1. Turning the wind into hydrogen: Long run impact on prices and capacity
Nicholas Vasilakos
(with R. Green and H. Hu)
Department of Economics University of Birmingham

2. Background and motivation
EU renewables target by 2020: 20%
For UK:
15% renewable energy
c. 40% renewable electricity…
…great part of which is likely to be wind.
But wind output is intermittent – issue of storage Vs high backup capacity building
Hydro plants and interconnectors
Hydrogen production and storage

3. Outline of questions and main results
Hydrogen can be produced when prices are low (i.e. high winds) and stored.
What will be the impact of large scale electrolyser capacity on prices and investment (capacity mix)?
Increased average price of electricity
More baseload capacity and less mid-merit capacity
But effect on price of hydrogen may not be as steep as previously thought, if capacity mix is allowed to adjust

4. Literature overview Troncoso and Newborough (2007)
Korpas and Greiner (2008)
Hydrogen as a tool to ease pressure on grids
Aguado et al (2009)
A wind farm can smooth its power sales through hydrogen storage
Only economical if prices are high enough
Floch et al (2007)
Shows how hydrogen production varies with maximum price paid by operators (using Powernext prices).
They derive an optimal load factor of 64% - corresponding to a maximum willingness to pay of 48 euros/MWh.

5. Methodology and data
We derive the optimal capacity mix using a cost-minimisation approach
Recent cost data for 5 types of plants is taken from Mott MacdDonald (2010) –“n”th of a kind.
Demand data and wind output taken from Green and Vasilakos (2010b)
Electrolyser cost estimates are taken from Ramsden (2008a,b)

6. Finding the equilibrium: electricity market (for a given capacity of electrolysers)
1) Select operating plants using screening curve
2) Choose max price electrolysers are willing to pay
3) Choose total capacity so that peakers make zero profits
4) Adjust peakers’ capacity so that 2nd most expensive plants make zero profits
5) continue till everyone makes zero profits
Electricity market is now at equilibrium (for a given amount of hydrogen capacity and a given marginal willingness to pay for hydrogen plants)

7. Finding the equilibrium: both markets
6) Using the estimated capacity mix, find AC for electrolysers
- if AC>MC, increase marginal willingness to pay and find a new set of generating capacities
7) Continue until AC=MC and then this is the price that clears both markets.
- will give optimal capacity mix for this price.
both markets are now at equilibrium.

8. Generation Cost Screening Curves
£/kW-year
Load factor 8

9. Main assumptions
carbon price of £50/tonne and all carbon permits are auctioned
Fuel price: £27/MWh for gas (+7% in winter, -7% in summer) and £6/MWh for coal.
30GW of wind capacity, spread across the UK
5GW reserve capacity
We follow Pouret et al (2009) in assuming minimum load factor for nuclear plants of 60% of their capacity.
Hydrogen plants are price-takers

10. Simulation results: Summer load-duration curve (demand slope -2)GW
(excluding electricity used for hydrogen production)
Hours 10

11. Simulation results: Winter load-duration curve (demand slope -2)GW
(excluding electricity used for hydrogen production)
Hours 11

12. How hydrogen affects the capacity mixGW
Hydrogen electrolyser capacity, GW

13. Hydrogen supply curve: base case
£/kg
Fixed generation capacity
Equilibrium generation capacity
Million
tonnes p.a. 13

14. Supply curves for hydrogen (higher electrolyser costs)
£/kg
Fixed generation capacity
Equilibrium generation capacity
Marginal cost with fixed generation and electrolyser capacity
Million
tonnes p.a.

15. Hydrogen supply curve: sensitivity fuel prices
£/kg
Generation capacity mix fixed at pre-wind levels
2005 electrolysers
Base case
2009 fuel prices
Million
tonnes p.a.

16. Conclusions
Integration of electrolysers has a long-term impact on capacity mix
Ignoring this impact can lead to overestimates for the price impact of hydrogen.
Fairly flat supply curve, once long-term adjustments in capacity mix are accounted for.
Still an expensive way to produce hydrogen
our baseload estimate of £4/kgr compares to conventional methods yielding about £2/kgr using current gas prices

17. Thank you!