Hydrogen Industry

A hydrogen economy is a concept of an energy industry that uses mainly or exclusively hydrogen as an energy carrier. So far, a hydrogen economy has not been realized in any country on earth.

Like electricity, hydrogen is not a source of primary energy, but must first be obtained artificially and with energy losses from other energy sources (fossil, nuclear or renewable energies). Thus, a hydrogen economy is not automatically sustainable, but only as sustainable as the primary energy from which the hydrogen is produced. At present, this is largely done with hydrogen for use in the chemical industry on the basis of fossil fuels, Concepts for future hydrogen economies, on the other hand, mostly envisage the generation of hydrogen from renewable energies, which could make such a hydrogen economy emission-free.

While no classic state-of-the- art hydrogen economy is currently being pursued in many countries, there are plans to integrate hydrogen or hydrogen-derived fuels such as methane or methanol into the existing energy infrastructure as part of the energy transition and the expansion of renewable energies. An important role is played by the power-to-gas technology, which is assigned an important role as long-term storage.

The levels of an energy industry
The ideas are based on the implementation of hydrogen at all levels of the energy industry:

Development of required primary energy sources
Energy produce
Energy storage
Use of energy
Energy trading and distribution
Sales and billing
Ensuring security of supply
Each of these levels is technically researched and partially realized for hydrogen.

Production, storage, infrastructure
Today’s hydrogen is mainly produced (>90%) from fossil sources. Linking its centralized production to a fleet of light-duty fuel cell vehicles would require the siting and construction of a distribution infrastructure with large investment of capital. Further, the technological challenge of providing safe, energy-dense storage of hydrogen on board the vehicle must be overcome to provide sufficient range between fillups.

Methods of production
Molecular hydrogen is not available on Earth in convenient natural reservoirs. Most hydrogen in the lithosphere is bonded to oxygen in water. Manufacturing elemental hydrogen does require the consumption of a hydrogen carrier such as a fossil fuel or water. The former carrier consumes the fossil resource and produces carbon dioxide, but often requires no further energy input beyond the fossil fuel. Decomposing water, the latter carrier, requires electrical or heat input, generated from some primary energy source (fossil fuel, nuclear power or a renewable energy). Hydrogen can also be produced by refining the effluent from geothermal sources in the lithosphere. Hydrogen produced by zero emission renewable energy sources such as electrolysis of water using wind power, solar power, hydro power, wave power or tidal power is referred to as green hydrogen. Hydrogen produced by non-renewable energy sources may be referred to as brown hydrogen. Hydrogen produced as a waste by-product or industrial by-product is sometimes referred to as grey hydrogen.

Current production methods
Hydrogen is industrially produced from steam reforming, which uses fossil fuels such as natural gas, oil, or coal. The energy content of the produced hydrogen is less than the energy content of the original fuel, some of it being lost as excessive heat during production. Steam reforming leads to carbon dioxide emissions, in the same way as a car engine would do.

A small part (4% in 2006) is produced by electrolysis using electricity and water, consuming approximately 50 kilowatt-hours of electricity per kilogram of hydrogen produced.

Kværner-process
The Kværner-process or Kvaerner carbon black & hydrogen process (CB&H) is a method, developed in the 1980s by a Norwegian company of the same name, for the production of hydrogen from hydrocarbons (CnHm), such as methane, natural gas and biogas. Of the available energy of the feed, approximately 48% is contained in the hydrogen, 40% is contained in activated carbon and 10% in superheated steam.

Electrolysis of water
Hydrogen can be made via high pressure electrolysis, low pressure electrolysis of water, or a range of other emerging electrochemical processes such as high temperature electrolysis or carbon assisted electrolysis. However, current best processes for water electrolysis have an effective electrical efficiency of 70-80%, so that producing 1 kg of hydrogen (which has a specific energy of 143 MJ/kg or about 40 kWh/kg) requires 50–55 kWh of electricity. At an electricity cost of $0.06/kWh, as set out in the Department of Energy hydrogen production targets for 2015, the hydrogen cost is $3/kg. With the range of natural gas prices from 2016 as shown in the graph (Hydrogen Production Tech Team Roadmap, November 2017) putting the cost of SMR hydrogen at between $1.20 and $1.50, the cost price of hydrogen via electrolysis is still over double 2015 DOE hydrogen target prices. The US DOE target price for hydrogen in 2020 is $2.30/kg, requiring an electricity cost $0.037/kWh, which is achievable given recent PPA tenders for wind and solar in many regions. This puts the $4/gge H2 dispensed objective well within reach, and close to a slightly elevated natural gas production cost for SMR.

In other parts of the world, steam methane reforming is between $1-3/kg on average. This makes production of hydrogen via electrolysis cost competitive in many regions already, as outlined by Nel Hydrogen and others, including an article by the IEA examining the conditions which could lead to a competitive advantage for electrolysis.

Experimental production methods

Biological production
Fermentative hydrogen production is the fermentative conversion of organic substrate to biohydrogen manifested by a diverse group of bacteria using multi enzyme systems involving three steps similar to anaerobic conversion. Dark fermentation reactions do not require light energy, so they are capable of constantly producing hydrogen from organic compounds throughout the day and night. Photofermentation differs from dark fermentation because it only proceeds in the presence of light. For example, photo-fermentation with Rhodobacter sphaeroides SH2C can be employed to convert small molecular fatty acids into hydrogen. Electrohydrogenesis is used in microbial fuel cells where hydrogen is produced from organic matter (e.g. from sewage, or solid matter) while 0.2 – 0.8 V is applied.

Biological hydrogen can be produced in an algae bioreactor. In the late 1990s it was discovered that if the algae is deprived of sulfur it will switch from the production of oxygen, i.e. normal photosynthesis, to the production of hydrogen.

Biological hydrogen can be produced in bioreactors that use feedstocks other than algae, the most common feedstock being waste streams. The process involves bacteria feeding on hydrocarbons and excreting hydrogen and CO2. The CO2 can be sequestered successfully by several methods, leaving hydrogen gas. In 2006-2007, NanoLogix first demonstrated a prototype hydrogen bioreactor using waste as a feedstock at Welch’s grape juice factory in North East, Pennsylvania (U.S.).

Biocatalysed electrolysis
Besides regular electrolysis, electrolysis using microbes is another possibility. With biocatalysed electrolysis, hydrogen is generated after running through the microbial fuel cell and a variety of aquatic plants can be used. These include reed sweetgrass, cordgrass, rice, tomatoes, lupines, and algae

High-pressure electrolysis
High pressure electrolysis is the electrolysis of water by decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) by means of an electric current being passed through the water. The difference with a standard electrolyzer is the compressed hydrogen output around 120-200 bar (1740-2900 psi, 12–20 MPa). By pressurising the hydrogen in the electrolyser, through a process known as chemical compression, the need for an external hydrogen compressor is eliminated, the average energy consumption for internal compression is around 3%. European largest (1 400 000 kg/a, High-pressure Electrolysis of water, acaline technology) hydrogen production plant is operating at Kokkola, Finland.

High-temperature electrolysis
Hydrogen can be generated from energy supplied in the form of heat and electricity through high-temperature electrolysis (HTE). Because some of the energy in HTE is supplied in the form of heat, less of the energy must be converted twice (from heat to electricity, and then to chemical form), and so potentially far less energy is required per kilogram of hydrogen produced.

While nuclear-generated electricity could be used for electrolysis, nuclear heat can be directly applied to split hydrogen from water. High temperature (950–1000 °C) gas cooled nuclear reactors have the potential to split hydrogen from water by thermochemical means using nuclear heat. Research into high-temperature nuclear reactors may eventually lead to a hydrogen supply that is cost-competitive with natural gas steam reforming. General Atomics predicts that hydrogen produced in a High Temperature Gas Cooled Reactor (HTGR) would cost $1.53/kg. In 2003, steam reforming of natural gas yielded hydrogen at $1.40/kg. In 2005 natural gas prices, hydrogen costs $2.70/kg.

High-temperature electrolysis has been demonstrated in a laboratory, at 108 MJ (thermal) per kilogram of hydrogen produced, but not at a commercial scale. In addition, this is lower-quality “commercial” grade Hydrogen, unsuitable for use in fuel cells.

Photoelectrochemical water splitting
Using electricity produced by photovoltaic systems offers the cleanest way to produce hydrogen. Water is broken into hydrogen and oxygen by electrolysis—a photoelectrochemical cell (PEC) process which is also named artificial photosynthesis. William Ayers at Energy Conversion Devices demonstrated and patented the first multijunction high efficiency photoelectrochemical system for direct splitting of water in 1983. This group demonstrated direct water splitting now referred to as an “artificial leaf” or “wireless solar water splitting” with a low cost thin film amorphous silicon multijunction sheet immersed directly in water. Hydrogen evolved on the front amorphous silicon surface decorated with various catalysts while oxygen evolved off the back metal substrate. A Nafion membrane above the multijunction cell provided a path for ion transport. Their patent also lists a variety of other semiconductor multijunction materials for the direct water splitting in addition to amorphous silicon and silicon germanium alloys. Research continues towards developing high-efficiency multi-junction cell technology at universities and the photovoltaic industry. If this process is assisted by photocatalysts suspended directly in water instead of using photovoltaic and an electrolytic system, the reaction is in just one step, which can improve efficiency.

Photoelectrocatalytic production
A method studied by Thomas Nann and his team at the University of East Anglia consists of a gold electrode covered in layers of indium phosphide (InP) nanoparticles. They introduced an iron-sulfur complex into the layered arrangement, which when submerged in water and irradiated with light under a small electric current, produced hydrogen with an efficiency of 60%.

In 2015, it was reported that Panasonic Corp. has developed a photocatalyst based on niobium nitride that can absorb 57% of sunlight to support the decomposition of water to produce hydrogen gas. The company plans to achieve commercial application “as early as possible”, not before 2020.

Concentrating solar thermal
Very high temperatures are required to dissociate water into hydrogen and oxygen. A catalyst is required to make the process operate at feasible temperatures. Heating the water can be achieved through the use of concentrating solar power. Hydrosol-2 is a 100-kilowatt pilot plant at the Plataforma Solar de Almería in Spain which uses sunlight to obtain the required 800 to 1,200 °C to heat water. Hydrosol II has been in operation since 2008. The design of this 100-kilowatt pilot plant is based on a modular concept. As a result, it may be possible that this technology could be readily scaled up to the megawatt range by multiplying the available reactor units and by connecting the plant to heliostat fields (fields of sun-tracking mirrors) of a suitable size.

Thermochemical production
There are more than 352 thermochemical cycles which can be used for water splitting, around a dozen of these cycles such as the iron oxide cycle, cerium(IV) oxide-cerium(III) oxide cycle, zinc zinc-oxide cycle, sulfur-iodine cycle, copper-chlorine cycle and hybrid sulfur cycle are under research and in testing phase to produce hydrogen and oxygen from water and heat without using electricity. These processes can be more efficient than high-temperature electrolysis, typical in the range from 35% – 49% LHV efficiency. Thermochemical production of hydrogen using chemical energy from coal or natural gas is generally not considered, because the direct chemical path is more efficient.

None of the thermochemical hydrogen production processes have been demonstrated at production levels, although several have been demonstrated in laboratories.

Hydrogen as a byproduct of other chemical processes
The industrial production of chlorine and caustic soda by electrolysis generates a sizable amount of Hydrogen as a byproduct. In the port of Antwerp a 1MW demonstration fuel cell power plant is powered by such byproduct. This unit has been operational since late 2011. The excess hydrogen is often managed with a hydrogen pinch analysis.

Storage
Although molecular hydrogen has very high energy density on a mass basis, partly because of its low molecular weight, as a gas at ambient conditions it has very low energy density by volume. If it is to be used as fuel stored on board the vehicle, pure hydrogen gas must be stored in an energy-dense form to provide sufficient driving range.

Pressurized hydrogen gas
Increasing gas pressure improves the energy density by volume, making for smaller, but not lighter container tanks (see pressure vessel). Achieving higher pressures necessitates greater use of external energy to power the compression. The mass of the hydrogen tanks needed for compressed hydrogen reduces the fuel economy of the vehicle. Because it is a small molecule, hydrogen tends to diffuse through any liner material intended to contain it, leading to the embrittlement, or weakening, of its container. The most common method of on board hydrogen storage in today’s demonstration vehicles is as a compressed gas at pressures of roughly 700 bar (70 MPa).

Liquid hydrogen
Alternatively, higher volumetric energy density liquid hydrogen or slush hydrogen may be used. However, liquid hydrogen is cryogenic and boils at 20.268 K (–252.882 °C or –423.188 °F). Cryogenic storage cuts weight but requires large liquification energies. The liquefaction process, involving pressurizing and cooling steps, is energy intensive. The liquefied hydrogen has lower energy density by volume than gasoline by approximately a factor of four, because of the low density of liquid hydrogen — there is actually more hydrogen in a liter of gasoline (116 grams) than there is in a liter of pure liquid hydrogen (71 grams). Liquid hydrogen storage tanks must also be well insulated to minimize boil off.

Japan have a liquid hydrogen (LH2) storage facility at a terminal in Kobe, and are expected to receive the first shipment of liquid hydrogen via LH2 carrier in 2020. Hydrogen is liquified by reducing its temperature to -253°C, similar to liquified natural gas (LNG) which is stored at -162°C. A potential efficiency loss of 12.79% can be achieved, or 4.26kWh/kg out of 33.3kWh/kg.

Storage as hydride
Distinct from storing molecular hydrogen, hydrogen can be stored as a chemical hydride or in some other hydrogen-containing compound. Hydrogen gas is reacted with some other materials to produce the hydrogen storage material, which can be transported relatively easily. At the point of use the hydrogen storage material can be made to decompose, yielding hydrogen gas. As well as the mass and volume density problems associated with molecular hydrogen storage, current barriers to practical storage schemes stem from the high pressure and temperature conditions needed for hydride formation and hydrogen release. For many potential systems hydriding and dehydriding kinetics and heat management are also issues that need to be overcome. A French company McPhy Energy is developing the first industrial product, based on Magnesium Hydrate, already sold to some major clients such as Iwatani and ENEL.

Adsorption
A third approach is to adsorb molecular hydrogen on the surface of a solid storage material. Unlike in the hydrides mentioned above, the hydrogen does not dissociate/recombine upon charging/discharging the storage system, and hence does not suffer from the kinetic limitations of many hydride storage systems. Hydrogen densities similar to liquefied hydrogen can be achieved with appropriate adsorbent materials. Some suggested adsorbents include activated carbon, nanostructured carbons (including CNTs), MOFs, and hydrogen clathrate hydrate.

Underground hydrogen storage
Underground hydrogen storage is the practice of hydrogen storage in underground caverns, salt domes and depleted oil and gas fields. Large quantities of gaseous hydrogen have been stored in underground caverns by ICI for many years without any difficulties. The storage of large quantities of liquid hydrogen underground can function as grid energy storage. The round-trip efficiency is approximately 40% (vs. 75-80% for pumped-hydro (PHES)), and the cost is slightly higher than pumped hydro. Another study referenced by a European staff working paper found that for large scale storage, the cheapest option is hydrogen at €140/MWh for 2,000 hours of storage using an electrolyser, salt cavern storage and combined-cycle power plant. The European project Hyunder indicated in 2013 that for the storage of wind and solar energy an additional 85 caverns are required as it cannot be covered by PHES and CAES systems. A German case study on storage of hydrogen in salt caverns found that if the German power surplus (7% of total variable renewable generation by 2025 and 20% by 2050) would be converted to hydrogen and stored underground, these quantities would require some 15 caverns of 500,000 cubic metres each by 2025 and some 60 caverns by 2050 – corresponding to approximately one third of the number of underground gas caverns currently operated in Germany. In the US, Sandia Labs are conducting research into the storage of hydrogen in depleted oil and gas fields, which could easily absorb large amounts of renewably produced hydrogen as there are some 2.7 million depleted wells in existence.

Power to gas
Power to gas is a technology which converts electrical power to a gas fuel. There are 2 methods, the first is to use the electricity for water splitting and inject the resulting hydrogen into the natural gas grid. The second (less efficient) method is used to convert carbon dioxide and water to methane, (see natural gas) using electrolysis and the Sabatier reaction. The excess power or off peak power generated by wind generators or solar arrays is then used for load balancing in the energy grid. Using the existing natural gas system for hydrogen Fuel cell maker Hydrogenics and natural gas distributor Enbridge have teamed up to develop such a power to gas system in Canada.

Pipeline storage
A natural gas network may be used for the storage of hydrogen. Before switching to natural gas, the German gas networks were operated using towngas, which for the most part consisted of hydrogen. The storage capacity of the German natural gas network is more than 200,000 GW•h which is enough for several months of energy requirement. By comparison, the capacity of all German pumped storage power plants amounts to only about 40 GW•h. The transport of energy through a gas network is done with much less loss (<0.1%) than in a power network (8%). The use of the existing natural gas pipelines for hydrogen was studied by NaturalHy Infrastructure The hydrogen infrastructure would consist mainly of industrial hydrogen pipeline transport and hydrogen-equipped filling stations like those found on a hydrogen highway. Hydrogen stations which were not situated near a hydrogen pipeline would get supply via hydrogen tanks, compressed hydrogen tube trailers, liquid hydrogen trailers, liquid hydrogen tank trucks or dedicated onsite production. Because of hydrogen embrittlement of steel, and corrosion natural gas pipes require internal coatings or replacement in order to convey hydrogen. Techniques are well-known; over 700 miles of hydrogen pipeline currently exist in the United States. Although expensive, pipelines are the cheapest way to move hydrogen. Hydrogen gas piping is routine in large oil-refineries, because hydrogen is used to hydrocrack fuels from crude oil. Hydrogen piping can in theory be avoided in distributed systems of hydrogen production, where hydrogen is routinely made on site using medium or small-sized generators which would produce enough hydrogen for personal use or perhaps a neighborhood. In the end, a combination of options for hydrogen gas distribution may succeed. While millions of tons of elemental hydrogen are distributed around the world each year in various ways, bringing hydrogen to individual consumers would require an evolution of the fuel infrastructure. For example, according to GM, 70% of the U.S. population lives near a hydrogen-generating facility but has little public access to that hydrogen. The same study however, shows that building the infrastructure in a systematic way is much more doable and affordable than most people think. For example, one article has noted that hydrogen stations could be put within every 10 miles in metro Los Angeles, and on the highways between LA and neighboring cities like Palm Springs, Las Vegas, San Diego and Santa Barbara, for the cost of a Starbuck's latte for every one of the 15 million residents living in these areas. A key tradeoff: centralized vs. distributed production In a future full hydrogen economy, primary energy sources and feedstock would be used to produce hydrogen gas as stored energy for use in various sectors of the economy. Producing hydrogen from primary energy sources other than coal, oil, and natural gas, would result in lower production of the greenhouse gases characteristic of the combustion of these fossil energy resources. One key feature of a hydrogen economy would be that in mobile applications (primarily vehicular transport) energy generation and use could be decoupled. The primary energy source would need no longer travel with the vehicle, as it currently does with hydrocarbon fuels. Instead of tailpipes creating dispersed emissions, the energy (and pollution) could be generated from point sources such as large-scale, centralized facilities with improved efficiency. This would allow the possibility of technologies such as carbon sequestration, which are otherwise impossible for mobile applications. Alternatively, distributed energy generation schemes (such as small scale renewable energy sources) could be used, possibly associated with hydrogen stations. Aside from the energy generation, hydrogen production could be centralized, distributed or a mixture of both. While generating hydrogen at centralized primary energy plants promises higher hydrogen production efficiency, difficulties in high-volume, long range hydrogen transportation (due to factors such as hydrogen damage and the ease of hydrogen diffusion through solid materials) makes electrical energy distribution attractive within a hydrogen economy. In such a scenario, small regional plants or even local filling stations could generate hydrogen using energy provided through the electrical distribution grid. While hydrogen generation efficiency is likely to be lower than for centralized hydrogen generation, losses in hydrogen transport could make such a scheme more efficient in terms of the primary energy used per kilogram of hydrogen delivered to the end user. The proper balance between hydrogen distribution and long-distance electrical distribution is one of the primary questions that arises about the hydrogen economy. Again the dilemmas of production sources and transportation of hydrogen can now be overcome using on site (home, business, or fuel station) generation of hydrogen from off grid renewable sources.. Distributed electrolysis Distributed electrolysis would bypass the problems of distributing hydrogen by distributing electricity instead. It would use existing electrical networks to transport electricity to small, on-site electrolysers located at filling stations. However, accounting for the energy used to produce the electricity and transmission losses would reduce the overall efficiency. Natural gas combined cycle power plants, which account for almost all construction of new electricity generation plants in the United States, generate electricity at efficiencies of 60 percent or greater. Increased demand for electricity, whether due to hydrogen cars or other demand, would have the marginal impact of adding new combined cycle power plants. On this basis, distributed production of hydrogen would be roughly 40% efficient. However, if the marginal impact is referred to today's power grid, with an efficiency of roughly 40% owing to its mix of fuels and conversion methods, the efficiency of distributed hydrogen production would be roughly 25%. The distributed production of hydrogen in this fashion would be expected to generate air emissions of pollutants and carbon dioxide at various points in the supply chain, e.g., electrolysis, transportation and storage. Such externalities as pollution must be weighed against the potential advantages of a hydrogen economy. Energetic use of hydrogen The most important element in the use of hydrogen is the fuel cell. It converts the energy contained in hydrogen into heat and electricity. Use in the house In the domestic power generation by the fuel cell can, as in the cogeneration equipment, a cogeneration be realized, which increases the overall efficiency. Since this mode of operation focuses on heat production, these systems are controlled according to the heat requirement, with the generated electric current being fed into the public power grid. Vaillant has developed a fuel cell heater that can also be operated with natural gas via a reformer. The theoretically achievable calorific value-related efficiency is approx. 83%. If the efficiency, as is the case with thermal power plants and internal combustion engines, is usually based on the calorific value, this results in a theoretical maximum efficiency of approx. 98%. Depending on the fuel cell type, the system efficiencies range between 40% and 65%, although it is unclear whether these are calorific value or calorific values. Use in traffic A hydrogen powered vehicle has i. A. a pressurized tank (eg 700 bar) that can be refueled at a hydrogen refueling station. As methods of force generation either a largely conventional internal combustion engine is possible, similar to driving with natural gas, or a "cold combustion" in a fuel cell. In the fuel cell vehicle, electric power is generated with the fuel cell, which drives an electric motor. Internal combustion engine As a combustible gas, hydrogen can be burned in a largely conventional internal combustion engine (" hydrogen combustion engine "), similar to natural gas-powered vehicles, to mechanical rotational energy (for example in the BMW Hydrogen 7). Fuel cell In the fuel cell vehicle, electric power is generated with the fuel cell, which drives an electric motor. Hydrogen technology is also being tested in practice on buses. The current generation of hydrogen buses (2009) achieves a range of around 250 km with 35 kg of hydrogen. Fuel cell cars are much more expensive than electric cars. According to Fritz Henderson (CEO of General Motors), such a vehicle will cost around $ 400,000 (as of 2009). Vehicle manufacturers Toyota, Nissan, Mercedes-Benz and Honda have reportedly cut production costs for hydrogen-powered vehicles drastically. (The Toyota Mirai, for example, is available in Germany for just under 80,000 €.) Toyota produces H 2 cars in small series and sets in a big way on the fuel cell. With the Mercedes B-Class F-Cell and two pre-production vehicles of the Hyundai ix35 Fuel Cell Electric Vehicle (FCEV) ranges of 500 km were reached at maximum speeds of 80 km / h. In order to demonstrate the suitability for everyday use of the hydrogen drive, Daimler successfully completed a "circumnavigation" of the world with several B-Class fuel cell vehicles. 200 series vehicles of this type were delivered to customers in 2010. There are now some buses, z. For example, the Mercedes-Benz Citaro FuelCELL hybrid from various manufacturers who work with fuel cells. In addition, with the technology of Hydrail since 2005, the rail vehicles have come into the perspective of the hydrogen economy. As one of the first companies to Japanese East Railroad Company took for testing a hybrid locomotive in operation. At the end of 2017, 14 trains with fuel cell drive were ordered from the manufacturer Alstom in Lower Saxony. The Swiss Federal Railways (SBB) has been introducing hydrogen fuel cells in its rolling minibars since spring 2014 in order to have enough energy for the integrated espresso machine on the road, which can now also offer cappuccino to passengers. The usual accumulators used so far would have been too heavy for this energy-consuming task. Hydrogen safety Hydrogen has one of the widest explosive/ignition mix range with air of all the gases with few exceptions such as acetylene, silane, and ethylene oxide. That means that whatever the mix proportion between air and hydrogen, a hydrogen leak will most likely lead to an explosion, not a mere flame, when a flame or spark ignites the mixture. This makes the use of hydrogen particularly dangerous in enclosed areas such as tunnels or underground parking. Pure hydrogen-oxygen flames burn in the ultraviolet color range and are nearly invisible to the naked eye, so a flame detector is needed to detect if a hydrogen leak is burning. Hydrogen is odorless and leaks cannot be detected by smell. Hydrogen codes and standards are codes and standards for hydrogen fuel cell vehicles, stationary fuel cell applications and portable fuel cell applications. There are codes and standards for the safe handling and storage of hydrogen, for example the standard for the installation of stationary fuel cell power systems from the National Fire Protection Association. Codes and standards have repeatedly been identified as a major institutional barrier to deploying hydrogen technologies and developing a hydrogen economy. To enable the commercialization of hydrogen in consumer products, new model building codes and equipment and other technical standards are developed and recognized by federal, state, and local governments. One of the measures on the roadmap is to implement higher safety standards like early leak detection with hydrogen sensors. The Canadian Hydrogen Safety Program concluded that hydrogen fueling is as safe as, or safer than, compressed natural gas (CNG) fueling. The European Commission has funded the first higher educational program in the world in hydrogen safety engineering at the University of Ulster. It is expected that the general public will be able to use hydrogen technologies in everyday life with at least the same level of safety and comfort as with today's fossil fuels. Source from Wikipedia