Decarbonizing Heat Essential To Combat Climate Change
Compared to electricity (20%) and transportation (30%), heat accounts for 50% of the world’s total energy consumption.
Decarbonizing heat is essential to combating climate change because it accounts for half of the world’s total energy consumption. Half of all heating is provided by industrial heat, so decarbonizing this sector will require new innovations.
Decarbonizing heat offers chances to cut carbon emissions while also possibly spawning entirely new industries. Compared to electricity (20%) and transportation (30%), heat accounts for 50% of the world’s total energy consumption. Unsurprisingly, more than 40% of the carbon dioxide (CO2) emissions related to energy come from heat.
However, decarbonizing cars and electricity has been the main focus of recent climate initiatives. Efforts to decarbonize heat only really accelerated last year, following Vladimir Putin’s invasion of Ukraine and the ensuing energy crisis. This may be the most difficult conflict—and greatest unrealized opportunity—in the struggle against global warming. In the United States, heating accounts for about 60% of total energy consumption at home, compared to about 80% in Europe.
Fortunately, because of the low temperature of the required heat here, electric heat pumps and renewable electricity are making progress in lowering emissions. In commercial and professional settings, the use of heat is even broader.
In addition to providing warm water and air, heating becomes essential in offices. Consider the fast-food burger you consumed, the roasted beans in your latte, the hotel laundry that cleaned your bed linens and towels, and the scalding hot water and steam that a hospital uses to sanitise everything from dishes to scalpels.
But industry, which uses 50% of all heat, is the biggest user. Heat is necessary for manufacturing processes like refining raw materials, smelting metals, and creating chemicals. Additionally, heat is used in the manufacturing of a wide range of food and beverage products, including baking bread, making beer, and pasteurising milk, as well as paper and rubber.
Indeed, the four materials that support human civilization—ammonia, cement, steel, and plastics—all rely heavily on heat during the manufacturing process. Let’s look at how green products are produced to better illustrate the difficulties of decarbonizing commercial and industrial heat.
Before it is installed on your roof, a finished solar panel generates heat almost everywhere in its production lifecycle. The silicon wafer, which is formed and purified at 1,400–1,700 °C to produce the silicon ingot, is the main component.
To increase conductivity, this silicon must then be doped, usually at temperatures above 800-1,000°C in a diffusion furnace. This solar cell is then sandwiched between layers of glass and resin that have been heated to cure the resin. Sand and other materials were used to create the glass, which was then melted in a furnace that reached a temperature of over 1,700°C.
If the panel has ceramic insulators, they were created by firing and sintering at temperatures over 1,000°C. The electrical components of the panel were soldered and bonded at temperatures over 400°C. Around 200°C was used to manufacture the cardboard and plastic packaging that was used to ship the finished solar product.
Heat is frequently used to extrude, mould, and even thermoset plastics, and to decompose and dry paper pulp. It goes beyond solar. Our wind turbines’ cement has undergone pyro processing in a kiln heated to 1,400–1,500°C. Even without considering all the metals and plastics that make up the car body, the copper in the electric vehicle’s wires was probably heated during the annealing, forming, and tempering processes.
The laws of thermodynamics prohibit electric heat pumps from efficiently producing high-temperature heat, making it difficult for businesses to switch to renewable power. Transmission and distribution costs are already 44% of the total cost of delivered electricity, meaning there is no efficiency and economic savings for going all electric.
One choice is to move your factory and business to a place where there is a reliable, affordable, and always-on supply of zero-carbon electricity. Due to the abundant and reasonably priced geothermal power available in the volcanic nation of Iceland, aluminium is the island nation’s top export.
Electric arc furnaces have limitations, such as the fact that they can only heat conductive materials like metals. They can use renewable electricity to reach high temperatures. Biofuels are an additional choice. Boilers and furnaces can burn organic fuels like wood chips, sawdust, and agricultural waste. This may work well with sectors that rely heavily on biomass.
Hydrogen can burn at around 2,000°C, providing a low retrofit solution to commercial and industrial heating equipment. However, traditional production of hydrogen emits plenty of CO2, so we need to produce hydrogen through water electrolysis powered by zero-carbon electricity, green hydrogen, or from natural gas and biogas with pre- or post-combustion carbon capture.
However, clean hydrogen is not yet affordable, and hydrogen is an uniquely challenging fuel to transport and distribute. These challenges must be solved before hydrogen is widely used.
The practise of carbon capture and storage (CCS) entails taking CO2 from smokestacks and burying it deep underground. Large point sources of carbon emissions, like sizable industrial factories, can be reduced using CCS.
However, the energy efficiency is decreased because it takes energy to capture and compress carbon. And because CO2 is a gas and therefore expensive to transport and store, the geological formations where it can be reliably sequestered without leakage are frequently very far from businesses and factories.
Last but not least, research is being done on thermal storage as a way to store extra renewable electricity generated during times of high generation, like solar at noon. Finding a low-cost storage option with excellent insulation that can keep the heat hot enough for hours and days presents a challenge.
It is also challenging to recover heat from storage, transport it to the factory, and then heat the target material, particularly in high-temperature applications where steam cannot be used. Another difficulty is the complexity cost of retrofitting a thermal storage solution.
Industrial heat cannot be decarbonized easily. Therefore, there isn’t yet a magic solution for decarbonizing commercial and industrial heat.
But before I go, let me offer some words of inspiration. Decarbonizing heat easily matches the market size and CO2 impact of the solar, wind, and electric car revolutions. There is no one-size-fits-all decarbonizing solution for the vast, significant, and diverse energy service of heating.