This retrofit replaces aging gas boiler systems with high-efficiency, natural refrigerant-based heat pump technology. With 275 guest rooms and high hot water demand during peak hours, this site presented an ideal opportunity to demonstrate the capability of CO₂ heat pumps in large commercial applications.
Accor’s sustainability roadmap targets a 5% reduction in energy consumption by 2025 and a 30% overall reduction by 2030. Decarbonising hot water generation is a critical component of this effort. The Mercure project aligns with these targets by eliminating Scope 1 emissions from natural gas use and leveraging Victoria’s increasingly low-carbon electricity grid.
The adoption of natural refrigerant CO₂ heat pumps underscores a commitment to environmentally responsible technology choices that support long-term carbon reduction.
Automatic Heating supplied Revere CO₂ heat pumps to replace the hotel's two gas boilers, previously responsible for 672 MWh of annual energy use.
The heat pump system was selected based on a detailed analysis of peak demand, recovery rates, and sustainability performance. Key selection criteria included high COPs (coefficient of performance), alignment with government incentive schemes, and the use of natural refrigerants.
Annual energy use has been reduced from 672 MWh with gas boilers to just 120 MWh with CO₂ heat pumps — an 82% decrease.
The hotel has achieved a 51% reduction in operating costs, with the annual energy bill dropping from $55,470 to $27,091, equating to annual savings of approximately $28,300.
By 2034, the CO₂ heat pump system is projected to emit only 15.60 tCO₂-e, down from 103.23 tCO₂-e in 2024, as Victoria's electricity grid decarbonises. This represents an 84% reduction in greenhouse gas emissions.
Source: Australian Emissions Projections 2023
| Year | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 | 2031 | 2032 | 2033 | 2034 | 2035 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Emission Factors | 0.86 | 0.75 | 0.74 | 0.69 | 0.61 | 0.39 | 0.40 | 0.38 | 0.32 | 0.24 | 0.13 | 0.01 |
The emission factors represent the amount of greenhouse gases released per megawatt-hour of electricity generated. As more renewable energy enters the grid, these factors decrease substantially, benefiting technologies like heat pumps that run on electricity.
The heat pump system becomes increasingly environmentally friendly over time, while gas systems cannot improve their emissions profile without replacing the equipment entirely. This makes heat pump technology not only the best choice for immediate emission reductions but also a future-proof solution that will continue to improve its environmental performance throughout its operational life.
The Hotel obtained pricing for a new gas & solar thermal plant with an estimated payback of 9 years.
The Revere CO₂ package payback is 5.12 years.
Government VEU rebates provided financial incentives for the high-efficiency heat pump technology, further reducing costs.
