Matthew Stocks, Bin Lu and Andrew Blakers

Pumped hydro energy storage:

Teaching old dogs new tricks

ECI Open Day 2016

Motivation

• Large penetration of renewable energy in

Australian electricity markets

• No heroic assumptions

– Energy generation dominated by wind and PV

– Maintain existing hydro and biomass

– No geothermal, CST, tidal, wave

0

10

20

30

40

50

60

70

80

90

100

GW

pa

Added in 2014

Added in 2015

New generation capacity worldwide

• Wind + PV

–50% worldwide

–100% in Australia

• Wind + PV grew 19%

– Everything else shrank

• 10-200 scale gap

Challenge – intermittent renewables

• Wind and PV are intermittent

– Energy supply depends on weather

– Can forecast but not control generation

• Balancing supply and demand requires

– dispatchable generation,

– flexible demand, and/or

– storage

World wide energy storage

Source http://www.energystorageexchange.org/projects/data_visualization

Established technology

Pumped hydro

97% of all storage

Tumut-3 (Snowy

Mountains), 1974250 MW x 6 units (36 h),

150 m Wivenhoe (Queensland), 1984250 MW x 2 units (10 h), 50 m

Shoalhaven (NSW), 197740 MW x 2 units (Bendeela), 130 m; 80 MW x 2 units

(Kangaroo Valley), 480 m

Existing Australian PHES

Gravitational field strength 10 N/kg

Gravitational potential energy = m × g × h × η

Generator efficiency 90%

Mass of water Hydraulic head

STORES

Short Term Off River Energy Storage

• Closely-spaced, large altitude difference (300-900 metres)

• No interaction with the ecology of river system

• No conflict with nature conservation, no competition with intensive land uses

• In close proximity to transmission lines maximising network benefits

Coffin Butte PHES

• Approx. 150 km east of Helena, Montana US

• Altitude difference 320 m with 1.5 km of distance

• Upper/lower reservoirs: 20 hectares with 15 m of dam height, storing 3 GL of water

• Power & storage capacities: 250 MW with 9 hours of storage

Source Absaroka Energy http://www.absarokaenergy.com/projects-coffin-butte.html; http://coffinbuttepumpedstorage.com/

ARENA STORES Project Aims

• Atlas of all potential off-river pumped hydro

energy sites in Australia

– To be publically available on AREMI

• Cost model for pumped hydro energy storage

• Simulations of supply/demand energy balance

with PV, wind and PHES at national, state and

regional level

Victoria/NSW• GIS site

identification

• Distributed

along Great

Dividing

Range

Terrain

Land use

Infrastructure

Transmission

Land area neededfor off-river PHES

Cost model

• Tender for publically available cost model

– Power system costs

• Generator, pump/turbines, powerhouse.

– Reservoir costs

– Penstock (piping cost)

– Infrastructure

• Connection to transmission, roads

• Enable ranking of identified sites

Supply/demand modelling

• Optimise system for energy balance

– Historic NEM demand data 2006-2010

– Historic weather (wind and insolation data)

– Retain existing hydro and biomass generation

• Use genetic algorithm to optimise wind/PV/PHES

– Size and location

Key

PV farm/rooftop PV

Wind farm

HVDC (submarine)

HVDC (overhead/underground)

2 x ± 400 kV

(submarine)

Supply/demand

modelling

NEM 100% RE

Source Australian Energy Resource Assessment (AERA) http://www.industry.gov.au/Office-of-the-Chief-Economist/Publications/Documents/GA21797.pdf

100% renewable scenarios

PV (GW/TWh)

Wind(GW/TWh)

PHES(GW/h)

Spillage

(%)

Levelised

Cost of

Balancing

($/MWh)

Levelised

Cost of

Generation

($/MWh)

Levelised

Cost of

Electricity

($/MWh)

PHES

($/MWh)

HVDC

&AC

($/MWh)

Spillage

& loss

($/MWh)

Unconstrained 23 / 36 45 / 168 16 / 31 7% 28 65 93 14 7 7

<12h PHES 26 / 41 51 / 186 20 / 12 17% 31 66 97 10 7 14

No North Qld 25 / 39 45 / 170 17 / 33 10% 30 65 95 16 5 9

Conclusions

• 100% renewables feasible with no

heroic assumptions

– PV + Wind + Pumped Hydro

• Many more sites available

than required

– Design flexibility

• Thanks to ARENA, Electranet and VTara

Household339

Agriculture296

Mining271

Manufacturing58

Others320

Gas industry15

Fossil-fuel power

stations18

Electricity & gas33

Off-river

Pumped hydro

4.8

Source Australian Bureau of Statistics (ABS)

http://www.abs.gov.au/ausstats/abs@.nsf/Latestproducts/4610.0Main%20Features32013-14?opendocument&tabname=Summary&prodno=4610.0&issue=2013-14&num=&view

Water consumption (GL)• WA (SWIS) case

study

• 1000 MW with 8 h of

storage

Qld Kidston 250 MW, 6 h

US Coffin Butte 250 MW, 9 h

Water consumption

• Coal 1.5 L/kWh

• Natural gas 0.56 L/kWh

• Off-river pumped hydro

0.26 L/kWh

Water sources

Nearby water sources

(pipelines, channels or

water trucks)