NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Wind Electrolysis – Hydrogen Cost 

Optimization 

Fuel Cell & Hydrogen 

Energy Conference

Washington, DC

Genevieve Saur

February 16, 2011

NREL/PR-5600-50810
NATIONAL RENEWABLE ENERGY LABORATORY

Project Background

• U.S. Department of Energy (DOE) and Xcel Energy’s 

Wind-to-Hydrogen Project at NREL, part of the 

Renewable Electrolysis task

• Examination of a grid-tied, co-located wind 

electrolysis hydrogen production facility

• 4 scenarios optimize wind farm size vs electrolyzer

requirements using hour-by-hour modeling

2

Electrolyzer

Electricity
NATIONAL RENEWABLE ENERGY LABORATORY

Key Parameters - System

8,760 hourly analysis based upon NREL’s H2A 

Production and Fuel Cell Power models

• Using hourly electricity market pricing and hourly 

wind data

Hydrogen production facility

• 50,000 kg H2/day nominal

4 grid-connected wind electrolysis scenarios

• Grid supplements wind to power electrolyzers

3

Scenarios

A) Cost Balanced : $ grid purchased = $ wind sold

B) Power Balanced : kWh grid purchased = kWh wind sold

C) Same as A) but no summer peak grid electricity purchased

D) Same as B) but no summer peak grid electricity purchased
NATIONAL RENEWABLE ENERGY LABORATORY

Key Parameters - Components

Electrolyzers

• Design capacity of ~51,000 kg/day with 98% capacity 

factor

• 106 MW electricity requirement (50 kWh/kg)

• $50.1M total depreciable capital cost

• Replacement, O&M costs also included

Wind Farm

• Multiples of 3 MW turbines

• Design performance based on class 4 wind site

• Wind costs 

4

Low Cost Current Cost

Installed wind turbine $1,148/kW $1,964/kW

O&M (incl replacement) $0.012/kWh $0.0074/kWh

Fixed charge rate 12.1% 12.1%
NATIONAL RENEWABLE ENERGY LABORATORY

Key Parameters - Infrastructure

Grid Electricity Pricing

• 6 tiered structure; 3 summer, 3 winter

• $0.039/kWh to $0.099/kWh

• “hotter” hours = higher price

5

Summer rates definitions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Sunday 6 6 6 6 6 6 6 6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6

Monday 6 6 6 6 6 6 6 6 5 5 5 5 5 4 4 4 4 4 4 5 5 5 5 6

Tuesday 6 6 6 6 6 6 6 6 5 5 5 5 5 4 4 4 4 4 4 5 5 5 5 6

Wednesday 6 6 6 6 6 6 6 6 5 5 5 5 5 4 4 4 4 4 4 5 5 5 5 6

Thursday 6 6 6 6 6 6 6 6 5 5 5 5 5 4 4 4 4 4 4 5 5 5 5 6

Friday 6 6 6 6 6 6 6 6 5 5 5 5 5 4 4 4 4 4 4 5 5 5 5 6

Saturday 6 6 6 6 6 6 6 6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6

Hour

Winter rates definitions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Sunday 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 2 2 2

Monday 3 3 3 3 3 2 2 2 2 2 1 1 1 2 2 2 2 2 1 1 1 2 2 3

Tuesday 3 3 3 3 3 2 2 2 2 2 1 1 1 2 2 2 2 2 1 1 1 2 2 3

Wednesday 3 3 3 3 3 2 2 2 2 2 1 1 1 2 2 2 2 2 1 1 1 2 2 3

Thursday 3 3 3 3 3 2 2 2 2 2 1 1 1 2 2 2 2 2 1 1 1 2 2 3

Friday 3 3 3 3 3 2 2 2 2 2 1 1 1 2 2 2 2 2 1 1 1 2 2 3

Saturday 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 2 2 2
NATIONAL RENEWABLE ENERGY LABORATORY

0.00

0.05

0.10

0.15

0.20

0.25

0.00 0.10 0.20 0.30 0.40 0.50

Cost of Wind Electricity 

($/kWh)

Wind Capacity Factor

Low Wind Cost Current Wind Cost

Key Parameters - Infrastructure

Wind Profiles

• NREL’s Western Wind data set

• 136 sites in California, class 1 to class 6

6
NATIONAL RENEWABLE ENERGY LABORATORY

Results - Comparison 

Power Balanced Scenario – range of costs

7

Current Wind Cost

Low Wind Cost

0

1

2

3

4

5

6

7

8

9

10

11

12

13

1 2 3 4 5 6

Cost of Hydrogen ($/kg)

Wind Class
NATIONAL RENEWABLE ENERGY LABORATORY

0

2

4

6

8

10

12

14

0.000 0.100 0.200 0.300

Cost of H2 ($/kg)

Cost of Wind Electricity ($/kWh)

a) Buy Summer 

Peak

c) No Summer 

Peak

0

2

4

6

8

10

12

14

0.000 0.100 0.200 0.300

Cost of H2 ($/kg)

Cost of Wind Electricity ($/kWh)

b) Buy Summer 

Peak

d) No Summer 

Peak

Results – Current Wind Costs

Cost Balanced 

Scenarios

Power Balanced 

Scenarios

8
NATIONAL RENEWABLE ENERGY LABORATORY

Results – Scenario Details

9

100

200

300

400

500

600

700

800

900

0.050 0.100 0.150 0.200 0.250

Wind Farm Size (MW)

Cost of Wind Electricity ($/kWh)

Scenario a

Scenario b

Scenario c

Scenario d

Wind Farm Sizes to Produce 50,000 kg/day H2
NATIONAL RENEWABLE ENERGY LABORATORY

Results – Case Example

10

0

50

100

150

200

250

Daily Averaged (MWh/day)

Wind to Electrolyzer Grid to Electrolyzer

Wind Sold to Grid

Averaged Yearly Profile
NATIONAL RENEWABLE ENERGY LABORATORY

Results – Case Example

11

Scenario

Wind 

Farm Size 

(MW)

# 3-MW 

Turbines

Grid 

Utilization 

(%)

Unmet H2 

Production 

(kg/yr)

Cost of 

H2 ($/kg)

(a) Cost-Balanced—Buy 

Summer Peak 210 70 94 0 3.80

(b) Power-Balanced—Buy 

Summer Peak 219 73 102 0 3.82

(c) Cost-Balanced— No 

Summer Peak 195 65 100 622,000 3.72

(d) Power-Balanced—No 

Summer Peak 213 71 120 602,000 3.77

Wind Site Details

• Class 5 wind site with capacity factor 47%

• Average wind speed at 100 m 8.5 m/s

• Produces electricity for $0.064/kWh
NATIONAL RENEWABLE ENERGY LABORATORY

Results – Case Sensitivity

12

3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60

Wind Farm Availability (90%, 88%, 86%)

Electrolyzer Capacity Factor (99.5%, 98%, 96%)

Electrolyzer Capital Cost (-/+ 20%)

Electrolyzer Energy Use (47.5, 50, 60 kWh/kg)

Wind Turbine Capital Cost (-/+ 20%)

Cost of Hydrogen ($/kg)

Sensitivity for power balanced case

• Baseline optimization and sizing held constant

• Other scenarios show similar ranges
NATIONAL RENEWABLE ENERGY LABORATORY

Acknowledgements

Xcel Energy

• Frank Novachek

DOE

• Roxanne Garland 

• Richard Farmer 

NREL

• Todd Ramsden (co-author)

• Kevin Harrison 

• Darlene Steward

• Greg Martin 

• Keith Wipke 

• George Sverdrup 

• Robert Remick 

13