In the context of human history the electric grid is quite recent. Until only 130 years ago, our ancestors, except for a few extremely rich early adopters in New York, used kerosene lanterns and candles to provide light in the evening. Lighting was just about the only use for electricity for the first two decades of the twentieth century. From these modest beginnings, electricity has changed our lives like few other inventions. Without electricity, we would not have telephone service, air-conditioning, radios, televisions, computers, the Internet, or even high-rise buildings.

In the beginning, electricity was provided almost exclusively by the private sector, although poles and wires were draped over pubic rights-of-way. Thomas Edison, George Westinghouse, and others competed for market share, resulting in a patchwork of separate but overlapping electrical networks that were consolidated and integrated in the first part of the twentieth century by industrialists like Samuel Insull. The combined electric utilities were considered natural monopolies, since it made no sense to have separate sets of wires and transformers serving a single geographic area. As monopolies, they were regulated at multiple levels of government.

The federal government stepped into the electricity business, both as a regulator and supplier, during the Great Depression. The Tennessee Valley Authority and the Bonneville Power Administration were created as government corporations. Our largest federally funded hydroelectric projects were constructed during this period.

Today, the electric grid is still primarily owned and managed by the private sector, but heavily regulated at all levels of government. Electric power producers are allowed to compete with each other at the wholesale level in most areas of the country, since the transmission and distribution systems are available for a fee to any power producer that wants to sell electricity into the grid.

The technologies used to make electricity vary widely in different parts of the country. The Rust Belt is powered almost entirely by coal and natural gas, while wind generators have a huge market share in Texas and Iowa. California has a little of everything, including solar, wind, geothermal, hydro, and natural gas. California has one remaining nuclear plant that is scheduled to be decommissioned in 2025.  The carbon emissions per unit of electricity produced also widely vary from state to state.

Power from wind and moving water has been a source of energy for millennia, but this kinetic energy was not used to generate electricity until Michael Faraday showed us how to convert rotation into electricity in the early 1800s. Hydropower is as old as the grid itself, but growth is limited and some even think it has already maxed out. In the last few decades, wind and solar technologies have matured and are gaining market share. Wind now produces more electricity in the United States than hydro, and the generation share for solar has been rapidly increasing for the last decade as costs continue to decline. Geothermal energy is limited mostly to the western United States, where thermal wells are fairly close to the surface .

If a utility or independent power producer wants to build a new plant and sell power into the grid, wind and solar are now as cost-effective as natural gas, and once the wind and solar plants are built, they cost practically nothing to operate. However, wind and solar are intermittent generators. Currently, gas is used to provide backup and to pick up the load at dusk, but batteries are beginning to supplement traditional energy storage techniques such as pumped storage to fill the gaps and make wind and solar a more independent source of power.

This part of the book describes the electric grid we now have, how it is managed, and how it came to be. It reviews the utility-scale renewable energy technologies now used, evaluates their relative cost, and assesses their future potential.