Although natural gas is an attractive fuel in many respects [56], given the rapidly dwindling reserves
and the environmental pollution it causes, it is not the ultimate solution to energy problems. In this
respect, hydrogen has more potential. When used in combustion engines or more efficiently in fuel
cells, hydrogen produces no greenhouse gases or harmful particulates. However, there are several
hurdles which must be cleared before hydrogen can be hailed as the energy carrier of the future.
Among them is that hydrogen does not exist as a free gas and hence must be produced for use as an
energy carrier. This can be done via steam methane reforming; via electrolysis of water using solar,
wind or geothermal energy; via coal and biomass gasification, but there are significant costs involved.
Despite this and other techno‐economic barriers, however, hydrogen is perceived as one of the
promising options for future energy systems.
As part of the national research agenda, the Netherlands initiated the Greening of Gas project to
investigate the feasibility of adding hydrogen to the Dutch natural gas network. The impetus was
two‐fold. Firstly, substituting a portion of the natural gas supply with hydrogen would reduce diffuse
CO2 emissions. If 10% of the natural gas was to be exchanged for hydrogen, a 3.6% emission
reduction would be achieved – this corresponds to 6 Mton CO2 savings, which would already amount
to half the Kyoto obligation of the Netherlands [56]. Secondly, it would allow gradual learning of how
to deal with hydrogen in the context of an already mature natural gas system. Mixing H2 into the
natural gas network, several technical and economic hurdles for using hydrogen could to be cleared
(see [56]). The blending, approach promises to ease a shift towards a hydrogen economy.