History of the U.S. Electrical Industry

Electricity Discovered

Since 1752, when Benjamin Franklin tied a metal key to a kite to prove that lightning is a stream of electrified air, scientists have studied new ways to tap into the possibilities of electrical power. Franklin’s famous experiment led him to coin terms about electricity: conductor, condenser, electric shock—and it inspired thousands of inventions, research discoveries, and technology advancements that have shaped modern methods of electrical power production and distribution. Today, as the electric utility industry works to meet the increasing energy demands of a growing society, the same ingenuity and progressive thinking of Benjamin Franklin is needed.

Transformers Invented

One utility component garnering the attention of safety- and environmentally-minded engineers is the electric utility transformer. First built in the United States at the end of the 19th century, transformers are an integral part of the utility grid. They are installed on utility poles, concrete pads in neighborhoods and shopping centers, under city streets, and in enclosed substations, where they serve to send power from the generating plant to commercial, industrial, and residential customers.

Initially, air served as the coolant factor in transformers, but in 1882, Elihu Thomas conceived and patented the method of using oil for insulating and cooling transformers. In 1892, after years of testing the fluid for effectiveness, General Electric became the first company to incorporate mineral oil into a transformer.

The Quest for a Better Transformer Fluid

Through the years, utility companies have experimented with a number of different coolant fluids as alternatives to mineral oil. While experimentation with natural fluid began at the same time that mineral oils were created, early methods of processing vegetable-based fluid were not adequate, and the resulting fluid suffered from high viscosity and unacceptable oxygen stability.

In the 1930s, due to the potential fire hazard of mineral oils, the industry began to use non-flammable, but ultimately hazardous, materials known as PCBs (polychlorinated biphenyls). In the 1970s, PCBs were banned due to their health and environmental hazards. That spurred a revival in the exploration of alternative fire-resistant transformer fluids. Among these were synthetic fluids, chemically somewhat similar to certain vegetable-based oils, but prohibitive due to their high cost, which prevented widespread demand.

Biodegradable Bio-based Fluids, Realized

Responding to the growing concern over environmental and safety risks associated with petroleum-based mineral oils, research and development of natural, vegetable-based fluid accelerated in the 1990s. By 1994, the ability to select additives that improved the effects of vegetable-based fluid was realized, which worked to pave new roads for future use of such coolants.

Trial installations of biodegradable bio-based fluid-filled transformers began in 1997. Two years later the products were commercialized and their use by utilities has grown significantly since then. Currently, there are more than 50,000 bio-based fluid-filled transformer installations across the country, representing utilities who have made the switch for all or part of their equipment.

Utilities Using Biodegradable Bio-based-Oil Coolant Fluid in Transformers

As utilities come to recognize the environmental, safety, and financial benefits of biodegradable bio-based coolant fluid, many have started the move away from petroleum-based mineral oil.

Click here to see a partial list of responsible utilities that are adopting the use of biodegradable bio-based fluid.