Technology Research Area:

Green Circuits

What are green circuits, and what do they have to do with TVA's mission?

When electricity is transmitted to homes and businesses, as much as 10 percent of the power can be lost in the process. As the cost of energy rises, electric utilities, including TVA, have begun looking for ways to stop these losses.

One possible option is to install green circuits, which have significantly lower losses. Green circuits reduce losses using a variety of technical approaches including optimal conductor sizing, reducing unbalance, VAR (volt-amp-reactive) control, and better transformer efficiencies.

Better system models and modeling capabilities allow for better estimation of losses, targeting of solutions, and ways to test and identify improvements. Better metering data allows better monitoring of results, and new communications and control capabilities allow more effective reduction of losses.

What is TVA doing about this technology?

TVA has launched a field demonstration in a handful of circuits converted to green circuits. Loss-reduction approaches that could be tested include optimal VAR reduction using switched capacitors, voltage control, efficient transformers and substations, and changes in system design. This project will push the envelope to improve efficiency as much as is economically feasible, and will help set the stage for larger green circuit deployments.

What are the possibilities for green circuits?

There may be significant potential to use green circuits to reduce losses in the delivery of electricity. More efficient power delivery means that less fossil fuel needs to be burned to deliver the same amount of power to consumers, and that means a reduction of greenhouse gases released into the atmosphere.

Based on the monitoring, staged tests and simulations, research will document the real-life performance and operational issues associated with implementing green circuits, estimating savings in energy, dollars and lowered emissions of greenhouse gases.