What Produces Waste Heat And How Can It Power Our Planet?
Terrapin Geothermics works with a wide range of waste heat producers to turn their valuable waste heat to energy. Some industries have higher quality heat waste than others. Read on to learn more about what produces waste heat and how it can power our planet.
Terrapin • January 11, 2022
5 minute read
What is waste heat?
Among the clean energy sources advancing our energy transition today, wind and solar may be the first to come to mind. These renewable resources harness natural elements to generate emission-free energy. As they are dependent on the wind blowing and the sun shining, they are considered intermittent energy sources, and therefore need to be supplemented by technological innovations and more constant sources of clean heat and power.
One untapped energy resource is the heat rejected from our industrial processes. When a car engine runs, or natural gas is fired up in a power plant, they are burning fuel. Some of the thermal energy used to power these processes is lost as “waste heat.”
It is impossible to not produce this heat when converting thermal energy to useful work. In fact, the world wastes 67% of the energy it produces, often in the form of heat. In 2020, the U.S. alone generated nearly 2,100 gigawatts of wasted energy – which is roughly equal to the amount of electricity produced by 764,400 utility-scale wind turbines. To make up for the lost energy, industries often need to combust additional fuels, which results in greater production costs and greenhouse gas emissions.
Fortunately, some of this heat waste can be captured. Waste heat recovery technology has been developed and refined over the decades to harness what would otherwise be discarded into our atmosphere or neighbouring bodies of water. These technologies recover waste heat and repurpose it as an additional energy source in a process called waste heat to power. This can help industries rely less on a carbon-intensive electrical grid by using emission-free energy generated in-house. By doing so, industries can reduce their scope 2 emissions profile, or emissions intensity – a critical path for a net-zero world by 2050.
What produces waste heat?
Producers of waste heat have a unique opportunity to be energy transition leaders by converting their waste heat resources into emission-free electricity.
Every industry produces waste heat. Industries that consume large amounts of energy often also generate high amounts of waste heat. Based on an ICF International report, the top three producers of waste heat in the U.S. are:
The petroleum and coal products industry. This includes oil refining and the production of gasoline and feedstock–raw material to be used for fuel–to power other manufacturing industries. With waste heat streams generally hotter than 450°F, this industry had reported a waste heat rate of 1,032 trillion BTUs annually, which is roughly equal to 178 million barrels of oil.
The chemical industry. The second largest consumer of energy in the industrial sector behind petroleum, the chemical industry produces 70,000 different products and significant amounts of waste heat. Major waste heat producers within this industry include petrochemicals, chlorine, plastic materials, and agricultural chemicals like fertilizers and pesticides. With waste heat streams ranging in temperature, this industry had reported a waste heat rate of 600 trillion BTUs annually, translating to around 103 million barrels of oil.
The metals manufacturing industry. This industry speaks to primary metals production, which includes steel, iron, aluminum, and silicon. From the steel structures in your buildings and cars to the microchips in your phones, these metals were refined using high temperature furnaces, emitting large quantities of waste heat. In general, the primary metals industry has waste heat streams that are either lower than 450°F or higher than 1200°F. The industry had reported a waste heat rate of 366 trillion BTUs annually, or 63 million barrels of oil equivalent.
Other industries that produce heat waste on a lesser scale include cement production, glass manufacturing, and paper manufacturing. These heavy industries also operate at high temperatures, using furnaces and kilns to create their products.
Waste heat is not just isolated to fossil fuel and manufacturing industries. Another industry that produces low-temperature waste heat and has a growing demand for energy and cooling is the information technology sector, particularly within large data centers. Ranging from 77°F to 104°F, a data center’s waste heat resource is generally lower in temperature than large industrial facilities, but the sheer amount of heat produced makes the resource significant.
How can wasted heat power our planet?
Today, waste heat projects are transforming into a crucial clean energy initiative, particularly in oil and gas, chemical refining, and manufacturing industries.
Waste heat can play an important role in our energy transition, as it can be captured and recycled as an emission-free source of electricity in a process called waste heat to power. According to ICF International, the U.S. alone has the potential to produce 15 gigawatts of power from its industrial waste heat. That’s equal to the amount of power generated by around 47 million solar panels. Since converting waste heat to electricity would result in zero additional emissions, waste heat conversion projects can also generate carbon offsets and lower the carbon intensity of the industries that develop them.
One industry where waste heat energy can have a significant impact on carbon footprints is the oil and gas sector. Previously, heat recovery projects were implemented for the purpose of energy conservation improvements, such as preheating furnaces with gas that would normally be vented to the atmosphere. If these exhaust gases are hot enough and other technical considerations are met, the waste heat can be circumvented to a waste heat to electricity system, where it would drive a turbine to create additional emission-free power. By generating clean energy from their heat waste, a refinery, power plant, or pipeline network could address their scope 2 emissions to comply with low carbon fuel standards and mounting Environmental, Social, and Governance (ESG) pressures.
By targeting emissions intensity through waste heat conversion projects, industries can improve on economic as well as environmental performances. Another area where this can be realized is the manufacturing world. The U.S. cement industry was considered one of the most energy-intensive manufacturing industries, as their national energy use in 2010 was 10 times its share of gross output. With energy costs varying between 25 percent and 35 percent of total direct costs, the cement industry has long recognized that its participation in the energy transition and energy efficiency improvements are not just environmental plays, but also economic ones. Fortunately, the cement industry often produces waste heat at high enough temperatures to be potentially converted to an emission-free power source. Instead of purchasing electricity, cement plants can use this waste heat energy to power their processes. Cement plants could also sell the power back to the electrical grid, generating additional revenue streams from a previously wasted resource.
Waste heat utilization technology can be deployed in industrial facilities like this cement plant. Where else can waste heat energy projects be developed? View case studies for natural gas, steel, and glass industries.
(Photo: Exergy International)
How can you harness the value of your heat waste?
The road to net-zero emissions is paved with making existing assets and industries as clean as possible. This starts with addressing the waste heat resources currently being vented into our atmosphere. With the right technology and business solutions, waste heat can be turned into a valuable source of emission-free power and heat for our clean energy future.
Terrapin Geothermics develops waste heat energy projects at zero cost to the client. We assess the profitability of the waste heat source, design the project, and engage the best technology, engineers, and construction partners to bring the project to life. Unlock your waste heat potential and contact our experts for a consultation today.