To maintain current standards of living in developed economies and raise them in developing ones, the world is going to need a lot more power than it is now producing. The impact of growth in world population occurring in a period of decreasing fractional use of fossil fuels for energy production, accompanied by a significant increase in affluence resulting from globalization of the world economy, will be a huge growth in the demand for energy over the 21st century.
The increase of growth in world electrification over the period from 1980 through 2000 and forecast though 2030 show an estimated 2-fold increase in electric energy intensity resulting from an estimated 4-fold increase in electric energy consumption by a world population that will increase 2-fold over the 50-year period.
Given a worldwide intensive effort for energy conservation, the addition of 3 billion people on Earth, coupled with additional large future applications of electric energy intensive technologies, and further coupled with the reduction of fossil fuel combustion for generation of electricity and automotive transportation raise serious concern about the sustainability of worldwide energy supply.
"The scale of the energy problem is huge. In 2001, the world used 13.2 TW (1 terrawatt=10*12 watts) of energy. By 2050, it will need 28 TW. This increase need of 15 TW is not feasible using existing energy sources like oil, gas coal and nuclear."
However, the potential of solar energy is enormous and, on a practical basis is >600 TW. Photosynthesis alone can provide 90 TW of energy resources.
The sun delivers more energy to the earth in one hour than civilization currently uses from fossil fuels, nuclear power and all renewable energy sources combined in a year. This solar energy can be captured and stored directly in the chemical bonds of a material, or fuel, and then used when needed. These chemical fuels, in which energy from the sun has deliberately been stored, are called solar fuels.
For more than 50 years, scientists have pursued the possibility of producing solar fuels in the laboratory. There are three approaches:
- Artificial photosynthesis in which systems made by human beings mimic the natural process;
- Natural photosynthesis; and
- Thermochemical approaches.
Significant progress has been made in producing two very important types of fuels:
- Hydrogen, which can be used as a transport fuel, and is an important feedstock for industry. Hydrogen can be produced by splitting water using sunlight.
- Carbon-based fuels such as methane or carbon monoxide (used with hydrogen as synthesis gas). These are key feedstocks for making a wide range of industrial products including fertilizers.
The goal is to a transition to a hydrogen-based economy based on renewable energy sources, mainly solar. The main barriers to a transition to hydrogen are the lack of development of technologies for hydrogen production, storage, transport, and distribution, and high costs compared with the current system.
The report is spanning over 224 pages and includes 74 figures and 40 tables.
Rather than seeing hydrogen as the exclusive fuel for the future, the specific roles to which it is uniquely suited in each major sector within an overall sustainable energy strategy need to be identified. With this approach, it is expected that hydrogen would still play a substantive and crucial role, but a role in concert rather than competition with that of electricity and technologies such as battery electric vehicles and a variety of shorter-term energy storage options for grid power.
The potential resource constraints in a hydrogen economy based on renewable energy sources have been investigated. It is estimated that the primary energy requirements of a global economy in 2050 that were 2.5 times those in 2005 could be met entirely from potentially collectable solar radiation (80% of the total supply), wind power (15%) and other renewables (5%).
The result would be no need for nuclear power or coal-fired power.
Hundreds of organizations are currently doing scientific research on solar fuels and artificial photosynthesis. A dozen European research partners, for example, form the Solar-H network, supported by the European Union. The US Dept. of Energy (DOE) Joint Center for Artificial Photosynthesis (JCAP), led by the California Institute of Technology (Caltech) and Lawrence Berkeley National Laboratory, has $122 million over 5 years to build a solar fuel system. Caltech and the Massachusetts Institute of Technology have a large National Science Foundation (NSF) grant to improve photon capture and catalyst efficiency, while several Energy Frontier Research Centers funded by the US DOE are focused on Global Artificial Photosynthesis (GAP)-related endeavors. Japan has established an Artificial Photosynthesis Group, based on the Catalysis Research Centre, Hokkaido University.
Hydrogen currently is produced via steam methane reforming (SMR), which is the commercial process of choice, since it has the lowest production costs of around $1.00/kg H2. The ultimate goal is to produce hydrogen without SMR.
The hydrogen market today is estimated at approximately USD35.9 billion. By 2023, it will be worth over USD55.2 billion. Making cleaner petroleum fuels in refineries is currently the biggest application for hydrogen, followed by steel and chemicals.
However, large-scale production of hydrogen via solar fuels would increase the available market into the trillions of dollars and could result in a large-scale reduction in the use of petroleum fuels. Global petroleum production in 2012 is estimated at approximately 4.5 billion tonnes, worth USD3.5 trillion.
The world vehicle fleet in 2000 was 700 million and may possibly reach 1500 million by 2050. Replacement of fossil fuels by hydrogen would require production of about 260 billion kg/year.
Four companies now control the global, outsourced hydrogen market. Air Liquide is estimated to be the leading supplier in 2012 with a 37% market share. It was followed by Air Products (23%), Linde (19%) and Praxair (16%). Another 190 companies have been identified as participants in the hydrogen industry.
This report is focuses on hydrogen produced by solar fuels. It provides an in-depth look at:
- Solar fuel technologies including photovoltaic artificial photosynthesis, photoelectrochemical, photobiological and concentrated solar thermal.
- Hydrogen as a fuel and energy carrier and its production by steam reforming and renewable technologies.
- Hydrogen, the future of clean energy, and the need for huge amounts of power in the 21st century.
- Fuel cell technologies, which use hydrogen to electrochemically convert chemical energy into electrical energy.
- Current and forecasted demand for hydrogen and fuel cells.
- Market drivers, applications and economics.
- Key strategic issues.
- Major opportunities.
- Competitive landscape.
- Leading industry players and researchers.
