GE taps into hidden energy with waste heat recovery

At GE’s Global Research Center near Munich, Germany, scientists have developed a breakthrough technology to help customers address the challenges of rising fuel costs and the increased demand for more efficient, environmentally friendly power systems and industrial plants. The solution is a new waste heat recovery technology called ORegen* — which is a device that converts waste heat from exhaust streams generated by equipment such as small gas turbines and industrial processes into usable electricity.

As Thomas Frey, research scientist at the Alternative Energy Lab of the GE Global Research Center Europe, explains: “Thousands of megawatts of heat are wasted through stacks, chimneys and coolers into the atmosphere every day via refineries, steel mills, cement plants, furnaces and power plants. The latter have only an average electrical efficiency of 33 percent in the U.S. The rest is thermal heat — a huge untapped source of energy. Experts have estimated that low-grade heat worth billions of dollars is wasted every year. Even a significant impact on CO2 emissions could be made, if only a fraction of that heat could be recycled to save fossil fuels rather than rejecting it to the atmosphere. ... However, cost-effective waste heat recovery systems for power production didn’t exist so far. This is exactly what motivated our waste heat recovery technology team at GE Global Research Munich to have a fresh look at an old technology: Organic Rankine Cycles (ORC). These systems have been known for more than a hundred years and operate very similarly to the conventional steam-based Rankine cycle — which is the basis of every conventional coal plant. The big difference is that ORCs don’t rely on high temperatures from burning fossil fuels but can use much lower heat input temperatures.”