Energy Storage: Technology and Market...

Copyright © Sustainable Energy Advantage, LLC.

Mimi Zhang, Sustainable Energy Advantage, LLC

EBC Renewables Committee Meeting

October 16, 2012

Energy Storage: Technology

and Market Overview


Overview

• Energy Storage Basics

• Technology and Cost

• Implementing Storage

– Renewables

– Markets/Applications

• Challenges/Looking Forward

2

Objective: to provide an overview of energy storage

technologies and applications rather than focus

specifically on storage and renewables


Energy Storage Basics

3


4

What is Energy Storage?

• Ability to control energy delivery timing

• Roles: Can be located at transmission, distribution, end-use,

and aggregated (community ES) for a number of applications

• Size range: kW up to MW-scale (this presentation will focus

on utility-scale storage)

• Technologies range from batteries to pumped hydro

Image sources: Beacon Power facility graphic from ecofriend.com; Okinawa pumped hydro from wastedenergy.net


Energy Storage Definitions

• Power and Energy: Different technologies will be designed to provide

different combinations of power and energy, making them ideal for different

applications

• Cycle Life: Number of times the system can charge/discharge before

replacement. This can vary based on “depth” of discharge (cycling between

50% and 100% wears down less than 0% and 100%)

• Efficiency: Accounts for energy losses between charge and discharge

(energy used for charging/energy discharged)

5

Power Energy

Units kW (instantaneous) kWh (amount over time)

Associated Terms Capacity Duration

Depends on: Power Electronics or Turbines Cells or Reservoirs


Uses of Energy Storage

• Storage can be used for

applications that address

different levels of the grid:

– Generation: time-shifting

and firming of renewables

generation

– Transmission/distribution:

capacity enhancement

deferrals, time-shifting,

reliability, ancillary services

– Commercial/Industrial:

Retail load shifting, backup

power, power quality

– Residential: community

energy storage

• Applications will be explained

in more detail

6

Image from Oncor.com: http://www.oncor.com/EN/Pages/Transmission.aspx

http://www.oncor.com/EN/Pages/Transmission.aspx


Technology and Cost

7


Main ES Technology Types

8

Technology Power (kW) Energy (kWh) Applications

Pumped Hydro Hundreds of MW 4+ hrs Time shift, reserve, black start

Compressed Air

(CAES)

~100 MW, (mini

CAES ~10 MW)

4+ hrs Time shift, reserve

Flywheels kW to MW Minutes Frequency regulation, power quality

Batteries (many other types not covered in detail)

Lead Acid

Modular: ~100

kW – MW-scale Hour+

Backup power, time-shift, black

start, capacity deferral

Sodium Sulfur Time-shift, black start, capacity

deferral

Flow Batteries Time-shift, black start, capacity

deferral

Lithium Ion Modular: kW to

MW

Minutes* Frequency regulation, backup

power, time-shift, capacity deferral

Other Technologies: Supercapacitors, temperature-based solutions

* Can be hours by adding cells


Pumped Hydro

9

• Two water reservoirs at different elevations. Water is

pumped to the higher reservoir during off-peak hours,

and released during peak hours.

(Image from Hawaii Electricity Company http://www.heco.com)

http://www.heco.com/


Pumped Hydro (cont.)

10

Power/Energy High/High, depends on reservoir and turbine sizes

Sizing Usually very large—hundreds to 1,000+ MW

Cost $1000-2000/kW (very dependent on site, transmission, etc.)1

Efficiency 85%1

Cycle Life 25,0001 (decades+)

Pros Mature technology, straightforward concept

Cons Environmental impact, geographically constrained, requires large

size to be economically viable

History Mature: >127,000 MW installed globally, 21,000 MW in the U.S as of

2009.2

Example Bear Swamp (600 MW in MA owned by Emera)3

Companies Brookfield, Suez, Riverbank

1. Schoenung, Susan. “Energy Storage Systems Cost Update”. SANDIA National Labs. 4/2011 (SAND2011-2730)

2. Oak Ridge National Laboratories. “Pumped Storage Hydropower”. September 20-21, 2010.

3. Emera website (http://www.emera.com/en/home/bearswamp.aspx)

http://www.emera.com/en/home/bearswamp.aspx


Compressed Air Energy Storage (CAES)

11

Off-peak hours: a

generator forces

air into a

reservoir (usually

underground)

On-peak hours:

compressed air

is released to

help drive

turbines to

produce power

(Image from State Energy Conservation Office of Texas, via Imperial College, London report

(http://www.seco.cpa.state.tx.us/re_wind-reserve.htm)

http://www.seco.cpa.state.tx.us/re_wind-reserve.htm




CAES (cont.)

12

Power/Energy High/High, depends on reservoir and turbine sizes

Sizing Underground CAES usually 100+ MW; new technology targeting smaller

above-ground units ~10 MW

Cost $600-800/kW (large underground CAES), $1000-2000/kW (smaller

above-ground units)1

Efficiency ~70% (not apples to apples comparison because of NG usage)1

Cycle Life 25,0001 (decades)

Pros Mature technology, low cost, long duration

Cons Requires natural gas (30-40% less than NG plant)2,

environmentally/geographically constrained

History Has been around for decades (~1980 unit in Germany, 290 MW). First

and only CAES in US was built in 1991, but other projects are ongoing3

Example McIntosh, AL (110 MW owned by PowerSouth Utility Cooperative and

built by Dresser-Rand)4

Companies Ridge Energy Storage, Dresser-Rand, Energy Storage and Power LLC


2. DOE Energy Storage DB (http://www.energystorageexchange.org/projects/136) updated 6/2012

3. Ridge Energy Storage (http://www.ridgeenergystorage.com/caes_history.htm)

4. PowerSouth website (http://www.powersouth.com/mcintosh_power_plant/compressed_air_energy)

http://www.energystorageexchange.org/projects/136

http://www.ridgeenergystorage.com/caes_history.htm

http://www.powersouth.com/mcintosh_power_plant/compressed_air_energy


Flywheels

13

• Flywheel storage systems

are mechanical/kinetic

batteries that store energy by

spinning.

• Small flywheels systems are

used for power quality

applications (a few seconds

of outage)

• Larger systems can be ~100

kW/flywheel, adding up to

MW+ systems (image to the

right shows Beacon Power’s

2 MW ISO-NE project made

up of 100-kW flywheels)

(Images from Beacon Power http://www.beaconpower.com)

http://www.beaconpower.com/


Flywheels (cont.)

14

Power/Energy Low-Medium/Low

Sizing Usually small but modular—can be a few kW (for power quality) or

hundreds of kW to MW (frequency regulation)

Cost $1000-$2000/kW for 15 min duration (grid-scale) 1

Efficiency 95%1

Cycle Life 25,0001 (decades)

Pros Requires less rare or toxic materials than batteries, very high cycle

life that is perfect for frequency regulation

Cons Costly, limited duration

History Utility-scale demos installed in last few years (2009)2, flywheels used

for power quality for decades

Example Beacon Power projects in ISONE and NYISO

Companies Beacon Power (utility-scale), Active Power and Pentadyne (retail

customers)


2. Beacon Power


Lead Acid Batteries

15

• Lead Acid batteries have been around for decades (think

car batteries), and are commonly used as backup power

for telecom and data uses. Advanced Lead Acid systems

with carbon-enhanced electrodes greatly increase cycle

life for grid-scale storage.

(Images from Axion Power http://www.axionpower.com)

http://www.axionpower.com/


Lead Acid Batteries

16

Power/Energy Med/Med-high

Sizing kW (backup power) or MW+ (advanced lead acid)

Cost $400/kW, $350/kWh1 ($750/kW for 1 hr, $1800/kW for 4 hrs)

Efficiency 75%1

Cycle Life 2,000-20,0001 (yrs)

Pros Long history, proven technology

Cons Safety concerns, Lead contamination (Xtreme Power’s

Kahuku unit caught on fire in 8/2012)2

History Oldest battery technology (1800s)

Example Xtreme Power’s 15 MW advanced lead acid project at First

Wind’s 30 MW Kahuku Wind Project in Hawaii (March 2011)3

Companies Xtreme Power, East Penn, Axion Power


2. Wesoff, Eric. “Battery Room Fire at Kahuku Wind-Energy Storage Farm”. Greentechmedia

(http://www.greentechmedia.com/articles/read/Battery-Room-Fire-at-Kahuku-Wind-Energy-Storage-Farm)

3. First Wind (http://www.firstwind.com/projects/kahuku-wind)

http://www.greentechmedia.com/articles/read/Battery-Room-Fire-at-Kahuku-Wind-Energy-Storage-Farm

















http://www.firstwind.com/projects/kahuku-wind




Sodium Sulfur Batteries

17

One of the more common large-scale batteries, with Sulfur

at positive electrode, Sodium at negative electrode, and

beta conductive ceramic separating the two.

(Image from NGK Insulators, Ltd. http://www.ngk.co.jp)

http://www.ngk.co.jp/


Sodium Sulfur Batteries (cont.)

18

Power/ Energy Med-High/High

Sizing Modular—can be multi-MW

Cost $350/kW and $350/kWh1 (~$700/kW for 1 hr, ~$1750/kW for 4 hrs)

Efficiency 75%1

Cycle Life 3,0001

Pros Track record, long duration, more compact than lead acid batteries

Cons Chemicals may pose safety concerns, limited cycle life. One of

NGK’s TEPCO systems caught on fire on 9/21/20112

History First installed in Tokyo in 1998 (6 MW/8hrs), 200 MW installed

worldwide

Example ERCOT’s “BOB” installed in Presidio, west TX in 2010 (Big-old

Battery, 4 MW for 8 hrs) for reliability applications3

Companies NGK (Japan)


2. NGK Insulators, Ltd. http://www.ngk.co.jp

3. NPR. “In Texas, One Really Big Battery”. 4/4/2010 (http://www.npr.org/templates/story/story.php?storyId=125561502)


http://www.npr.org/templates/story/story.php?storyId=125561502


Flow Batteries

19

Similar to other

batteries, but stores

electro-active chemicals

in external electrolyte

– Often uses an ion

membrane to prevent

mixing

– Hybrid flow batteries (1

electrolyte is stored

separately)

– Certain fuel cells are

flow batteries (H2-Br2)

Image from Nguyen and Savinell. “Flow Batteries”. Electrochemical Society Interface. Fall 2010


Flow Batteries (cont.)

20

Power/Energy Medium/Medium-High

Sizing Varies, can be kW to MW+

Cost ~$400/kW, $400-600/kWh ($800-1000/kW for 1 hr, $2000-

2400/kW for 4 hrs)1

Efficiency 65-85%1

Cycle Life 3,000-5,0001

Pros Lasts longer than NaS and traditional Lead Acid, scalable

Cons New technology, relatively unproven, requires pumps and

other equipment to manage electrolyte flow2

History Very few deployed, usually as demos

Example VRB installed a 250 kW (2 MWh) Vanadium Redox battery for

Pacificorp in Utah (2004)3

Companies Premium Power, ZBB, Prudent Energy (formerly VRB)


2 Nguyen and Savinell. “Flow Batteries”. Electrochemical Society Interface. Fall 2010.

3 VRB Presentation to CA Energy Commission 2/2005 (http://www.energy.ca.gov/research/notices/2005-02-

24_workshop/07%20Kuntz-VRB%20PacifiCorp%20Flow%20Battery.pdf)

http://www.energy.ca.gov/research/notices/2005-02-24_workshop/07 Kuntz-VRB PacifiCorp Flow Battery.pdf








More Flow Batteries Examples

21 1. Nguyen and Savinell. “Flow Batteries”. Electrochemical Society Interface. Fall 2010.


Lithium Ion Batteries

22

Lithium Ion batteries have very high energy density and

slow degradation, making it already popular for consumer

electronics and vehicles.

(Image from Greentech Media http://www.greentechmedia.com/articles/read/a123-lands-grid-batteries-in-maui-massachusetts)

http://www.greentechmedia.com/articles/read/a123-lands-grid-batteries-in-maui-massachusetts














Lithium Ion Batteries (cont.)

23

Power/ Energy Med/Low-Med

Sizing Modular—can be multi-MW

Cost $400/kW and $400/kWh1 (~$800/kW for 1 hr, ~$2000/kW for 4 hrs)

Efficiency 85%1

Cycle Life 4,0001

Pros Fast response, high energy density

Cons Higher cost, shorter duration, less likely than lead acid to overheat

History Installed grid-scale as demo projects in the last 5 years, over 100

MW installed to-date worldwide, mostly by A123

Example A123 installed 32 MW/8MWh at AES’s Laurel Mountain Wind Farm

(98 MW in WV) in 9/20112

Companies A123, Altair Nano, Saft


2. A123 (http://www.a123systems.com/smart-grid-storage.htm)

http://www.a123systems.com/smart-grid-storage.htm






Other ES Technologies

• Other Batteries:

– Nickel Cadmium

– Nickel Metal Hydride

– Magnesium Ion (Pellion)

– Ambri (previously Liquid Metal

Batteries—uses 2 metals and

a salt at high temperatures)

• Supercapacitors

• Electric Vehicles

24

Image: European Commission (http://ec.europa.eu/research/energy/eu/research/smartgrid/index_en.htm)

http://ec.europa.eu/research/energy/eu/research/smartgrid/index_en.htm


Storage Technology Comparison

25

Minutes

Hours

Day

10 kW 100 kW 1 MW 10 MW 100 MW 1,000 MW

compressed air

batteries

flywheels

capacitors

Pumped hydro

Power/Size

En

erg

y/D

isch

arg

e


Cost Comparison

• Storage costs cannot be compared on a straight $/kWh

basis due to power and energy factors

26 Schoenung, Susan. “Energy Storage Systems Cost Update”. SANDIA National Labs. 4/2011 (SAND2011-2730)

Frequency Regulation

(15 min)

$/kW 0 1,500 500 1,000

NaS

Lead Acid

Flow Batteries Pumped Hydro

CAES

Flywheels

LiOH Batteries

Time Shift

(1 hr)

$/kW 0 1,500 500 1,000

Time Shift/Deferral/Reserve

(4 hrs)

$/kW 0 2,500 1,000 2,000


Technology Recap

27

Technology Power (kW) Energy (kWh) Efficiency Cycle Life Cost

Pumped Hydro Hundreds of MW High 85% 25,000 $1000-2000/kW

Compressed Air MW+ (though

companies are

exploring small-

scale CAES)

High ~70% 25,000 $600-800/kW (large

underground CAES), $1000-

2000/kW (smaller above-ground

units)1

Flywheels kW to MW Low 95% 25,000 $1000/kW (15 min)

Batteries

Lead Acid Modular: usually

~100 kW – MW-

scale

High

80% 2,000-

20,000

$400/kW, $350/kWh1 ($750/kW

for 1 hr, $1800/kW for 4 hrs)

Sodium Sulfur High 75% 3,000 $350/kW, $350/kWh1 ($700/kW

for 1 hr, $1750/kW for 4 hrs)

Flow Batteries High 65-80% 3,000-

5,000

~$400/kW, $400-600/kWh

($800-1000/kW for 1 hr, $2000-

2400/kW for 4 hrs)1

Lithium Ion Modular, up to

MW+

Low 85% 4,000 $400/kW and $400/kWh1

(~$800/kW for 1 hr, ~$2000/kW

for 4 hrs)

(Many other battery types are not covered in detail)

Other Technologies: supercapacitors, temperature-based solutions

Schoenung, Susan. “Energy Storage Systems Cost Update”. SANDIA National Labs. 4/2011 (SAND2011-2730)


Markets/Applications

28


Energy Storage Applications

29

• Table Time Scale Application Description

seconds-

minutes

Frequency

Regulation

Seconds-minute fast response for system

load changes (ancillary service)

Power Quality Seconds-minutes fast response to prevent

outages (end-use)

1 hr+ Renewables Addressing challenges from RE integration

(reliability, time-shift, capacity deferral)

Load Shifting Hour+ shifting for price arbitrage (charge off-

peak, sell on-peak)

Capacity

Deferral

Using storage to bypass or delay expensive

T&D upgrades

Backup Power Hour+ backup power systems (end-use)

Reserves Storage for spinning reserve on a system

(ancillary service)


Renewables + Energy Storage RE Integration poses a number of challenges that storage can address: time-

shifting, capacity enhancement deferral, reliability, and ancillary services

30

Time-shift: store wind at night,

sell during the day; or shift solar

to be peak coincident

Capacity Deferral: certain T&D

upgrades required to integrate

new RE could be deferred with

properly placed ES

Reliability: power quality for solar

project under cloud cover or wind

cut-out (firming). “Firming” RE

could enhance capacity value

Ancillary Services: system-

related reliability needs stemming

from large % of variable

resources—increased demand for

FR, load following, spinning

reserve

Image from Renewable Energy World

(http://www.renewableenergyworld.com/rea/blog/post/2012/03/minnesota-

electricity-could-be-100-renewable-100-local)

http://www.renewableenergyworld.com/rea/blog/post/2012/03/minnesota-electricity-could-be-100-renewable-100-local
















Ancillary Services • Frequency Regulation is the most attractive

market for storage (requires fast response)

– Market size: FR requirements are 0.5-1% of

a system’s peak load (~130 MW in ISONE)

– FR payments fluctuate with energy prices:

ISONE is now $5-10, was ~$30 in 2007-08

– FERC Order 755 requires ISOs to

compensate more for faster response

(October 2011), and ISOs are in the process

of implementing fast FR programs2

• Storage can provide other ancillary

services on a longer timescale (pumped

hydro provides spinning reserve)

• Increased RE penetration increases need

for FR and other ancillary services

• Technologies for FR: flywheels, batteries

(preferably with high cycle life)

31

1. ISONE Historic data (http://www.iso-ne.com/markets/)

2. FERC Order 755 (http://www.ferc.gov/whats-new/comm-meet/2011/102011/E-28.pdf) 10/20/2011

Figures: Markov et al. “Incorporating Wind Generation and Load Forecast Uncertainties into Power Grid Operations”.

PNNL-19189 1/2010

http://www.iso-ne.com/markets/



http://www.ferc.gov/whats-new/comm-meet/2011/102011/E-28.pdf








Time-Shift (arbitrage, peak-shifting)

• Value of price arbitrage is not high enough to pay for storage

– In the past week, ISONE’s average daily differential was $17.631 (~$6,500/yr)

– A 1 MW (1hr) storage unit with 85% efficiency would earn ~$5,500/yr, would not

justify $700,000 capital cost

– Costs only work with further incentives

• Technologies: Pumped hydro, CAES, Batteries

32 Image: http://greensmith.us.com/applications/peak-shifting/

1. ISONE Historic data (http://www.iso-ne.com/markets/)

•Storing off-peak/selling on-peak, value comes from price arbitrage and

reducing system peak

http://greensmith.us.com/applications/peak-shifting/







Capacity Enhancement Deferral

• Storage can be used

to bypass or delay

T&D upgrades

– Best for urban

locations with

expensive upgrade

costs

– Limited to “critical

peak” situations that

occur only a few times

a year (peak shaving)

• Technologies:

Batteries, mini CAES

33

(Image from NGK Insulators, Ltd. http://www.ngk.co.jp)



End-User Applications

• Backup Power – Longer duration (4+ hours) to cover an outage

– Technologies:

• Lead Acid batteries have highest market penetration

• LiOH batteries could also perform well

• Power Quality – Seconds-minutes energy to cover power quality events

– Technologies:

• Small flywheels

• Fast response batteries could provide this, but may be oversized

• Retail Load Shifting/Demand Charge Reduction – Similar to time-shift but on a smaller scale

– End-users with spiky loads could get significant cost savings from

decreasing demand charges

34

Residential backup

generator (bowa.com)


Summary of Applications

35

Power/Size

En

erg

y/D

isch

arg

e

Minutes

Hours

Day

10 kW 100 kW 1 MW 10 MW 100 MW 1,000 MW

Spinning Reserve

End-use

power

quality

Time-shift (arbitrage and RE

shifting) T&D Upgrade Deferral

Frequency Regulation

Power/Size

En

erg

y/D

isch

arg

e

Renewables

Firming

End-use

backup

power


Challenges and Looking

Forward

36


Barriers to Widespread Implementation

37

• High Cost

– Storage technologies usually don’t pay for themselves under current

market structures

– New technologies are still in R&D phase or have safety concerns

– Costs have been declining and are expected to keep doing so

• Policy/Incentives

– Regulatory barriers have delayed adoption of storage

• ISO rules originally required 1-hr availability for all ancillary services,

including frequency regulation, which precluded flywheels and some LiOH

• FERC Order 755 will result in premiums for fast frequency response,

rewarding energy storage systems

• Asset classification confusion may deter deregulated utilities from trying to

own and operate storage systems

– Storage incentives/policies are difficult to frame because of the wide

variety, applications, and system vs. project uses


Looking Forward Storage is part of a portfolio of solutions to RE integration as well

as an important part in upgrading our power infrastructure

38

Image from Mark Thiele article (http://www.infowars.com/smart-grid-the-cloud-why-are-they-linked/)

http://www.infowars.com/smart-grid-the-cloud-why-are-they-linked/
















Sustainable Energy Advantage, LLC

Mimi Zhang

10 Speen Street

Framingham, MA 01701

tel. 508.665.5860

[email protected]

www.seadvantage.com

39

mailto:[email protected]

http://www.seadvantage.com/

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