Energy Storage and

the Built Environment

Steve Saunders

Associate Director

Arup

t +44 (0)113 242 8498

steve.saunders@arup.com

www.arup.com

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the creative force behind many of the

world's most innovative projects

founded in 1946

employee owned

~12,000 staff

~ £1B turnover

Activities cover a wide range of

applications

High energy usage

Improve renewable energy

offering

Waste heat recovery

We are technology neutral

Waste Incineration

Embedded Generation

Why are we here?

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Electricity Storage

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Energy storage in the built environment

Historically, storage of heat (and cold) has been incorporated in buildings infrastructure.

Examples range from: Hot water storage tanks and off-peak storage heaters Phase change heat stores serving HVAC in large and/or

specialist buildings

Electricity storage has tended to be confined to UPS systems or small off-grid applications

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Why increased focus on electricity storage?

Source: National Grid

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How can storage help?

Energy System Need

Required

Discharge Time

Frame

Required

Storage

Capacity

Shift generated energy to when it is needed Minutes - Hours kW - MW

Peaking plant services Hours MW

Load following to increase the efficiency of thermal

generation

Minutes - Hours MW

Reserve capacity if usual electric supply is

unavailable

Hours kW - MW

Maintain frequency / voltage following a large

disturbance

Milliseconds -

Seconds

MW

Mitigate system congestion during periods of peak

demand

Hours kW - MW

Delaying or avoiding distribution system upgrades Hours kW - MW

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Transformers

Transmission

Distribution

Generation

Sub Station

Commercial and industrial customers Residential customers

Storage

Storage

Storage

Storage

Storage

Grid Stabilisation

Renewable storage

UPS and

Arbitrage Domestic

Arbitrage

Peak load

relief

Storage applications in the grid

Modes of Energy Storage

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Sodium Sulphur (NaS) Batteries Technology Description A sodium sulphur battery is a molten state battery with

sodium (Na) and sulphur (S) as the energy carrier.

Applications There are over 300 grid applications of NaS batteries

worldwide. Can be used for many grid applications such

as: Power quality applications and the integration of

renewable energy sources. 34MW of NaS batteries have

been integrated to the Futamata wind farm in Japan.

Disadvantages •Heating loss

•Safety issues

Advantages •High energy density

•Long life cycle

•Quick response

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NaS (Sodium Sulphur)

Source: AEP NAP

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Lithium ion (Li-ion) Batteries Technology Description Li-ion batteries are a type of rechargeable battery which

are powering the current class of electric vehicles.

Applications Frequency regulation, voltage regulation and the

integration of renewable energy sources. There are limited

worldwide commercial installations to date. An example

being a 20MW installation in Johnson City, NY, USA to

provide regulation services.

Disadvantages •Cost

•Negative effects of

overcharging/over

discharging

•Self discharge

Advantages •High energy density

•High discharge cycles

•High efficiency

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Flow Batteries Technology Description Flow batteries are a rechargeable battery using two liquid

electrolytes stored in tanks as the energy carriers.

Applications Time shifting, standby power and the integration of

renewable energy sources. There are limited worldwide

commercial installations to date. A 200kW flow battery

was used to store renewable energy from the Huxley Hill

Wind Farm in Tasmania.

Disadvantages •Low energy density

•Not commercially

mature

Advantages •Withstand high depths of

discharge

•Large number of

charge/discharge cycles

•Virtually unlimited capacity

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Compressed Air Energy Storage (CAES) Technology Description CAES involves compressing and storing air in order to

store energy.

Applications Worldwide, there is approximately 400 MW of CAES

capacity installed. This capacity comprises of a 290 MW

scheme in Germany and a 110 MW scheme in the USA.

CAES is mainly suited to applications where a large

quantity of energy is needed. CAES is also particularity

suited to balancing variable renewable loads.

Disadvantages •Requires fuel

•Low efficiency

•Geographically

constrained

Advantages •Rapid start up times

•The mechanical system is

extremely simple

•Longer asset life than

technologies such as batteries

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CAES (Compressed Air Energy Storage)

Source: US DoE

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Liquid Air Energy Storage

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Pumped Hydro Energy Storage (PHES) Technology Description Pumped storage hydro is currently the most established

utility scale method for energy storage with approximately

99% of the world’s grid energy storage being pumped

storage.

Applications Pumped storage is commonly used for peak load

generation, but can also be used for black starting

electricity grids in the event of a complete system failure

and for providing fast reserve response for grid frequency

control.

Disadvantages •Geographically

constrained

•Away from demand

centres

Advantages •Mature large scale technology

•Large power and energy

capacity

•Fast response times

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Pumped Storage Hydro (PSH)

Source: Scottish & Southern Energy

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Flywheels Technology Description Flywheel energy storage makes use of the mechanical

inertia contained within a rotating flywheel in order to

store energy.

Applications Suited to improving power quality by smoothing

fluctuations in generation, as opposed to having long

output durations. There are limited grid scale installations

to date, an example being a 20 MW installation at

Stephentown, New York, USA.

Disadvantages •Variable speed rotation

as energy is extracted

•High price

Advantages •Rapid response times

•Effective way of maintaining

power quality

•Virtually unlimited number of

charge/discharge cycles

Development status of storage technologies

kW 100 kW MW 10 MW 100 MW

Superconducting

Batteries ( lead acid, NiCd ) Pumped hydro

Sto

rage technolo

gie

s

Develo

ped

Compressed air

Micro CAES

Hydrogen storage

NaS

Power

rating

Note: the width of

the bar indicates

storage capacity

Li - ion

Cryogenics

Liquid Air

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Typical Storage development process

Feasibility Development Deployment Evaluation

Strategy

Site Selection

Issue Identification

Size + Capacity

Technology Selection

Business Case

Environmental Assessment

Socio-economic Evaluation

Stakeholder Management

Detailed Design

Economics, Finance, ESCo

Planning & Consent

Programme Management

Procurement Management

Risk Management

Value Engineering

Construction Management

Health and Safety

Performance Monitoring

Asset Management

System Health

Maintenance Optimisation

Outage Management

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Storage Financial Model

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Applicable Solutions

Small to Medium Demand Batteries Sodium Lithium

Flywheels

Medium to Large Demand Flow Batteries Compressed Air Energy Storage Liquid Air Energy Storage Pumped Hydro Storage

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Barriers to ES

Knowledge

High Maintenance costs

Perceived low benefit

Need for cost savings

Incentives not guaranteed

Ownership

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Design for Energy Storage

Physical Making space Adapting designs Integrating with architecture

Other factors Policy Ownership Education Public Acceptance

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Summary

Electricity Storage

Multiple Technologies

Increasing Need

Many Benefits for

Many Stakeholders

Need to Bundle

Revenue Streams

Thank you

Steve Saunders

Associate Director

Arup

t +44 (0)113 242 8498

steve.saunders@arup.com

www.arup.com

http://publications.arup.com/Pub

lications/A/a_five_minute_guide

_to_electricity_storage.aspx