but it can be captured and stored. The idea of hydrogen economy has been heavily criticized from the moment it was proposed. The main issues with the H2E scenario are as follows: The human civilization does not have a clean, energy-efficient and low-cost source of H2. The current production methods either produce a large amount of carbon dioxide per kW than direct burning of coal, or are more expensive or are less energy efficient. Storage of H2 within a transportation vehicle for its own motive power faces cost and safety issues. Conversion of H2 into electricity in fuel cells have a low (ca. 60%) energy efficiency, with issues of durability and cost remaining unresolved. Rationale In the current hydrocarbon economy, heating is fueled primarily by natural gas and transportation by petroleum. Burning of hydrocarbon fuels emits carbon dioxide and other pollutants. The demand for energy is increasing, particularly in China, India, and other developing countries. Hydrogen can be an environmentally cleaner source of energy to end-users, without release of pollutants such as particulates or carbon dioxide. Hydrogen has a high energy density by weight but has a low energy density by volume. Even when highly compressed, stored in solids, or liquified, the energy density by volume is only 1/4 that of gasoline, although the energy density by weight is approximately three times that of gasoline or natural gas. Hydrogen can help to decarbonize long-haul transport, chemicals, and iron and steel and has the potential to transport renewable energy long distance and store it long term, for example from wind power or solar electricity. History The term hydrogen economy was coined by John Bockris during a talk he gave in 1970 at General Motors (GM) Technical Center. The concept was proposed earlier by geneticist J.B.S. Haldane. A hydrogen economy was proposed by the University of Michigan to solve some of the negative effects of using hydrocarbon fuels where the carbon is released to the atmosphere (as carbon dioxide, carbon monoxide, unburnt hydrocarbons, etc.). Modern interest in the hydrogen economy can generally be traced to a 1970 technical report by Lawrence W. Jones of the University of Michigan. A spike in attention for the concept during the 2000s was repeatedly described as hype by some critics and proponents of alternative technologies. Interest in the energy carrier resurged in the 2010s, notably by the forming of the Hydrogen Council in 2017. Several manufacturers