ドイツ、過剰な水素投資で450億ユーロの納税者負担の危険性

Germany risks leaving taxpayers liable for at least €34.7 billion ($40.8 billion) in unrecovered hydrogen infrastructure costs by 2055, the Institute for Energy Economics and Financial Analysis (IEEFA) says in a new report, putting the true regulated cost base at approaching €50 billion against the commonly cited €19.8 billion construction figure. Germany risks leaving taxpayers liable for at least €34.7 billion ($40.8 billion) in unrecovered hydrogen infrastructure costs by 2055, the Institute for Energy Economics and Financial Analysis (IEEFA) says in a new report, putting the true regulated cost base at approaching €50 billion against the commonly cited €19.8 billion construction figure. Germany risks leaving taxpayers liable for at least €34.7 billion ($40.8 billion) in unrecovered hydrogen infrastructure costs by 2055, the Institute for Energy Economics and Financial Analysis (IEEFA) says in a new report, putting the true regulated cost base at approaching €50 billion against the commonly cited €19.8 billion construction figure. The difference between a rapid and limited hydrogen uptake scenario amounts to €45 billion in additional public funding requirements – around €1,000 per German taxpayer – driven primarily by unrecovered pipeline financing costs, according to IEEFA’s new “Rethinking Germany’s hydrogen-led transition: Demand shortfalls, infrastructure risk and the public cost of overbuilding” report . The €19.8 billion figure commonly cited for Germany’s hydrogen core network covers construction costs only. Modeling by Fraunhofer Research Institution for Energy Infrastructures and Geotechnologies IEG for Germany’s Federal Network Agency (BNetzA) puts the full regulated cost base – including financing charges, repurposed legacy pipeline assets, and operating expenditure – close to €50 billion. Network operators are separately projecting at least €5 billion in additional costs from procurement and project revisions, at a stage when approximately 4% of the pipeline has been completed. Germany’s Federal Network Agency (BNetzA) adopted a transport tariff cap of €25/kW of booked capacity per year, informed by Fraunhofer modeling. The cap is applied through a state-backed credit facility – the amortization account, pre-financed through state-owned bank KfW – that absorbs early revenue shortfalls. The account must be cleared by 2055, with the state legally obligated to cover at least 76% of any unrecovered balance. Under IEEFA’s limited uptake scenario – in which pipeline utilization peaks at around 20% of network capacity by 2037 – the amortization account balance reaches €45.7 billion by 2055, leaving the state liable for at least €34.7 billion. Tariff adjustment does not function as a viable recovery mechanism under weak demand. Fraunhofer identifies fees above €35/kW of booked capacity per year as commercially unviable in the most adverse scenario – the point at which higher charges suppress demand faster than they raise revenue. Under a limited uptake scenario, clearing the account by 2055 would require fees exceeding €100/kW, a level IEEFA said is incompatible with market participation. IEEFA’s demand analysis strips out sectors where electrification offers a cheaper decarbonization path – heating, transport, and most power generation – and applies further adjustments for derivative imports that would bypass pipeline infrastructure entirely. IEEFA said Germany’s 2045 hydrogen demand could sit at or below the lower end of official scenario ranges. The Federal Ministry for Economic Affairs and Energy’s monitoring report puts normative demand scenarios at 163 TWh to 605 TWh by 2045. But IEEFA’s adjusted estimate sits near the midpoint of the exploratory range of 71 TWh to 262 TWh and well below the previous government’s system development strategy range of 360 TWh to 500 TWh. IEEFA points to early market indicators consistent with this more limited demand outlook. Around one-eighth of Germany’s 10 GW 2030 electrolyzer target – approximately 1.2 GW to 1.3 GW – has reached final investment decision. Approximately 400 km of the hydrogen backbone, around 4% of the planned network, has been completed and pressurized, with no supply contracted and no customers connected. IEEFA uses Germany’s emergency liquefied natural gas (LNG) terminal buildout as a cautionary precedent for infrastructure built ahead of demand. Those terminals averaged 36.3% utilization in 2025, and analysis cited by IEEFA puts total public exposure at €17 billion or more. The report said the same risk-transfer logic now underpins the hydrogen core network, at a larger fiscal scale and without the justification of an acute supply crisis. The report identifies blue hydrogen – produced from natural gas with carbon capture and storage – as a compounding risk rather than a solution. Germany’s Hydrogen Acceleration Act, passed by parliament in February 2026, designated blue hydrogen infrastructure as being in the “overriding public interest.” IEEFA said the shift layers a second capital-intensive infrastructure system – reforming capacity, carbon capture equipment, and carbon dioxide transport and storage – on top of the hydrogen backbone, while re-anchoring production in volatile gas markets. Carbon capture costs and performance remain highly uncertain, adding a further layer of fiscal exposure. The report said the greater long-term risk to public finances is not a hydrogen network that fails outright, but one that partially succeeds by locking in gas dependency and driving open-ended demand subsidies across the economy. IEEFA recommends phasing the pipeline buildout to confirmed industrial offtake, publishing a transparent amortization account repayment path with automatic policy reviews triggered if utilization falls below defined thresholds, and prioritizing imports of hydrogen derivatives – ammonia, methanol, and green iron – for hard-to-abate sectors over domestic pipeline infrastructure.