Montana's Renewable Energy Storage

January 2, 2012 – Vol.16 No.42

MONTANA’S RENEWABLE ENERGY STORAGE.
by Bruce Mulliken, Green Energy News

This may sound like a skipping record. (For those of you who remember what a record is anyway.) I’ve said it over and over. Intermittent renewable energies need energy storage. Badly. To compete with 24/7 fossil fuel and nuclear power, wind, solar, tidal or wave energies need to be linked energy storage devices or facilities so they can provide power nonstop.

Right now there is no one technology that stands out in the pack as being a universal energy storage solution. That’s OK. Like the renewable resources themselves, energy storage technology probably has to match the location and type of renewable generation employed.

The more energy storage projects get built, the closer it becomes mainstream. Where energy storage is high-technology oriented, such as state-of-the-art batteries, more installations will eventually translate into lower costs.

Thanks to the “Montana Means Energy” e-newsletter from the Montana Energy Promotion and Development Division of that state’s Department of Commerce, here’s news of three energy storage projects in that state, and one with Montana-based technology.

Utility company NorthWestern Energy has signed a lease agreement with Beacon Power Corporation for a one-megawatt Beacon Smart Energy Matrix flywheel system to be installed at NorthWestern’s Dave Gates Generating Station at Mill Creek. The 150 MW natural gas fired facility, near the town of Anaconda, was designed to function as a regulating resource capable of precise load following. That is, Dave Gates will provide a smooth flow of electricity, including that from intermittent renewables, to the grid. The flywheel system will help smooth that flow.

Montana Means Energy describes the technology:

“Flywheel energy storage works by accelerating a cylindrical assembly called a rotor (flywheel) to a very high speed and maintaining the energy in the system as rotational energy. The energy is converted back by slowing down the flywheel. The flywheel system itself is a kinetic or mechanical battery, spinning at very high speeds to store energy that is instantly available when needed.”

“Instantly available” are the key words here. When the grid needs power there is no waiting with flywheels. Flywheels also have the ability to power up or “recharge” themselves very rapidly, unlike electrochemical batteries that can take hours.

Beacon Power, you may have heard, is under bankruptcy reorganization, but not liquidation. It can still do business.

Next up are two pumped energy storage facilities to be built as part of the massive Wind Spirit project being developed by Grasslands Renewable Energy.

Wind Spirit is a 3000 MW integrated energy transmission, energy storage and marketing solution under development for the Northern Plains states. The plan is to utilized renewable energies, mostly wind from in geographically diverse areas, and send power from them through a innovative transmission collector system would manage the intermittent wind resource through several energy storage applications. Wind Spirit will deliver 1,000 megawatts of consistent 24/7 power to areas across North America. Energy storage at those pumped storage facilities will play a big role in the project.

Let’s let Montana Means Energy describe the pumped storage projects:

“Both projects are closed loop pumped-storage hydroelectric projects that utilize the natural topography of landscapes near existing transmission lines to create pumped hydroelectric storage systems. These storage facilities will firm variable electric generation from renewable energy resources. Each project will consist of two lined reservoirs, a buried pipeline with reversible turbines, and connector transmission lines in order to use low-cost energy during off-peak hours to pump water from the reservoir lower in elevation to a reservoir at a higher elevation. During peak hours, when the price of electricity is higher, water is then released from the upper reservoir and pushed through turbines to generate power to be sold on the grid. Coffin Butte is a 250 MW capacity project while Gordon Butte is a 400 MW project. Environmental and engineering studies have been conducted for the Gordon Butte project; the Coffin Butte project is currently conducting environmental and engineering studies.”

The final energy storage project as actually in Minnesota, but it utilizes technology provided by a Montana company. There Juhl Wind Inc. recently signed a Letter of Intent with Zinc Air Inc. (ZAI) for the installation of a 1 megawatt advanced energy storage system. Juhl Wind plans to install the system at its recently acquired Woodstock Hills wind farm located near the its headquarters in Woodstock, Minnesota.

Zinc air technology (a favorite of this editor) is a battery or fuel cell technology the includes atmospheric air (or really the oxygen in the air) in its electrochemistry. The big advantage of zinc air is the potential for very low cost. Unlike lithium, zinc is plentiful on the planet and is easy to obtain and work with. Current, the most common use for zinc air batteries is on the small scale: It makes a great hearing aid battery. In the past, though, there have been zinc air powered experimental cars, trucks and buses as well as zinc air portable generators.

In battery form, zinc air cells can be disposable (as in those hearing aid batteries) or be recharged electrically. Zinc air batteries can also be flow batteries. ZAI will be providing this zinc air variety to Juhl Wind. Wikipedia describes flow batteries as “a form of rechargeable battery in which electrolyte containing one or more dissolved electroactive species flows through an electrochemical cell that converts chemical energy directly to electricity.”

In fuel cell form, the zinc is a fuel that is consumed (actually oxidized) and the devices are refueled mechanically by removing and replacing the zinc metal within the device with fresh zinc. The oxidized zinc fuel can be deoxidized, also known as reduced, and used again.

Zinc is not the only metal that has been used in mechanically refueled clean energy devices, by the way. Magnesium air fuel cells are currently available. In the past aluminum air fuel cells were developed but never fully commercialized.

Montana Means Energy is happy about Juhl Wind’s upcoming zinc air installation saying, “This is good news for Montana wind developers. Montana has the wind generating potential for over 20,000 megawatts, or enough to power 120% of the nation’s cars, light trucks, and SUVs. Having a field tested storage technology like the Zinc Redox battery by Zinc Air in our back yard could prove to be an incredibly valuable asset to Montana energy development.”

Links:

“Montana Means Energy” e-newsletter from the Montana Energy Promotion and Development Division
http://www.commerce.mt.gov/Energy/newsletter.mcpx

Grasslands Renewable Energy.
http://www.gre-llc.com

Juhl Wind Inc.
http://www.juhlwind.com

Zinc Air Inc.
http://www.zincairinc.com