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Single-phase and three-phase boundaries for a multigenerational home in New Zealand

New Zealand planning guidance for a specific property and load boundary. Avoid relying on one inaccessible control point. H2OME remains in early development.

Single-phase and three-phase boundaries: the decision to make

The phase arrangement influences which loads can be supported and how demand is distributed. A property may have three-phase machinery alongside single-phase household appliances. Supply type must be established from authorised service information and professional inspection, not guessed from appliance size.

A 10 kW design target does not establish phase capability, phase balancing or compatibility with a three-phase motor. Ask for the actual proposed equipment configuration and tested limitations. Treat large production loads as a separate engineering scope.

Priorities for multigenerational home

Multiple hot-water cylinders, heaters and kitchen appliances need a staggered-use assessment rather than a blanket inclusion.

The property boundary

Different sleeping patterns, separate kitchenettes and mobility needs can extend the essential operating window. A single family representative may miss appliances used in another part of the house.

In a multigenerational home, locate the real circuits supporting two refrigeration loads, assumed combined average through professional assessment. The additional single-phase load cannot be divided across phases merely to make a worksheet fit; each phase and any multiphase equipment need their actual design limits.

Avoid relying on one inaccessible control point. Accessibility and medical needs require their own contingency arrangements. An unproven energy system cannot be the sole basis for a care or evacuation decision.

A worked demand worksheet

All numbers below are hypothetical teaching inputs, not measured appliance specifications or product performance. The topic-specific extra load is separate from the base set; omit it if your real inventory already counts it. This worksheet does not include conversion overhead, protection design or a contingency allowance.

For a multigenerational home, assume the selected base loads average 0.36 kW for 16 hours: 0.36 × 16 = 5.76 kWh. Separately, an additional single-phase appliance draws an assumed 900 W for 1 hours: (900 ÷ 1,000) × 1 = 0.9 kWh. The combined illustrative demand is 6.66 kWh.

This total cannot be spread across phases by arithmetic unless the physical equipment and circuit design permit it.

For arithmetic only, if the complete storage chain had a hypothetical 30% round-trip efficiency, delivering 6.66 kWh would require 6.66 ÷ 0.30 = 22.2 kWh of charging input. This is not a measured H2OME efficiency or recovery result. Ongoing demand during charging would add to the required input.

Base assumptions

Base operating window: 16 hours. Extra illustrative load: An additional single-phase appliance, 900 W for 1 hours. Replace every input with a measured or professionally established value.

Topic checks

Property checks

Professional review in New Zealand

In New Zealand, discuss supply arrangements and connection questions with your electricity retailer and distributor. Ask the local council about relevant siting, building and water-use requirements. Use appropriately qualified electrical and hydrogen professionals, and refer workplace safety questions to WorkSafe guidance. This page does not establish a consent or compliance outcome.

For medically dependent people in New Zealand, register with your electricity retailer, the company that bills you, and keep that registration current. Re-register when switching retailers; ask the retailer how the distributor is informed and what clinical confirmation is needed. Follow the clinician and equipment provider's contingency plan. Registration does not guarantee uninterrupted electricity, and H2OME is not a substitute for that plan.

H2OME is in early development. Its 10 kW output figure is a design target, not a proven specification. There is no confirmed price, certification, commercial availability or guaranteed runtime in this guide.

Hydrogen is an energy store, not free energy. Grid input, wind and micro-hydro are the charging options considered here. Each requires its own supply assessment. Do not install hydrogen equipment, modify fixed wiring, bypass protection or improvise a connection from this guide.

Background sources

These official resources provide energy, consumer and technical background. They are not endorsements of H2OME, proof of its performance or a substitute for site-specific professional advice.

Questions

What changes for a multigenerational home?

Different sleeping patterns, separate kitchenettes and mobility needs can extend the essential operating window. A single family representative may miss appliances used in another part of the house. Avoid relying on one inaccessible control point.

Does this calculation show how long H2OME would run a multigenerational home?

No. The 6.66 kWh total is an illustrative demand worksheet, not a runtime result. Actual appliance measurements, usable storage output, starting demand, conversion overhead and reserve limits are needed. The 10 kW design target is not demonstrated output capability.

Who should review the proposal?

In New Zealand, discuss supply arrangements and connection questions with your electricity retailer and distributor. Ask the local council about relevant siting, building and water-use requirements. Use appropriately qualified electrical and hydrogen professionals, and refer workplace safety questions to WorkSafe guidance. This page does not establish a consent or compliance outcome. Use the worksheet to brief the relevant professionals, not to install, modify or operate hydrogen equipment.

Continue the assessment

Contact us

Ask us about H2OME, tell us about your property or register your interest in the proposed system. We are in early development. No payment or purchase commitment; contacting us does not guarantee a pilot installation.