The Case for Expanding Pumped Hydroelectric Storage.
The title of this diary is the title of an article from a March 21, 2008 essay by Harry Valentine on Energy Central's "Generation Technologies" Industry Article page. I'm not a big fan of Energy Central. I think they engage in far too much speculative energy writing that is often more fantasy than physical. Valentine, in my not-so-humble opinion is probably the worst of these. His articles border on the sci-fi under titles like:
Transmitting Natural Lighting around the world
Downstream Thermal Energy from Natural Gas Pipelines
Tidal Mega-Power and Hydrogen Production in Northeastern Canada
Micro-hydroelectric Power from Fog Fences
The articles try to be as well researched from an engineering perspective as they are wishful thinking in demeanor. A bundle of contradictions, lets say.
But one theme that Valentine has harped on in a number of articles is pumped storage. In his latest article on this top he focuses in on Niagara Falls and the recent proposals to expand existing hydro-electrical production. He argues, strongly and, convincingly, to make such expansions of this valuable resource into a combined engineering project by installing not just hydro turbine-generator sets but to hydro turbine-generator-pumped storage sets.
Pumped storage is not an energy source. It simply is a way of husbanding overproduction in an energy sector or region by storing it in the form of water to be used when ever the demand is there.
Diablo Canyon, PG&E's nuclear power plant in California, was built along with a 1200 MWs pumped storage facility across the state at Helms Pump Storage Facility. Built in tandem it allows Diablo Canyon to run flat out 24/7 and storing the unused power at night. During peak times, say, 1500 hours through 1900 hours on a hot, windless and hazy summer day, we get the power back 'for free'.
Helms, however, is a dedicated pump storage facility. It can run flat out for 14 days at 1200 MWs and drain it's upper reservoir if need be in an emergency. Valentine's proposal is more ambitious. He has been arguing to covert most of our big hydro projects in the US to pumped storage. Usually this means rewinding the generators to allow for them to have their polarity reversed to turn them into motors, rebuild the turbines so they can pump out water as well as receive water and a host of other engineering details that would have to be met.
The great thing about Valentine's proposals on pumped storage is that they can be done incrementally, during overhauls, or whenever funding becomes available.
But so what? What's the big deal. The big deal is efficiency. Now, Valentine suggests that using new Ultra-High Voltage DC lines we could transport large volumes of "surplus" South-West based solar energy to the Northeast in Niagara Falls and "store it". Well, we 'could', but we 'can't' because there in NO "surplus" nor is their likely to be surplus, ever, of solar energy. Even the largest scale projects would have on site hot-salt storage (assuming it could ever be economical) and most solar energy, I predict, would be used up as it was produced. You'd have to have a HUGE solar project to produce a 'surplus'. A project that itself would become environmentally questionable in it's own right if it were big enough to produce enough power to wheel across country.
But Valentine tries to be objective. He speaks out for nuclear energy as a source of this surplus power. Indeed, what to do with "excess" nuclear energy after peak and before 0700 hours in the morning is a problem in some places. Indeed, pumped storage could this problem with nuclear's inherent efficiency in producing cheap power around the clock.
Recently, many un-educated solar and wind advocates see pump storage as their solution to the thorny issue of reliability. They fall to understand even what pumped storage is. They think you can simply build it anywhere, as if vast quantities of water at the proper elevations are easy to design. Valentine's proposals seem more appropriate for the high-power centralized energy production of a single nuclear power plant than the diffuse, spread-all-over-the-country-side wind and solar proposals. Financing, for example, a new light water reactor of 1200 MWs could be done in conjunction with a re-powering scheme for, say, the Grand Coulee Damn set on the Columbia River. With UHVDC also financed as part of the revenue stream from the nuclear power plant.
We could, for example, build a string of low-cost Liquid Fluoride Thorium Reactors, say, 6 GWs, in Wisconsin on Lake Michigan, and wheel the power to any number of hydro-converted-to-pump-storage facilities in the Eastern Rockies and upper Midwest or even to Quebec. The possibilities are endless.
David Walters