Technical Note 01/2023
The global trend of shifting from fossil fuel-powered equipment to alternative energy sources has become a megatrend aimed at reducing CO2 emissions from fossil fuels. Many industrial processes require high temperatures to be effective, while approximately 50% of them operate at temperatures lower than 400ºC. Both types of processes could easily transition from consuming oil, natural gas, or coal to electricity or green hydrogen.
Minimizing the carbon footprint in the industrial sector involves transitioning from the current use of fossil fuels for generating electricity and steam to generating steam with electrical energy while relying on alternative energy sources to supply electricity. Systems based on gas and petroleum-derived fuels have become widespread due to their perceived abundance, cost-effectiveness, technological maturity, and easy access to existing infrastructures, without giving much consideration to their long-term economic and environmental impacts and the resulting carbon footprint.
Electrical equipment shows a 24% advantage in efficiency compared to fossil fuel-powered equipment, primarily due to significantly lower heat losses. As a result, gas heating systems are often oversized by at least that percentage. In some cases, multiple boilers are installed to compensate for the considerable loss of operational efficiency at low loads. This phenomenon does not occur in electrical installations, as they can respond promptly to dynamic demands due to their characteristics and design.
Burners require an optimal and precise fuel mixture to operate efficiently, which is not easy to achieve due to the variability of fuels available in the market. This results in an expensive and incomplete combustion process, as excess air necessary for combustion exits the chimney at high temperatures. Although this is a necessary evil to prevent the formation of corrosive mixtures that could degrade the equipment rapidly, it does not prevent soot from accumulating on the internal tubes of fuel-fed boilers, significantly reducing the thermal efficiency of the equipment.
Maintenance of these systems is extensive and tedious due to the complexity of burners, fans, ducts, fuel mixing, flue gas temperature control, scale accumulation, corrosion, and pollution control.
A steam boiler or any other industrial process fueled by fossil fuels requires an elaborate maintenance program that involves weeks of inspection by highly qualified technicians using sophisticated tools. This means extended downtime and high maintenance costs, not to mention the opportunity costs associated with facility shutdowns. At this point, we must not overlook the more complex and time-consuming Regulatory Control compared to electrical equipment.
Heating using electrical energy is notably simpler and more scalable than using a fuel burner, significantly reducing the probability of technical failure or breakdown. There are no parasitic losses since there is no combustion, and technical interventions are usual without any issues. Maintenance is straightforward, involving purging, inspection of electrical connections, and no leaks. These interventions typically take only a few hours annually.
For industrial facilities seeking to minimize both capital expenditures (CAPEX) and operating expenses (OPEX) due to maintenance and high utilization, migration to electric machines should be considered. Electrical heating elements, such as electric resistance heaters, have been used in the industry for over a century due to their simple and effective design methodology.