Volume 4 fuel cells and hydrogen technology 4 14 – future perspective on hydrogen and fuel cells

Volume 4 fuel cells and hydrogen technology 4 14 – future perspective on hydrogen and fuel cells Volume 4 fuel cells and hydrogen technology 4 14 – future perspective on hydrogen and fuel cells Volume 4 fuel cells and hydrogen technology 4 14 – future perspective on hydrogen and fuel cells Volume 4 fuel cells and hydrogen technology 4 14 – future perspective on hydrogen and fuel cells Volume 4 fuel cells and hydrogen technology 4 14 – future perspective on hydrogen and fuel cells

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K Hall, Technology Transition Corporation, Ltd., Tyne and Wear, UK

Demand-side management (DSM) Modification of (IGCC) Technology that turns coal into a synthesis gas

consumer demand for energy through education or and involves generating electricity from gas turbines as

Holistic Relating to or concerned with wholes or with

complete systems rather than with the analysis of,

treatment of, or dissection into parts [1]

4.14.1 Overview

Population growth is projected to continue in the foreseeable future (Excerpted from data from US Census Bureau 2009, Population Reference Bureau, and UN Department of Economic and Social Affairs as follows: [2 –11] ) More a nd more people are living in metropolitan areas Roads are becoming more congested [12] , with incentives for mass transit and tariffs for driving personal automobiles in crowded cities becoming more commonplace As ultralow emission vehicles, such as hybrid electric vehicles, do not contribute to the growing production of carbon emissions from vehicles, these are often exempted from congestion charging and are therefore highly sought after vehicles in areas such as London, where congestion-charging policies are in place

The future presents an image of vehicles that rely less on a diminishing supply of fossil fuels and more on clean energy choices –

such as a cleaner energy mix for electricity, clean efficient hydrogen fuel cells, and even hydrogen internal combustion engines Added to a growing mix of taxis and buses running on cleaner energy technologies [13 –16] the near- to mid-term future looks much like the present day, only with cleaner air and fewer harmful emissions from transportation applications (Table 1)

Hydrogen energy can contribute significantly to the future energy mix due to its versatility Not only can hydrogen be produced from fossil fuel feedstocks, it can also be produced from renewable energy resources and nuclear power The production of hydrogen

in any of these ways provides many benefits, including the ability to store intermittent energy (e.g., from wind or PV) for use when demand outstrips supply, or in another application (such as transport) or another location This solution affords greater options for producing energy using renewable resources and providing this energy in many usable forms in the growing cities, providing clean stationary power as well as transport fuel

Producing hydrogen from fossil fuels makes sense when and where the fossil fuels are abundant, providing energy to the end user without the carbon Large-scale power plants, therefore, could sequester the carbon, and provide power as electricity, gaseous hydrogen, or even liquid hydrogen if desired The ability of large-scale power plants to provide energy in these three forms opens new markets and delivers clean, reliable power

It is important to understand that hydrogen energy will be used alongside many other forms of energy and enhance the overall efficiency of delivering clean fuel for a variety of applications How hydrogen will be used in the future depends on the specific needs

of the community This chapter will describe many anticipated needs and how hydrogen can play a role in addressing those needs Today, there are many pre-commercial and early market applications of technologies that are critical on the path to a future energy mix that do not rely on imported fossil fuels, and which contribute to carbon-reduction targets and allow communities to make the most of the energy resources available to them We will explore a number of these technologies and discuss their roles in the transition to a low-carbon energy future where hydrogen energy plays a dominant role alongside clean electricity

And finally, the chapter will describe the future applications of hydrogen energy with respect to the projected energy supply needs

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Future Perspective on Hydrogen and Fuel Cells

Table 1 Projected increases in world population

United States Census Bureau (2009)a

Population Reference Bureau (1973–2008) b UN Department of Economic

and Social Affairs (2008) c

2010

2020

2030

2040

2050

6 830 586 985

7 557 514 266

8 202 205 367

8 748 743 446

6 908 688 000

7 674 833 000

8 308 895 000

8 801 196 000

9 149 984 000

4.14.2 Why Hydrogen?

Let us begin by discussing the reasons why hydrogen is of interest There are many, and in reviewing the key policy drivers for hydrogen energy in a number of countries, The author has selected the predominant drivers that tend to appear in National policy documents more often than not: Security of Energy Supply, Greenhouse Gases/Climate Change, and Air Pollution/Environmental (United Kingdom Hydrogen Association [17] , U.S Department of Energy [18] , Canadian Hydrogen Association [19] , European Comission [20] , Ministry of New and Renewable Energy, India [21] )

By their nature, fossil fuels are used faster than they are produced Although there continue to be significant resources discovered, the cost of accessing these resources has to be balanced against the cost of obtaining energy from other resources The issue is not one

of scarcity of supply of fossil fuels; it is more about the difficulties of increasing that capacity to keep pace with increasing demand [22] In addition, carbon-based fuels contribute greenhouse gases to the atmosphere To ensure future supplies of fuel, and mitigate potential damage to the environment from combustion of fossil fuels, there is a trend toward sustainable supplies of energy The World Commission on Environment and Development defined sustainable development as development that “meets the

needs of the present without compromising the ability of future generations to meet their own needs” [23]

In practical terms, resources that are used more quickly than they can be renewed and create environmental damage cannot meet the requirement

Therefore, although it is quite reasonable to expect that fossil fuels will continue to be a key part of our future energy mix, it is also reasonable to expect a growing portion of this energy mix to come from low-carbon and diverse supplies, with a growing emphasis on sustainability

It is worth noting that indigenous, low-carbon energy supplies tend to be less dispatchable, or less capable of following demand variations, than conventional technologies Notable exceptions include large-scale hydroelectric and coal with precombustion carbon capture and storage (CCS) [2] (Figure 1)

Therefore, a key risk associated with a decarbonized grid is supply variability resulting from the relatively poor dispatchability of many low-carbon generators This could result in increased difficulty in maintaining grid stability as low-carbon options are taken up Demand-side management (DSM) solutions are needed to ensure the necessary grid balancing There are many DSM solutions available, distinguished mainly by the storage timescales they provide Batteries, flow cells, flywheels, and supercapacitors are examples of short time-scale energy storage (less than a second to a few hours)

Electricity storage and pumped hydroelectric are examples of medium time-scale energy storage (hours to a few days)

It is important to recognize that the intermittent nature of many renewable energy technologies necessitates longer-term energy storage (can be weeks or more) Hydrogen has a unique role to play in meeting these longer-term needs

Hydrogen, like electricity, is an energy carrier, rather than an energy source So, we are concerned with production, storage, and use, as in the case of electricity Assuming that the end products meet standard quality requirements, neither electricity nor hydrogen retains any ‘memory’ of the feedstocks or methods used to produce it Both are flexible that they can be produced from a variety of

feedstocks, providing energy in a usable form where and when it is needed The societal movement to low-carbon options for energy generation is compatible with both electricity and hydrogen; however with this shift comes new issues which must be addressed

As renewable energy increases penetration in the energy supply, the need for longer-term storage becomes greater [24] Generators such as conventional coal power plants, flexible combined cycle gas turbines, and open cycle gas turbine power plants are low load-factor generators with a relatively low capital expenditure required

Adding postcombustion CCS increases both the load factor and capital expenditure One way this could be offset is to consider precombustion CCS with open cycle gas turbine power plants Precombustion CCS technologies are being developed One leading method currently being developed is a system called integrated gasification combined cycle (IGCC), which involves generating electricity from gas turbines as well as steam-powered ones [25] This approach enables the sale of hydrogen for industrial uses as well as a transport fuel

As the energy supply becomes decarbonized and gas becomes more expensive, hydrogen from coal plus CCS or from electrolysis becomes a viable option; and in fact becomes a very attractive option [26]

The point at which decarbonized hydrogen is competitive with conventional fossil fuel technologies depends on several factors –

including the price of carbon and the price of the fossil fuels For example, when the CO 2 value offsets the fuel conversion costs for a given application, the use of CCS and hydrogen as an intermediary energy vector becomes competitive with natural gas for energy generation

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Changing energy markets

These tend to be less ‘dispatchable’ (i.e., less capable of following demand variations)

Legend

Hydro Geological, constrained resource Open cycle gas turbine

Geological, abundant resource

combustion CCS

Renewable, constrained resource Renewable, abundant resource Combined cycle gas

supply-side management

Coal with oxy-fueling or

Solar (PV & thermal)

Wave Wind

demand-side management

Figure 1 Dispatchability versus sustainability Reproduced with permission from Gammon R (2010) Dispatchability versus Sustainability

Loughborough Leicestershire, UK: Bryte-Energy Limited [2]

4.14.3 Hydrogen for Transport

There are currently many regions demonstrating hydrogen vehicles and refueling technologies In September 2009, nine major automotive manufacturers signed a letter of understanding to develop and launch fuel cell electric vehicles, with commercialization anticipated in the 2015 timeframe [27]

Development of a hydrogen infrastructure for vehicles is well underway, with hydrogen stations across the world [28] The author has personally visited operating stations in California, Washington DC, Japan, Korea, the United Kingdom, and Germany The high energy density of hydrogen and rapid refueling times for hydrogen vehicles provide a distinct advantage to public charge points for electric vehicles In addition, home hydrogen refuelers are being developed which overcome the early difficulties of deploying widescale infrastructure in advance of mass commercialization of vehicles [29] (Figure 2)

Research and development of hydrogen infrastructure is being conducted worldwide The economics depend on a number of factors including geographical location, hydrogen production techniques, storage technology and timeframe, and distribution methods Most cost-effective production techniques may vary as each region considers the resources available to them

Japan is intensely investigating options to provide sustainable stationary and transportation power to large cities and has identified utilization rate as the key factor in making a hydrogen infrastructure economical [30]

Electrification of vehicle power trains is required to decarbonize transport Batteries and hydrogen are two ways of achieving this and all leading OEMs that have active programs in both areas It is worth noting that commercial fuel cell vehicles under development are hybrids, combining batteries, and fuel cells The hybrid electric vehicle operates the fuel cell as an alternative power unit to supply the power required by the vehicle, to recharge the batteries, and to power accessories such as the air conditioner and heater According to a US training module developed by the College of the Desert,

Hybrid electric cars can exceed the limited 100 mile (160 km) range-per-charge of most electric vehicles and have the potential to limit emissions to near zero A hybrid can achieve the cruising range and performance advantages of conventional vehicles with the low-noise, low-exhaust emissions, and

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2 Hydrogen fuel cell vehicles introduction scenario

The densitiy of vehicles in the area Initial market for fuel cell vehicles (Areas)

2500 vehicles/km2

(Yokohama, Kawasaki/Nagoya, Osaka)

2000−3500 Passenger cars in the central of Tokyo vehicles/km2 Fleet vehicles in the central of Tokyo (Passenger car and light duty van) 100−400

vehicles/km2

T

a

r

g

e

t

(Passenger vechicles in mega

(Yokohama, Kawasaki/Nagoya, Osaka)

2500 vehicles/km2

vehicles/km2

(Passenger vehicles in

suburb of mega cities)

vehicles/km2

Time

Figure 2 Honda solar hydrogen filling station in Torrence, California Reproduced with permission from ENEA (2010) Vision of a Hydrogen/Electric Energy Scenario Rome, Italy: ENEA

4.14.4 Stationary Power

Fuel cells that operate on hydrogen energy are available on the market today They come in a variety of sizes for a variety of applications The solution is carefully matched with the problem that needs to be solved

There is much more information on the variety of fuel cell technologies available today elsewhere in this volume They are mentioned here only to provide a brief context for a transition from the energy mix of today, to the energy mix of the future, where hydrogen plays a more dominant role It is anticipated the market penetration for stationary fuel cells will continue to grow, as hydrogen becomes more widely available

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Primary resource GHG impact Distributed Electricity Demand Additional Transport

Post & Oxy

ICE

Coal

Pre combustion

Fischer

H2 pipe

Tropsch

or store

fuel-Good

Gas

Pre combustion

no CCS response

Other chemicals &

products

H2 ICE

Biomass

Oil

1st generation

impacting

land use

2nd generation

careful land

use

Additional benefits with CCS

Not sustainable

Good only

if small scale

Good

Responsive

Good response

Time shift

Smart electrolysis

H2 pipe

or store

H2 Fuel cell

Residual needs use fossil fuels

Batteries

(# Higher temperature reactors will be able to directly produce hydrogen-this benefit is not shown here) AMEC October 2010

4.14.5 The Efficiency Debate

Efficiency is a key issue that is often raised by those who believe hydrogen energy has no future Some ask why we would convert electricity to hydrogen, and then back to electricity To answer this question, keep in mind that efficiency must not be considered in isolation of the needs of society In addition, consideration must be given to efficiency gains of capturing energy that would otherwise be lost in order to gain a more complete picture

How, for example, does one measure the efficiency of a system that allows you to capture renewable energy that otherwise would have not been captured? Rather than turning some wind turbines off at night when supply outstrips demand, the turbines can be allowed to operate fully, thereby increasing the utilization rate of the wind energy system Wind power that cannot be used for stationary power or exported to the grid could be used in power electrolyzers to produce hydrogen This hydrogen could then be used in stationary or transport applications where and when needed Thus, although there will undoubtedly be efficiency losses in each step of transfer or conversion, you are starting with a resource that was not going to be used at all Therefore, even if you achieve

a system efficiency of 45%, for example, does it make sense to imply you are somehow ‘losing’ 55% of the energy when your starting

position was to lose 100% by switching off the wind turbines?

Even so, if we want to simply look at the efficiency of the stack and the electrolyzer system, recent progress reports show electrolyzer stack efficiencies between the low seventies and the upper eighties, depending on the specific components and materials used System efficiencies, however, vary with the power of the system Let us take sample data from recent research at NREL [32] Looking at a 6.5 kW system at 135 A, a measured hydrogen flow of 1.05 Nm 3 h −1 , the reported High Heat Value system efficiency is 57.4 and the low heat value system efficiency is 48.5%

4.14.5.1 A Holistic Approach

Hydrogen is meant to be considered holistically – throughout the energy chain It complements electricity, allowing for useful

energy to be available in an appropriate form where and when it is needed Both electricity and hydrogen will continue to be important throughout the heat, electricity, and transport sectors; and both will continue to be produced in more sustainable, environmentally friendly ways

There have been many critics of hydrogen energy who point to narrow applications and show, correctly, that hydrogen may be less efficient or more expensive than other technologies [33] However, these critics fail to look at hydrogen ’s role across the energy

spectrum, and therefore give any credit for hydrogen serving multiple needs simultaneously

The following figure from AMEC depicts the potential complex role of hydrogen for providing the capacity, the flexibility, and the sustainability of a future energy system across heat, electricity, and transport sectors (Figure 3):

Figure 3 A holistic approach for hydrogen Reproduced with permission from ITM Power (2010) Hydrogen Powered Home Sheffield, UK: ITM Power

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10 kW

Photovoltaics

Bergey 10 kW Wind turbine

Excess grid-compatible

Converter

DC–DC

Converter

NPS 100 kW wind turbine

Power converter

Utility grid

AC power

ASCO transfer switch

Proton energy

HOGEN 40RE (PEM)

Proton energy HOGEN 40RE (PEM)

Teledyne HM-100 (Alkaline) center 60 kW genset Hydrogen engine

Hydrogen Output

H2 filling station

Hydrogen compression and strorage 3,500 PSI

115 kg hydrogen storage capacity

NREL [34] has shown That hydrogen can be produced at the wind site for prices ranging from $5.55 per kg in the near term to

$2.27 per kg in the long term A research opportunity in this scenario is the elimination of redundant controls and power electronics

in a combined turbine/electrolysis system

Hydrogen fuel cells can be used as a buffer for intermittent renewable resources

There are examples of systems that use solar or wind turbines, coupled with electrolysis for hydrogen production Renewable energy resources are not distributed equally throughout the world, and require significant areas to deploy technologies to gather sizeable amounts of energy In order for these types of energy resources to become more practical, the energy needs to be easy to store, transport, and use Coupling renewable resources with hydrogen not only achieves this, but it also allows this stored energy to be used

as a sustainable transport fuel [35] One such project is the Wind2H2 project in the United States, which links wind turbines and photovoltaics to electrolyzers, which pass the renewably generated electricity through water to split it into hydrogen and oxygen The hydrogen can then be stored and used later to generate electricity from an internal combustion engine or a fuel cell (Figure 4) The Wind2H2 project seeks to improve the system efficiency of producing hydrogen from renewable resources in quantities large enough and at costs low enough to compete with traditional energy sources such as coal, oil, and natural gas Some success has already been achieved in optimizing power electronics [36]

Renewable electricity, particularly which is above and beyond the demand for the direct electricity at the time and therefore would not be captured, can be converted via electrolysis to produce hydrogen This hydrogen can then be used to power the fuel cell during peak demand Critics will point to the fact that it is more efficient to use the renewable electricity directly – which is true when that is an

option However, the nature of intermittent resources and transmission lines means that there will be times when the system is capable

of generating more electricity than is needed Often, this results in some wind turbines being switched off, for example The electricity which could be generated by these turbines could be used to electrolyze water to store hydrogen for those times when demand is greater than can be supplied directly from the renewable resources In a case like this, how does one characterize the efficiency? The system is using energy which otherwise would not have been captured at all The turbines are already in place

The efficiency debate applies to all areas of hydrogen production, storage, and use The same debate can be made of electricity, but rarely is made, because we do not wish to burn coal in our homes to heat water or power our television or computers Both hydrogen and electricity are used in a form which is clean and quiet easy to use where and when it is needed Electricity provides electrons, and hydrogen can provide electrons with gaseous or liquid storage Yes, it takes energy to provide any of these As society moves to more environmentally sustainable energy resources, the game becomes one of capturing more of this energy, not only how efficiently we use but also what has been captured

Consider the case of renewable resources where 50% of the available energy is captured, and that is used 80% efficiently versus adding hydrogen storage to capture 80% of the available energy which may be used 50% efficiently The current efficiency debate focuses only on the efficiency of use after conversion losses; however these two scenarios actually are comparable Now when 95%

Figure 4 Overall Wind2H2 system diagram

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of the available energy is captured and used 60% efficiently, more overall energy is available for use So in this case, the efficiency debate needs to include the ability to capture the resource in the first place as well as the conversion losses prior to use

Recall the need for long-term storage of intermittent renewable energy discussed previously The addition of electrolysis and hydrogen storage means that the renewable resource need not be turned off overnight or during other times of low demand Capturing and storing some of this energy for use when demand outstrips supply increases the energy output from the renewable energy system, helps manage supply and demand issues, and creates a store of energy which can be used in a number of applications, including fueling hydrogen vehicles Farms that operate wind turbines may use the excess hydrogen to power farm equipment, becoming more self-sustaining; or the excess hydrogen can be sold as a commodity In fact, hydrogen opens new markets for electricity to include fuel for vehicles

Critics will point out that electricity can be used directly as a vehicle fuel in battery electric vehicles (BEVs) Yes, of course, this is true The difficulty has been in ensuring the capacity required to provide the electricity to the vehicle while maintaining capacity for other uses In the case of hydrogen, which can be delivered as a gas or liquid as well as electrons, there are simply more options When and where it is not convenient to deliver electrons to the vehicle, hydrogen can be delivered as a gas or liquid, reducing refueling/recharging times and avoiding an additional demand on the electrical grid In areas where there is no electrical grid or no additional capacity, this is especially attractive

One reason someone may want to suffer the efficiency losses in converting electricity to hydrogen, and then back to electricity, may relate to intermittency of renewable energy During the times when a photovoltaic system or wind turbine is capable of producing more electricity than the user can use at the time, the surplus renewable power could be used to make surplus electricity

If there is a need to store this electricity, one option for this is through hydrogen production by electrolysis Although there are efficiency losses in this conversion, we are starting with energy that was not usable Any energy captured in this way is basically bonus energy that would have been lost otherwise

What is then done with this energy is a matter of individual needs and circumstances Someone may choose to store the hydrogen, and then run the hydrogen through a fuel cell to create electricity locally when the demand for the renewable electricity exceeds the supply In this way, more of the renewable energy is captured than can be used directly, and this helps resolve the intermittency issues with renewable energy Hydrogen is used as an energy storage mechanism for renewable resource

Perhaps there is not a need to capture the energy for local use Or perhaps the renewable energy system is capable of providing more electricity than can be used locally, even accounting for intermittency issues In this case, the excess energy could still be converted to hydrogen, but now the hydrogen could be sold as a commodity, or used to power vehicles The ability to gain revenue from this energy as a vehicle fuel may be an attractive option

The author believes the key to the future of hydrogen energy lies in its flexibility No single production method is expected to dominate the future of hydrogen production Precombustion CCS, electrolysis, nuclear, bio-energy, and others all will likely have a role to play The flexibility in production methods provides greater flexibility in solving a broader array of energy issues than a single production method would

It is worthwhile to consider the broader energy picture to better understand why energy conversion is not the barrier that it may seem to be at first glance

Figure 5 depicts a vision of a future hydrogen/electric energy scenario It shows the flexibility in generation described in this chapter, and how the hydrogen, regardless of how it is produced, can be delivered as electricity, gas, or liquid for a variety of applications

In this hydrogen vision, hydrogen is produced from all available feedstocks, including fossil fuel power plants that utilize Carbon-Capture technologies The hydrogen that is delivered to the filling station has no memory – it may have come from any of

the available feedstocks Yet, it is delivered to the grid, fuel cell, or vehicle in a standardized form, ensuring a consistent, robust hydrogen infrastructure throughout the world

The concept of sustainable energy with hydrogen as a key component is one that is embraced all over the world [38] Even in countries where hydrogen demonstrations are not yet as prevalent as they are in North America, Germany, and Japan, we are seeing promising advanced research results Scientists at Korea ’s S&P Energy Research Institute, for example, are working on chemical

processes for manufacturing hydrogen that can reduce the cost of producing hydrogen by 20 –30 times [39] And in the last 3 years, India formed a hydrogen association [40] and installed its first hydrogen fuel-dispensing bunk [41] In addition, the first hydrogen highway opened in Norway in 2009 [42]

4.14.6 From Here to There

To appreciate the potential of hydrogen energy, it is important to understand from the beginning The starting point for a transition that includes abundant clean hydrogen is where we are today Presently, there is a robust electricity network and fossil fuel infrastructure Electricity is made predominantly from coal and nuclear feedstocks, with a growing portion coming from a variety

of renewable energy technologies Supporters for hydrogen energy point out that as power production in general moves away from fossil fuels, the amount of hydrogen produced from clean resources will also grow Renewable resources will become the dominating energy source and renewable electricity will require new energy storage capacities [43] In this way, the carbon footprint

of hydrogen tracks the carbon footprint of electricity

Figure 6 shows a home scenario where the homeowner is using renewable energy for electricity and generating hydrogen gas for home appliances as well as the family car

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Hydropower Thermal solar

Wind turbine

Biomass

PV plant

H2

Power generation Plant

H2 production plant

H2

CO2

Fuel cell plant

Filling station

Natural gas

HYDROGEN

VISION Future Perspective on Hydrogen and Fuel Cells

Figure 5 Vision of a hydrogen/electric energy scenario, used with permission from ENEA Reproduced with permission from ENEA (2010) Vision of a Hydrogen/Electric Energy Scenario Rome, Italy: ENEA [37]

Figure 6 Hydrogen powered home used with permission from ITM Power Reproduced with permission from ITM Power (2010) Hydrogen Powered Home Sheffield, UK: ITM Power [44]

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In this scenario, hydrogen again plays the role of energy buffer with intermittent renewable resources In addition, it allows for a separate stream of gaseous energy, suitable for home appliances and vehicles

4.14.7 Conclusions

Hydrogen will have an important role to play in decarbonized transport and electricity generation, as part of a mix that includes a range of other technologies (e.g., biofuel, BEVs, renewable resources, nuclear, and fossil fuel with CCS) (Orion Innovations [45] )

A major decarbonization problem will be heat, in particular season peak loads Such loads may benefit from hydrogen, which is commercially more attractive over longer-term storage

The use of hydrogen energy offers benefits (United Kingdom Hydrogen Association [17] ) at the large scale, such as hydrogen from precombustion CCS, off-peak and grid balancing of national grid electricity, storage and supply of low-carbon energy for heat, and particularly transport applications, as well as at the small scale, such as community and distributed systems utilizing wind, tidal, wave, photovoltaic, and other renewable resources with hydrogen fuel cell systems, standby and mobile, and auxiliary power, just to name a few Hydrogen can contribute by acting as an energy store to balance supply and demand, in a similar manner to batteries with electricity but at a lower storage cost; and providing an energy storage medium or a transport fuel as a sidestream from precombustion CCS power stations

Hydrogen is available today from refinery gasifiers with a wide range of inputs, natural gas, biogas or waste, and electrolysis of water at overall efficiencies ranging from 50% to 70% The hydrogen can already be made in large centralized plants or in smaller distributed units located close to refueling requirements

Construction of a hydrogen infrastructure will follow demand, under normal commercial terms However, like recharging points, the first refueling stations do need deployment support

Improvements in utilization of renewable resources and hydrogen, as well as in system efficiencies will make these technologies commercially attractive over a wider range of applications

Electrolytic hydrogen is an embedded solution and will track the carbon footprint of the grid and the adoption of embedded and off-grid renewable resources

References

[1] http://www.merriam-webster.com/dictionary/holistic (accessed 19 October 2011)

[2] Gammon R (2010) Dispatchability Versus Sustainability Loughborough Leicestershire, UK: Bryte-Energy Limited

[3] U.S Census Bureau (2009) International data base estimates updated December 2009 (accessed 21 January 2010)

[4] Haub C (2008) 2008 World population data sheet Population Reference Bureau

[5] Haub C (2007) 2007 World population data sheet, 2006 estimate Population Reference Bureau

[8] Haub C (2002) How many people have ever lived on earth? Population Today 30(8): 3–4 (Estimates prior to 2002)

[9] Haub C (1995) How many people have ever lived on earth? Population Today 23(2): 5–6

[10] 1950–2050 estimates (only medium variants shown): World Population Prospects: The 2008 Revision United Nations Department of Economic and Social Affairs, Population Division

[11] Estimates prior to 1950: The World at Six Billion, 1999 United Nations Department of Economic and Social Affairs, Population Division

[12] Mayerowitz S (2010) America’s most congested highways and roads ABC News, 25 February http://abcnews.go.com/Travel/traffic-delays-americas-congested-highways roads/story?id=9932888

[13] Fuel cell transit bus evaluations, joint evaluation plan for the U.S Department of Energy and the Federal Transit Administration Technical Report NREL/TP-5600-49342-1, November 2010

[14] Greater London authority press release: Mayor unveils hydrogen bus fleet for the capital, 10 December 2010

[15] Hydrogen taxis for London roads from 2012 Taxi Insurance Cost Auto News, 22 July 2011

[16] Motor trend, Tokyo testing: Toyota rolls out hydrogen fuel cell taxis Donny Nordlicht, 31 January 2011

[17] United Kingdom Hydrogen Association (2007) Policy priorities UKHFCA http://www.ukhfca.co.uk/wp-content/uploads/2011/03/policyPaper_adopted.pdf

[18] U.S Department of Energy (2002) A National Vision of America’s Transition to a Hydrogen Economy – To 2030 and Beyond Washington, DC: U.S Department of Energy

[19] Canadian Hydrogen Association (2007) Hydrogen Systems: The Canadian Opportunity for Greenhouse Trois Rivieres, Canada: Canadian Hydrogen Association [20] Roads2HyCom: Socio-economic conditions for fuel cell and hydrogen technology development, Roads2HyCom project, a deliverable of the European Commission Framework Six Program, January 2009

[21] National hydrogen energy roadmap: Path way for transition to hydrogen energy for India National Hydrogen Energy Board, Ministry of New and Renewable Energy, Government

of India, 2006

[22] Boscheck R (ed.) (2007) Energy Futures Palgrave Macmillan

[23] World commission on environment and development, our common future, Brundland, 1987

[24] INFORM, Harnessing hydrogen – The key to sustainable transportation, Cannon 1995

[25] Science and environment ‘Clean’ coal plants get go-ahead, BBC News, 3 September 2008 http://news.bbc.co.uk/1/hi/sci/tech/7584159.stm

[26] UK HFCA letter to Prof David MacKay, Chief Scientific Advisor to DECC http://www.ukhfca.co.uk/wp-content/uploads/2011/03/Meeting-Prof-MacKay-Follow-up-Letter-final pdf (accessed March 2011)

[27] Doggett S (2009) 9 major automakers sign letter agreeing to develop and launch fuel-cell vehicles blogs.edmunds.com

[28] Ludwig-Bölkow-Systemtechnik GmbH and TÜV SÜD, Hydrogen filling stations worldwide – Overview http://www.h2stations.org/ (accessed 19 October 2011)

[29] Fuel Cell Today (2008) ITM Power Launches Hydrogen Home Refueller London, UK: Fuel Cell Today

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[30] IEA/IPHE Workshop: Building the Hydrogen Economy: Enabling Infrastructure Development: Transition Scenario for Hydrogen Infrastructure for Fuel Cell Vehicles in Japan; Mitsubishi, 11 July 2007

[31] Fuel cell hybrid electric vehicles: Training module 8, College of the Desert, December 2001 http://www1.eere.energy.gov/hydrogenandfuelcells/tech_validation/pdfs/fcm08r0 pdf (accessed 19 October 2011)

[32] Harrison KW, et al (2009) The wind-to-hydrogen project: Operational experience, performance testing, and systems integration Technical Report NREL/TP-550-44082, March

2009

[33] Bossel U, Eliasson B, and Taylor G (2004) The future of the hydrogen economy: Bright or bleak? 15 April 2003 – Revised 28 October 2004

[34] Levene J, Kroposki B, and Sverdrup G (2006) Wind energy and production of hydrogen and electricity – Opportunities for renewable hydrogen – preprint National Renewable Energy Laboratory (accessed 20 October 2008)

[35] INFORM, Harnessing Hydrogen – The Key to Sustainable Transportation, Cannon, 1995

[36] Harrison K and Ramsden T (2010) NREL hydrogen and fuel cell technical highlights, NREL improves system efficiency and increases energy transfer with Wind2H2 project, enabling reduced cost electrolysis production http://www.nrel.gov/hydrogen/pdfs/48435.pdf

[37] ENEA (2010) Vision of a Hydrogen/Electric Energy Scenario Rome, Italy: ENEA

[38] Partnership for advancing the transition to hydrogen Annual Report on World Progress in Hydrogen Energy

[39] Korean research makes hydrogen manufacture 30 times cheaper http://gizmodo.com/5065847/korean-research-makes-hydrogen-manufacture-30-times-cheaper (accessed 19 October 2011)

[40] Inauguration of hydrogen association of India (HAI) on 16 December 2010 http://www.hai.org.in/past_events_2.html (accessed 19 October 2011)

[41] Hill K, Gasworld.com, hydrogen bunk means hydrogen cars for India 14 January 2009

[42] Navarro X (2009) Green car news, first hydrogen highway opened in Norway, 14 May 2009 http://green.autoblog.com/2009/05/14/first-hydrogen-highway-opened-in-norway/ (accessed 19 October 2011)

[43] Wurster R et al Energy infrastructure 21 role of hydrogen in addressing the challenges in the new global energy system

[44] ITM Power (2010) Hydrogen Powered Home Sheffield, UK: ITM Power

[45] Orion Innovations (2009) Hydrogen Future Study – HyFuture Glasgow, UK: The Scottish Hydrogen and Fuel Cell Association

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