Thousands of factories across Australia could save money on energy today, by replacing their gas-fired boilers with industrial heat pumps.
For manufacturers to transform raw materials into everyday products they require enormous amounts of heat, which contributes 8% of Australian greenhouse gas emissions.
Climate change think tank, Beyond Zero Emissions’ has prepared a report showing how manufacturers can generate heat differently, through the smart use of renewable electricity.
The Electrifying Industry Report said it can power any industrial heat process and can double the efficiency of many industrial processes. The report warns that businesses wedded to high carbon strategies are at risk from the global transition to a low carbon economy.
Beyond Zero Emissions CEO, Vanessa Petrie, said Australian manufacturers are fighting a doubling of costs in gas and electricity bills by doing business as usual.
“By electrifying industrial heat processes, supported by renewables, Australian manufactures can reclaim control of their energy costs and enjoy the benefits of falling renewable energy costs for years to come,” she said.
Renewable energy is cheaper and could drop a further 30 to 50 per cent in the next decade. Leading companies of all sizes are signing power purchase agreements to secure low-cost electricity from solar and wind, typically paying 20 to 50% less than the standard market price.
So far, manufacturers are simply using renewables in place of grid electricity. But abundant, cheap renewable electricity opens up an even more far-reaching possibility: the electrification of manufacturing processes that currently rely on burning fossil fuels.
Head of Research and lead author of the report, Michael Lord, says there is a missed opportunity for thousands of businesses across Australia.
“We found many manufacturers could save money today simply by replacing their gas-fired boilers with industrial heat pumps. It’s just not widely taken up yet,” he said.
“As the world transitions away from fossil fuels, we will see most industrial processes becoming emissions free. Our report shows it’s possible now.”
By switching to electrical heating it is possible to double the efficiency of many industrial processes, according to the report which provides examples across a range of different industries.
This greater efficiency is due to the ability of electrical heating technologies to:
• deliver heat at the precise temperature required (traditionally, industrial heat is often provided at temperatures well above what is needed);
• transfer heat directly to a material, with very little heat escaping to the environment;
• provide heat at the point of use, minimising distribution losses.
Industrial heat pumps
Heat pumps use electricity to make hot water, air or steam. They can produce several times more thermal energy than they use in electrical energy, leading to remarkable efficiencies of 300 to 700%.
Heat pumps also enable manufacturers to reuse sources of energy that are otherwise wasted, such as the heat expelled by refrigeration systems. Heat pumps save so much energy their installation cost can often be paid back within two years.
The most exciting potential application for heat pumps is as an alternative to the inefficient centralised gas boiler systems found in most factories. The report also examines electromagnetic heating technologies which can cut energy use in half.
Electromagnetic technologies are safer than gas-fired heating, more controllable and produce a more consistent output, the report said listing the benefits of infrared radiation, induction heating and dielectric heating.
“Electric resistance heating has huge potential as it is a simple alternative to most industrial gas-fired heating systems. For example, electric resistance boilers produce hot water or steam up to 220°C and could replace gas-fired boilers,” the report said.
"Some industries, such as carbon fibre production, already run predominantly on electric resistance heating due to its greater controllability, lower maintenance and absence of emissions from combustion.”
A heat pump system costs around $500-1000 per kilowatt of heating capacity for heat pumps with capacity below 500 kW, and around $275-500 per kilowatt for systems of 1 MW and above, according to Beyond Zero Emissions.
The total cost might be two or even three times the up-front cost of an equivalent gas boiler, however the heat pump can pay for itself in just a few years thanks to cheaper running costs.
“Most heat pumps in use today supply temperatures below 100°C. The efficiency, flexibility and reliability of heat pumps have improved considerably in recent years,” the report said.
“Heat pumps are now available that can supply steam or hot water up to 165°C, or hot air up to 120°C. Within a decade heat pump manufacturers expect to commercialise industrial systems capable of reaching 200°C. The heating capacity of single modules is also growing, with several available in the megawatt range.”
So far there are very few industrial heat pumps installed in Australia. Despite this heat pumps have huge potential to replace gas and other fossil fuels in most processes requiring hot air, water or steam up to about 160°C. They could provide most of the heat energy required by the food, paper, wood and textiles industries.
The report estimates heat pumps could displace one third of the energy used by chemical sectors to generate steam.
In total heat pumps could eliminate the need for 95 GJ of fossil fuels used for industrial heat – 15% of the total.
When powered by renewable energy this would eliminate nearly 5 million tonnes of greenhouse gas emissions.
“This report promotes heat pumps that use refrigerants with low global warming potential. This includes natural refrigerants such as CO2, ammonia and water, as well as some newly-developed HFCs," the report said.
Case Study: Food industry
The report provides a number of case study examples such as the food industry and shows how electrifying food preparation can halve the amount of energy required. This approach relies on electric heat pumps and infrared ovens, both of which are three times more efficient than the existing gas-fired systems.
The heat pumps recover the large amount of waste heat expelled from the refrigeration compressors, and operate with an average effective efficiency of 300% (a coefficient of performance of 3). Two of the heat pumps have cooling capability, reducing demand on the refrigeration units by 1.5%.
The key components of the all-electric system are outlined below:
Heat pumps 1 & 2 –
The main 4 MW gas boiler can be replaced with two 1 MW heat pumps.
These heat pumps use only 29% of the energy of the existing boiler. This impressive efficiency gain is achieved because the heat pumps:
1. reuse warm air expelled by the condensers of the refrigeration system at 25-30°C.
2. deliver steam at 110°C, the temperature required to cook the raw food. The current
system, like many central boilers, over-heats the steam to 180°C.
3. operate with an effective efficiency of 300% (COP of 3), compared to only 82% for the current boiler.
The heat pumps' combined heating capacity of 2 MW is sufficient because the existing 4 MW
boiler is twice as large as it needs to be.
Heat pump 3 –
The 50 kW gas-fired hot water boiler can be replaced with a 60 kW heat pump capable of providing heating and cooling simultaneously. This heat pump reuses waste heat from the refrigeration system, as well as providing 40 kW of cooling capacity. It operates with a combined coefficient of performance of 4.5.
Heat pump 4 –
The oil heater can also be replaced with a 60 kW heat pump capable of providing heating and cooling simultaneously. The heat pump reuses waste heat from the refrigeration system and raises the temperature of the oil to 90°C. An electrical resistance heater is then used to boost the temperature up to 240°C.
Infrared pizza ovens –
The gas-fired pizza ovens can be replaced by commercially-available infrared ovens. Infrared ovens are faster and three times more efficient.
Just this week the UK Committee on Climate Change called for the UK to reach zero emissions by 2050.
To do this British residents have been told to keep heating down to 19°C, to ditch gas boilers, cut meat consumption, shun air travel and take the train.
The government has backed the plan and said it would legislate to make Britain the first major world economy to reduce its carbon footprint to zero.
About 90% of British households have gas boilers, most of them fitted in the last 20 to 30 years. The government will need to consider policies that encourage householders to move away from gas heating to alternatives such as heat pumps and hydrogen burning radiators.
The UK will join Sweden which is one of the few countries to have a legislated zero emissions target (by 2045).