And renewables can achieve the high heats needed for a large share of industry’s needs.
Photo credit: Jens Büttner / picture alliance via Getty Images
Photo credit: Jens Büttner / picture alliance via Getty Images
Editor’s note: This piece was adapted from the book Zero-Carbon Industry: Transformative Technologies and Policies to Achieve Sustainable Prosperity, by Jeffrey Rissman, out now from Columbia University Press.
Renewables and electric vehicles are cutting emissions from the power and transport sectors, but too little is being done to address emissions from industrial firms: the companies that produce the products and materials we rely on every day. As a result, industry will be the United States’ largest source of greenhouse gas emissions by 2035.
We can’t stop producing products like steel, concrete, or chemicals. Fortunately, we can cut industrial emissions by replacing fossil fuels with zero-emissions energy sources. Clean electricity is the most efficient way to provide zero-carbon heat to industrial processes at all temperatures, so it should be embraced at every opportunity.
Heat accounts for 91% of combustible fuel use for industrial processes in the U.S., excluding feedstocks. Therefore, electrifying industry largely boils down to producing heat from electricity.
Different industries have different temperature requirements. For instance, chemical industry steam crackers operate at 850 degrees Celsius, while steelmaking blast furnaces operate at up to 1800 C.
The processes best-suited to electrification in the short-term are those that use low-temperature heat. In Europe, 12% of industrial heat demand is for temperatures under 100 C and another 26% is for temperatures between 100 C and 200 C. These temperatures are common in processing food and beverages, manufacturing pulp and paper, and fabricating machinery or vehicles from purchased materials.
Electricity can be converted into heat for industrial processes using several methods. Each has pros and cons in terms of efficiency, heat delivery to the processed material, and achievable temperature.
Heat pumps are unique among electrical heating options. Rather than create heat, a heat pump moves heat from one place to another like a refrigerator, by pressurizing and depressurizing a refrigerant pumped in a closed loop. This allows them to deliver two to five times more useful heat than the amount of electricity they consume. Most heat pumps are home appliances, but they can also fill a unique niche in an industrial context. In Fort Collins, Colorado, the New Belgium Brewery is installing an industrial heat pump to replace natural gas used to make steam for brewing its beer, which currently emits about half of its direct carbon dioxide emissions.
A thermal battery converts electricity into heat and stores the heat until it is needed for an industrial process. By allowing electricity to be purchased at low-cost times or from cheap off-grid sources, it can lower a firm’s electricity costs by one half to two thirds. In Pixley, California, a two megawatt-hour thermal battery is helping Calgren Renewable Fuels produce the world’s lowest-carbon-intensity ethanol and biodiesel by storing energy when grid prices are low and providing continuous heat at temperatures exceeding 1,000 C.
Several other electrified heating technologies — including electrical resistance, induction heating, and infrared radiation — hold similar promise for cleaning up industrial emissions. While they vary in their degree of technological readiness, enough options are ready to go that industry has already begun using them to cut emissions. Researchers with the Potsdam Institute for Climate Impact Research found commercialized technologies can directly electrify 78% of non-feedstock European industrial energy demand, while 99% could be electrified when including technologies under development.
The key barrier to electrifying industrial heat is cost, not physics.
Grid electricity costs several times more than natural gas — though by precisely how much depends on the country (and the year, since natural gas prices are volatile). However, energy prices do not tell the whole story. It is necessary to consider how efficiently each fuel is converted into heat and how much of that heat can be applied to the material or part being processed. Electricity has efficiency advantages that partially or fully compensate for higher prices.
Burning fossil fuels wastes energy when heat and water vapor are lost in exhaust gasses. Electrical technologies do not produce exhaust gas, so they avoid these inefficiencies. Also, some electrical technologies (like induction and electric arcs) transmit heat to materials very efficiently. And industrial heat pumps have unparalleled efficiency and can produce temperatures high enough to meet one-third of global industrial heat demand.
Electrical technologies can sometimes have lower capital costs as well. For example, an electric resistance boiler will typically have lower capital costs than a combustion boiler due to less complexity, fewer moving parts, and no need for exhaust pipes.
However, such a head-to-head comparison assumes a facility already has enough electrical capacity to operate the boiler — and overlooks opportunities to replace steam with a more efficient heat delivery mechanism. The more accurate way to assess the costs of electrified technologies versus fossil-fueled ones is to compare entire systems delivering equivalent services rather than individual pieces of equivalent equipment.
Decarbonizing industrial non-feedstock uses of fossil fuels — such as providing heat to cook food, melt metals, and drive chemical reactions — will require a lot of electricity. Direct electrification of all industrial heat could increase global electricity demand by around 65%.
(And if industry instead burned green hydrogen for this heat, the increase in electricity demand would be twice as large, since burning hydrogen has the same heat loss modes as burning fossil fuels, alongside the efficiency losses that come from converting electricity into hydrogen.)
In order to make sure this growth in electricity demand doesn't throw off decarbonization goals, industry can implement energy efficiency, material efficiency, and circular economy measures. And some industrial facilities can use demand response to allow more electricity demand to be met with less capacity.
While its use won’t come without challenges, clean electricity is the most efficient way to provide zero-carbon heat to industrial processes at all temperatures. It should be prioritized wherever possible, for instance via replacing most industrial fossil fuel uses other than in primary steelmaking, refining, and chemical feedstocks.
However, even after considering electricity’s efficiency benefits, in most places it remains cheaper to obtain heat from natural gas or coal.
This central challenge can be addressed by reducing clean energy costs through technological innovation, deployment of industrial heat pumps and thermal batteries, financial incentives for clean production, and imposing a carbon price to level the playing field by making fossil fuel users pay for their pollution. Electrification can also be driven by non-financial policies like emissions standards, while research and development efforts can help create and improve electrified versions of industrial technologies.
A new industrial revolution is unfolding. It’ll change the way we make everything, and it will be powered by clean electricity.
Jeffrey Rissman is senior director of industry at Energy Innovation and the author of Zero-Carbon Industry: Transformative Technologies and Policies to Achieve Sustainable Prosperity from Columbia University Press. The opinions represented in this article are solely those of the author and do not reflect the views of Latitude Media or any of its staff.