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POWER-TO-GAS & METHANATION – PATHWAYS TO A
‘HYDROGEN ECONOMY’
14TH ANNUAL APGTF WORKSHOP - LONDON, 12-13TH MARCH 2014
DR JOHN NEWTON
Contents:
• Introduction
• P2G Energy Storage Rationale
• P2G Economics
• Compliance
• Additional applications: Methanation, Bio-gas upgrading, Fuel
• Summary
POWER-TO-GAS & METHANATION – PATHWAYS TO A
‘HYDROGEN ECONOMY’
GROWING WIND GENERATION
20% (55GW) Winter
20% (40GW) Summer
ENERGY STORAGE: THE NEED
HYDROGEN ENERGY SYSTEMS
• Evidence of grid balancing problems from Germany and Denmark
• Problems start at 20% capacity; UK hit this threshold at the end of 2013
• Energy Storage is a Market Pull
Source: ITM Power plc, data from BWEA
ENERGY STORAGE: THE NEED
HYDROGEN ENERGY SYSTEMS
• Evidence of grid balancing problems from Germany and Denmark
• Problems start at 20% capacity; UK hit this threshold at the end of 2013
• Energy Storage is a Market Pull
UK WIND CURTAILMENT
THE NEED: GRID BALANCING
ENERGY STORAGE | CLEAN FUEL
BALANCING SUPPLY AND DEMAND:
• A total of £725m paid for balancing services in 2010-11
• Estimates in 2020 are: circa £1.9bn - £5.9bn pa
• Tariffs already operational in the UK: FCDM response <2 seconds
ENERGY STORAGE | CLEAN FUEL
WHY POWER-TO-GAS?
POWER-TO-GAS RATIONALE
Electricity cannot be stored easily | Hydrogen can be stored easily in the gas grid
Source: ITM Power plc
ENERGY STORAGE | CLEAN FUEL
ENERGY STORAGE TECHNOLOGIES
ENERGY STORAGE TECHNOLOGIES
Power-to-gas is efficient | long term | low energy cost
Source: ITM Power plc
0%
5%
10%
15%
20%
25%
30%
35%
0.0%
0.5%
1.0%
1.5%
2.0%
2.5%
3.0%
3.5%
0 2 4 6 8 10 12
Frac
tio
n w
ind
ou
tpu
t cu
rtai
led
Hyd
roge
n f
ract
ion
(vo
l%)
Excess wind (TWh pa)
725 TWh p.a. natural gas consumption, 30 GW wind capacity (2020)
Hydrogen fraction
Curtailment
HYDROGEN FRACTION V’S EXCESS WIND LEVELS
ENERGY STORAGE | CLEAN FUEL
• Capturing 2.8 TWh pa of excess wind (i.e. 4% of 2020 output)
• Requiring 978MW of electrolysis at 30% utilisation
• Results in average national hydrogen content of 0.5%, reducing carbon footprint by 0.2%
Source: ITM Power plc
POWER-TO-GAS IN THE UK
ENERGY STORAGE | CLEAN FUEL
EU POWER-TO-GAS ENERGY STORAGE
EU Hydrogen Limits for Injection into the HP Gas Grid
Covered by a range of local laws and EU Directives Note: interpretation of these rules is complex
Limit falls to 2% if there is a
CNG station downstream
ENERGY STORAGE | CLEAN FUEL
WHERE DOES THE GAS GO?
GAS USAGE IN THE UK (DUKES 2013)
Source: Dukes 2013
Where does the gas go?
• 906 TWh of natural gas consumed in the UK in 2011
• 52% was used to provide heat
• 34% burned in power stations to make electricity
DECC: UK HEAT STRATEGY
The Future of Heating: Meeting the challenge
• 70% of UK heat comes from natural gas
• Low penetration of renewable heat in the UK
RHI launched Nov. 2011
• 12% of heating from renewables by 2020
• 57 TWh hydrogen
• Circa 18,600 MW Electrolysis
ENERGY STORAGE | CLEAN FUEL
DECC: UK HEAT STRATEGY
P2G: ELEMENTS OF VALUE
ENERGY STORAGE | CLEAN FUEL
Value to the Power Grid
•Avoided wind curtailment
•Avoided infrastructure upgrades
•Reduced reserve power
•Reduce CO2 from open cycle GTs
•Absorbing reactive power
Value to the Gas Grid
•Decarbonising gas
•Providing renewable heat
•Reducing GHG emissions from gas transportation
Value to the UK Economy
•Reducing fuel imports
• Improved energy security
•Creating jobs in manufacturing
• Value to the power grid
• Value to the gas grid
• Value to the economy
P2G: ELEMENTS OF VALUE
RENEWABLE HEAT INCENTIVE (RHI)
ENERGY STORAGE | CLEAN FUEL
DECC: UK HEAT STRATEGY
A cost-based tariff scheme
Where tariff levels vary depending on the
cost of the technologies at different scales
• compensate for the additional cost of
the renewable technology over fossil
fuel heating;
• provide an incentive to overcome non-
financial barriers; and
• provide a return on the additional
capital invested
• Annual payments over a 20 year period
index linked
ENERGY STORAGE | CLEAN FUEL
ELECTROLYSER COSTS FOR 1MW MODULES
ELECTROLYSER COSTS
Cost Estimates
1,700
1,400
1,200 1,100
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
1 10 50 100
Co
st (
£k)
1 10 50 100
A cost-based tariff scheme
Where tariff levels vary depending on the
cost of the technologies at different scales
• Modular system
• Scale ~ Volume
13.9
6.9
4.6
3.52.8 2.3
2.0 1.7 1.5 1.4
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Elec
trol
yser
cos
t (p
/kW
h ch
)
Utilisation
ENERGY STORAGE | CLEAN FUEL
ELECTROLYSER COSTS VS. UTILISATION
1MW electrolyser: 70% efficient | £1.7m Capex (over 20 years)
100% utilisation (Consumes 8760MWh per year)
• Cost = 0.97 p/kWh of electricity consumed = 1.4p/kWh of H2 Produced
50% utilisation (Consumes 4380MWh per year)
• Cost = 1.90 p/kWh of electricity consumed = 2.8p/kWh of H2 produced
Source: ITM Power
ELECTROLYSER COSTS FOR 1MW MODULES
RHI FOR P2G APPLICATIONS
ENERGY STORAGE | CLEAN FUEL
Off Grid
30% utilization onshore
50% utilisation offshore
Technically very challenging
Grid Connected
100% utilisation
Technically straightforward
Demand Side Managed
Excess wind utilisation
Rapid response essential
Technically challenging
POWER-TO-GAS IN THE UK
OFF GRID P2G
ENERGY STORAGE | CLEAN FUEL
10p
Generation Tariff
5p
Export Tariff
10p
Generation Tariff
5p
Electrolyser Tariff Burner
The ultimate in renewable heat | Simplest tariff structure
• Where a grid connection is too expensive
• FIT for the turbine can be achieved by making RH
• Replace the existing export tariff with ……
• An “Off Grid Electrolyser Tariff” of the same value
POWER-TO-GAS IN THE UK
GRID CONNECTED
ENERGY STORAGE | CLEAN FUEL
Green hydrogen generated by means of electrolysis of
water must have a greenhouse gas reduction potential of
at least 75 per cent compared to the currently valid
reference value for fossil fuels of the “Bio fuel
Sustainability Act” or conventionally generated hydrogen.
Based on the Carbon Footprint of the grid:
• The UK grid is 164gCO2/kWh in 2030 (DECC)
• Produces H2 of 234gCO2/kWh | Methane is 198gCO2/kWh
• TUV definition of “Green Hydrogen” is 50gCO2/kWh
• DSM and rapid response needed to produce green hydrogen
POWER-TO-GAS IN THE UK
DEMAND SIDE MANAGED
ENERGY STORAGE | CLEAN FUEL
A Matrix of possibilities:
• Accessing renewable power via the grid
• Grid balancing | DSM | Utilising curtailed wind
• Significant modelling work undertaken
Grid electricity @ 9p/kWh
Green Hydrogen
at 50gCO2/kWh
Curtailed wind @ 0p/kWh
POWER-TO-GAS IN THE UK
DEMAND SIDE MANAGED
ENERGY STORAGE | CLEAN FUEL
A Matrix of possibilities:
• Accessing renewable power via the grid
• Grid balancing | DSM | Utilising curtailed wind
• Significant modelling work undertaken
2015 2020 2030 2050
Electrolyser CAPEX £m 1.7 1.4 1.2 0.8
Electrolyser Utilisation
Excess Energy 16% 25% 42% 51%
Grid 1% 2% 2% 3%
Total 18% 27% 44% 54%
CO2footprint of H2 gCO2/kWhch 27 16 7 1
Electrolyser cost p/kWhe 5.43 2.93 1.55 0.84
p/kWhch 7.75 4.18 2.21 1.20
Hydrogen cost p/kWhe 0.74 0.60 0.48 0.47
p/kWhch 1.05 0.86 0.68 0.68
POWER-TO-GAS IN THE UK
An international network
• Needs a coordinated approach
• International standards
• 0.1% Vol H2 limit needs revisiting
• Needs the formation of an
international standards group
ENERGY STORAGE | CLEAN FUEL
P2G IN THE NATIONAL TRANSMISSION NETWORK
P2G IN THE NTS
Open and Closed Network Compliance
• The current 0.1% Vol H2 is NOT based on safety!
• Network entry rules are based on gas refineries
• Recommend revising for small green gas facilities
• We recommend increasing the GS(M)R limit to 3%
• Standardise the procedure for exemptions to HSE
• Form a standards working group specifically looking at
hydrogen in the gas grid
GAS DISTRIBUTION NETWORK
ENERGY STORAGE | CLEAN FUEL
GAS DISTRIBUTION NETWORK
H2 Clean Gas Contract for Domestic Customers
• Analogous to a Green Power contract
• Therm for Therm offering*
• Reinvestment in P2G plant
DOMESTIC RENEWABLE GAS OFFERING
ENERGY STORAGE | CLEAN FUEL
DOMESTIC RENEWABLE GAS OFFERING
*1 therm = 100,000 British thermal units = 29.3kWh
ADDITIONAL
APPLICATIONS
METHANATION
UPGRADING BIOGAS
P2G AND FUEL
Production of SNG from Renewable Hydrogen and CO2
• Need to source (pure) CO2
• Process design can minimise or eliminate storage
• Multi-stage depending on the level of H2 compliance
METHANATION
ENERGY STORAGE | CLEAN FUEL
METHANATION
METHANATION
ENERGY STORAGE | CLEAN FUEL
METHANATION
Production of SNG from Renewable Hydrogen and CO2
• Need to source (pure) CO2
• Process design can minimised or eliminate storage
• Multi-stage depending on the level of H2 compliance
CHEMICAL V’S BIOLOGICAL METHANATION
ENERGY STORAGE | CLEAN FUEL
CHEMICAL VS. BIOLOGICAL METHANATION
Production of SNG from Renewable Hydrogen and CO2
• Chemical: An industrial process for ~80yrs.
• Operates continuously – requires considerable storage
• Biological: Able to follow varying wind profile
• Minimal buffer storage
Parameter Chemical Biological
Max scale sold ~500 MW ~500kW
Pressure ~50bar Atmospheric, up to 50bar
Temp 300 – 400C ~50C
Heat produced in reaction Useful Useless
Operating range 50-100% (needs H2 storage) 0-100% in <5mins (less H2 storage)
During off periods... No energy required Need to prevent freezing
Size of reactor Thin tubes ~ 10m long 3m3 reactor vessel
Methanation for BioGas | CO2 removal
• A modular and scalable technology for CO2 removal
• BioGas typically min. 35% CO2 | Brings BioGas into
Compliance
• Increases calorific value | Increases output
• DECC Methanation feasibility project in progress
• High value application
REMOVING CO2 FROM BIOGAS
ENERGY STORAGE | CLEAN FUEL
REMOVING CO2 FROM BIOGAS
H2 Fuel cost reduction using P2G Co-location
• Energy Hub for P2G and Fuel
• Reduces the cost of H2 by maximising electrolyser utilisation
• More work needed | particularly siting and economics
ENERGY HUB FOR P2G & FUEL
ENERGY STORAGE | CLEAN FUEL
ENERGY HUB FOR P2G & FUEL
Summary:
• Renewable power needs energy storage
• Power-to-Gas is at the required scale
• Power-to-gas energy storage provides renewable heat
• A tariff structure comparable to Bio-Methane | Recommendation to DECC
• The 0.1% Vol H2 legislation needs revisiting in the UK | Recommendation to the HSE
POWER-TO-GAS & METHANATION – PATHWAYS TO A
‘HYDROGEN ECONOMY’