JUICE: I’ll Be Dammed

By Published On: September 3, 2010

Pacific Gas & Electric stands on the edges of the barbeque, gnawing on a corn cob, alone. It was that way for the company thirty years ago. PG&E’s still hovering around the party’s periphery. Not that it will help its social skills much, but PG&E’s plan for a new pumped storage facility may move it within reach of the host’s graces. PG&E in late August applied to state regulators to allow it to spend $33.5 million on a feasibility study to build new pumped storage (Current, Aug. 27, 2010). The facility, at a potential cost of $2.5 billion, could be embraced by some environmentalists who may possibly sit next to PG&E if it offered them free beer at the picnic. Other environmentalists, with hiking boots and fishing poles at the ready, might spit in the utility’s sauce. The catch is that while pumped storage doesn’t have to be a fossil fuel energy-wasting, expensive, environmentally-unfriendly plan, it’s an expensive, energy-wasting, environmentally-unfriendly plan that can facilitate expanded use of renewable energy. It’s environmentally-friendly at one barbeque, an environmentally-unfriendly picnic at another. The pumped storage plant is seen as a potential “battery” for solar and wind power. When the wind blows, and the sun’s out, those renewable energy sources can send their power to reservoirs along the Mokelumne River. The electricity would be used to pump water from a lower reservoir to a higher one--and could tap into surplus energy created when the wind is blowing and sun is shining. When utility customers need electricity, the upper reservoir releases hydropower to fuel the grid. PG&E envisions using its current reservoir on Lower Bear River (tributary to the Mokelumne River) and the adjacent Salt Springs reservoir for the task. The facility would still lose a good deal of the power it finally releases because the energy used to pump the water up to the higher reservoir is more than that produced by reservoir releases that feed the grid. But, it’s still a “battery” that stores renewable power for later use. Any battery takes its own bite out of potential power to be released. It would also use electricity from fossil and nuclear sources to pump that water, as electrons are indifferent. So, PG&E cannot sell the pumped storage plant solely on its renewable cred. In other words, it can be billed as a renewable battery, but there is no way to monitor where the electricity sent to the plant is coming from. The facility’s approval faces at least two kinds of environmentalists. Supporting PG&E’s pumped storage plan may be those developing and supporting renewable power. In developing renewables, they face the problem of being required to provide back-up services to the grid. That is, solar and wind power cannot always run when they are required. (At the same time, though, when they can run and aren’t required, without storage their power simply goes to ground and becomes unused and worthless.) Looking at the pumped storage plan, one has to differentiate between its use for immediate power--just like calling on any generator--and its use for grid support. Used as a place for renewables storage--and thus, immediate power--it can fill in the gaps to release energy when wind and solar are unavailable directly. Then, there’s grid support value. PG&E also is promoting the project on its ability to provide grid support, just like other fossil and hydro--support that is unavailable at this time from renewables (see sidebar). Just like fossil-fueled power, when renewables push electrons into the grid, the grid needs other stabilization tools. Think of it like watering your garden. You turn on the hose and it spurts out all over the neighbors, your shoes, and the yowling cat. What you need is a device that controls the volume and granularity of the spray where you want it to go. That’s sort of like what is required from renewables (as well as any other electricity source) on the grid. In this case it has names like “voltage support” and “reactive power.” Because of their 24/7 availability, fossil plants are the first in line to use their power to stabilize the grid. With pumped storage--renewables developers, as well as state policy makers--could put a dent in the carbon footprint by lessening use of fossil fuel. In the future, that stabilization could come from batteries or flywheels or other systems. But, pumped hydro is a known technology. Then there are other environmentalists. Those are the ones who like rivers, the ones who despair over the steep decline of anadromous fish. The ones who want no more impact on fragile public lands like the Stanislaus National Forest--very near what’s set aside by the nation as beautiful and fragile lands in the Mokelumne Wilderness area. (That’s where this pumped storage facility would be built.) Existing dams would be raised by seven feet. The short-term environmental effects would come from building; the long-term effects from radically altered stream flows. What are an environmentalist and a regulator to do? Let’s look at a timeline. While pumped storage is a known and tested method of storing electricity, the pumped storage plant faces a raft of approval processes. PG&E director of new generation development, Mike Jones assumes that the pumped storage facility could be online about 2020. PG&E applied to the Federal Energy Regulatory Commission for a “preliminary permit” in 2008 while it does a feasibility study. An August 26 report to federal regulators noted that the utility has been meeting with stakeholders on the plan over the summer. By the time that PG&E is all permitted, all ready to spend that money and fuel up the D9 earthmovers, the battery technologies that are taking baby steps now for storing renewable energy should be ready for commercialization. Batteries would be distributed, thus, less susceptible to outages as well as contributing to increased reliability--that is, if one goes out, others in the region kick in. Would they be more expensive than a $2.5 billion centralized facility? Unknown. Would they be owned and operated by a single utility? Unlikely. The judgment call is whether to roast fish and riparian habitat on the grill. It could be a renewables-fired grill. PG&E still won’t be the bon vivant that everyone wants to sit next to it at the party, but between shareholders (who would profit from the $2.5 billion investment), and renewables developers (who wouldn’t be so pressed to develop their own grid stabilization methods), it may not be so lonely.

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