The Transition from Natural Gas to 100% Hydrogen in an Existing Distribution Network

Abstract

Climate change, earthquakes in Groningen and the desire to become more energy independent in the future are all reasons for the Netherlands to strongly reduce the use of natural gas. To realize this ambitious goal the domestic environment will also have to stop using natural gas and start heating, cooking and using warm water sustainably. The distribution system operator Stedin has developed a method/tool that helps munic- ipalities in identifying a viable energy carrier as alternative to natural gas. Stad aan ’t Haringvliet is the first town that approached Stedin about the prospects of hydrogen as an alternative to natural gas. Stedin has made an initial review and concluded that hydrogen could be a promising alternative to natural gas in the case of Stad aan ’t Haringvliet.
The objective of this research project is to improve the existing approach for identifying the ideal future energy carrier for different locations within Stedin’s operating area by making a technical assessment of all necessary activities and changes when switching from natural gas to 100% hydrogen in an existing distribu- tion network.
All identified relevant aspects of hydrogen are taken into account in the case study of Stad aan ’t Har- ingvliet. The case study shows that the local gas network can be isolated from the larger gas network and function as a hydrogen network. Also, nearly no unfavorable materials (cast iron and asbestos cement) are present in the local network which underscores the suitability. If the town is isolated from the larger network it could be fed from north-west of the town by an alkaline electrolyser. However, a stand-alone system at this scale is not a cost effective scenario in the Netherlands. Therefore, an alternative system comparison was made to verify if hydrogen is indeed a viable option for Stad aan ’t Haringvliet. In the chosen system compar- ison a scenario was sketched in which ’gray’ hydrogen was received from a large industrial hydrogen network to the east of Goeree-Overflakkee. This scenario was compared to an all-electric scenario which utilized the current electricity mix which can also be considered ’gray’, due to that the majority of the generation is from fossil fuels.
The system comparison shows that with cost-effective insulation, a hydrogen scenario can be nearly as expensive as an all-electric scenario in Stad aan ’t Haringvliet regarding annual costs. The average initial in- vestment for a home owner in an all-electric scenario is estimated to be e50,000 and the initial investment in the hydrogen scenario is e11,000 on average. The annual costs are e1,540 and e1,460 for hydrogen and all-electric respectively. The carbon footprint of both scenarios is nearly equal at 4000 kg/CO2/year. The costs for adapting the local electric and gas distribution network is also significantly less expensive for a hydrogen scenario compared to the all-electric scenario. This is due to the fact that the natural gas network would have to be removed and the electric network would have to be heavily reinforced in an all-electric scenario in con- trast to light reinforcements to the electric network in the hydrogen scenario to facilitate electric cooking.
No ’show stoppers’ were identified in the general part nor in the case study part of this research. Several requirements and favorable characteristics were determined which could help identify other areas in which hydrogen could be a potential energy carrier. The first characteristic of a suitable area is predominantly hous- ing which is very costly to sufficiently insulate for all-electric heating. Large consumers of natural gas in the area are also not favorable due to the fact that they might not be able to switch to hydrogen yet. The following characteristics relate to the network. Areas at the periphery of the local gas network are favorable due to the fact that they can more likely be isolated without creating capacity issues for itself or other areas. Also, areas which have little to no cast iron or asbestos cement are favorable due to increased risk of fractures inherent to these materials. Finally, a credible source of hydrogen is identified as a requirement for a suitable area.