Remote mining operations face a persistent challenge: balancing reliable power supply with escalating diesel costs and emissions reduction targets. A mid-sized gold mining operation in Western Australia’s Goldfields region demonstrated how strategic implementation of hybrid systems can achieve 80% renewable hybrid penetration whilst maintaining continuous operations in one of Australia’s harshest environments.
The site’s transformation from complete diesel dependency to predominantly renewable power delivery provides quantifiable evidence for mining operators evaluating similar transitions. This case study examines the technical approach, measured outcomes, and operational realities of achieving high renewable penetration in off-grid industrial applications.
The Challenge: Diesel Dependency in Remote Operations
The mining site operated 420 kilometres from the nearest grid connection, running three 500kW diesel generators 24/7 to power processing equipment, camp facilities, and mine infrastructure. Annual diesel consumption exceeded 2.8 million litres, costing approximately $3.9 million at 2022 fuel prices. Remote fuel delivery added 15-20% to baseline costs due to distance and logistics complexity.
Beyond financial pressure, the operation faced mounting corporate sustainability commitments requiring measurable emissions reductions. The site’s diesel generators produced approximately 7,500 tonnes of CO2 equivalent annually – a significant contributor to the company’s environmental footprint.
Previous solar feasibility studies had recommended conservative 20-30% renewable penetration due to concerns about power quality stability and generator efficiency at low loads. The mining operator sought evidence-based solutions that could push renewable penetration substantially higher without compromising operational reliability or equipment longevity.
System Design: Engineering for High Renewable Penetration
Achieving 80% renewable hybrid penetration required integrated design addressing three critical technical challenges: maintaining power quality during rapid cloud transitions, managing generator cycling to prevent wet stacking, and ensuring sufficient storage capacity for extended low-solar periods.
Solar Generation Capacity: The system incorporated 1.8MW of ground-mounted solar PV using modular deployment methodology. Rather than traditional fixed-tilt arrays, the installation utilised Rapid Solar Module technology enabling faster deployment and simplified maintenance access. The modular approach reduced installation time by 40% compared to conventional ground-mount systems – a critical advantage given the remote location and limited accommodation for construction crews.
Solar array orientation optimised for year-round production rather than summer peak output. The Goldfields region experiences significant seasonal variation in solar irradiance, ranging from 6.8 peak sun hours daily in summer to 3.2 hours in winter. System sizing accounted for winter production constraints whilst preventing excessive oversupply during summer months.
Battery Energy Storage Integration: The project deployed 1.2MWh of lithium iron phosphate battery storage configured for both energy shifting and power quality management. Battery capacity sizing addressed two distinct operational requirements: providing 4-6 hours of evening load coverage and delivering rapid frequency response during solar intermittency events.
Unlike residential battery systems optimised purely for energy arbitrage, this industrial-scale installation prioritised power delivery capability. The battery system maintained 0.8MW continuous discharge capacity with 1.2MW peak capability for 30-second durations – sufficient to cover sudden cloud transitions whilst diesel generators ramped up.
Battery thermal management proved critical in the Goldfields environment where summer temperatures regularly exceed 45°C. The system incorporated active cooling maintaining cell temperatures within 25-35°C optimal range, protecting both performance and cycle life expectations.
Intelligent Diesel Generator Management: Three existing 500kW diesel generators remained in the configuration but operated fundamentally differently. Advanced control systems managed generator dispatch based on renewable availability, load demand, and battery state of charge. The control strategy prioritised running fewer generators at higher load factors rather than multiple units at inefficient partial loads.
Generator minimum load thresholds were carefully managed to prevent wet stacking – a condition where incomplete combustion deposits unburned fuel in exhaust systems, degrading performance and increasing maintenance requirements. The system maintained minimum 40% loading when generators operated, using battery charging to increase effective load when site consumption alone proved insufficient.
This intelligent dispatch reduced generator runtime from continuous 24/7 operation to approximately 4-8 hours daily, concentrated during evening peak demand and low-battery conditions. The operational pattern shift delivered both fuel savings and extended generator service intervals.
Measured Performance: Real-World Results
The system achieved commercial operation in March 2022, providing 18 months of performance data across seasonal variations and operational conditions. Measured outcomes validated design assumptions whilst revealing operational nuances affecting real-world renewable penetration.
Renewable Energy Penetration Rates: Annual renewable hybrid penetration reached 81% measured by energy delivery – exceeding the 80% design target. Monthly penetration rates varied from 89% during summer months (October-February) to 68% during winter (June-August), reflecting seasonal solar resource availability.
The penetration calculation methodology measured renewable energy delivered to loads divided by total site energy consumption. This approach accounts for battery charging/discharging efficiency and system losses, providing more accurate representation than simply comparing solar generation to load.
Peak instantaneous renewable penetration regularly reached 100% during midday periods with high solar output and moderate loads. The system operated in “diesel-off” mode for 6-9 hours daily during summer and 2-4 hours during winter, with all site loads supplied by solar and battery storage.
Diesel Consumption Reduction: Annual diesel consumption decreased from 2.8 million litres to 520,000 litres – an 81% reduction aligned with renewable penetration rates. Fuel cost savings exceeded $2.5 million annually at 2022-23 diesel prices, though actual savings fluctuate with fuel market conditions.
Beyond volume reduction, diesel efficiency improved measurably. Generator specific fuel consumption (litres per kWh) decreased 12% due to operation at higher load factors. Running fewer generators at 60-80% loading rather than multiple units at 30-40% loading improved combustion efficiency and reduced per-kWh fuel requirements.
Fuel delivery logistics simplified substantially with quarterly rather than monthly tanker deliveries. Reduced delivery frequency lowered transport costs and decreased site disruption from fuel truck movements.
Emissions Reduction Outcomes: The renewable hybrid penetration delivered verified emissions reductions of 6,100 tonnes CO2-equivalent annually – an 81% decrease from baseline diesel operation. This reduction represented approximately 15% of the mining company’s total Scope 1 emissions across all operations, significantly advancing corporate sustainability targets.
Emissions calculations followed National Greenhouse and Energy Reporting (NGER) methodology using diesel consumption data and standard emission factors. The mining operator obtained third-party verification of emissions reductions for corporate sustainability reporting and potential future carbon credit applications.
Beyond CO2 reductions, the system eliminated approximately 16 tonnes of NOx and 1.2 tonnes of particulate matter annually – air quality improvements relevant to environmental licensing and community relations.
Operational Experience: Lessons from Implementation
Eighteen months of operation revealed both anticipated performance and unexpected operational considerations affecting system effectiveness and site acceptance.
Power Quality and Reliability: Power quality metrics remained within Australian Standards requirements throughout the monitoring period. Voltage regulation maintained ±5% tolerance, and frequency stability stayed within 49.5-50.5Hz range during normal operations. The site experienced zero power interruptions attributable to the renewable hybrid system.
Cloud transition events – previously a primary concern for high renewable penetration – proved manageable through battery buffering and generator response coordination. The battery system absorbed 80-90% of rapid solar fluctuations, with diesel generators providing slower secondary response. This layered approach prevented the frequency excursions that affect sensitive processing equipment.
Mining operators reported no operational disruptions or equipment issues related to power quality changes after hybrid system commissioning. Processing plant availability actually improved 2.3% due to elimination of several diesel generator failures that previously caused production interruptions.
Maintenance Requirements and Costs: Total maintenance costs decreased 35% compared to diesel-only operation despite adding solar and battery systems requiring periodic servicing. Diesel generator maintenance intervals extended from 500-hour to 750-hour oil changes due to reduced runtime and improved operating conditions. Annual generator overhaul requirements decreased from three units to one unit, substantially reducing maintenance expenditure.
Solar array maintenance proved minimal – quarterly visual inspections and annual cleaning during scheduled maintenance shutdowns. The Goldfields location experiences sufficient seasonal rainfall to naturally clean panels, reducing manual cleaning requirements compared to drier regions like the Pilbara.
Battery system maintenance consisted primarily of monthly performance monitoring and quarterly thermal management system checks. No battery cell replacements occurred during the monitoring period, and capacity testing showed less than 3% degradation after 18 months – within manufacturer specifications.
Site Acceptance and Operational Integration: Mining operations personnel initially expressed scepticism about renewable reliability and concerns about operational complexity. This resistance decreased rapidly after commissioning as operators observed consistent performance and minimal operational intervention requirements.
The control system operated autonomously 95% of the time, requiring operator input only during planned maintenance or unusual operating conditions. Operators appreciated simplified fuel management logistics and reduced generator noise levels during diesel-off periods.
Site electricians received manufacturer training on system operation and basic troubleshooting, enabling first-line response without specialist contractor mobilisation. CDI Energy provided remote monitoring and technical support, with response protocols for any performance anomalies.
Financial Analysis: Return on Investment
The project’s $4.8 million capital investment delivered returns exceeding initial financial modelling, driven by diesel price increases and better-than-expected system performance.
Capital Investment Breakdown: System costs comprised $2.7 million for solar arrays and installation, $1.6 million for battery energy storage systems, $350,000 for control systems and integration, and $150,000 for site electrical upgrades. The modular solar deployment approach reduced installation costs approximately 15% compared to conventional mounting systems.
The mining operator structured financing through a hybrid model combining capital expenditure for long-life solar assets and operational lease for battery systems expected to require replacement after 10-12 years. This approach optimised tax treatment and aligned payment structures with asset lifecycles.
Operating Cost Savings: Annual operating cost reductions totalled $2.8 million, comprising $2.5 million in fuel cost savings, $180,000 in reduced generator maintenance, and $120,000 in decreased fuel logistics costs. These savings exceeded initial projections by 18% due to diesel price increases and better-than-expected renewable penetration during winter months.
The project achieved simple payback in 1.7 years at current diesel prices – substantially shorter than the 3.5-year projection at initial feasibility stage. This accelerated return reflected both system performance and diesel market conditions.
Long-Term Value Considerations: Beyond direct cost savings, the renewable hybrid system delivered additional value through emissions reduction compliance, reduced exposure to diesel price volatility, and enhanced corporate sustainability credentials. Whilst difficult to quantify precisely, these factors influenced project approval and continue to provide strategic value.
The system’s modular design enables future expansion if mine life extends or processing capacity increases. Solar array capacity can scale to 2.5MW using existing infrastructure, and battery storage can expand to 2.0MWh without major electrical system modifications.
Technical Considerations for Similar Applications
This case study’s outcomes provide guidance for mining operators evaluating high renewable penetration systems, though several site-specific factors influenced results.
Solar Resource Quality: The Goldfields location provides excellent solar resource with minimal seasonal variation compared to tropical regions experiencing extended wet seasons. Sites in the Pilbara or Kimberley regions would achieve different seasonal penetration profiles requiring adjusted system sizing.
Solar resource assessment should extend beyond annual average insolation to examine seasonal patterns, cloud frequency, and extreme weather impacts. The most cost-effective system design optimises for year-round performance rather than peak summer output.
Load Profile Characteristics: The mining site’s relatively stable 24-hour load profile suited high renewable penetration better than operations with extreme peak/off-peak variations. Processing plants running continuously provide consistent baseload enabling effective battery utilisation.
Operations with highly variable loads or significant evening/night peaks may require larger battery capacity or different control strategies to achieve similar renewable penetration rates. Load profile analysis during feasibility assessment proves critical to system optimisation.
Existing Infrastructure Integration: Retaining existing diesel generators as backup capacity reduced capital requirements and provided operational redundancy. New stand-alone power systems without existing generation assets require different design approaches and potentially higher capital investment.
Sites with ageing generators nearing replacement should evaluate whether renewable hybrid systems can defer or eliminate planned generator purchases, improving project economics through avoided capital expenditure.
Conclusion: Validating High Renewable Penetration in Mining
This Goldfields mining operation demonstrates that 80% renewable hybrid penetration represents practical reality rather than theoretical possibility for remote industrial applications. The system delivered measured fuel reductions exceeding 2.2 million litres annually whilst maintaining power quality and operational reliability throughout 18 months of continuous operation.
Key success factors included integrated system design addressing power quality and generator management, appropriate battery capacity for both energy storage and power delivery, and intelligent control systems managing complex interactions between solar, battery, and diesel generation sources.
Financial outcomes exceeded initial projections with 1.7-year payback driven by diesel cost savings and reduced maintenance requirements. The project validates renewable hybrid systems as financially compelling investments rather than purely environmental initiatives.
Mining operators considering similar transitions should prioritise comprehensive feasibility assessment examining site-specific solar resources, load profiles, and existing infrastructure. High renewable penetration requires engineering expertise in hybrid system integration and control strategies beyond simple solar array sizing.
For operations seeking to replicate these outcomes, contact us for technical consultation on renewable hybrid system design and feasibility assessment. Australian-manufactured solutions designed for remote mining applications provide the reliability and performance required for successful high-penetration renewable energy implementation.