Understanding Dishwasher Energy Ratings in Australia

When you're standing in an appliance store looking at dishwashers, the energy rating labels might seem like just another marketing claim. But those star ratings have real implications for your household budget and environmental footprint. Over a dishwasher's 10-15 year lifespan, the difference between a 3-star and 6-star model can amount to hundreds of dollars in electricity and water costs.

This guide explains exactly what those energy labels mean, how to calculate real-world running costs, and how to balance efficiency ratings against purchase price to find the best overall value.

The Australian Energy Rating Label Explained

All dishwashers sold in Australia must display the Energy Rating Label regulated by the government's Greenhouse and Energy Minimum Standards (GEMS) scheme. This standardised label allows direct comparison between different models.

Components of the Energy Label

• Star rating (1-6 stars): More stars indicate greater energy efficiency. Half-star increments are possible.
• Energy consumption (kWh/year): Estimated annual energy use based on 280 standard wash cycles per year
• Model and brand information: For reference and verification
• Comparative Energy Consumption (CEC): A number allowing technical comparison between models

Water Efficiency (WELS) Rating

Alongside energy ratings, dishwashers also carry a Water Efficiency Labelling and Standards (WELS) rating. This is equally important, especially in drought-prone Australia.

Understanding WELS Ratings

• Star rating (0-6 stars): More stars = less water used
• Water consumption: Litres per wash cycle on the normal program
• Registration number: Allows verification on the government database

Typical Water Usage by Rating

• 6-star: Less than 7 litres per cycle
• 5-star: 7-9 litres per cycle
• 4-star: 9-11 litres per cycle
• 3-star: 11-14 litres per cycle
• 2-star: 14-18 litres per cycle

Calculating Your Actual Running Costs

The energy label estimates annual usage based on 280 cycles. Your actual usage may differ. Here's how to calculate your real costs:

Step 1: Determine Your Cycle Frequency

• Single/couple household: 3-4 cycles per week (156-208/year)
• Small family (3-4): 5-6 cycles per week (260-312/year)
• Large family (5+): 7-10 cycles per week (364-520/year)

Step 2: Calculate Energy Costs

Find the kWh per cycle (label figure ÷ 280), then multiply by your actual cycles and your electricity rate.

Step 3: Calculate Water Costs

Water costs vary significantly across Australian states. Use the litres per cycle from the WELS label multiplied by your cycles and local water price.

• Sydney: ~$2.50 per 1,000 litres
• Melbourne: ~$3.00 per 1,000 litres
• Brisbane: ~$3.50 per 1,000 litres
• Perth: ~$2.00 per 1,000 litres
• Adelaide: ~$3.00 per 1,000 litres

Step 4: Total Annual Running Cost

Add electricity and water costs together for your total annual running cost. For a typical 4-star energy, 5-star water dishwasher run 5 times per week, expect approximately $70-90 per year in combined utilities.

Comparing Models: Total Cost of Ownership

The smartest way to compare dishwashers is to calculate Total Cost of Ownership (TCO) over the expected lifespan.

TCO Comparison Example

Comparing two dishwashers over 12 years, running 5 cycles per week:

Despite costing $250 more upfront, Model B saves $206 over its lifetime. This is why looking beyond the sticker price matters.

When Higher Ratings Don't Make Sense

Higher efficiency isn't always worth it. Consider these scenarios:

• Very low usage: If you only run 2-3 cycles per week, the savings from higher ratings take longer to recoup
• Huge price premiums: A $500 premium for an extra star rarely pays back within a reasonable timeframe
• Short-term living situations: Renters who might move in 2-3 years may not benefit from investing in high efficiency
• Planning kitchen renovation: If you'll replace the dishwasher within 5 years anyway, buy for current needs

Program Selection Impacts Efficiency

The energy label is based on the "Normal" program. Your actual efficiency depends on which programs you use:

Program Energy Comparison

• Eco program: 20-40% less energy than Normal (longest cycle time)
• Normal program: Baseline as per energy label
• Intensive program: 10-20% more energy (for heavily soiled dishes)
• Quick/Express: Often similar energy but compressed time
• Heated dry: Adds significant energy; air dry is more efficient

Future Efficiency Standards

Australia's GEMS scheme periodically updates minimum efficiency standards, pushing the market toward better performance. What was a 4-star rating in 2020 might only achieve 3 stars under new 2025 standards. When comparing ratings, ensure you're comparing against the same standard version (shown on the label).

Making Your Final Decision

Here's a practical framework for balancing efficiency with other factors:

1. Calculate your likely annual running cost using the method above
2. Compare Total Cost of Ownership across your shortlist
3. Consider your usage patterns—heavy users benefit more from efficiency
4. Factor in environmental values—efficiency reduces your carbon footprint
5. Don't sacrifice reliability for efficiency—a breakdown-prone efficient dishwasher isn't truly economical

For most Australian households running 4-6 cycles per week, a 4-star or 5-star energy rating offers the best balance of efficiency, features, and value. Going higher makes sense for heavy users or those prioritising environmental impact; going lower is reasonable for light users or tight budgets.