Why Energy Storage? | Grant Wilson

Why Energy Storage ?

Dr Grant Wilson

The University of Sheffield

EPSRC’s Energy Storage for Low Carbon Grids consortium

[email protected]

#driagwilson

09/01/2015 © The University of Sheffield 2

• The talks this morning have provided details on

several different uses and technologies of

energy storage

• They all have a common goal to provide a

buffer, a balance between the supply of energy

and the demand of that energy – the differences

are in the scale, type of energy transformation or

final energy use, and the timeframes that the

energy is expected to be stored for


• This has always been the case - energy

networks have always depended on energy

storage to help match supply with demand over

different timescales

• It is a question of where the boundary is drawn

for analysis – this presentation considers grid

level energy flows

• So rather than imagine that a large amount of

energy storage is something novel – let us

rather imagine that the tasks we wish energy

storage to fulfill are changing


• The ‘Why Energy Storage ?’ question may be

easy to answer - we have always had it – and

will always need it – but it depends

• Energy systems are changing, and that change

is providing some challenges that different types

of energy storage may help to mitigate


• Main driver for change: to decarbonise the

electrical network – the UK seems likely to have

a combination of Nuclear, Onshore and Offshore

Wind, Coal & Gas with Carbon Capture

• Nuclear, Coal & Gas are dispatchable to a

degree, but dependent on the technology and

the carbon capture process too

• On electrical demand – lets have a look at

recent history for some indication of the

challenges for balancing within a day

Electrical network

09/01/2015 © The University of Sheffield

GB electrical load curve


GB Daily energy graph

Each box on the grid is ~ 6,000

GWh = 600 Dinorwigs

8


Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2013 2014

200 GWh/day

400 GWh/day

600 GWh/day

800 GWh/day

1000 GWh/day

30GWh/day

Gas and electrical data derived from National Grid plc website.

Transport fuels derived from Table 3.13 Deliveries of petroleum products for inland consu mption from DECC website

2000 GWh

3000 GWh

GB Daily energy graph


GWh

9


• Energy storage has vastly different types of

scale. At the 1000s of GWh size – (fossil) fuels

are the usual choice for stored energy

• Immensely useful – risks are well known

• However, they cause greenhouse gas emissions

when combusted and are finite

• Can be thought of as pre-conversion storage

(electricity or indeed heat)

A matter of scale


Total existing

(30GWh) and

potential (60GWh)

would be less than

100 GWh of

electrical energy

storage

Currently Scotland

has nearly 60% of

GB’s energy

capacity of PS,

and if schemes

are built – it would

have over 85%

© The University of Sheffield 12

One Q-Max class LNG tanker

has an energy capacity of > 1,600 GWh (£16million for each

1p/kWh)

@ 50% conversion efficiency CCGT equates to 800 GWh

~ 29 times all GB pumped storage (80 Dinorwigs)

Pictures sourced from www.gcaptain.com

A matter of scale


A matter of scale

Mild winter caused

less draw down on

coal stocks ?


• GB’s electrical demand follows a daily cycle

• Within day storage/balancing is a focus for much

research and pilot stage activity

• Any mention of seasonal storage is well into the

TWh region – which suggests fuels or thermal

storage rather than electrochemical storage

• 1 GWh of storage at £300 per kWh is

£300million

• 1 TWh of storage at $100 per kWh is $100billion

A matter of timescale


Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2013 2014

200 GWh/day

400 GWh/day

600 GWh/day

800 GWh/day

1000 GWh/day

30GWh/day


Transport fuels derived from Table 3.13 Deliveries of petroleum products for inland cons umption from DECC website


15


GWh


Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2013 2014

200 GWh/day

400 GWh/day

600 GWh/day

800 GWh/day

1000 GWh/day

30GWh/day




16


GWh


Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2013 2014

200 GWh/day

400 GWh/day

600 GWh/day

800 GWh/day

1000 GWh/day

30GWh/day




Purple line is gas to gas storage

17


GWh


EV sales in UK

Plug-In Car Grant: Since the launch of the Plug-In Car Grant in January 2011,

there have been 14,274 eligible cars registered

There are approximately 29 million cars registered in the UK

What about electric vehicles ?

18


• Lets take 1/10th of a round figure of 30 million

vehicles = 3 million vehicles

• Lets take an average battery pack of 33 kWh

• This gives a value of 99 GWh – in daily terms a

sizeable manageable demand but in weekly or

seasonal terms – not very much at GB level

• Also – this presumes that each battery would

require charging every day (unlikely) e.g. if 20%

of the charge was used each day on average –

the figure would be even lower at 20 GWh

What about electric vehicles ?


Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2013 2014

200 GWh/day

400 GWh/day

600 GWh/day

800 GWh/day

1000 GWh/day

30GWh/day




99 GWh per day is half of the difference between a

week day and a weekend or roughly half the UK’s

nuclear output (before the drop off this August)

20


GWh


• Cheapest post conversion storage is pumped

hydro

• Coire Glas suggested price of £800 million

equates to <£30 per kWh installed

• Order of magnitude less than battery based

systems

A matter of cost


• If storage is providing a service of matching

demand and supply – what else can help ?

• And what are the comparative advantages and

disadvantages ?

• Does it compete or complement

• Interconnection to enlarge the network (same

energy carrier)

• Demand side management

• Interconnection (change of energy carrier)

A matter of what else is available


Scotland gas transit

Each rectangle on the grid is ~ 6,000 GWh


• Up to 800 GWh per day transmitted to England,

equating to equivalent power of 33 GW

• Electrical connection between Scotland and

England is thought to be 3.3 GW – but

increasing to 6.5 GW by end of 2015

A matter of what else is available



Each rectangle on the grid is ~ 100 MWh


• We have not mentioned frequency control or

distributed energy storage – which are both

likely to be major areas of growth

• Also – if an energy system is to be

decarbonised, it needs low-carbon energy

sources and low carbon balancing

• Finally, there is the question of access to any

large storage scheme – maybe lessons to be

learnt from interconnectors ?

Why Energy Storage? | Grant Wilson

Environment

Transcript of Why Energy Storage? | Grant Wilson