Kevin Harrison* Robert Remick*Aaron Hoskin

Gregory Martin*

World Hydrogen Energy Conference

Essen, GermanyMay 19, 2010

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.

NREL/PR-560-48269

Hydrogen Production: Fundamentals and Case

Study Summaries

20% Wind by 2030 Scenario

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ulat

ive

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alle

d C

apac

ity (G

W) Offshore

Land-based

2010

As of December 31, 2009 - 34,863 MW of wind power have been installed across the United States.

Challenges to 20%

• Growth in installations – 8 GW installed in 2008– 9 GW installed in 2009– Total 34 GW 2009

• 50 GW offshore– Cape Wind approved– 130 wind turbines– 420 MW

• Performance is critical– Gearbox reliability– Capital cost– Capacity Factor– O&M

Competitive Energy Storage Technologies

Source: Energy Storage Association

Solar Energy

Heat

Hydrogen

Thermolysis

Mechanical Energy

Electricity

Electrolysis

Biomass

Thermo-Chemical & Biological

ConversionPhotolysis

Sustainable Paths to Hydrogen

Sustainable Hydrogen Potential

Wind Biomass

Solar

• Examine benefit to utility by time shifting wind and PV energy with hydrogen production

• Research optimal wind/hydrogen through systems engineering and power electronics integration

• Characterize and control wind turbine/PV and H2-producing stack

• Evaluate synergies from co-production of electricity and hydrogen

NREL/Xcel Energy Wind to Hydrogen - Objectives

New Wind2H2 Configuration

PV Configuration Testing

Direct connect versus various input voltages (Ein) through power controller

85% -92%

100%

Round I - PV Powered Electrolysis• Onboard power electronics account for 15 – 30% of the

overall electrolyzer system cost • The data illustrates improvement in energy capture to stack

when using MPPT power electronics• Testing showed a 10% – 20% increase in energy capture

depending on input voltage to power electronics

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ck P

ower

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E-130 connected through MPPT

power electronics

E-120 direct connect to PV Direct connect

MPPT power electronics

PV-to-Stack Optimization

• Installed 10-cell stack in series with existing 20-cell stack to better align PV and stack operating points

• Improved PV-to-stack sizing enabled 2nd phase direct coupling versus MPPT power electronics

Impact of Shifting Operating Point

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PV Array IV

20-cell stack Relocated with 10 additional cells

PV array maximum power point

Solar Irradiance

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Electrolyzer Fault

Performed IV sweeps of PV

array

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ime

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Direct Coupling v. Power Electronics

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tack

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er/Ir

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ance Power Electronics

with MPPTDirect Coupling

General Electrolyzer System Data

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Hyd

roge

n Fl

ow [k

g\h]

Although stack efficiency is higher at lower current the hydrogen flow (thus system efficiency) is zero at currents

below 15 A

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ffici

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Electrolyzer consumes hydrogen to maintain the desiccant drying system

New techniques and incremental improvements in drying systems will

improve system efficiency

Higher pressure electrolyzers will dissolve more hydrogen that is also

wasted

350 bar Vehicle Fueling SystemNew System Components• Storage tank, compressor and

dispenser– 18 kg @ 6000 psi– 120 kg @ 3500 psi

• June 2010– Additional 6000 psi storage– Cascade filling– Total 250 kg (including 3500 psi tanks)

• 9 months of refueling A-Class Mercedes (~2 kg, 110 miles)

• Proterra Fuel Cell Bus – March 2010, 20 kg

• Yesterday, Ford H2 ICE shuttle leased by NREL

Integrated Renewable Energy SystemIntegrated Systems• 5 kW fuel cell (PEM)• 5 kW to 10 kW PV array• 10 kW wind turbine

TEST: Dynamic response (both DC and AC) of fuel cell with both PV and wind systems

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ianc

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7.25 kWh / m2

1 minute → Increase 536 W/m2

→ Decrease 518 W/m20

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Variable Stack Current Testing

Comparison TestingPEM: 3-stack design withIndividual power supplies

Alkaline: New stack installation

Test: Long duration testing of stacks with highly variable (wind profile) current

WIND ENERGY & HYDROGEN INTEGRATION

International Energy Agency, Hydrogen Implementing Agreement, Annex 24

To explore in detail all possible issues (technical, economical, social,

environmental, market and legal) related to hydrogen production using electrolysis with

wind energy.

National Renewable Energy Laboratory Innovation for Our Energy Future

Recent Publications

Technical ReportNREL/TP-581-44082April 2009

Technical ReportNREL/TP-TP-550-44103December 2008

http://www.nrel.gov/hydrogen/proj_wind_hydrogen.html

Thank you for your attention!

Questions?