Wind Turbine Energy Storage – PG&E Opts for Energy Storage by Jonathan Marshall

PG&E Opts for Energy Storage

Posted by: Jonathan Marshall

When the wind stops blowing or the sun goes behind a cloud, where will we get the clean, renewable energy we need for a sustainable economy?

From storage–batteries, fuel cells, flywheels or other devices that convert surplus electricity to chemical or mechanical energy, then feed it back into the grid on demand.

Cheap energy storage is sometimes called the holy grail of renewable energy and a key component of future "smart grids" envisioned by utilities like Pacific Gas and Electric Company. It’s also one of the hottest areas of clean-tech investing.

Now PG&E is taking steps to make it a reality, applying today to the Department of Energy for a $25 million Smart Grid stimulus funding grant, under the American Recovery and Reinvestment Act, for a large compressed air energy storage (CAES) project.

The application follows a previous PG&E request this month for a $42.5 million Smart Grid grant for a Home Area Network deployment project, in collaboration with the city of San Jose, Stanford University and several leading technology companies. Building on the utility’s advanced SmartMeter(tm) program, it will help customers lower their energy costs and usage by installing 75,000 in-premise energy displays and controllers at select mid-sized commercial and industrial customers.

PG&E also joined a Smart Grid grant application this month led by the Western Electricity Coordinating Council to install high-tech devices called synchrophasors to monitor and enhance the reliability and performance of the Western electric grid.

With its latest project, PG&E plans to pump compressed air into an underground reservoir, using mainly wind energy produced during non-peak hours, and then release it to generate electricity during periods of peak demand. The project has an output capacity of 300 megawatts–similar to a mid-sized power plant–for up to 10 hours. It will take an estimated five years to design, permit and build.

"Energy storage is a strategic complement to the generation resources that provide power to our customers," said Hal La Flash, director of emerging clean technologies at PG&E. "This project will help us maximize the efficiency and flexibility of our system while enabling the delivery of clean, renewable energy."

Large-scale energy storage holds tremendous promise for helping the environment, improving grid reliability and reducing energy costs:

* It will reduce greenhouse gas and other undesirable air emissions by enabling greater use of intermittent renewable resources and by reducing the need to use conventional fossil-fuel "peaking" plants to meet peak demand.
* It will improve asset utilization by absorbing excess generation during periods of low demand and reducing the need to add new generation for peak periods.
* And it stands to lower costs by storing energy produced when prices are low (off-peak) and returning it to the grid when prices are high, avoiding the need to buy costly on-peak electricity.

CAES has orders of magnitude more capacity than typical utility batteries and appears to be the most cost-effective form of storage, according to technical experts at the Electric Power Research Institute. The concept has been proven by projects in Alabama and Germany. Several utilities, backed by DOE and Sandia National Laboratory, are working on a major CAES facility in Iowa.

A massive study of CAES at Princeton University last year concluded that it is ideally suited to smoothing out the ups and downs of wind energy, which often peaks at night:

CAES appears to have many of the characteristics necessary to transform wind into a
mainstay of global electricity generation. The storage of energy through air compression
may enable wind to meet a large fraction of the world’s electricity needs competitively in
a carbon constrained world.

This project isn’t PG&E’s first foray into energy storage. For many years it has operated a 1.2 gigawatt hydroelectric plant near Fresno, the Helms Pumped Storage Facility, that uses inexpensive power at night to pump water into a higher reservoir for release during the day, when power is more costly. PG&E received permits last year from the Federal Energy Regulatory Commission to explore two additional pumped hydro sites totaling up to 2 GW in capacity.

Other utilities are also beginning to incorporate storage into their operations. Ohio-based AEP is installing utility-scale batteries on its network and says it plans to install a total of 1,000 MW of storage in its system over the next decade. Beacon Power Corp. was awarded $43 million in loan guarantees from the DOE to complete a 20 MW storage project for National Grid in New York state using flywheels. Japanese utilities have installed sodium sulfur and vanadium flow batteries to integrate wind power into their networks. And Southern California Edison just requested a DOE grant to partner with A123 Systems to build the world’s biggest lithium-ion battery assembly–32 megawatt-hours in capacity–to help balance out intermittent wind power in the Tehachapi Wind Resource Area.


SoCal Edison Wants A123’s Biggest Grid Battery Ever

The utility wants about $60 million in smart grid grants for two ambitious demonstration projects involving GE, Cisco, SunPower, IBM and Boeing. It also wants A123 to build the world’s biggest lithium-ion battery to help manage wind power.

Southern California Edison wants A123 Systems to build the world’s biggest lithium-ion grid storage battery, and it’s asking the Department of Energy for $25 million to help.

That’s just one of the new technologies that the utility wants to test in two projects worth an estimated $120 million that Paul De Martini, Southern California Edison’s vice president of advanced technologies, outlined Tuesday.

The other, a roughly $70 million regional smart grid integration project, would include smart appliances, home energy management systems, distribution grid and wireless communications – including WiMax and proprietary 900-megahertz technologies – from General Electric, De Martini said.

IBM and Cisco may also play a part in the project, for which the utility is seeking about $35 million from the DOE.

Both grant requests are aimed at the $615 million smart grid demonstration grant program created in June, he said. That’s the smaller of two programs that have a combined $3.9 billion available to help build smart grid projects (see DOE Issues Rules for $3.9B in Smart Grid Stimulus Grants).

The bigger, $3.4 billion pool for commercial-scale projects has already seen the first application deadline pass (see Green Light post).

But the $615 million pool has seen few publicly announced applicants, beyond a set of previously funded projects that were awarded $47 million in July (see DOE Hands Out $47M For Smart Grid Demos). Tomorrow is the first application deadline for the smart grid demonstration grant program.

SCE has lined up supporters and partners including the University of Southern California, University of California at Irvine, Electric Power Research Institute and fellow utilities Pacific Gas & Electric, Sempra Energy and Idaho Power, De Martini said. That could give it a boost in securing the grants, which are expected to see the first round of approvals later this year, he said.

The approval of SCE’s application could be big news for A123’s push into grid storage batteries.

The Watertown, Mass.-based developer of lithium-ion batteries has been making batteries for portable and vehicle power applications, and landed a $249 million DOE grant to build a battery factory in the United States (see By The Numbers: A123’s IPO Papers).

But it’s also worked with GE and utilities on batteries for grid storage (see A123 Batteries to Help Stabilize the Electric Grid). While lithium ion batteries remain expensive today compared to grid storage alternatives like flow batteries or sodium sulfur batteries, industry observers say they could come down in price as their mass manufacturing ramps up (see Green Light post).

In SCE’s case, it wants A123 to assemble a 32-megawatt-hour battery out of racks of smaller batteries in a 8,000-square-foot building at a substation in the Tehachapi Mountains. That battery would stabilize the flow of wind power from the mountains to the utility’s load centers to the west and south, De Martini said.

That could free up about 300 megawatts of wind power that might otherwise be undeliverable if the utility had transmission line problems in the region, he said.

The utility expects to have about 4,500 megawatts of wind turbines in the Tehachapi region by 2015 or so, and finding ways to store and manage that power will be critical to linking it to the grid at large, he said.

SCE’s other demonstration project involves what De Martini called a "deep vertical slice" into smart grid technologies to be tested in Irvine, Calif. That includes test homes outfitted with GE’s smart appliances and home energy management systems, he said (see GE’s Smart Appliances: Smarter With GE Home Energy Manager).

Those homes will also have solar panels from SunPower and small-scale, 50-kilowatt batteries from a yet to be determined vendor, he said. Those will all be connected to a distribution grid outfitted with the latest in GE’s distribution automation technology, he said.

GE will also provide a communications network for the project, including WiMax and another, proprietary wireless technology, he said. Texas utility CenterPoint Energy is using GE WiMax radios for similar purposes, and San Diego Gas & Electric wants DOE stimulus grants to help pay for WiMax radios in a project it’s proposing as well (see Green Light post).

As for securing the system, SCE is looking to Boeing, which has developed secure communications in work with the U.S. military, De Martini said. Boeing has not yet been an often-named player in smart grid technologies, but it and other military contractors like Lockheed Martin could have some advantages when it comes to meeting security requirements being developed for the smart grid (see Green Light post).

SCE may use one of A123’s trailer-sized batteries for grid storage in the Irvine project, De Martini added.