Hydrogen and the city: Smart, but still a promise for the future

Recently, Amsterdam[1] and Nijmegen published their plans for energy transition. The obvious conclusion is that they need a lot of hot water for district heating from still unknown underground sources and a decuple supply of wind and solar energy. Looking for other supplies, the idea of hydrogen soon comes up.

Before answering the question about the feasibility of hydrogen as an additional source of heat and electricity, some characteristics of hydrogen will have to be discussed.

The process of electrolysis brings water into contact with electricity, resulting in oxygen and hydrogen. A 100% clean process, provided the use of energy from carbon-free sources. ‘Blue’ hydrogen occurs when the CO2 released during the production of electricity is collected and stored.

The storage of hydrogen is easy, particularly if conversed into ammonia. A kilo of hydrogen is producing the same amount of energy as a fully-fledged Tesla Power Wall. A tank with 60,000 m3 of ammonia can deliver more than 200 million kilowatt hours. That is the annual production of 30 wind turbines on land. The problem with hydrogen is that 60% of energetic value is lost when electricity is used to make hydrogen and hydrogen is converted it into electricity again. Storing electricity in a battery yields only 5% loss of value.

Hydrogen plant in Rotterdam (blue containers) and the apartment complex (left center) that will be heated with hydrogen. Photo: DNV GL

 

As a consequence, the most obvious application of hydrogen is as a substitute for natural gas, which limits energy loss to 30%. The Dutch grid operator Stedin will use green hydrogen gas to heat an apartment complex in Rotterdam. The hydrogen will be produced locally and transported via dedicated gas pipelines (photo). An electric heat pump would have reduced energy use with 75%, given perfect isolation. Exactly to avoid this costs, housing corporations are considering hydrogen in older houses. However, the financial advantages of ‘green’ hydrogen in the long run have to be seen. Eventually, heating on hydrogen will be reserved for historic city centers, where few alternatives are available.

But what if hydrogen will become much cheaper?  In the near future, the Gulf States will export cheap ‘green’ hydrogen converted into ammonia on a large scale. The production costs of solar energy in desert areas are considerably lower than in Europe, because the yield of solar panels and collectors is twice as large due to the high intensity of insulation. The feasibility of this alternative depends on geopolitical considerations in the first place: Many Western countries will be reluctant to become dependent again from ‘former’ oil producing countries. However, the advantages are obvious.

Another attractive prospect is that hydrogen (ammonia) offers a new destination for a couple of brandnew but already depreciated energy plants. In this respect, an experiment in the Magnum power plant at the Dutch Eemshaven (Eems harbor) is of great importance. Electricity company NUON is investigating whether this type of power plants can be used in a flexible way for the production of electricity while deploying various types of low- or no-emission fuels like hydrogen. In times of a surplus of green electricity, these plants can be used to produce hydrogen. If there is a shortage of electricity, the power plant can convert imported cheap hydrogen into electricity. In the future, probably one of the gas-powered energy plants in Amsterdam will be deployed in the same way.

An also frequently mentioned application of hydrogen is transport. In the meantime, for all forms of transport – even cycling – hydrogen models are available.

e-Bike on hydrogen. The Alpha 2.0. Photo Pragma Industries

 

With the foregoing in mind, hydrogen as fuel for passenger cars – not to speak of bikes –  is quite odd. Although the range is about 600 km and refueling is fast, the difference with electric cars is reducing fast. There are few car brands left that go for passenger cars on hydrogen; Toyota is one of these. The development of a hybrid car that runs on electricity with a battery that can be charged by a fuel cell while driving is noteworthy. Daimler is working on this, after having stopped the development of a fully hydrogen-powered passenger car recently.

For other means of transport, the verdict may be more positive. The rule is, the larger the desired range and the heavier the load, the more the benefits of hydrogen equal or outweigh the advantages of batteries. Examples are buses, lorries, but also planes and ships. The Dutch province of Groningen and QBuzz, a regional transport company, are experimenting with buses on hydrogen. The 20 buses will run on the long routes. This in contrast with the rest of the fleet, which will become electric because loading can be fitted into the timetable.

The conclusion is that the use of Dutch solar or wind energy for the production of hydrogen is costly and does not qualify mostly when electricity can be used directly. The availability of cheap imported hydrogen might be a gamechanger. In the first place, it is a ‘green’ alternative for the use of natural gas particular in buildings or parts of the town where a high level of isolation is costly or infeasible at all. In the second place it is an excellent alternative for long-term energy storing probably in combination with depreciated gas-powered energy plants. Buses, trucks, trains, ships and planes might be a third application.

 

 

[1] MRA Warmte Koude – Grand Design 2.0: Handelingsperspectief en Analyse, september 2018 Metropoolregio Amsterdam

 

*) Source header: Hydrogen storage. Photo NASA (public domain)

**) This article was brought to you by Professor Herman van den Bosch, Professor at Open University of The Netherlands.

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