ei storage presentation

Electricity StorageWindfarm and Industrial Applications

L. Staudt, Centre for Renewable Energy

Dundalk Institute of Technology

Presentation Summary

Technology overview

Windfarm application

Industrial application

Conclusions

Technology Overview

Technology Overview

Economics

Profit per transaction (P)

value of sales must exceed value of purchases

Number of transactions per year (n)

As many as possible!

Good business: when product of both is

maximized (P x n = max)

Technology Overview

Why flow and NaS batteries (for windfarm and industrial applications)?

Flow batteries (and NaS) provide high power andhigh energy

You can easily and independently select both power and energy, as the products are modular

They have no special site requirements

Will first discuss flow batteries, then NaS

Technology Overview

A flow battery is an electrochemical electricity storage device, somewhere between a standard rechargeable battery and a fuel cell

The energy is stored (only) in the electrolytes, which can be fully discharged and recharged

Power and energy are independent

More power: add flow cells

More energy: add electrolyte

Technology Overview

Basic flow battery schematic

Technology Overview

Technology Overview

Moab, Utah

250kW 8 hour installation

Technology Overview

Technology Overview

Moab, Utah

Tomamae windfarm, Japan4MW, 1.5 hour flow battery installation

Technology Overview

RISO 15kW, 8-hour flow battery

Technology Overview

Advantages of flow

battery technology

Flexible location

Good energy density

Independent energy and

power sizing

Thousands of deep

charge/discharge cycles

(long lifetime)

Operate at ambient

temperatures

Acceptable cycle

efficiency

Mass market should lead

to lower costs

Quiet operation

Technology Overview

Flow battery concerns

Cost

Proven reliability

Proven efficiency

Technology not mature –

may have “surprises”

Maintaining electrolyte

purity (appears OK)

Current density can be

improved

Environmental issues

(appears OK)

Needs a building

Business stability (early

days)

Technology Overview

Technology Overview

NGK Sodium Sulphur battery

(not a flow battery)

Technology Overview

NGK NaS battery

Technology Overview (NaS)

NaS vs. flow battery

Longer commercial history

Cycle life depends on DOD

Better energy density

No building required

Higher efficiency

Lower cost?

Technology Overview

Vanadium

Redox (VRB)

Zinc Bromine

(ZBB)

Cerium Zinc

(Plurion)

NaS (NGK)

Efficiency 65-75% 60-70% 70-80% 75-85%

Lifetime >10,000 cycles >1500 cycles >15,000 cycles ~5000 cycles

Cost

4-hour system

8-hour system

(w/o building)

€1800/kW

€2600/kW

(w/o building)

€1800/kW

€2600/kW

(w/o building)

€1800/kW

€2600/kW

€1400/kW

€2400/kW

O&M cost 0.5% of Capex 0.5% of Capex 0.5% of Capex 0.25% of Capex

Wind projects Kings Island

200kW/800kWh

Tomamae

4MW/6MWh

n/a n/a Hachijo Island

400kW/3MWh,

many non-wind


Technology overview



Conclusions

We created a model that optimally dispatched storage at a 12MW windfarm in the UK (using real UK market prices and windfarm output)

Our model determined maximum revenue over the course of a year (purchase cost less sales cost for each half hour)

Usually resulted in full charge/discharge each day, but may not e.g. if efficiency is low and price spread is low


A number of cases run for different sizes (MW and MWh) and different efficiencies

Base case: 5MW/20MWh with 75% efficiency

Gives an optimistic result, due to optimal operation Selectable battery cost: €X per MW plus €Y per MWh (base case of €1m per MW and €200k per MWh)

Adjustable O&M cost (base case of 0.5% of Capex)



Effect of battery energy rating for a 5MW battery system on a 12 MW windfarm


Effect of battery power rating for a 20MWh battery system on a 12 MW windfarm

Base case efficiency and prices achieve a minimum payback period of 35 years

Efficiency is very important – 60% to 80% efficiency gives a 31 to 54 year payback

Halving battery costs gives minimum payback of 17 years for base case

Further benefit possible by considering balancing penalties and ancillary services value


Conclusions (windfarm application)

Battery costs must decrease substantially

Factors that will improve economics:

Mass production

Improved efficiency

Electricity market price spread

Value given to ancillary services

Technological breakthroughs



Technology and Application overview



Conclusions

In 2005 we installed a large scale commercial

wind turbine on the Dundalk IT campus

It operates as an autoproducer which results in

the reduction in electricity bills

Excess electricity generated is exported to grid

Electricity deficit is imported from grid

Now Dundalk IT is installing a flow battery for

primarily research purposes but will also further

reduce annual electricity bills

Dundalk IT storage project

The Campus Wind Turbine at Dundalk Institute of Technology


PCS/Battery

To other DkIT

transformers

(10kV/400V)

Grid (10kV 3 phase) Wind Turbine

690V/10kV

10kV 3Phase690V 3Phase

Transformer in base of turbine

10kV/400V

To DkIT Loads

400V 3 phase

On site transformer

Circuit

Breakers

& MeteringSCADA PC

Incomer Meter

(Grid)

Wind Turbine Meter

DkIT HV switchroom


Monthly Data

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

Jan

Feb Mar A

prM

ay

June

July

Aug

Sep Oct

Nov

Dec

Month

kW

h

DkIT consumption with no WTG

WTG Production

Monthly DkIT energy production and consumption


Monthly Electricty Demand vs Wind Turbine Production (No Storage)

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

Jan

Feb

Mar

Apr

May

June

July

Aug

Sep O

ctNov

Dec

Month

kWh DkIT consumption with no WTG

Total WTG Production

DkIT consumption with WTG

WTG Exported Energy


Following a successful application to Enterprise Ireland

for a Capital Equipment grant, Dundalk IT tendered for a

125kW, 500kWh flow battery – September 2008

Tender awarded to ZBB (USA) – end of 2008

Battery system manufactured and tested – February to

May 2009

Battery acceptance testing – June 2009

Shipped to Dundalk IT – August 2009

Installation preparation underway at DkIT



50kWh 50kWh 50kWh 50kWh 50kWh

50kWh 50kWh 50kWh 50kWh 50kWh

PC

S

AC

DC

Sea box container

Chiller Unit

Cell

stacks


Power conditioning

system during FAT


Control

system

display


Battery

foundation


Economics depend on a number of factors

including:

Electricity tariffs

Battery capital costs

Battery efficiency

Value given to potential utilization of waste heat


A model was developed by DkIT to evaluate the addition of electricity to the wind turbine

It takes half hourly power production and consumption data and MIC for a year and then calculates the annual savings for a given battery rating (kW), capacity (kWh) and efficiency using given electricity tariffs

Option to give value to waste heat is included


Various model outcomes Battery capital cost €575,000

Battery efficiency 65%


Some Scenarios Value given to exports (€/kWh)

Value given to waste heat (€/kWh)

Total DkIT Annual Costs (€)

Annual savings due to battery (€)

No storage NA N/A 330,025 N/A

125kW, 500kWh 0.00 0.00 322,156 7,488

125kW, 500kWh 0.057 0.00 290,620 3,597

125kW, 500kWh 0.00 0.04 318,622 11,022

125kW, 500kWh 0.057 0.04 287,086 7,131

As wind autoproducers operate differently to

conventional power generators no value is available at

present for:

Operating Reserve

Reactive Power Generation

Black Start

Capacity


Conclusions (industrial application) Battery storage in commercial industrial wind

autoproduction applications difficult to justify economically at present

Significant reduction in system costs in mass production coupled with increasing electricity prices should make these systems viable with wind autoproduction in the medium term


However, it is a research project..

The flow battery facility at DkIT will allow:

Development and test of control

(charge/discharge) algorithms so that the

operation of system will maximise economic return

This will incorporate a number of factors including,

electricity prices, wind and load forecasting

Practical experience and assessment of actual

performance of this technology



Technology and Application overview



Conclusions

Electricity storage has a bright future

Storage will be ubiquitous in electricity grids, becoming “The Fourth Element”

There are presently a number of immature but promising storage technology

The technology is not yet generally economic in windfarm and industrial applications

Economics will improve with mass production, and with value being given to ancillary services

Overall conclusions

Questions?

[email protected]

ei storage presentation

Documents

presentation summary technology

technology overview moab

flow battery

industrial applications

windfarm application

storage project

technology overview

base case