Sustainable Systems / Energy Engineering
—
2026
Sustainable Rural Energy System
My Role
Design Engineer — responsible for energy sizing, demand analysis and determining the required solar and battery capacity.
Project Type
University Team Sustainable Engineering Project
University Subject
41201 Designing Sustainable Engineering Projects
Tools & Technologies
Energy Sizing · LCA · LCC · NPV / IRR · MCDM · Project Planning
Team Context
Six-person university project evaluating a long-term sustainable energy system for a rural NSW property.
Overview
The project developed a sustainable energy system for a rural property at 407 Squires Road, Wootton NSW.
Instead of choosing technology based only on annual generation, the team evaluated the system as a complete lifecycle decision. Household demand, solar resource, battery storage, passive efficiency, EV readiness, lifecycle impacts, long-term cost and project implementation influenced the recommendation.
The selected solution was a grid-connected 8.645 kW solar-battery system with 22.08 kWh usable storage.
My Contribution
What I owned
As a Design Engineer, my main responsibility was the energy-sizing component of the proposal. I analysed the property's electricity demand and used the required annual generation, daily consumption and peak demand to determine an appropriate renewable-energy system size. I contributed to determining the required photovoltaic capacity and battery storage needed to meet the client's current demand while supporting resilience and future EV integration.
The Challenge
The client needed a system that could meet household demand, reduce fossil-fuel dependence, support future EV charging and remain environmentally and financially sensible over a long lifecycle.
The challenge was to balance technical adequacy with capital cost, lifecycle impact, resilience, maintenance and future expansion.
Constraints
Annual household demand: ~9,199.99 kWh/year.
Average demand: ~25.21 kWh/day.
Peak recorded daily demand: ~53.8 kWh/day.
Seasonal solar variation.
Reliable long-term energy supply.
Future EV charging.
Long lifecycle financial evaluation.
Passive demand reduction and digital integration.
Environmental, economic and social sustainability.
System & Design Development
How the system took shape
System Architecture
Grid
↔ hybrid inverter / energy-control system
↔ 8.645 kW PV array
↔ 22.08 kWh usable battery storage
↔ household / shed loads
↔ future EV charging
Passive measures reduce demand before additional generation is added. Digital monitoring tracks generation, storage, load and grid exchange.
Design Process
Household electricity use was analysed to establish daily, annual and peak requirements.
Solar sizing used an adopted Wootton yield of approximately 1,401.6 kWh/kW/year. The selected configuration used 19 × 455 W modules, giving 8.645 kW PV capacity and expected generation of ~12,118.83 kWh/year.
Battery sizing, passive energy measures and EV readiness were integrated.
Alternative concepts were compared through lifecycle assessment, lifecycle costing and multi-criteria decision making. Solar-battery was preferred over solar-wind-battery because it offered a better balance of cost, simplicity, environmental impact and long-term performance.
Key engineering decisions
Prefer solar-battery over solar-wind-battery
Wind improved source diversity but increased cost, maintenance, structural requirements and site uncertainty. Solar-battery delivered the required outcome through a simpler architecture and stronger financial case.
Reduce demand before only increasing generation
Passive insulation, shading and roof ventilation were included as part of the energy system, reducing demand instead of relying only on more generation and storage.
Design for EV integration without assuming full off-grid operation
The battery was sized for load shifting and short-term resilience rather than peak-day complete autonomy. EV charging is intended to use solar surplus when possible and grid support when required.
Testing & iteration
This was primarily an analytical design-validation project.
Energy sizing was checked against annual demand, average demand, peak load and solar yield. Alternative configurations were compared through lifecycle analysis, financial cash-flow modelling and multi-criteria evaluation.
The final report also incorporated feedback from the earlier proposal stage by putting the recommendation and measured outcomes at the front of the argument.
Final outcome
The project produced a technically sized, financially evaluated and lifecycle-aware sustainable energy proposal combining generation, storage, passive demand reduction, EV readiness and digital monitoring.
Results & Measurements
The final recommendation was an 8.645 kW grid-connected solar-battery system with 22.08 kWh usable storage.
Expected generation is ~12,118.83 kWh/year versus current demand of ~9,199.99 kWh/year.
With EV integration, the model produced an NPV of ~A$31,098.73 and IRR of ~13.42%.
Limitations
The design depends on assumptions about future energy prices, inflation, degradation, EV use, solar yield and maintenance costs.
Final installation would require site survey, network approval, electrical verification and supplier quotations.
Reflection
The project showed that the system with the greatest theoretical generation is not automatically the best engineering solution if it creates higher cost, maintenance and lifecycle impacts.
The strongest part of the process was connecting technical sizing to lifecycle and financial consequences.
Project Links