1001 Smart Cities
🇯🇵 Tokyo

HARUMI FLAG Hydrogen Infrastructure

🤖 AI-generated summary of the sources below · 🔎 Last verified · ◆ 8 sourced claims, none individually verified yet

This overview was generated with AI from the public sources listed below and checked against them before publication. It has not had a complete human fact-check — treat it as a starting point and follow the sources.

How this atlas is made · What “last verified” means · What “source-checked” means · The full record behind this page

✎ Corrected 21 Aug 2026 1 source added. What changed →

On the former Tokyo 2020 Olympic Village on Tokyo Bay, an underground pipeline feeds pure-hydrogen PEFC (PEM) fuel cells in each residential block — Japan's first full-scale hydrogen infrastructure in a housing district. The cells power common areas and shared facilities across 5,632 homes, which the developer expects to house as many as 12,000 residents, run by an energy-management system that predicts peak demand.

Live 📅 since 2024
Outcome🔄 Ongoing
Evidence🏛️ Officialgrades the sourcing — this entry states no impact figure
what does this mean?The strongest source is the operator's or the city's own reporting — an official report, dataset or press release. It grades who did the looking — not how well the project went. All four grades →
Run byHARUMI FLAG consortium (Panasonic / Tokyo Waterfront City Development)
Scale🏘️ District
The HARUMI FLAG development on Tokyo Bay, built on the former 2020 Olympic Village
The HARUMI FLAG development on Tokyo Bay, built on the former 2020 Olympic Village — Dick Thomas Johnson, CC BY 2.0, via Wikimedia Commons
⚡ EnergyHydrogenSmart grid & energy

Sources

↗ Panasonic Newsroom (consortium partner)Operator/solution-provider account of the hydrogen fuel-cell generators and MEMS energy management.
↗ Panasonic Newsroom — HARUMI FLAG, the City That Brings the Future to Today's Tokyo (Part 1 of 2)Published 6 September 2019Developer-side account of the district; carries the 5,632 flats in 23 buildings and the projection of 'as many as 12,000 residents by 2024'.
↗ Fuel Cells Works (trade)Trade coverage; supports 'first full-scale hydrogen infrastructure in Japan' and PEFC fuel cells in each block.
↗ Hydrogen Insight (press)Reporting on the pipeline delivering hydrogen to the blocks.
Show your work What this page rests on and what it can’t tell you · all 8 claims with their sources · the forensic record

Evidence Passport · public beta 8 addressable claims, 4 source dossiers, one permanent baseline. The passport is unreviewed — an AI-assisted structural migration, not a human or expert endorsement. Every revision keeps a permanent copy under revision history.

Inspect the claims, one by one — verbatim text, sources and caveats for all 8

The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.

Claim 1 clm-1b413809c85329ce quantitative
the former Tokyo 2020 Olympic Village on Tokyo Bay
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic's account of the project states that the development was originally built as the athletes' village for the Tokyo 2020 Games: "Harumi Flag is originally being built as the Olympic Village for the Tokyo 2020 Games." The Hydrogen Insight headline describes the same site as "Tokyo's former Olympic village"; that outlet's article body sits behind a paywall, so only its headline and standfirst could be read.
Caveat
Neither listed source uses the words "Tokyo Bay". Panasonic places the site in "Harumi, Tokyo, the transport nodal connecting urban and bay areas" on an 18-hectare plot; the bay location is a geographic description added by this entry.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
  2. Hydrogen Insight (press)
Claim 2 clm-db2e96752d0c62e5 descriptive
an underground pipeline
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic reports that hydrogen produced at a neighbouring station is "sent out to residential blocks via the pipelines buried under the streets", and that "The work of laying underground pipelines to deliver hydrogen from the station to five residential blocks has already been completed." The same account describes the safety specification agreed with Japan's trade ministry: the pipes are laid no shallower than 120 cm and covered with a protective iron plate. The Hydrogen Insight headline, published 28 March 2024, reports the blocks were about to "start receiving hydrogen by pipeline".
Caveat
The Panasonic account dates from 2019 and describes the pipeline as laid but not yet in service; only the Hydrogen Insight headline dates the start of actual deliveries, and its article body is paywalled. Both sources refer to pipelines in the plural, where this entry writes of a single pipeline.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
  2. Hydrogen Insight (press)
Claim 3 clm-a388d85cb519fdc3 descriptive
pure-hydrogen PEFC (PEM) fuel cells
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic captions the unit as a "Hydrogen fuel cell generator (PEFC) to be installed in each block" and specifies 5 kW per cell at a rated conversion efficiency of 56 per cent (LHV). That the gas is pure hydrogen rather than a blend or a reformed fuel is confirmed by Tokyo Gas's Fumihiko Fukuchi, who describes the regulatory problem as one of "the business of pure hydrogen supply" not being covered by the Gas Utility Industry Law.
Caveat
No listed source writes "PEM"; the abbreviation is this entry's gloss on the Japanese term PEFC (polymer electrolyte fuel cell). The Fuel Cells Works piece is a verbatim republication of the same Panasonic account rather than independent trade reporting, and its text beyond the opening paragraph is behind a membership wall.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
  2. Fuel Cells Works (trade)
Claim 4 clm-9dcb02e95b6e2ab8 descriptive
in each residential block
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic states that it "is responsible for the supply of hydrogen fuel cell generators to each residential block", with six cells combining "to supply electricity, at a total power output of 30 kW to each residential neighborhood". The generators are owned by Harumi Eco Energy, a wholly owned Tokyo Gas subsidiary, which lends them to the blocks' management unions.
Caveat
The same source gives two different block counts: the pipeline is described as reaching "five residential blocks", while the supply coverage is said to encompass "all four residential blocks in HARUMI FLAG". The contradiction sits in the source and is not resolved here.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
Claim 5 clm-dade3e31086f970a descriptive
Japan's first full-scale hydrogen infrastructure in a housing district
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic's account makes the claim twice: "As Japan's first full-scale hydrogen infrastructure, it will leave a legacy as a 'smart town' to future generations", and "The power system producing hydrogen-generated electricity to cover an entire residential area is the first practical application of its kind ever operated in Japan." The Fuel Cells Works headline repeats it: "A City with the First Full-Scale Hydrogen Infrastructure Japan Has Ever Seen".
Caveat
A first-of-its-kind claim made by a member of the consortium that built the system. The Fuel Cells Works item reproduces the same Panasonic text rather than testing the claim, so the two sources are not independent of one another, and no listed source checks it against other Japanese developments.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
  2. Fuel Cells Works (trade)
Claim 6 clm-e5a4c5ea993ee8d1 descriptive
The cells power common areas and shared facilities
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The Tokyo Metropolitan Government plan reported by Panasonic sets out as its second pillar: "Install next-generation fuel cells for common-use spaces and commercial buildings." Panasonic adds that the electricity and heat the generators produce are used by the blocks' management unions, and that heat also goes to "a condominium with a footbath lounge and another that has elderly housing with shared bathing facilities". The Hydrogen Insight standfirst, one of the few lines readable outside its paywall, says: "H2 will be used for electricity generation in communal areas, with waste heat from fuel cells being used for washing pets' paws".
Caveat
Both sources describe electricity for shared spaces only; neither claims that hydrogen powers the individual flats, which Panasonic says are fitted with separate gas-fed EneFarm residential fuel cells and also draw grid electricity.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
  2. Hydrogen Insight (press)
Claim 7 clm-30800687132c41c5 quantitative
5,632 homes
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic gives the build-out of the 18-hectare site as "A total of 5,632 privately-owned/rental flats will be completed by 2024", which is also the year this entry records as the start of operation.
Caveat
The figure counts flats due for completion, owned and rented together, as forecast in 2019; no listed source confirms after the fact how many were finished or occupied.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
Claim 8 clm-91a8b3d4b29013fa descriptive
run by an energy-management system that predicts peak demand
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Panasonic quotes Yoichiro Takagi of Mitsui Fudosan Residential, the developer group's lead company: "Maison Energy Management System (MEMS) collects data on energy supply and consumption per residential block. The data is captured by the server for the area energy management that covers the entire town, and then is analyzed. Analysis results report the current trend of power consumption, predict peak demand, and help lower the reliance on conventional grid-supplied power and in turn reduce the cost for energy." The article adds that a Panasonic-made MEMS sits in each residential block.
Caveat
Described by the developer in 2019 as a design intention. No listed source reports how the prediction has performed since the system went into service, or what it does with the forecast.

Sources carrying this claim

  1. Panasonic Newsroom (consortium partner)
Forensic record — source dossiers, gaps, hashes and the exact revision this page renders

This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.

unreviewed Revision 2026-08-21-unsourced-text-correction effective 2026-07-15 · created 2026-08-21

Awaiting operator and domain-expert review; publication of this revision implies neither.

sha256:870cfa2ab6e546147077c3a3b45e073f25aec498ff58f62cf01f1c76dad0b7c2
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
8
of 8 claims mapped
4
source dossiers
1
publication dates recorded
0
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
HARUMI FLAG consortium (Panasonic / Tokyo Waterfront City Development)
Actor types
private
Funding model
private
Funding description
Not recorded
Cost
Not recorded
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

4 source dossiers

Panasonic Newsroom (consortium partner) news.panasonic.com · 8 linked claims

Open original source ↗

Stable source ID
src-62f3de71acc3d59c
Publisher
Name not classified · news.panasonic.com
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-15
Dossier created
2026-08-21
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Operator/solution-provider account of the hydrogen fuel-cell generators and MEMS energy management.

Descriptive only — not page/paragraph exact
Claims linked
Panasonic Newsroom — HARUMI FLAG, the City That Brings the Future to Today's Tokyo (Part 1 of 2) news.panasonic.com · background

Open original source ↗

Stable source ID
src-a5378cdbfcdd45f7
Publisher
Name not classified · news.panasonic.com
Type / language
web-page · language not classified
Published
2019-09-06
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-15
Dossier created
2026-08-21
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Developer-side account of the district; carries the 5,632 flats in 23 buildings and the projection of 'as many as 12,000 residents by 2024'.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Fuel Cells Works (trade) fuelcellsworks.com · 2 linked claims

Open original source ↗

Stable source ID
src-f004ec802c87015f
Publisher
Name not classified · fuelcellsworks.com
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-15
Dossier created
2026-08-21
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Trade coverage; supports 'first full-scale hydrogen infrastructure in Japan' and PEFC fuel cells in each block.

Descriptive only — not page/paragraph exact
Claims linked
Hydrogen Insight (press) hydrogeninsight.com · 3 linked claims

Open original source ↗

Stable source ID
src-ffc169f436b381dc
Publisher
Name not classified · hydrogeninsight.com
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-15
Dossier created
2026-08-21
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Reporting on the pipeline delivering hydrogen to the blocks.

Descriptive only — not page/paragraph exact
Claims linked
Known limits of this passport
  • Publisher names and source languages have not yet been classified; domains are recorded without guessing.
  • Existing source notes are descriptive locators, not page- or paragraph-exact citations.
  • A missing archive, publication date or content hash is shown as null rather than inferred.
  • The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim.

Continue exploring

Compare this project

🇦🇪 Masdar City · Abu Dhabi Masdar bet a whole city on solar in 2008 and fell short; Harumi delivered Japan's first full hydrogen-powered housing in 2024. 🇨🇭 GeniLac Lake-Water Thermal Grid · Geneva Two district-energy bets: Harumi Flag heats Tokyo homes with piped hydrogen (2024); Geneva cools buildings with cold lake water (2009). 🇸🇬 Marina Bay District Cooling Network · Singapore Two district-energy systems: Tokyo's Harumi Flag pipes hydrogen (2024); Singapore chills a district from central plants (2006).

Explore the wider context

⚗️ Hydrogen guide🏙️ Tokyo city profile⚡ Energy projects🧪 Coming to Life📖 Fuel cell📖 Smart grid📖 Building performance standard (BPS)
📎 Cite this project

1001 Smart Cities (2026). “HARUMI FLAG Hydrogen Infrastructure” — Tokyo, Japan. The Smart City Atlas. https://1001smartcities.org/projects/harumi-flag-hydrogen/ (last verified 2026-07-15). Data: CC BY 4.0.

The underlying data is free to reuse with attribution — see the open data page.

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