Waste Heat Recovery: The Next Wave of Clean Tech

The terms renewable energy and clean technology conjure up certain images. It could be a photovoltaic panel baking in the desert, or perhaps a wind turbine slowly rotating in the Great Plains. Or, even a massive dam generating hydropower. However, there is another important and growing clean energy technology the average consumer often hasn’t heard of yet: waste heat recovery.

Waste heat recovery employs a process that has been around since the 1960s, called the organic Rankine cycle (ORC), which easily integrates into existing manufacturing infrastructures. ORC units capture heat that is currently being released into the atmosphere and converts it into useable CO2-free electricity.

The ORC process uses organic, environmentally benign refrigerants that are able to produce electricity from low-temperature heat sources and in water-restricted environments. ORC technology has a small footprint-approximately the size of a tractor-trailer flatbed. Interest in this energy generating skid is on the rise as companies look to maximize the efficiency of existing investments and infrastructures.

This technology has a proven track record with more than 150 installations in operation around the world-including 25 in the US-that have produced millions of hours of emission-free electricity. Given its relative simplicity, carbon neutrality and diminutive physical footprint, ORC is also one of the cheapest sources of renewable power generation currently available. The economic benefits of waste heat recovery systems are significant when compared to wind or solar power generation. ORC’s utilization factor of more than 95{40f8b9e939a1f8880e4e068699181ea0c065f7fafc0e6f64c88497a3f07e42aa} far eclipses the 25{40f8b9e939a1f8880e4e068699181ea0c065f7fafc0e6f64c88497a3f07e42aa} to 35{40f8b9e939a1f8880e4e068699181ea0c065f7fafc0e6f64c88497a3f07e42aa} utilization factors seen in other renewable solutions like wind and solar.

The market for waste heat recovery is virtually limitless. According to researchers at University California Berkley, the US currently consumes about 100 quadrillion BTUs of energy per year. However, between 55 and 60 quadrillion BTUs are currently vented into the atmosphere as unused waste heat. With ORC technology, these emissions are harnessed on-site to generate useable CO2-free electricity that is fed directly back into a manufacturing process. Pulp and paper, lumber, refinery, cement, and power plant operations are especially well suited for waste heat recovery systems since they consume large amounts of electricity and maintain consistent waste heat streams with temperatures between 400° F and 800° F.

A wave of new focus and project development activity has occurred as a result of rising energy costs, growing environmental concern, and improvements to the ORC manufacturing process. Today’s new systems are modular, customizable, easily deployed, and economical to the facilities that deploy them.

The rise of independent project developers and new financing models have also helped accelerate customer adoption of waste heat recovery systems. Project developers shoulder the responsibilities of designing, engineering, constructing, and operating the ORC systems for their industrial customers. Additionally, project developers can offer customers financing options that allow resource-constrained organizations to explore the myriad benefits of waste heat recovery projects. Popular financing options include the purchase of a complete turnkey power system, leasing the system, or simply purchasing energy produced from a system installed at their site. The latter model, often referred to as the “PPA Model” (because the customer enters into a Power Purchase Agreement), relieves a company of capital expenditures and substantially shortens the sales cycle for new ORC systems. After all, who can say “no” to an offer of clean electricity, at a lower price than the utility can deliver, without any capital investment?

Facility managers, environmental experts, and forward-thinking legislators are beginning to recognize waste heat recovery as a win-win clean energy solution. Now it is time to get Congress to pay attention to this renewable energy “hidden gem” and recognize waste heat as a renewable resource eligible for tax and environmental credits. By tapping into existing but unused energy sources, American companies can reduce energy spending, reduce carbon footprints, and reduce dependence on non-renewable sources of energy. And that’s why waste heat is about to become a lot more relevant.