The Promise of Aquabank™
"one of the best kept secrets”
- Energy Secretary Dr. Steven Chu [Sept 2009]
"astoundingly efficient… In this future world where we want renewables to get 20, 30, 50 percent of our electricity generation, you need pumped hydro storage. It's an incredible opportunity and it's actually the lowest cost clean energy option. So I will do my best to make that known to the United States. And directly under our control in the DOE we will be pushing this.”
- Energy Secretary Dr. Steven Chu [Sept 2009]
“The good news is that there is a potential for pumped storage….
one of the things we need to look into is how to overcome the environmental sensitivities...
if you do, this is a perfect system….for….
going to a much higher renewable system”
- Energy Secretary Dr. Steven Chu, DOE-NARUC National Electricity Forum [Feb 18, 2009]
“We should start to invest heavily in pumped hydro storage”
- Energy Secretary Dr. Steven Chu, National Clean Energy Project [Feb 23, 2009]
“Integration of large amounts of … storage and demand response programs may provide additional resource flexibility and influence bulk power system reliability and should be considered in planning studies.”
- North American Electric Reliability Corporation, Accommodating High Levels of Variable Generation [April 2009]
“Energy storage technologies are not an alternative to any particular resource decision; rather, they are a valuable adjunct to all resources, and they will allow increased capacity to be derived from any given quantity of physical resources.”
- Department of Energy, Bottling Electricity [December 2008]
“Hydro capacity and energy storage are valuable resources that should be used to balance the system, not just the wind capacity.”
- Department of Energy, 20% Wind Energy by 2030 [July 2008]
In 1929, the first hydroelectric pumped storage facility in the United States went into operation at Connecticut Light & Power’s Rocky River Station. The Rocky River plant, with two surface reservoirs and an installed capacity of 31 Megawatts (MW), led to significant improvements in the operating efficiency of the company’s network of power generating plants.
The majority of electrical utility systems are confronted with substantial fluctuation in load demand, which poses a great challenge for grid management. Pumped storage is the most practical way to store large amounts of energy to meet peak demands and to provide clean reserve generation. Because of these advantages, the utilization of this technology experienced rapid development from the late 1950s to the late 1980s. In a period of 30 years, approximately 19,500 MW of pumped hydroelectric storage facilities were brought into service in the United States. However, the growth has slowed, due primarily to the difficulty in finding satisfactory sites. By 2008, the nation’s pumped storage generating capacity had reached only 20,800 MW.
On February 18th, 2009, 80 years after operations commenced at the Rocky River plant, pumped storage once again claimed the attention of the energy world. In his first public address, US Energy Secretary Dr. Steven Chu commented on the need for pumped storage in the context of the development of wind energy generation.
As part of their renewable energy portfolios, many states have set aggressive goals to increase wind generation capacity. The state of Maine, for example, plans to add 3,000 MW of wind capacity by 2020. Because of its intermittent nature, when wind generation accounts for over 20 percent of a system’s total energy generation, a serious problem arises, as acknowledged by Secretary Chu.
Any electricity transmission and distribution system—the “grid” itself—has a certain carrying capacity for intermittent sources of power. Pumped storage demonstrably and significantly increases that carrying capacity. A 2008 report released by the Department of Energy explores a modeled energy scenario in which wind provides 20% of US electricity by 2030. That is equivalent to the addition of 300 Gigawatts (GW) of wind power. To achieve this target, approximately, 50 GW of new peaking/storage plants would have to be used to supplement and balance the variability of the wind power output. Among all the possible sources of peaking generation, pumped storage is the only one that generates power without generating any air pollution or fuel stock waste.
“The good news is that there is a potential for pumped storage”. This verdict from Dr. Chu provides us with the key to our nation’s energy future—the path to the “smart grid" with its “green collar jobs” and enhanced “energy independence.” The key is hydroelectric pumped storage, and plenty of it. This is why storage is at the top of the energy agenda for Secretary Chu. Pumped storage, as the one technological option that can provide large-scale energy storage, has a tremendous role to play in the years ahead. The only issues that remain to be overcome relate to siting and environmental sensitivities. If these can be tackled, pumped storage is indeed “a perfect system for… going to a much higher renewable system”.
Riverbank Power Corporation, an alternative energy developer, is proposing an innovative solution to the siting and environmental issues—the solution is underground pumped storage. Underground pumped storage, relying on advanced but tried and true mining techniques, has become an economically viable and technically feasible approach. By locating the lower reservoir in excavated underground galleries, underground pumped storage facilities relieve the surface topography of all but a very few insignificant structures and features, and they also avoid negative environmental impacts such as the flooding associated with the traditional pumped storage design.
Riverbank has announced two projects in Wiscasset, Maine and in Sparta, New Jersey. The two proposed underground pumped storage facilities will be the first of their kind in the world. They will mark a new era in the world of hydropower and, most importantly, they will help to make a reality of the planet’s sustainable energy future.