PUMPED STORAGE HYDRO BASICS
Pumped storage hydro is a game-changer when it comes to supporting modern smart-grid technology and renewable energy deployment. Transmission grid operators are required to keep electricity generation perfectly in balance with load demand. Pumped storage hydro is capable of providing that balance, along with mechanical inertia, frequency support, and voltage support.
In a pumped storage hydro system, water is pumped from a lower reservoir to an upper reservoir using excess power from the grid. The water is stored in the upper reservoir as a potential energy source until the grid requires additional electricity. When energy is needed, the water is released through power hydroelectric turbines and then returns to the lower reservoir.
This process uses inexpensive energy generated during the solar peak or at night when demand is low to pump water to the upper reservoir. Energy is then generated during the day when electricity demand is high and prices spike. The ability to store and generate energy simultaneously enables a more efficient use of the transmission grid, as it can be operated at a constant load rather than cycling up and down to meet load demand.
Pumped storage is also a sustainable technology. It utilizes water as a storage medium, has a 50 to 100 year lifespan, and does not have cradle-to-grave disposal issues. Traditional battery storage on the other hand has a very short lifespan, requires the extraction of precious metals, and lacks an environmentally sound disposal method.
WHAT MAKES GORDON BUTTE PUMPED STORAGE HYDRO UNIQUE?
The key to the flexibility of pumped storage hydro systems is the speed with which the facility can go from storing energy to generating energy. Standard reversible turbine equipment requires stopping and reversing the water flow when switching from pumping to generating, which can take 20-30 minutes per cycle. The Gordon Butte Pumped Storage Hydro equipment is designed in a Quaternary configuration which will consist of 3 unit pairs. Each pair will include a pump and a turbine with a dedicated 134 MW motor and a 134 MW generator respectively. Through this unique equipment configuration and the use of hydraulic short circuit, the Gordon Butte facility can be generating power at the same time as it pumps water for storage. This provides for immediate response to changing energy needs.
The Gordon Butte Pumped Storage Hydro Project will be a versatile tool with all the attributes necessary to quickly and reliably service the modern energy and transmission needs of the Northern Plains and Pacific Northwest.