There is an enormous push of hydrogen in the world. Given sufficient policy support, there will be low-carbon1 hydrogen available. The discussion on the availability and cost of different options is found in a contribution by Jean-Michel Glachant and Piero Carlo Dos Reis.
Here, we attempt to estimate an order of magnitude on how much sustainable fuels including hydrogen will be needed in the future energy system. We follow the communication2 of the EU on system integration:
- Energy efficiency first, including use of waste heat,
- Then electrification of those applications that can be technologically and cost-efficiently electrified,
- If the first and the second approach are not feasible, sustainable fuels have to used (amongst them hydrogen)
For 2018 an overall figure of 10.929 TWh (electricity 2512 TWh, solid fuels 268 TWh, oil and petroleum products 4013 TWh, gas 2397 TWh, renewable energies 1150 TWh, heat 537 TWh) of final energy supplied in EU-27 is mentioned3.
Transport overall requires 3.335 TWh4. By far the largest energy demand in this sector is the road transport (3114 TWh). Individual transport of persons is transitioning to electricity.
An overview of electric cars shows an average of 20-25 kWh/100 km5. For smaller cars, the electric energy demand is lower than 20 kWh/100 km. We assume an average fuel consumption of 5,1 (Europe) – 7,2 (global) l/100 km6. With a weighted average of 46% petrol and 54 % diesel passenger cars7, this leads to 73,2 kWh/100 km with a minimum of 52 kWh/l for the lowest European figure: overall, electric cars consume 2.5 to 3 times less energy than ICE cars.
Heavy-duty vehicles, lorries, buses and coachesare responsible for about a quarter of CO2emissions from road transport in the EU8. Local buses can be costeffectively electrified, given the fact that the trajectory and charging times can be planned. The electrification of trucks is more difficult but seems to be taking off9. Given full electrification of road transport, the energy use could be reduced to circa 1050-1250 TWh assuming constant mobility demand. Electrification of road transport implies an enormous gain in energy efficiency.
The overall demand for liquid oil and petroleum products for aviation and shipping is 1053 TWh. In Eurostat, the fuel for international navigation and aviation is not included in the energy for transport. With the exception of a small share of domestic navigation, the potential for electrification is limited and hydrogen or synthetic/biofuels will be required.
The energy consumption in residential and commercial buildings in 2018 in EU-27 was 4405 TWh. The non-electrical part (75 %) of the energy supply is dedicated to heating. Assuming that, in line with EU ambitions10, three quarters of the energy demand can be saved through renovation, the decarbonization of 1846 TWh (natural gas and petroleum) remains.
Electrification implies great gains in energy efficiency. A coefficient of performance of 4 for heat pumps would mean that around 462 TWh of carbon neutral heat and electricity has to be supplied as input to heat pumps. This leads to an extra electricity demand of 121 TWh.
The decarbonization of the industry carbon-based energy supply is a patchwork, with many approaches for the different products. A mixture of CCS/CCU, biofuels, circularity of materials and hydrogen/sustainable fuels from green electricity is to be considered. When studying literature, most technologies are still in a premature status, and often 2035 is mentioned as a starting date of full industrialization. Eurostat distinguishes 13 industrial sectors consuming 2816 TWh not including the 1032 TWh of carbon-based fuels for non-energy use. Two examples illustrate the challenges faced in aiming at a carbon neutral industry.
For the steel industry, a number of new manufacturing options are present. One of them, Hydrogen Direct Reduction, uses electricity and hydrogen as inputs. First installations are designed in Sweden11. The approach requires 3200 kWh/ton steel extra electricity input, of which 2600 kWh/ton for hydrogen production12. Given an overall production of steel in Europe of 169 Mt/year in 2018, a full decarbonization via the H2-DRI leads to 540 TWh extra renewable electricity demand, to be compared with the present energy carbon based energy supply of 198 TWh. The example shows that the opposition electrification versus hydrogen is artificial: the technique is “hydrogen based”, but from the outside, the energy flow is purely electric.
At this moment 293 TWh (264 TWh in chemical industry) of hydrogen is already used, mostly produced by Steam Methane Reforming of Natural Gas13. A lot of it is used for the production of ammonia. The production via electrolysis of the hydrogen for the ammonia as such would require 161 TWh.
This approach is extreme: it assumes that everything that can be electrified is. Transport and buildings will need an additional 1200 to 1400 TWh of electricity. In parallel 1050 TWh of sustainable fuel will be used for aviation and navigation. Industry is a patchwork. The separation between sustainable fuels, hydrogen and electricity sometimes becomes artificial, making future energy flow diagrams as used by Eurostat challenging.
It is evident that a much more detailed modelling is needed and a lot of parameters are neglected here. Future studies will give far more insight.
1 Taxonomy of “renewable & low-carbon” vs “fossil H2” introduced Ilaria Conti “Which future gas markets?” https://fsr.eui.eu/publications/?handle=1814/66356