Green hydrogen explained: ask where the electricity comes from

Green hydrogen usually describes hydrogen produced by splitting water with renewable electricity. That is a useful starting point, but it leaves several practical questions unanswered. Where does the electricity come from? When does the electrolyser run? What happens between the production site and the customer? Those details determine how useful the label is for a particular purchase or project.

For a driver, a station's fuel claim needs evidence from its supply chain. For a fleet or developer, a renewable production announcement needs a delivery plan and a credible customer. This guide explains what to ask without assuming that every green label describes the same emissions, operating costs, or level of readiness.

Start with the production process

An electrolyser uses electricity to separate water into hydrogen and oxygen. The Department of Energy's electrolysis overview explains the process and why the electricity source affects its environmental performance. Renewable electricity can supply that process, but hydrogen still needs conditioning, storage, and sometimes transport before it becomes a usable product at a customer's site.

It helps to distinguish the equipment from the fuel claim. Installing an electrolyser establishes a production pathway. It does not, on its own, establish which electricity supplies it or the emissions associated with each kilogram delivered. Our electrolysis guide follows the process from inputs to usable output, including the equipment around the electrolyser.

Ask what the reported production figure measures. A project's installed electrical capacity, theoretical annual output, and contracted delivery volume are different quantities. A large capacity announcement may assume operating hours that have not yet been secured. Look for the planned electricity supply, expected utilisation, and actual product specifications before translating equipment size into reliable fuel availability.

Examine the electricity arrangement

A project might connect directly to a renewable generator, buy electricity through a contract, or draw from a grid while using an accounting arrangement to support its claim. These approaches have different physical and contractual characteristics. Ask the supplier to describe its arrangement in plain language and identify the records used to substantiate renewable sourcing.

Time matters as well as annual totals. Wind and solar output vary, while an industrial customer's demand may continue through periods of low generation. The project can respond with storage, flexible production, additional supply arrangements, or some combination. Each choice changes the equipment required and the way the renewable claim should be explained to a buyer.

Treat an annual renewable electricity purchase and continuous operation from a dedicated generator as separate descriptions. Neither phrase provides the complete answer by itself. A useful disclosure explains the geographical boundary, time matching, and treatment of electricity drawn outside the preferred supply arrangement. If the project relies on certification, request the applicable scheme and supporting documentation.

Compare emissions using the same boundary

Colour labels are shorthand rather than complete measurements. The IEA's work on hydrogen definitions discusses emissions intensity as a basis for comparing pathways. A numerical claim becomes more useful when it identifies its units, calculation method, included stages, and verification. Without those details, two impressive figures can describe different parts of the supply chain.

For example, one supplier might report emissions at the production gate while another includes compression and delivery. A customer comparing those figures could mistake a difference in reporting boundary for a difference in performance. Ask for like-for-like results at the point that matters to your decision, such as delivered hydrogen at a depot or a public station.

Separate measured results from forecasts. A planned renewable project can estimate its performance using expected electricity and transport arrangements, but those estimates are not operating records. Record which assumptions remain open. A transparent forecast can still support a decision, provided the buyer understands what could change and how the contract will handle that change.

Check the water question properly

Water is an input to electrolysis, so local water availability and treatment deserve attention. The amount used by the complete facility includes more than the reaction itself. Treatment losses, cooling arrangements, and other site services can affect demand. Ask for the site's water balance rather than extrapolating a chemical minimum into a claim about total facility consumption.

Location changes the significance of that demand. The same volume can have different implications in a water-stressed area and a site with an appropriate, dependable industrial supply. A credible proposal identifies its water source, required quality, treatment process, and discharge arrangements. These are normal project questions, not reasons to assume that every electrolysis site has the same constraint.

Avoid describing hydrogen as energy made from water alone. Electricity supplies the energy that drives the separation process. Water supplies the material being split. Keeping those roles clear makes conversations about costs and environmental performance more accurate, and prevents a misleading suggestion that a water supply is equivalent to a free or unlimited energy source.

Follow the route to the customer

Hydrogen at a production site is not automatically fuel at a roadside dispenser. It may require compression, storage, transport, quality checks, and further conditioning. Our production pathways comparison provides a consistent framework for examining these steps. A buyer should ask who is responsible for each stage and where ownership or custody changes.

Delivery distance and demand pattern influence the chosen arrangement. A nearby industrial customer with steady demand presents a different problem from several small stations spread across a region. Neither case can be assessed from the electrolyser's nameplate capacity alone. Request a description of delivery frequency, storage capacity, backup arrangements, and the consequences of an interruption.

For road fuel, verify that the product meets the vehicle and station requirements through the actual supply chain. Renewable sourcing does not replace fuel-quality controls or suitable dispensing equipment. A green production claim and a compatible, accessible refuelling location answer different questions. Drivers still need to check their vehicle's approved fuel and the station's supported service.

Read the commercial proposal carefully

A quoted hydrogen price needs a clear delivery point and service boundary. Does it cover production only, transport to the customer, or dispensing into a vehicle? What quantity is committed, and what happens if demand is lower than expected? Comparing prices without those terms can hide costs that appear later as transport charges, minimum purchases, or equipment obligations.

Electricity costs and operating hours both influence the production economics. Flexible operation may capture favourable electricity periods while reducing annual output from a given plant. Longer operation can spread some fixed costs across more hydrogen but requires suitable power arrangements. Ask the developer to show its assumptions rather than treating either operating strategy as automatically cheaper.

Keep subsidies, certificates, and other support separate from the physical process. They may affect a project's commercial case, but eligibility and duration need their own verification. Do not assume a benefit applies to your organisation because it appears in an announcement. For an important purchase, obtain current programme information and advice appropriate to the jurisdiction and contract.

Turn the label into useful questions

Before relying on a green hydrogen claim, request four connected descriptions: how the hydrogen is produced, how electricity sourcing is evidenced, how delivered emissions are calculated, and how supply reaches the customer. The answer should distinguish current operating performance from future plans. Missing information is a reason to investigate further, rather than a reason to invent an optimistic assumption.

For an announced facility, our renewable project guide helps distinguish development milestones from operating output. For a vehicle journey, use the station map to identify a possible stop and verify access and current service with the operator. Green hydrogen is most useful as a specific, supported supply description that connects environmental claims with dependable delivery.