I recently wrote a piece titled, “A Path to Sustainable World Energy,” and received numerous questions about what we need to do to update the electricity distribution infrastructure that powers our lives.

Fortunately for all of us, the July 2010 issue of National Geographic has an excellent discussion of how we can upgrade the 150,000 miles of high-voltage transmission lines that carry power from 5,400 generating plants owned by more than 3,000 utilities operating relatively well most of the time, But power interruptions annually cost the American economy about $80 billion.

Most of our electricity comes from burning fossil fuels, about half of it from coal. Hydroelectric, wind and solar power account for less than 10 percent. Our existing infrastructure perpetuates this; we need to incorporate more solar and wind energy, and more efficiently use what is available.

Unlike our interstate highway system, no one planned the existing grid. It’s a patchwork of local utilities. And individual states regulate the construction of transmission lines. We need a better integrated and smarter grid.

In 1881, Thomas Edison, inventor of the light bulb, designed and installed the first grid. It delivered power from the Pearl Street Station in mid-New York City to the offices of J.P. Morgan and the adjacent area.

By 1890, power lines were running from the Niagara Falls generating station to a distance of 20 miles away. By 1920, electricity only accounted for about 10 percent of the U.S. energy supply. Today, about 40 percent of the energy we use goes to making electricity.

Early utilities were local operations that generated electricity and distributed it locally. Over time, a patchwork of local grids developed across the United States, which eventually became large regional interconnections. Today, there is no single grid in the U.S. There are three relatively independent ones, and they are essentially based on technologies from the 1960s.

But constructive changes are planned.

Nearly $30 billion in new generation plants and high-voltage transmission lines are planned in the West. State goals and federal subsidies favor renewable energy — 30 percent in New York by 2015, 33 percent in California by 2020. Also, the grid needs to get smarter as utilities increase their ability to monitor the flow of electricity from generator to customer.

At home, smart meters will allow customers to program appliances to turn on at off-peak hours when electricity is cheaper, and customers who generate energy from solar panels or wind turbines can sell it to the grid.

Locally, the utility can use data from homes and offices to monitor electricity use and adjust thermostats to reduce spikes in demand. Regionally, long-distance transmission lines will stretch to remote areas where there is plenty of sun and wind, and new technologies will help store power during off-peak hours.

Because wind and solar power are intermittent, there is a need to find ways to store energy for round-the-clock distribution. The Obama administration has allocated $185 million of stimulus money to develop promising technologies.

Compressed air can be stored underground when the wind blows and later released to make electricity. Pump-storage hydropower consists of pumping water into storage ponds when electricity demand is low and releasing it to turn a turbine when demand is high. And conventional batteries can be used to store energy in a small space, as lithium batteries do for electric cars.

To accommodate green energy, the grid needs both more storage and more high-voltage power lines. There aren’t enough running to places where it’s easy to generate the energy. To connect wind farms in Kern County, Calif., with Los Angeles, Edison Internationa, is building 250 miles of line.

Green energy would get a boost if there were more and bigger connections between the three quasi-independent grids in the U.S. A proposed project called Tres Amigas SuperStation would allow Texas wind — and Arizona sun — to supply Chicago or Los Angeles.

Recent blackouts and global warming have provided a strong impetus for grid reform. A smarter grid would reduce the probability of blackouts by providing faster and more detailed information on the status of the grid. Excel Energy has installed an upgraded smart grid at Boulder, Colo. It provides customers options of using expensive or cheap electricity, which should reduce demand, save energy and help integrate renewables like wind and solar sources.

Sweden, Denmark and Italy are already ahead of the U.S. in upgrading their electrical intelligence. Nine northern European countries have agreed to link their grids by building transmission lines under the North Sea. A more futuristic vision is new cable under the Mediterranean to connect with solar power from the Sahara.

It is imperative that we improve the effectiveness of our antiquated electric grid and incorporate greater proportions of renewable energy resources.

Dr. Lloyd V. Stover is an environmental scientist who has been involved in energy policy issues for half a century. He may be reached at ursine005@gmail.com