Solar planning for container and modular homes
Plan energy needs before choosing a solar system.
Off-grid power can suit some remote properties, but it requires careful load assessment, battery planning and specialist system design. This guide explains the early questions to discuss with a qualified solar professional.
Start with the objective
Grid connected, battery backup or fully off-grid?
These systems solve different problems. Most Australian rooftop solar systems remain grid connected, while a fully off-grid system must supply the property independently through changing weather and seasonal demand.
- Lower daytime grid consumption
- Store excess solar energy for later use
- Provide selected backup circuits during outages
- Operate independently where grid connection is impractical
Understand the difference
Off-grid systems require a larger safety margin.
Grid-connected solar
The grid can supply electricity when solar generation is low. Batteries may improve self-consumption or provide backup, but only when the system is designed and configured for those functions.
Fully off-grid solar
The system must cover the full load without mains support. That usually means substantial battery storage, specialist controls and often a backup generator for extended low-sun periods.
Off-grid is not automatically cheaper. The Australian Government’s Solar Consumer Guide notes that stand-alone systems generally have higher upfront costs and require specialist design experience.
Four inputs that shape the system
Give the solar designer accurate project information.
System size should be based on the real site and load profile—not only the size of the home.
Daily loads
List cooking, hot water, refrigeration, lighting, pumps, air conditioning and other appliances.
Timing of use
When electricity is used matters, especially overnight and during periods of low generation.
Site conditions
Available roof area, orientation, shading, climate and equipment locations affect design.
Future demand
Allow for planned air conditioning, pumps, workshops, electric vehicles or additional buildings.
Coordinate early
Solar planning should inform the home and site design.
Early coordination can reduce later changes to the roof, switchboard, service routes and equipment locations.
Prepare the load brief
Document appliances, occupancy, operating hours and backup expectations.
Review the site
Assess roof space, shading, orientation, battery location and access for maintenance.
Engage a specialist
Have an experienced solar professional size the panels, inverter, battery and controls.
Coordinate the build
Confirm structural, electrical and service requirements before construction is finalised.
Questions to ask
Before accepting a solar or battery proposal.
What assumptions were used?
Ask how electricity use, seasonal solar generation, shading, battery reserve and future demand were allowed for.
Will it provide power during an outage?
Many grid-connected systems shut down during a blackout. Backup or islanding must be specifically designed and configured.
Where will the battery be installed?
Battery location is subject to safety and installation requirements. Confirm the proposed position early with the installer.
Who completes the electrical work?
Electrical work in Queensland must be completed by appropriately licensed people. Check licences and responsibilities before work begins.
Queensland electrical licencesCheck licensing information and search electrical contractor licence details.
This page provides general planning information only. My Own Modular Home does not provide solar-system design or electrical installation through this guide. Obtain project-specific advice and quotations from appropriately qualified and licensed solar and electrical professionals.