs of variable generators and the electric load of the Northwest. A significant portion of this flexibility is used to compensate for wind energy’s inherent variability.

Each spring as runoff increases, Bonneville manages the heavy river flow to protect fish populations by keeping TDG levels within legal limits. In order to keep TDG levels low, Bonneville runs more water through the dams’ generators and creates more power. In order to balance the addition of this unscheduled power on its system, Bonneville first freely gives away the power, adjusts the level of reservoir reserves (including pump reserves), reduces generation at other generation facilities, and operates hydro projects inefficiently.

In response to Bonneville’s offer of free hydropower, many fossil fuel-powered generators shut down, saving the cost of fuel those generators would have incurred by running. Wind generators, which do not have fuel costs and must produce energy in order to receive renewable energy credits (RECs) and federal production tax credits (PTCs), do not voluntarily stop generating power. Voluntary actions did not reduce power generation enough, so in the last two weeks Bonneville ordered wind generators to stop producing power, resulting in lost income for wind developers. Instead of ordering other generators not to produce, wind developers urged Bonneville to pay wind facilities not to produce.

Bonneville specifically decided not to pay negative prices for its energy, providing two explanations to support this decision (see page 12 of the Record of Decision). First, paying negative prices is not “consistent with traditional principles of cost causation,” since Bonneville’s preference customers in the Northwest would pay the cost of displacing wind generation, while the majority of wind power is sent to California. “The costs of Federal and state production incentives should be borne by a broad group of taxpayers and ratepayers receiving the wind power, not concentrated on [Bonneville’s preference] consumers with limited economic interest or benefits from the renewable generation.” Second, Bonneville “believes that its statutory responsibilities and the objectives of the Northwest Power Act would be frustrated if BPA were required to pay negative prices in order to ensure compliance with BPA’s environmental obligations.”

The legal limit of total dissolved gases used to protect fish is in dispute

Save Our Wild Salmon Coalition responded to Bonneville’s proposed policies by arguing “that there is no need to pit salmon and wind farms against one another,” contending that Washington state’s 115% TDG “standard contradicts the best available science and stands in opposition to the 120% level put in place by the State of Oregon that would allow for more spill at these same dams.” Moreover, Washington state’s TDG standard is under attack in the Thurston County (WA) Superior Court. (See Northwest Sportfishing Industry Assn. v. Wash. Dept. of Ecology, Case No. 10-2-01236-0). In addition to arguing that higher TDG limits will not harm fish, wind developers point out that operational measures can be taken to decrease the potential of, or eliminate the need for, environmental redispatch.

Additional steps can be taken to maximize the flexibility of Bonneville’s transmission system

Detractors of the Environmental Redispatch policy argue that the use of intra-hour scheduling and dynamic transfers can maximize the flexibility of the FCRPS and defer, if not eliminate, the need for environmental redispatch. Intra-hour scheduling reduces the need for large balancing reserves, and dynamic transferring allows the real-time movement of power from one BAA to another. Both practices will allow Bonneville to run more water through the dams’ turbines and reduce TDG levels. Page 9 of Bonneville’s Record of Decision notes that “[t]o the extent [intra-hour scheduling will] successfully help accommodate the variability of wind generation, BPA hopes to be able to partially reduce reserve amounts. Continued growth of wind generation, however, will require BPA to increase the amount of reserves it must carry. As a result, while intra-hour scheduling may help reduce reserves in the near term, it will not solve the overgeneration condition itself since the region will still face more on-line generation than there is load to absorb it.”

Currently, Bonneville and most western states schedule power transmission on an hourly basis. For example, a wind facility predicts that it will produce 20 MW for the hour. 20-30 minutes ahead of the start of the hour, the facility schedules 20 MW of transmission for the hour, and this schedule generally cannot be modified. Due to the wind facility’s intermittent nature, it will likely produce less than 20 MW of power for a portion of the hour, and may produce over 20 MW for a portion of the hour. These inaccuracies are compounded by the fact that transmission schedules are often 90 minutes old by the end of the scheduled hour. In order to ensure that enough power is always available to serve the BAA’s load, the BAA maintains “balancing reserves,” which are fast-responding generation facilities that have the ability to compensate for the difference between the scheduled output and the actual output.

Intra-hour scheduling allows generation facilities to schedule their transmission in 15 or 30 minute intervals. Scheduling in smaller increments of time produces more accurate schedules and results in less deviation of actual production from scheduled production. In addition, intra-hour scheduling limits the lag time between scheduling and power production. The increased accuracy resulting from intra-hour scheduling will likely result in the need for less balancing reserves. Bonneville uses the FCRPS dams as balancing reserves, so when more reserves are needed, less water is guaranteed to flow through the turbines of the dams. As a result of implementing intra-hour scheduling, Bonneville will likely be able to hold less balancing reserves and guarantee that more water can flow through the dams’ turbines.

Transmitting power between BAAs on an intra-hour schedule is facilitated by dynamic transfer systems that enable the real time monitoring and administration of energy transfers. Allowing the transfer of power to other BAAs on an intra-hour schedule can also reduce Bonneville’s need for balancing reserves and guarantee that more water can flow through the turbines.

A regional effort to allow intra-hour scheduling and dynamic transfers in the western states is currently underway. This voluntary effort is known as the Joint Initiative and will allow for the scheduling of generation and transmission in 30 minute intervals. Bonneville has partially implemented this practice, and plans to participate in a wider rollout of intra-hour scheduling on July 1, 2011. Moreover, the Federal Energy Regulatory Commission issued a “Notice of Proposed Rulemaking for the Integration of Variable Energy Resources” which, if implemented, will require scheduling in 15 minute intervals.

An Uncertain Flow

The Citizens’ Utility Board has not issued an opinion on Bonneville’s Environmental Redispatch policy. Most publicly-owned power producers support it, and almost all other stakeholders oppose it. As the spring runoff season continues and the next chapter of Bonneville’s balancing act is written, renewable energy developers hope that policies that allow for the continued expansion of wind power are implemented. Developers facing Environmental Redispatch policies complain of lost profits and fear that these policies will stunt the growth of renewable energy in the Pacific Northwest. Accordingly, wind developers have asserted legal claims against Bonneville’s policy and will likely appeal the decision implementing this policy to the courts.

CUB will continue to monitor the impacts of high flow and wind development on the region’s power supply, but we do not anticipate taking a position on this contentious issue.

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