Australia’s energy landscape is transforming rapidly—but not all energy sources are created equal. The often-overlooked metric of Energy Return on Investment (EROI) is now centre stage, shaping policy, investment, and the transition to a low-carbon future.
What Is Energy Return on Investment (EROI)?
EROI (or EROEI) measures how much usable energy is obtained from a resource versus the energy expended to obtain it. For example, if an oil field delivers 30 units of energy for every 1 unit used to extract and process it, its EROI is 30:1. The higher the EROI, the more net energy is available to power society’s needs—transport, manufacturing, homes, and more.
In 2025, EROI has become a crucial lens for policymakers and investors evaluating Australia’s energy future. As we transition from fossil fuels to renewables, understanding EROI helps answer questions like:
- Which energy sources deliver the most bang for our buck?
- Are renewables genuinely sustainable from an energy input/output perspective?
- How does EROI influence electricity prices and grid reliability?
EROI Across Australia’s Energy Mix
Australia’s energy portfolio is a blend of coal, gas, solar, wind, and emerging technologies like battery storage and green hydrogen. But EROI figures vary dramatically:
- Coal: Historically, black coal in Australia boasted EROI ratios above 30:1. However, as easily accessible reserves dwindle and environmental regulations tighten, extraction becomes more energy-intensive, pushing EROI down.
- Natural Gas: Conventional gas has EROIs in the 10–20:1 range, but unconventional sources (like coal seam gas) can be much lower due to higher extraction costs.
- Solar Photovoltaics (PV): As panel efficiency improves and manufacturing becomes less energy-intensive, solar’s EROI has risen sharply—recent studies put modern Australian solar PV at 10–20:1, with some large-scale projects exceeding that.
- Wind: Onshore wind farms in Australia typically report EROIs from 20:1 to 40:1, making them highly competitive with traditional fossil fuels.
- Battery Storage: While batteries are vital for grid stability, their EROI is lower (often below 10:1) due to the significant energy required for mining, manufacturing, and recycling. However, as battery technology improves and recycling rates increase, EROI is expected to rise.
Australia’s 2025 Integrated System Plan (ISP) from AEMO continues to prioritise renewables with high EROI, while encouraging investment in technologies that lift the EROI of grid storage and demand management.
EROI, Policy, and the Economics of Transition
Why does EROI matter for your power bills, your investments, and the nation’s economic health? Here’s how:
- Policy Targeting: The Albanese government’s 2025 National Energy Performance Strategy places EROI at the heart of funding decisions. Projects with higher EROI are favoured for grants and fast-track approvals, ensuring taxpayer dollars deliver maximum net energy.
- Grid Stability and Costs: High-EROI resources mean more surplus energy for society, translating into lower electricity prices and more reliable supply. This is especially critical as coal exits the grid and intermittent renewables take the lead.
- Investment Decisions: Superannuation funds and green investment vehicles now factor EROI into risk models. Projects with low EROI may struggle to attract capital or deliver competitive returns.
- Emissions Reduction: EROI is a silent partner in decarbonisation. Higher EROI for renewables means less fossil fuel backup is needed, accelerating Australia’s path to net zero by 2050.
For example, in early 2025, the proposed Hunter Valley “Renewable Energy Zone” was greenlit in part because aggregated wind and solar projects demonstrated EROI ratios above 18:1, outperforming legacy coal plants on both energy and emissions metrics.
The Future of EROI: Challenges and Opportunities
EROI is not static. Technology, resource quality, and supply chain dynamics all play a role. Looking ahead:
- Technology Boost: Advances in solar panel efficiency, battery recycling, and offshore wind could lift EROI further, making renewables even more dominant in Australia’s energy mix.
- Resource Quality: As we tap harder-to-reach gas and minerals, extraction EROI can drop—highlighting the urgency of rapid renewables deployment.
- Lifecycle Accounting: New 2025 standards from the Clean Energy Regulator require full “cradle-to-grave” EROI reporting on major energy projects, ensuring transparency and accountability.
- Green Hydrogen: Australia’s push into green hydrogen hinges on EROI. Early pilot projects show EROI between 5–10:1, but improvements in electrolysis and renewable integration could push this higher by decade’s end.
Staying alert to EROI trends can help households, businesses, and investors future-proof against rising costs and policy risks.
Conclusion: Why EROI Should Be on Your Radar
Energy Return on Investment is more than an academic metric—it’s a practical guide for navigating Australia’s energy transition. In 2025, EROI is influencing where governments spend, where investors place capital, and how quickly we can build a resilient, affordable, and low-carbon grid.
