Today, after the coal and transferring from the oil eras, we are once again living through a period of profound transformation in the way h...
Today, after the coal and transferring from the oil eras, we are once again living through a period of profound transformation in the way humanity uses energy, both economically and socially. We are moving from the energy sources we used to use to new ones. The change is inevitable, and maintaining the natural environment we are used to requires a shift from non-renewable to renewable energy sources.
The current revolution in energy sources is disrupting many long-standing processes in the economy and creating many new ones. One promising area of change is the use of hydrogen in the transforming energy economy.
Hydrogen is an excellent energy source to protect the natural environment, and its use does not directly change the nature we live in. Hydrogen is an economically and technologically viable resource, easy to use and efficient energy source, as long as safety rules are respected. Elementary hydrogen is an efficient medium for high-density energy storage.
Currently, hydrogen is used as an energy source, mainly to fuel electric vehicles. In this field, there are many revolutionary promises of hydrogen powered transportation, but the adoption of hydrogen powered vehicles is still progressing quite slowly. Despite its benefits and promises, the penetration of the hydrogen energy economy is still a while away. The barrier to the adoption of hydrogen as an energy source, like other technologies that start out promising and then fail, is certainly that it is not being used where and how it is supposed to.
Facts about hydrogen:
Hydrogen is the most abundant element accessible from the Earth's surface, but it is virtually non-existent in nature in its elemental, directly usable form. Hydrogen is a component of water and hydrocarbons in a bonded state.
Hydrogen can be used in the energy economy in its elemental state, so hydrogen must be produced from its compounds in a technological process. Hydrogen can be produced from water in a simple and environmentally friendly way, using electricity and electrolysis, while taking into account the environmental considerations. The process requires significant amounts of electricity.
Hydrogen can still be produced efficiently from saturated hydrocarbons by chemical processes, with energy input, resulting in two types of product, both of which are useful commodities in the economy. The generated hydrogen can be used primarily in the energy economy, and the produced unsaturated hydrocarbons are essential commodities in the chemical industry. Both end products of the process are valuable, so hydrogen can be produced cost-effectively and economically from saturated hydrocarbons.
Elementary hydrogen is a low-density, flammable gas at room temperature. It can be transported efficiently over short distances by pipeline. It can be stored and transported over long distances efficiently in tanks at high pressure as gas or at very low temperatures as liquid.
In the energy sector, elemental hydrogen is converted into water by combining with oxygen from the atmosphere, releasing large amounts of energy. In practice, hydrogen is used efficiently and the energy released is produced in a form that is easily usable in so-called fuel cells, which generate electricity in a continuously operable way, producing water as a by-product. In fuel cells, the process of combining hydrogen and oxygen from the air, the opposite of electrolysis takes place in a highly efficient way,. The production of fuel cells requires advanced technology, but the technology is already available. Fuel cells can be produced economically in large quantities.
Having set out these relevant facts about hydrogen, where and how should hydrogen be used in the energy economy?
Currently, hydrogen is used as energy source, mainly as a fuel in electric cars. Hydrogen stored in high-pressure tanks in cars is converted into water in fuel cells to generate electricity, which drives the car using electric motors. Hydrogen-based fuel is environmentally friendly and, because of its high energy density, hydrogen offers a long range drive. However, there are also fundamental disadvantages associated with hydrogen fuel for vehicles:
1. High-pressure storage of fuel creates a risk of explosion in the event of an accident.
2. Fuel is gaseous and can easily leak dangerously as the vehicle wears out, so regular vehicle maintenance is crucial.
3. The technology of hydrogen refueling stations differs significantly from that of hydrocarbon refueling stations. The use of hydrogen as a fuel requires the construction of new fueling stations and entire refueling network. Although hydrogen as a fuel offers long range driving and therefore requires less frequent refueling, so in principle there is no need for a dense network of refueling stations, in practice a car owner does not want to travel a significant distance and spend a lot of time using sparsely located stations. The use of hydrogen in personal cars requires a dense network of refueling stations, which requires significant investment in the industry.
Compared to electric cars powered by electricity stored in batteries, hydrogen propulsion is not competitive, mainly because of the difficulty of practical recharging. Even if charging with electricity is currently slower and offers a shorter driving range, the electric grid for electric charging is available throughout the entire populated area and charging can be done just about anywhere.
Despite the obvious benefits, the expansion of the use of hydrogen as a fuel in passenger cars is not rational until an adequate hydrogen refueling network has been built.
However, the investment is risky because the operational risks of hydrogen propulsion remain, and the development of battery energy storage may overcome the practical disadvantages to hydrogen propulsion.
Where and how can hydrogen be used efficiently as an energy source? What is the feasibility of the hydrogen-based energy economy? Hydrogen in the energy economy seems to be practically applicable in two areas:
Hydrogen as a fuel for high-power electric engines:
Based on the above reasoning, hydrogen is not suitable as a fuel for passenger cars, but there is area where the disadvantages of using hydrogen as a fuel can be significantly reduced. This area is the operation of heavy duty engines with hydrogen propulsion capable of powering large vehicles moving on surface (trucks, buses, trains, ships).
1. Large vehicles size allows for safer positioning of hydrogen fuel tanks.
2. Owners of large vehicles are mostly companies, whose legal regulation is simpler than for private individuals. For companies, compulsory and regular maintenance is easier to impose.
3. Large vehicles typically follow a well-defined route between fixed stations. As hydrogen fuel allows a long range of travel, hydrogen refueling stations are only required at the terminals or along the route of large vehicles, at less frequent intervals. For large vehicles, the number of hydrogen fueling stations needed is orders of magnitude less and would be sufficient for efficient operation.
Hydrogen can be used efficiently as a fuel to run high-performance engines in heavy-duty vehicles.
Challenge: The task of the industrial manufacturing technology is to create a complete hydrogen propulsion system with fuel tank, fuel cell, high performance electric motor, which can operate as a performance based standard engine in large vehicles. In addition, a properly distributed hydrogen refueling network and a hydrogen transport system for supplying it between chemical plants converting saturated hydrocarbons and hydrogen refueling stations are also needed. Hydrogen-based electric power propulsion for ships will result in a significant reduction in environmental impact and emissions, and in addition for trains, it will eliminate the need for an expensive electrical power transmission system. The installation of hydrogen fueling stations for buses and trucks along their routes, for example alongside freeways, is sufficient.
Hydrogen as an energy storage tool:
Hydrogen is particularly suitable for storing electricity because of its high energy density and its direct applicability to electricity. Electricity production from renewable energy is highly unsteady. The wind does not always blow, the sun does not always shine. The biggest problem for renewable electricity generation is the efficient storage of electric energy. Solutions exist to store electricity, but they are either expensive and difficult to scale up, such as gravity or pressure-based energy storage, or the storage medium is not environmentally friendly and expensive, such as electrochemical energy storage in solid or liquid phase batteries.
Hydrogen-based technology can create a closed-system, continuous operation, long-life, easily scalable, easy to install, environmentally friendly, and low-cost electricity storage system. Electric energy can be stored by electrolysis to produce hydrogen with high efficiency and high energy density, and can be directly recovered as electricity in fuel cells with high efficiency on demand.
Hydrogen is a convenient way to store electrical energy.
Challenge: The task of the industrial production technology is to create a complete, fully enclosed, continuously operating, standardized system with hydrogen tank, fuel cell, electrolysis equipment, which can be directly connected to the electrical grid, and which allows a simple, scalable method of storing electrical energy in a modular system according to the storage needs from households to large industrial applications.
It makes sense to apply environmentally friendly and sustainable hydrogen technology economically in the energy economy in the two areas proposed. The technology is available, but the commercial intention towards it is required. However, the societal need and the economic and environmental benefits promise a rapid return of investment.
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