Fuel from the air?

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Electrofuels are fuels that have been produced by decomposing water into hydrogen and oxygen with the aid of electricity. The process is called electrolysis. Hydrogen can be used as such, but it can also be converted to a form that is easier to store and more readily suitable for current areas of use, i.e. synthetic hydrocarbon, for example, methane or even petrol and diesel. Hydrogen can be used in various applications as such, but it can also be converted to synthetic hydrocarbons, which are easier to store and more readily suitable for current areas of use. Well-known examples of such hydrocarbons are methane (natural gas), petrol and diesel. The fuzzy talk about electrofuels has accelerated in the past few years, and sometimes electrofuels, or more widely Power-to-X (PtX) solutions, are presented almost as a silver bullet for climate change mitigation.

In addition to hydrogen, hydrocarbons need carbon that can be obtained from carbon dioxide. In the most advanced visions, this carbon dioxide is separated from the atmosphere, in which the excessive amount of carbon dioxide is the key reason for climate change. When the aim is to get rid of the current sources of carbon dioxide, separating it from the atmosphere is a good goal in the long term. However, these days it is better to separate carbon dioxide from sources with a higher content, because it is more practical and thus also cheaper. In terms of climate change, separating carbon dioxide from the chimney stack is as useful as removing it from the atmosphere if, in the latter alternative, carbon dioxide is still released into the air from the stack. Therefore, it pays to separate carbon dioxide from applications that are not being phased out, so called unavoidable CO2 sources. As electrofuels are particularly well suited for long-term energy storage, carbon dioxide should be available especially in the summer. These kinds of applications are, e.g. many industrial plants and waste incineration.

In terms of the climate impacts of electrofuels, the source of carbon dioxide is a secondary matter. For climate, it is crucial which kinds of impacts hydrogen production has on electricity production and that way on emissions. All energy of synthetic fuel produced comes from electricity via hydrogen, and therefore the efficiency of the system crucially depends on the efficiency of electrolysis. The total efficiency can be significantly improved if the heat from electrolysis can be utilised. The role of hydrogen is crucial also in terms of the cost of production. In most cases of electrofuels, the most important cost factors are the price of the electricity consumed and the investment cost of electrolyser. The costs of both of these should fall significantly in order for extensive use of electrofuels to become available without subsidies. However, the reduction in prices to a sufficient level requires multiplying emission-free electricity production and technological maturing of large-scale electrolysis solutions. These will be reached through brave and publicly supported demonstration projects.

At the Finnish level, a sufficient increase in emission-free energy production and PtX solutions needs billions of euros in investment. These require political steering in order to be implemented rapidly and extensively enough with respect to climate change mitigation. However, it is worth aiming in that direction. Finland must play its part in climate change mitigation, but we also have an excellent opportunity to do it in a profitable way from an economic perspective. In terms of the balance of trade, we are currently a clear importer of energy and are using billions of euros’ worth of imported fuels every year.

Solar and wind power are the least resisted ways of producing more electricity for growing needs. They are available easily in excess of our own needs, even in Finland. The problem lies in the timing of matching production and use, or rather the lack of it. Storage of energy is needed. Batteries are well suited for short-term storage, but the need to store energy in the summer for the winter is emphasised in the Nordic countries. The solution for this is hydrogen. Electrolysis is highly suitable to balancing the production variations in solar and wind power from the perspective of the energy system, and the produced electrofuels reduce consumption of fossil fuels in transport and thus emissions at the same time as electric vehicles become more common.

Of the electrofuels, the hydrocarbon with the highest hydrogen content is methane. Vehicles running on methane gas (CNG) are already available for several common car models and financial viability for those considering buying a new car. As the range of electric vehicles increases and the prices come down, the need for CNG vehicles in passenger traffic will decrease at some stage in future. However, methane will for long be an excellent alterative for the needs of heavy transport, ships and, with an even longer perspective, finally for balancing the energy system, i.e. for producing heating fuels for the winter in the summer. Where the use of CNG vehicles is already financially viable, long-term storage of energy and carbon-neutral production of peak loads are expensive. In a carbon-neutral future, even expensive methods must be taken into use.

The electrofuel project of Vantaa Energy is an important step on the above-described path towards carbon-neutral and energy self-sufficient Finland. The project combines the above-described strengths of electrofuels efficiently in terms of both climate and economy. The operational economy of the Vantaa project is not dependent only on cheap electricity, but the heat of electrolysis is utilised with a heat pump as district heat, and the options of utilising oxygen produced as a by-product are investigated. The project demonstrates all the necessary stages at once, from the separation of carbon dioxide to production of transport fuels and covering the peak load of district heat. If successful, the solution can be multiplied for several similar district heating systems in Finland and abroad. In addition, the demonstration enables development of Finnish expertise and technology and that way promotes new export products for a sector with a strong growth outlook.

Dr. Eemeli Tsupari
Principal Scientist
VTT

Dr. Antti Arasto
Vice President, Industrial energy and hydrogen
VTT

Read more about Vantaan Energy’s Power-to-gas-project