Read Time: 5 mins
Background
Diesel is not a minor fuel in Australia. It delivers more end-use energy than electricity. In 2023–24, diesel supplied 1,224.8 petajoules of final energy, while electricity supplied 869.4 petajoules. Diesel therefore delivered about 41% more end-use energy than electricity.
That is not an academic point. Diesel sits under long-haul road freight, agriculture, mining, construction equipment, backup generation and parts of rail. Official energy data says road transport used 1,263 PJ in 2023–24, and recent growth in road transport energy use was driven largely by diesel, especially commercial vehicles.
So the first fact to understand is simple: diesel is one of the country’s main working fuels. It is not a side issue.
Links to Sections
- Diesel versus electricity
- Could wind and solar replace that energy?
- A rough replacement size
- A rough replacement cost
- CSA position statement
Diesel versus electricity
If you compare final energy actually used by end users, diesel beats electricity in Australia. The official figures for 2023–24 are:
- Diesel: 1,224.8 PJ
- Electricity: 869.4 PJ
That means diesel supplied about 30.4% of Australia’s total final energy use, while electricity supplied about 21.5%. Diesel exceeded electricity by about 355.4 PJ. The rest of Australia’s final energy use comes mainly from other refined petroleum products such as petrol and aviation fuel, plus gas, a small amount of coal, and some direct renewable energy such as firewood, bagasse and solar hot water.
In plain English: Australia currently gets more usable end-energy from diesel than from electricity. That fact alone should force a more honest discussion about what diesel does in the real economy.
Could wind and solar replace that energy?
Not directly. Diesel and wind-and-solar electricity do different jobs.
Diesel is a stored transport fuel. It can sit in tanks, be moved where needed, and used on demand in trucks, machinery and generators. Wind and solar produce intermittent electricity, which then needs firming, storage, transmission and backup if supply is to be reliable. Even AEMO’s 2024 national power-system roadmap, built around a very large renewable expansion, still includes 49 GW / 646 GWh of dispatchable storage and 15 GW of flexible gas.
So replacing diesel’s energy contribution with wind and solar is not a neat one-for-one swap. You would not just be replacing fuel. You would be trying to replace a portable, dispatchable, stored energy system with an electricity system that needs major supporting infrastructure. That is a much bigger task than slogans make it sound. This is an inference from the physical differences between diesel use and variable electricity supply, together with AEMO’s storage-and-firming requirements.
A rough replacement size
Diesel’s 1,224.8 PJ equals about 340.2 TWh of end-use energy. That is already larger than Australia’s current annual electricity generation, which the Australian Energy Update reports at about 284 TWh in 2023–24.
A simple engineering guestimate shows the scale. To produce 340.2 TWh a year from wind and solar, you would need roughly:
- 97.1 GW of nameplate capacity at a 40% average capacity factor
- 111.0 GW at 35%
- 129.5 GW at 30%
That is before allowing for heavy overbuild to cover low-wind periods, weak solar periods, storage charging, curtailment and network losses. If you assumed 1.5 times overbuild, the range becomes roughly 146 to 194 GW. At 2 times overbuild, it becomes roughly 194 to 259 GW. Those figures are not official published numbers; they are my guestimates from the energy requirement and the assumed average capacity factors. They are useful because they show the order of magnitude.
The blunt point is this: to replace diesel’s present energy contribution with wind and solar, you are talking about a buildout on the scale of another enormous national electricity system, plus overbuild.
A rough replacement cost
Here the only honest answer is: very large, and highly sensitive to how much reliability you demand.
CSIRO’s GenCost work says the average cost of electricity in the National Electricity Market consistent with the 2030 82% renewables target is projected to be about A$91/MWh including transmission. For 2050, CSIRO says electricity costs associated with the electricity sector’s efficient role in net zero are projected at A$135–148/MWh including transmission. CSIRO also says it is not efficient to eliminate all emissions from the electricity sector, because the final push becomes disproportionately expensive.
If you apply that A$135–148/MWh range to 340.2 TWh, you get a rough annual system-energy cost of about A$45.9–50.4 billion per year.
That is only a broad proxy, not a full diesel-replacement cost. It does not include replacing diesel trucks, plant and machinery, building charging systems for remote and heavy-duty uses, expanding networks into places where diesel currently works without them, or covering the extra firming needed to guarantee supply at all times. So the real full-system cost of trying to replace diesel’s current energy role with wind and solar plus enough supporting infrastructure would likely be well above that A$45.9–50.4 billion annual proxy. That last sentence is an inference, but it follows directly from what the proxy excludes.
The blunt conclusion is this:
A wind-and-solar system big enough to replace diesel’s current energy contribution would have to be enormous, heavily overbuilt, backed by storage and firming, and could not honestly be described as cheap.
CSA position statement
Replacing diesel with renewable electricity would not be a simple fuel swap. It would require an enormous new power system, major overbuild for reliability, vast storage and transmission, and the conversion of much of the heavy transport fleet to battery power, likely followed by road upgrades to cope with heavier long-haul electric trucks.
CSA’s position is simple: Australia should treat diesel as a strategic national fuel. Any proposal to replace it must be judged against physical reality, full system cost and real-world reliability, not slogans.
Click for Sources
"""^^rdf:XMLLiteral ; sioc:content """ Read Time: 5 mins Background Diesel is not a minor fuel in Australia. It delivers more end-use energy than electricity. In 2023–24, diesel supplied 1,224.8 petajoules of final energy, while electricity supplied 869.4 petajoules. Diesel therefore delivered about 41% more end-use energy than electricity. That is not an academic point. Diesel sits under long-haul road freight, agriculture, mining, construction equipment, backup generation and parts of rail. Official energy data says road transport used 1,263 PJ in 2023–24, and recent growth in road transport energy use was driven largely by diesel, especially commercial vehicles. So the first fact to understand is simple: diesel is one of the country’s main working fuels. It is not a side issue. Links to Sections Diesel versus electricity Could wind and solar replace that energy? A rough replacement size A rough replacement cost CSA position statement Diesel versus electricity If you compare final energy actually used by end users, diesel beats electricity in Australia. The official figures for 2023–24 are: Diesel: 1,224.8 PJ Electricity: 869.4 PJ That means diesel supplied about 30.4% of Australia’s total final energy use, while electricity supplied about 21.5%. Diesel exceeded electricity by about 355.4 PJ. The rest of Australia’s final energy use comes mainly from other refined petroleum products such as petrol and aviation fuel, plus gas, a small amount of coal, and some direct renewable energy such as firewood, bagasse and solar hot water. In plain English: Australia currently gets more usable end-energy from diesel than from electricity. That fact alone should force a more honest discussion about what diesel does in the real economy. Could wind and solar replace that energy? Not directly. Diesel and wind-and-solar electricity do different jobs. Diesel is a stored transport fuel. It can sit in tanks, be moved where needed, and used on demand in trucks, machinery and generators. Wind and solar produce intermittent electricity, which then needs firming, storage, transmission and backup if supply is to be reliable. Even AEMO’s 2024 national power-system roadmap, built around a very large renewable expansion, still includes 49 GW / 646 GWh of dispatchable storage and 15 GW of flexible gas. So replacing diesel’s energy contribution with wind and solar is not a neat one-for-one swap. You would not just be replacing fuel. You would be trying to replace a portable, dispatchable, stored energy system with an electricity system that needs major supporting infrastructure. That is a much bigger task than slogans make it sound. This is an inference from the physical differences between diesel use and variable electricity supply, together with AEMO’s storage-and-firming requirements. A rough replacement size Diesel’s 1,224.8 PJ equals about 340.2 TWh of end-use energy. That is already larger than Australia’s current annual electricity generation, which the Australian Energy Update reports at about 284 TWh in 2023–24. A simple engineering guestimate shows the scale. To produce 340.2 TWh a year from wind and solar, you would need roughly: 97.1 GW of nameplate capacity at a 40% average capacity factor 111.0 GW at 35% 129.5 GW at 30% That is before allowing for heavy overbuild to cover low-wind periods, weak solar periods, storage charging, curtailment and network losses. If you assumed 1.5 times overbuild, the range becomes roughly 146 to 194 GW. At 2 times overbuild, it becomes roughly 194 to 259 GW. Those figures are not official published numbers; they are my guestimates from the energy requirement and the assumed average capacity factors. They are useful because they show the order of magnitude. The blunt point is this: to replace diesel’s present energy contribution with wind and solar, you are talking about a buildout on the scale of another enormous national electricity system, plus overbuild. A rough replacement cost Here the only honest answer is: very large, and highly sensitive to how much reliability you demand. CSIRO’s GenCost work says the average cost of electricity in the National Electricity Market consistent with the 2030 82% renewables target is projected to be about A$91/MWh including transmission. For 2050, CSIRO says electricity costs associated with the electricity sector’s efficient role in net zero are projected at A$135–148/MWh including transmission. CSIRO also says it is not efficient to eliminate all emissions from the electricity sector, because the final push becomes disproportionately expensive. If you apply that A$135–148/MWh range to 340.2 TWh, you get a rough annual system-energy cost of about A$45.9–50.4 billion per year. That is only a broad proxy, not a full diesel-replacement cost. It does not include replacing diesel trucks, plant and machinery, building charging systems for remote and heavy-duty uses, expanding networks into places where diesel currently works without them, or covering the extra firming needed to guarantee supply at all times. So the real full-system cost of trying to replace diesel’s current energy role with wind and solar plus enough supporting infrastructure would likely be well above that A$45.9–50.4 billion annual proxy. That last sentence is an inference, but it follows directly from what the proxy excludes. The blunt conclusion is this: A wind-and-solar system big enough to replace diesel’s current energy contribution would have to be enormous, heavily overbuilt, backed by storage and firming, and could not honestly be described as cheap. CSA position statement Replacing diesel with renewable electricity would not be a simple fuel swap. It would require an enormous new power system, major overbuild for reliability, vast storage and transmission, and the conversion of much of the heavy transport fleet to battery power, likely followed by road upgrades to cope with heavier long-haul electric trucks. CSA’s position is simple: Australia should treat diesel as a strategic national fuel. Any proposal to replace it must be judged against physical reality, full system cost and real-world reliability, not slogans. Click for Sources """ ; sioc:topic