Energy Systems With Renewable Hydrogen Compared to Direct ... PDF... · electric vehicle will not be further developed to a feasibly wide-spread application for transportation service

WHEC 16 / 13-16 June 2006 – Lyon France

Energy Systems With Renewable Hydrogen Compared to Direct Use of Renewable Energy in Austria

Gerfried Jungmeiera, Kurt Könighofera, Josef Spitzera, R. Haasb, A. Ajanovicb

aJoanneum Research, Elisabethstrasse 5, A-8010 Graz, AUSTRIA; [email protected] University Vienna, Energy Economic Group, Vienna, Austria; [email protected]

ABSTRACT:

The current Austrian energy system has a renewable energy share of 20% - 11% hydropower and 9 % biomass - of total primary energy consumption. Whereas a possible future introduction of renewable hydrogen must be seen in the context of current energy policies in Austria e.g. increase of energy efficiency and use of renewable energy, reduction of greenhouse gas emissions. The aim of the research project is a life cycle based comparison of energy systems with renewable hydrogen from hydropower, wind, photovoltaic and biomass compared to the direct use of renewable energy for combined heat and power applications and transportation services. In particular this paper focuses on the main question, if renewable energy should be used directly or indirectly via renewable hydrogen. The assessment is based on a life cycle approach to analyse the energy efficiency, the material demand, the greenhouse gas emissions and economic aspects e.g. energy costs and some qualitative aspects e.g. energy service. The overall comparison of the considered energy systems for transportation service and combined heat and electricity application shows, that renewable hydrogen might be beneficial mainly for transportation services, if the electric vehicle will not be further developed to a feasibly wide-spread application for transportation service in future. For combined heat and electricity production there is no advantage of renewable hydrogen versus the direct use of renewable energy. Conclusions for Austria are therefore: 1) renewable hydrogen is an interesting energy carrier and might play an important role in a future sustainable Austrian energy system; 2) renewable hydrogen applications look most promising in the transportation sector; 3) renewable hydrogen applications will be of low importance for combined heat and electricity applications, as existing technologies for direct use of renewable energy for heat and electricity are well developed and very efficient; 4) In a future “100% renewable energy scenario” 63 PJ/a renewable hydrogen from hydro and wind seem possible in Austria.

KEYWORDS : renewable hydrogen, life cycle assessment, transportation sector, combined heat and electricity production.

1 Motivation

Today about 520 billions Nm³ of hydrogen are produced worldwide mainly as raw chemical material and for metal industry. This amount has an energy content of about 5.700 PJ, (for comparison, the Austrian final energy consumption is about 1,000 PJ/a). Hydrogen can be produced in different processes using fossil or renewable energy. As energy carrier hydrogen can be used in many different ways: hydrogen can be stored, transported and used for the production of electricity, heat and transportation services. International R&D activities are under way to analyse hydrogen technologies for different applications, cost, potentials and market implementation strategies the technical with the aim to describe the possible role of hydrogen in a future energy system. The motivation for these activities is the vision of a global hydrogen economy, as hydrogen is seen as one of the cleanest energy carriers in end-use applications, if the hydrogen is produced with renewable energy (“renewable hydrogen”). Therefore, this study concentrates on the production of hydrogen from renewable energy sources.

IntroductionHydrogen is a flexible energy carrier that is able to provide different kind of energy services. The main future wide spread applications for hydrogen are seen in the transportation sector and in the stationary combined heat and electricity production in fuel cells. An assessment for hydrogen applications for the other sectors, heat and stationary mechanical energy production, was already made in a previous study [1].

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The European Commission has developed a future vision of a possible hydrogen energy future (Figure 1), where hydrogen might play a major role as energy carrier for different energy services. To initiate current activities a skeleton proposal for European hydrogen and fuel cell roadmap was developed (Figure 2). This European roadmap is also guidance for national activities in Austria towards hydrogen as energy carrier. Since in the medium- and long-term perspective the use of sustainable hydrogen is the main challenge, the main focus on this assessment lies on the use of renewably produced hydrogen from hydro power, wind, photovoltaic and biomass. The current Austrian energy system has already a high amount of renewable energy (Figure 3) characterised by the following figures:

- 11% hydropower of primary energy consumption- 75% hydropower in electricity sector- 9% biomass of primary energy consumption- 20% biomass in heating sector- 83% energy efficiency from primary energy (1,162 PJ/a) to final energy (965 PJ/a)- 51% overall energy efficiency (1,162 PJ/a primary energy, 591 PJ useful energy).

Figure 1 : Hydrogen Energy and Fuel cells – a vision of our future [2]

Figure 2 : Skeleton proposal for a European hydrogen and fuel cell roadmap [2]

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0

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400

600

800

1000

1200

1400

primary energy supply final energy consumptionAus

tria

n en

ergy

con

sum

ptio

n [P

J/a]

oil natural gas coal biomass hydropower others electricity district heat

1,162

965

mechanical use

10%

process heat21%

space heat36%

mobility30%

lighting, IT3%

Figure 3 : The Austrian Energy System (derived from [3])

The introduction of renewable hydrogen must be seen in the context of current energy policies in Austria (and Europe), which is lead by the following principles

- Reduction of energy consumption- Increasing of energy efficiency- (Further) Increase of renewable energy- Reduction of greenhouse gas emissions- Reduction of air pollutants in cities (e.g. PM10, NOx)

So far the perspectives for renewable hydrogen in the Austrian energy system are seen in the transportation sector as main application and for stationary combined heat and power production as a possible further application. Transportation counts for about 30% (293 PJ), process heat for 21% (205 PJ) and space heat for 36% (339 PJ) of the total annual final energy consumption of 965 PJ. The annual demand of electricity is about 190 PJ/a, corresponding to 20% of 965 PJ/a final energy consumption.

2 Goal and scope

The aim of this paper is to analyse under which conditions renewable hydrogen might be an energy carrier of tomorrow in Austria. The advantages and disadvantages of renewable hydrogen energy systems are compared to other energy systems by an assessment of technologic, economic, environmental and social aspects. The focus is on the production methods of producing renewable hydrogen and where and how renewable hydrogen should be used. The following technologies to produce renewable hydrogen are considered: gasification of wood, steam reforming of biogas made of manure and maize silage, electrolysis with electricity from hydro, wind and photovoltaic power. The assessment of the energy systems with renewable hydrogen is based on the seven principles of sustainable technology development from the program „Sustainable economy“ of the Austrian Ministry of Transportation, Innovation and Technology (BMVIT), to identify possible advantages of using renewable energy via the production of hydrogen for heat, electricity and transportation services. The results should outline possible additional opportunities for applications of renewable energy that could be made accessible via renewable hydrogen.

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Based on the results of the most interesting future perspectives of renewable hydrogen in Austria, possible Austrian demonstration projects with renewable hydrogen were identified, in which an efficient and flexible energy system based on hydrogen from renewable energy might be demonstrated. The identification of hydrogen energy system should demonstrate the future possibilities and the relevance of hydrogen as energy carrier in a future sustainable Austrian energy system.

The focus of the study lies on the assessment of technologies and components for the production of hydrogen with renewable energy and the hydrogen use (incl. transport and storage) in transportation sector as “alternative fuel” and – as far as feasible – for the combined electricity and heat production in the residential sector. The current state of technology (year 2005) and the future possible state of technology (year 2050) are considered. The reference energy systems considered are the direct use of renewable energy (hydro, wind, photovoltaic power, biomass incl. biogas) for electricity and heat and transportation biofuels and the fossil energy systems using natural gas and oil. To account for the specific characteristics of these energy systems a total of 31 energy systems with renewable hydrogen and 32 reference energy systems – 21 with the direct use of renewable energy and 11 with fossil energy – are analysed (Figure 5).

Since in the mid- and long-term perspective the use of sustainable hydrogen is the main challenge, the main focus on this assessment lies on the use of renewably produced hydrogen from hydro power, wind, photovoltaic and biomass, as the most promising domestic resources of renewable energy in Austria.

This assessment concentrates on the possible need for significant or large amount of renewable hydrogen applications in the Austrian energy system; e.g. more than > 5 PJ/a, which means excluding niche markets. As the increase of renewable energy is an important driver for current and future energy policies, this analysis concentrates on the main question, if renewable energy should be used directly (e.g. combustion of biomass) or via electricity for heat and stationary use or if renewable energy should be converted into renewable hydrogen (Figure 4).

The assessment is based on life cycle approach to analyse the energy efficiency (respectively the cumulated primary energy demand), the material demand, the area demand and the greenhouse gas emissions. A comparison for the supply of transportation services and combined heat and power with renewable hydrogen to the direct use of renewable energy (e.g. renewable electricity, biomass combustion) is made. The assessment focuses on possible hydrogen applications in Austria, which are starting to be implemented around the year 2020.

In Figure 5 the considered systems to produce and use renewable hydrogen „Ren-H2“ are shown. Biomass covers wood chips from forest residues and biogas from maize silage. The hydrogen from wood chips is produced via gasification and from biogas via steam reforming. The renewable hydrogen from renewable electricity is produced via electrolyses.

Direct use ofrenewable energy

“Ren-energy”

Indirect use of renewableenergy via hydrogen

“Ren-H2”


“Ren-energy”

Indirect use of renewableenergy via hydrogen

“Ren-H2”

Figure 4 : Comparison of direct use of renewable energy or indirect use via renewable hydrogen

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Ren-H2

Biomass

Gasification andH2-production

Fermentation andsteam reforming

Biomass

Gasification andH2-production

Fermentation andsteam reforming

Hydro power Wind Solar

Electrolysis

Hydro power Wind Solar

Electrolysis

TransportationStorage,

CompressionLiquefaction

Transportation Electricity&heat

TransportationStorage,

CompressionLiquefaction

Transportation Electricity&heat

Figure 5 : Systems considered to produce and use renewable hydrogen „Ren-H2“

3 Methodology

For the identification possible future role of hydrogen in the energy system the assessment is made based on the seven principles of sustainable technology development from the program „Sustainable Economy“ of the Austrian Ministry of Transportation, Innovation and Technology (BMVIT). These principles are used for the comparison of the energy systems based on renewable hydrogen with energy systems based on the direct use of renewable energy and fossil energy. A qualitative assessment is done for the following three principles:1. „Principle of energy service and consumer needs“, 2. „Principle of adjusting, flexibility, adaptability and learning ability“ and3. „Principle of error and risk tolerance“

A quantitative assessment is done for the following four principles:

1. „Principle of using renewable resources“, e.g. greenhouse gas emission of energy service g CO2-eq/km2. „Principle of efficiency“, e.g. cumulated primary energy demand per energy service kWh/km3. „Principle of recyling capability“, e.g. cumulated non-recyling material demand of energy service g/km4. „Principle of securing employment, income and quality of life “, e.g. cost of energy service €/km.

The assessment of energy systems based on renewable hydrogen and the comparison to the reference energy systems is done on the basis of a life cycle assessment (LCA). This approach assures, that all elements from the extraction of primary energy to the supply of an energy service are included, which is necessary for the identification of a future possible role in the energy system. The main elements of an energy system based on renewable hydrogen starting with the renewable energy source are

- Production: e.g. gasification of wood, electrolysis with green electricity- Processing: e.g. compression, liquefaction- Distribution: e.g. truck, pipeline, intermediate storage- Storage and delivery: e.g. storage of compressed hydrogen, dispenser at filling station - Conversion to useful energy: e.g. fuel cell or internal combustion engine.

One main issue of comparing energy systems is the possibility to store energy in order to balance the differences of supply of renewable energy and the demand of transportation service or combined heat&electricity. In general hydrogen is seen as a feasible energy storage for renewable energy. In the assessment here different storage systems for renewable energy are considered (Figure 6). At the supply side the storage of biomass and hydropower, via hydro storage power systems are comparable to hydrogen. The storage of electricity from wind and solar power is more difficult, especially for consideration of stand

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alone systems. But as in this assessment large volume application and use of renewable energy is analysed, it is assumed, that the Austrian energy system e.g. the total electricity system allows or will allow combining storage possibilities of hydropower and biomass as back up systems for electricity from wind and solar power. In addition it is possible at the consumer site that heat is stored in heat storage systems, hot water boiler or steam, and if necessary small amounts of electricity might also be stored ion battery systems. These storage systems are used in the energy system comparison of direct and indirect use of renewable energy.

For this project an advisory board „Renewable hydrogen in Austria“ was established, which met three times – at the start, evaluating of draft results in the middle and at the end of the project. In this advisory board the Austrian hydrogen activities were monitored, discussed and interlinked e.g. Hydrogen Centre Austria (HyCentA) with representatives from industry, administration and research. The aim was to identify possible future collaboration activities, which are necessary for the future challenges of renewable hydrogen in Austria and to analyse and discuss the feasibility for the realisation of demonstration projects with renewable hydrogen.

The main results are summarized and conclusions are made.

On-site at the consumer hydrogen biomass heat storage (hot water, steam) battery mechanical storage

On-site at the consumer hydrogen biomass heat storage (hot water, steam) battery mechanical storage

StorageSystems

Renewable Production Energy System hydro power storage system mix of different renewable electricity systems backup with biomass and/or natural gas hydrogen

Renewable Production Energy System hydro power storage system mix of different renewable electricity systems backup with biomass and/or natural gas hydrogen

Off-site at supply side

Stand alone renew-able energy plant hydrogen biomass water

Off-site at supply side

Stand alone renew-able energy plant hydrogen biomass water

Figure 6 : Renewable energy storage for hydrogen, electricity and heat

4 Example

In the following example the assessment procedure is described.

4.1 Description of example

In Figure 7 the three process chains for transportation systems in 2050 are shown: one for the renewable hydrogen energy system and the two reference energy systems:

- Ren-H2 FC vehicle: Renewable hydrogen energy system (indirect use of renewable energy) - fuel cell vehicle with gaseous hydrogen (700 bar) made from hydro power

- Ren-electric vehicle: Direct use of renewable energy - electric vehicle with battery, electric engine and electricity from hydro power

- Diesel ICE vehicle: Fossil energy system - vehicle with a diesel internal combustion engine.For these three systems the life cycle assessment is made to quantify and qualify the seven principles of sustainable technology development.

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Hydro power

Electricity grid

Pressurised electrolysis *)

H2-vehicle withPEM fuel cell

700 bar H2-storage

Compression 880 bar

Ren-electricity

Ren-H2 30bar

*) with oxygene and heat use


Transport

Ren-H2energy system

Fossilenergy system

Reference Energy Systems

Oil extraction

Transport

Refinery

Diesel-vehicle withInternal

combustion engine

Distribution

Raw oil

Diesel

Hydro power

Electricity grid

Electric vehiclewith battery

Ren-electricity

Figure 7 : Process chain for fuel cell vehicle with gaseous hydrogen (700 bar) from hydro power, electric vehicle with battery and diesel vehicle with internal combustion engine

4.2 Principle of using renewable resources - greenhouse gas emissions

As an example for the principle of using renewable resources the greenhouse gas emissions are analysed in a life cycle assessment. As shown in Figure 8, the greenhouse gas emissions for

- technology 2005 “Ren-H2 FC vehicle” are 66.4 g CO2-eq/km, of “Ren-electric vehicle” 31.3 g CO2-eq/km and “Diesel ICE vehicle” 206 g CO2-eq/km;

- technology 2050 of “Ren-H2 FC vehicle” are 34.5 g CO2-eq/km, of “Ren-electric vehicle” 16.8 g CO2-eq/km and “Diesel ICE vehicle” 138 g CO2-eq/km.

The diesel vehicle has the highest and the electric vehicle the lowest greenhouse gas emissions. A main part of the greenhouse gas emissions derives from the production of the PEM fuel cell, as platinum is associated with a significant CO2-eq emission.

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206

31,3

66,4

138

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34,5

0 50 100 150 200 250

Diesel ICE vehicle

Ren-electricvehicle

Ren-H2 FC-vehicle

Greenhouse gas emissions [g CO2-eq/km]

Technology 2050Technology 2005

Figure 8 : Greenhouse gas emissions of fuel cell vehicle with gaseous hydrogen (700 bar) from hydro power, electric vehicle with battery and diesel vehicle with internal combustion engine

4.3 Principle of recycling capability - material demand

As an example for the principle of recycling capability the cumulated non-recycling material demand is quantified in a life cycle assessment. As shown in Figure 9, the cumulated material demand for

- technology 2005 “Ren-H2 FC vehicle” is 57.1 g/km, of “Ren-electric vehicle” 24.6 g/km and “Diesel ICE vehicle” 12 g/km;

- technology 2050 of “Ren-H2 FC vehicle” are 30.7 g CO2-eq/km, of “Ren-electric vehicle” 13.3 g/km and “Diesel ICE vehicle” 6.9 g/km.

The diesel vehicle has the lowest and the electric vehicle the highest demand of non-recycling material demand. A main part of the high cumulated material demand of the Ren-H2 FC vehicle derives from the platinum production of the PEM fuel cell.

12

24,6

57,1

6,9

13,3

30,7

0 10 20 30 40 50 60

Diesel ICE vehicle

Ren-electricvehicle

Ren-H2 FC-vehicle

Cumulated non-recycling material demand [g/km]

Technology 2050Technology 2005

Figure 9 : Cumulated non-recycling material demand of fuel cell vehicle with gaseous hydrogen (700 bar) from hydro power, electric vehicle with battery and diesel vehicle with internal combustion engine

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4.4 Principle of energy service and consumer needs

The principle of service and user orientation is qualified by disaggregating it to different aspects, e.g. driving range, refuelling time, that are shown in Figure 10. These aspects are assessed according to the following system:

- 0....fulfilled- 1....fulfilled well- 2....fulfilled very well

With technology 2005 the “Ren-H2 FC vehicle” has with 75% the highest degree of fulfilment and the “Ren-electric vehicle” with 40% the lowest, the “Diesel ICE vehicle” has 75%. Referring to the expected further technological development with future technology 2050 the “Ren-H2 FC vehicle” might have with 95% the highest degree of fulfilment and the “Ren-electric vehicle” with 75% the lowest, the “Diesel ICE vehicle” might have 95%.

Principle of energy service and consumer needs

assessment of vehicle

Ren-H2 FC-

vehicle

Ren-electric vehicle

Diesel ICE vehicle

Ren-H2 FC-

vehicle


Diesel ICE vehicle

driving range 1 0 2 1 0 2local emissions (z.B. CxHy, NOx, PM) 2 2 0 2 2 1noise 2 2 0 2 2 2propulsion power 1 0 2 2 1 2acceleration I (0 - 30 km/h) 2 2 1 2 2 2acceleration II (0 - 100 km/h) 1 0 1 2 1 2space offer 2 1 2 2 2 2thermal comfort in vehicle 2 0 2 2 1 2refueling time 1 0 2 2 1 2maintenance and service comfort 0 1 2 2 2 2passive vehicle safty 2 1 2 2 2 2overall assessment (max 22) 16 9 16 21 16 21degree of fulfilment (rounded) 75% 40% 75% 95% 75% 95%

2005 2050

Legend:0.....fulfilled1....fulfilled well2....fulfilled very well

Figure 10 : Qualitative assessment of the principle of energy service and consumer needs of the considered vehicles

4.5 Overall assessment of example

In Figure 11 the assessment according to the 7 principles of sustainable technology is shown for the example. Because of the higher efficiency, the electric vehicle with renewable electricity is better concerning the greenhouse gas emissions, the total and fossil primary energy consumption and the material demand compared to the vehicle with renewable hydrogen. The diesel vehicle shows the highest greenhouse gas emissions and the highest fossil energy consumption, but the lowest material demand. The vehicle with renewable hydrogen shows the highest transportation service costs.Therefore the electric vehicle with renewable electricity fulfils the “Principle of using renewable resources”, “Principle of efficiency” and “Principle of recycling capability” very well. The “Principle of service and user orientation“ is better fulfilled by the vehicle with renewable hydrogen compared to the electric vehicle. The hydrogen vehicle fulfils the „Principle of adjusting, flexibility, adaptability and learning ability“ currently equally and in future better than the electric vehicle. For the „Principle of error and risk tolerance“ it is assumed for all vehicles, that safety and security standards, rules and laws, are fulfilled, otherwise the technologies will not be on the market. The „Principle of securing employment, income and life quality“ will be fulfilled by vehicle with renewable hydrogen and with renewable electricity, e.g. the same costs of transportation service, to ensure, that the technology will be on the market.

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The 7 principles of sustainable technology development Ren-H2

FC-vehicle


Diesel vehicle

Ren-H2 FC-

vehicle


Diesel vehicle

1. Principle of energy service and consumer needs [qualitative] 1) 75% 40% 75% 95% 75% 95%2. Principle of using renewable resources [g CO2-eq/km] 66,4 31,3 206 34,5 16,8 1383. Principle of efficiency [kWh/km] (bzw. kWhfossil/km) 0.74

(0.15)0.37

(0.07)0.73

(0.72)0.55

(0.08)0.28

(0.04)0.49

(0.48)4. Principle of recycling capability gnicht recyclingfähig/km] 57,1 24,6 12 30,7 13,3 6,9

5. Principle of adjusting, flexibility, adaptability and learning ability [qualitative] 1) 80% 80% 30% 100% 90% 50%

6. Principle of error and risk tolerance [qualitative] 1), 2) 100% 100% 100% 100% 100% 100%

7. Principle of securing employment, income and quality of life [Euro/km, qualitative 2) 2,05 0,36 0,24 100% 100% 100%

1) degree of fullfillment [%]2) assumption for technology year 2050: principle must be fullfilled for the technology to enter the market

Technology 2005 Technology 2050

Figure 11 : Assessment according to the 7 principles of sustainable technology development for transportation services, example vehicles with renewable hydrogen, renewable electricity and diesel

5 Results

The results of the assessment of all considered energy systems with renewable hydrogen compared to the direct use of renewable energy and fossil energy are summarized as follows, whereby the different application options for renewable hydrogen are addressed.- Electricity and heat: The technologies for the direct use of renewable energy for heat and electricity are

highly developed and energy efficient. They fulfil the 7 principles of sustainable technology development significantly better than renewable hydrogen, especially in terms of energy efficiency, greenhouse gas emissions and costs.

- Transport: Renewable hydrogen and electric vehicles might contribute to the reduction of greenhouse gas emissions and the use of fossil energy by substituting gasoline and diesel vehicles. Electric vehicles are under development and are available for specific applications only. Hydrogen vehicles are under development too and concept vehicles are tested. Vehicles with renewable hydrogen show higher greenhouse gas emissions and a lower energy efficiency that electric vehicle with renewable electricity.

- Production: In the short to medium-term perspective the production of renewable hydrogen with electricity from hydro and wind power is more attractive than the production from biomass. Only in a long-term perspective renewable hydrogen from biomass might become relevant, because heat, electricity and biofuels produced from biomass fulfill the 7 principles of sustainable technology development significantly better. The use of the by-products oxygen and heat from electrolysis may become interesting. The hydrogen production via steam reforming of natural gas seems only of interest in a transition period to renewable hydrogen, if the CO2 is sequestered, mainly because of the necessary greenhouse gas reduction in Austria in the coming years.

- Energy storage: The storage capabilities of biomass and pumping storage hydro power stations prove to be similar to renewable hydrogen. The storage of so called “excess“ renewable electricity from wind and photovoltaic power in combination with the production and use of renewable hydrogen as transportation fuel might be of interest under specific circumstances.

- Infrastructure for transportation sector: In short to medium-term perspective the „on-site electrolysis with renewable electricity and the use of gaseous hydrogen at the filling station might be interesting. The filling station might be at the same location as the production of renewable electricity or the renewable electricity is transported with the electricity grid to the filling station. For this purpose a powerful electricity grid is necessary, whereby electrolysis and the storage of hydrogen could provide synergies for the load management, if the electrolysis is operated with “excess electricity” during low load periods. Liquid renewable hydrogen seems possible in medium-term perspective, but it needs big liquefiers (with a production capacity of more than 5 t/day) with the adequate infrastructure to supply and deliver renewable hydrogen.

- Vehicles: Hydrogen vehicles are under development and in demonstration stage („concept vehicles“). In a medium to long-term perspective the vehicle concepts with PEM fuel cells have the potential of a higher energy efficiency and lower or no emissions (“zero-emission”) compared to the internal combustion engine. The current status of technology development of a hydrogen internal combustion engine is higher that the Proton Exchange Membrane (PEM)-fuel cell with an electric engine. The internal combustion engine can also be operated in a bivalent mode with gasoline and renewable hydrogen, which might be of significant importance for the transition period to hydrogen as alternative fuel or the early market introduction. PEM-fuel cells need very clean hydrogen (V5.0).

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- Hydrogen storage in vehicles: Currently the storage of gaseous hydrogen at 350 bar is demonstrated in vehicles. In a medium-term perspective it is foreseen, that the storage at 700 bar seems technically feasibly. Also the liquid hydrogen storage in vehicles is demonstrated currently, which needs big liquefiers for production and the distribution infrastructure.

- Possible future role of renewable hydrogen: Under the scenario assumption, that an energy system using only Austrian domestic renewable energy sources may be realised, in which the final energy consumption in transportation sector is significantly reduced (from currently 293 PJ/a to 117 PJ/a), hydrogen from renewable electricity might about 65 PJ/a, which corresponds to about 12% of the total final energy consumption in this scenario of 503 PJ/a (currently 1,000 PJ/a).

6 Conclusions

The assessment, if anyway and under which conditions renewable hydrogen might be an energy carrier of tomorrow in Austria, is summarized in the following conclusions: 1. Electricity and heat: The stationary combined electricity and heat production with renewable hydrogen

might be successful in niche applications, but will not become an economic option.2. Transport: In a medium- to long-term perspective renewable hydrogen might be an interesting economic

option, if electric vehicle will not enter the market. 3. Production: Electrolysis with renewable electricity (in particular with the use of the by-products oxygen

and heat) might become an interesting option to produce renewable hydrogen in a medium-term perspective.

4. Storage of renewable electricity: In a medium-term perspective renewable hydrogen as energy storage might improve the grid integration of renewable electricity and become important for load management. But beside the electricity production from renewable hydrogen the use as a transportation fuel should be considered.

5. Infrastructure: The use of the existing electricity grid and the “on-site” production of gaseous renewable hydrogen at the filling station might become an interesting option in short- to medium-term perspective.

6. Hydrogen vehicles: In the medium-term perspective hydrogen vehicles might be available on the market with (bivalent) internal combustion engines. In the long-term perspective the fuel cell vehicles will be used, but for this a successful technological development and a significant cost reduction is necessary.

7. Hydrogen storage in vehicles: In a short- to medium-term perspective the storage of gaseous hydrogen at 350 bar (increasing to 700 bar) will be an option. The storage of liquid renewable hydrogen at a temperature of minus 253 °C might become interesting in a long-term perspective, if big liquefiers and a suitable hydrogen infrastructure will be established.

8. Possible role in the energy system: In a future sustainable Austrian energy scenario, which is based on Austrian renewable energy only and has a significant lower final energy consumption for the same amount of energy services, hydrogen produced from renewable electricity might contribute about 65 PJ/a.

9. Austrian economy: From a national economic point of view, the introduction of a comprehensive renewable hydrogen economy is not to be expected in a short- to medium-term perspective, because the direct use of renewable energy to provide energy services is much cheaper.

10. R&D-Demand: To be able to use the long-term opportunities of renewable hydrogen as energy carrier, further R&D efforts are necessary, mainly the development of specific components of hydrogen technologies and the demonstration of an energy system based on renewable hydrogen. These R&D efforts should be linked closely to existing and upcoming international networks and activities.

Summing up, the medium- and long-term perspective of renewable hydrogen in a sustainable Austrian energy system is the supply of transportation services with vehicles, that use renewable gaseous hydrogen produced from renewable electricity from hydro and wind power. For the efficient use of the existing electricity grid infrastructure the electrolysis should take place at the filling station. In a short-term perspective vehicles with internal combustion engines using gaseous hydrogen have the most favourable conditions for market introduction, as gasoline can be used in a bivalent mode. Only after a further technological development that effects in significant cost reduction, fuel cell vehicles with gaseous renewable hydrogen will be used. To be able to use the medium- and long-term opportunities of renewable hydrogen further R&D efforts, demonstration activities of renewable hydrogen technologies are necessary already now. R&D activities should be done in a close linkage to existing and planned international networks e.g. European Hydrogen and Fuel Cell Technology Platform (HFP), IEA Hydrogen Implementing Agreement (HIA) and the International Partnership on Hydrogen Economy (IPHE). The following possible demonstration projects are

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recommended: renewable hydrogen from electrolysis with wind electricity, renewable hydrogen use in a refinery and demonstration of vehicles fuelled with renewable hydrogen.

7 References

This project was financed in the program “Energy Systems of Tomorrow” an initiative of the Austrian Ministry of Transportation, Innovation and Technology. All the results are documented in

Gerfried Jungmeier, Kurt Könighofer, Josef Spitzer, Lorenza Canella, Amela Ajanovic, Reinhard Haas, Nebojsa Nakicenovic: Wasserstoff aus erneuerbarer Energie in Österreich - Ein Energieträger der Zukunft?Renewable hydrogen in Austria: Future perspectives for the production and use of hydrogen from renewable energy in Austria with the identification of projects to demonstrate the role of renewable hydrogen in an efficient and flexible energy system, Graz, Austria 2006[1] Gerfried Jungmeier, Kurt Könighofer, Josef Spitzer: Assessment of renewable hydrogen applications for heat and stationary mechanical use; National Hydrogen Conference, Washington March/April 2005

[2] European Commission, Directorate-General for Research, Directorate-General for Energy and Transport, 2003[3] Energy flow in Austria 2000, Austrian Energy Agency, Vienna 2003

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Energy Systems With Renewable Hydrogen Compared to Direct ... PDF... · electric vehicle will not be further developed to a feasibly wide-spread application for transportation service