Technical challenge
Efficiency changes with equipment load, starts, temperature, storage pressure, transport distance and the useful heat or power recovered.
Introduction
Efficiency Losses Through the Complete Energy Chain.
Measure every conversion step so hydrogen is compared fairly with direct electrification and other energy pathways.
Energy is lost during electrolysis, conditioning, compression or conversion, storage and final use; auxiliary equipment and part-load operation add further demand.
Useful output, not input energy alone, should be the common basis for comparing electricity, hydrogen, batteries and fuels.
The Challenge
Define the service problem before selecting technology.
Because renewable electricity has valuable direct uses in New Zealand, projects should demonstrate why conversion to hydrogen creates sufficient additional value.
Business challenge
Reliability, utilisation, logistics, asset life and future demand must be translated into a commercial requirement that can be compared consistently across competing solutions.
Human challenge
The selected pathway must be understandable, maintainable and safe for the people operating it. Training, access, disruption, noise, local air quality and confidence in support can be as important as equipment performance.
The Goal
Turn the challenge into measurable project requirements.
The goal is to deliver the required service with a practical combination of efficiency, electrification, renewable energy, storage, hydrogen and operational controls—not to maximise any one technology.
Information to establish early
Define system boundaries, metered inputs, usable hydrogen, auxiliary energy, losses, final useful output and emissions factors.
- Define the required output, operating pattern and acceptable interruption.
- Separate peak capacity from total daily or annual energy.
- Record present costs, constraints and service problems.
- Identify safety, consent, access and workforce requirements.
- Agree measurable performance, emissions and commercial outcomes.
Understanding the Technology
Follow the complete energy and hydrogen pathway.
Create a Sankey-style energy balance from renewable electricity through production, conditioning, storage, delivery and final useful energy.
01
Primary input
Identify the electricity, renewable resource, delivered fuel, water or existing process input and when it is available.
02
Hydrogen supply
Define production or delivery, hydrogen quality, pressure, usable kilograms, storage duration and replenishment.
03
Conversion and control
Select equipment around useful output, response, efficiency, operating hours, redundancy and integration with existing assets.
04
Final service
Measure the useful transport, electricity, heat or industrial service actually delivered to the user.
Important: equipment ratings describe only part of a solution. The system boundary must include energy supply, conversion losses, auxiliaries, storage, delivery and the operating reserve.
What are the Options?
Compare hydrogen with direct electrification and established alternatives.
Where hydrogen may fit
Lower efficiency can be justified where hydrogen provides duration, mobility, process chemistry, storage or logistics that direct electricity cannot provide.
Where another pathway may be better
Where a service can be directly electrified, electric motors, heat pumps or batteries will often require substantially less renewable generation.
Decision principle: compare complete systems against the same operating requirement, site conditions, safety obligations, emissions boundary and lifecycle period.
Typical Use Cases
Look first for demanding applications with a clear service value.
Because renewable electricity has valuable direct uses in New Zealand, projects should demonstrate why conversion to hydrogen creates sufficient additional value.
Direct electricity to motion
Battery-electric vehicles avoid electrolysis and fuel-cell conversion, making them the efficiency benchmark where route and charging fit.
Electricity to hydrogen to motion
Hydrogen adds conversion losses but can offer faster replenishment, lower onboard mass for some duties and transportable stored energy.
Hydrogen used directly
Using hydrogen as a molecule in industry avoids reconversion to electricity and may create more value than electricity storage.
Solution Size
Size the service, energy pathway and reserve together.
Efficiency changes with equipment load, starts, temperature, storage pressure, transport distance and the useful heat or power recovered.
Calculate useful output from measured electricity, hydrogen kilograms and final service. A high-efficiency device can still be uneconomic if infrastructure is poorly utilised.
| Measure | Why it matters | Evidence to collect |
|---|---|---|
| Maximum output | Sets peak equipment and connection capacity. | Measured peaks, route demand, starting loads or process rate. |
| Useful energy | Determines fuel, storage and replenishment. | Hourly, daily, seasonal or route-level consumption. |
| Operating window | Shapes utilisation, recovery and maintenance. | Shifts, dwell time, event duration and annual hours. |
| Reserve and redundancy | Protects service through credible failures or delays. | Criticality, outage tolerance, alternative supply and resupply time. |
These measures structure an initial conversation; they are not a design or equipment recommendation.
Benefits and Limitations
Understand both the potential value and the hard constraints.
Potential benefits
Transparent efficiency accounting improves equipment sizing, operating cost, emissions claims and technology selection.
Limitations to resolve
Vendor efficiencies may use different boundaries and ideal conditions; actual auxiliary loads and part-load performance must be verified.
Practical Considerations
Plan the site, supply chain and operating organisation.
Meter electricity, water, hydrogen mass and pressure, delivery energy and useful end output at consistent points.
Site and access
Confirm space, access, foundations, ventilation, weather exposure, security, vehicle movements and future expansion.
Operations
Define trained roles, monitoring, inspections, planned maintenance, spare parts, alarms and emergency response.
Supply resilience
Test production or delivery capacity, hydrogen quality, refill intervals, route disruption, reserve and recovery after an event.
Safety
Use application-specific design, controls and competent advice.
Efficiency analysis does not replace engineering safety requirements; the physical pressure and gas system still requires compliant design.
Hazard controls
Address loss of containment, ignition, ventilation, pressure, impact, electrical hazards, hazardous areas and emergency isolation.
People and procedures
Define competence, training, inspection, permits, signage, access control, incident response and communication with emergency services.
Site-specific compliance
Applicable requirements depend on quantities, pressure, equipment, location and activity. Separation distances and approvals cannot be selected from a generic web page.
Commercial Considerations
Compare the cost of delivering the required service.
Convert losses into renewable capacity, grid demand, kilograms, operating cost and delivered-service cost rather than treating efficiency as an abstract percentage.
Capital
Equipment, civil works, connection, storage, controls, consent, engineering and contingency.
Operating
Electricity, hydrogen, delivery, labour, maintenance, inspections, consumables and replacement parts.
Utilisation
Annual output, shared infrastructure, contracted demand and the effect of idle capacity on unit cost.
Value and risk
Avoided downtime, emissions, noise, constrained infrastructure, fuel volatility, residual value and technology maturity.
New Zealand Examples
Use verified local evidence and state project maturity clearly.
New Zealand hydrogen activity includes operational trials, demonstrations, commercial proposals and developing supply chains. Examples added to this page should identify what operated, where, for how long, the measured output and the source of the claim.
Measured vehicle trial
NZ Post XCIENT exceeds 100,000 km
EECA reports the NZ Post fuel-cell truck completed over 100,000 km, saved more than 40,000 litres of diesel and reduced CO₂ by over 110 tonnes. The hydrogen production pathway still determines full-chain emissions.
Read the EECA case studyNZ comparison evidence
Battery trucks on Auckland routes
EECA documents Reliance Transport's two Scania 25P battery-electric trucks operating point-to-point freight in Auckland from 2022, illustrating the direct-electric alternative.
Read the battery-truck caseApplication Evidence
What these examples establish
The two NZ cases support a route-by-route comparison. They do not prove one drivetrain is universally superior; infrastructure, payload, distance, dwell and fuel source determine the complete-chain result.
Project Process
Progress from interest to an evidence-based proposal.
01
Discovery
Confirm the service problem, stakeholders, timing, present system and reasons for considering change.
02
Measure
Collect operating data, site constraints, supply information, safety requirements and commercial assumptions.
03
Compare
Screen credible pathways on the same system boundary and document exclusions, sensitivity and uncertainty.
04
Develop
Complete concept design, stakeholder engagement, approvals, procurement, implementation and performance verification.
Suitable Products
Build the system from compatible supply, storage and conversion components.
Product suitability depends on the measured requirement and complete system design. Review the current ranges as starting points rather than standalone recommendations.
Hydrogen supply and production
Review electrolyser and supply options around required quality, production rate and operating schedule.
Explore product rangesStorage and delivery
Match usable kilograms, pressure, refill route, transport and reserve to the operating requirement.
Explore storage productsFuel-cell power and integration
Coordinate continuous power, transient response, batteries, inverters, controls and monitoring.
Explore power systemsFAQ
Common early questions.
Is hydrogen automatically the best low-emissions option?
No. Where a service can be directly electrified, electric motors, heat pumps or batteries will often require substantially less renewable generation. The correct comparison uses the same final service, site conditions, reliability and lifecycle boundary.
What information is needed before selecting equipment?
Define system boundaries, metered inputs, usable hydrogen, auxiliary energy, losses, final useful output and emissions factors.
Where can hydrogen add value?
Lower efficiency can be justified where hydrogen provides duration, mobility, process chemistry, storage or logistics that direct electricity cannot provide.
What usually has the greatest effect on project cost?
Convert losses into renewable capacity, grid demand, kilograms, operating cost and delivered-service cost rather than treating efficiency as an abstract percentage.
Can this page be used to determine safety distances?
No. Required controls and separation distances depend on the actual inventory, pressure, equipment, activity and site. Use current requirements and appropriately competent project specialists.
Scope and Limitations
Use this page for orientation, not final design or professional advice.
This material is general information for early customer and project conversations. It does not replace engineering, financial, legal, safety, environmental or regulatory advice. Technology performance, prices, hydrogen availability, standards and legal requirements change; verify current information for the actual New Zealand site and proposed activity.
Further Reading
Continue with authoritative and current information.
Project Support
Define the requirement before selecting equipment.
Share the operating requirement, location, timing and constraints so the next questions and evidence can be identified.