In 1879, soon after developing the light bulb, Thomas Edison realized that in order to make his invention a product, he would need to develop a system to bring electricity into homes and business. By 1882 he had built a steam engine generator and transmission system in New York City’s financial district allowing storefronts to be lit using the miracle of modern power[i]. As of 2011 there were “5,800 operational power plants in the United States” offering reliable and seemingly inexhaustible electricity to American homes and businesses. [ii] Today we pay to not have to think about our electrical utilities, but this mysterious system is more closely monitored than ever before offering consumers an opportunity to look back stage. Below is a great graphic I recently found that maps the United States’ energy use.[iii]
I’m shocked at how inefficient our electrical system is. For every 100 units of energy used to generate electricity, 67.8 units of energy are lost before they are put to use. A major cause for this inefficiency is heat lost at power plants where [fossil, biomass, nuclear] fuel produces steam to drive huge turbines. (For a video showing how steam is used drive generators look here[iv]) These plants commonly have efficiencies below 40%.[v] Some plants, like Dartmouth’s power plant, put that energy to use by heating (and cooling) buildings, a process called cogeneration which improves efficiency.[vi] But this is not the norm as the added cost of using the heat often outweighs the profit.
But there is a reason why the market still prefers these inefficient power plants. The current electrical transmission and distribution system has been called a “just in time system” meaning that energy is produced to meet that moment’s demand.[vii] Unlike a car with its gas tank, most homes have no means of storing energy (electrical energy at least). That means that when you decide to stay up until three in the morning watching TV, some huge steam generator somewhere far away is spinning to keep your picture rolling. When we demand power, the plant will throw another coal in the fire or (more and more popularly) pump in more natural gas.
And this is ultimately why such an unimpressive percentage of our power comes from renewable sources. The most popularly demanded renewables, wind and solar, don’t fit very well into this “just in time system.” You can confirm this for yourself if you look at the red and yellow sections of the energy map. The harvested power can’t be controlled to match demand, and that makes it harder to play the markets. And if you can’t play the markets, you’re not making as much money as the other guys.
Nonetheless, our transmission and distribution system is changing, and our sources of energy will as well. The long anticipated “smart grid” will computerize our power utilities making processes automated and more transparent. The Department of Energy predicts that non fossil fuel related industries will benefit as information systems begin “handling sources of electricity like wind and solar power and even integrating electric vehicles onto the grid”. [viii] The prospect is exciting, but it will take much more than just a smart grid to revolutionize our energy use—especially in our transportation sector.
Looking at that dark green section on the energy map, you can see transportation ran almost exclusively on petroleum, consuming 71% of all petrol in the US. That is approximately 195 billion gallons of gas.[ix] Attempts to significantly substitute gasoline with electricity would put a large strain on the power grid. If we wanted to replace say half of the gas burned (97.5 billion gallons) with electricity, we would need to produce twice as much electricity as we do now.[x] Improved battery and motor efficiencies, smarter transmission and distribution, and substantial increases in electrical generation will all be necessary for our transportation sector to plug in rather than fill up. And even then the system probably wouldn’t be carbon neutral.
This is particularly problematic for those of us concerned with carbon emissions and in extension climate change. Electrical power is at the center of sustainability as an alternative to fossil fuels, but for as long as coal and natural gas remain cheap, Americans seem content to blissfully consume even if the energy they use is produced in inefficient power plants. After all, for the average person today, the process through which electricity gets to their huge array of electronics is as mysterious as it was for Edison’s contemporaries 150 years ago. Perhaps the only clear answer is to use less energy, become better informed consumers, and support efforts that promote a healthier carbon cycle.
[ix] (25.1% of 97.3 quads)*(8 billion gallons of gasoline per quad [Wikipedia] ) = 195 billion gallons of gas
[x] This calculation assumes that the transportation sector would produce the same ratio of reject energy to service energy. The transportation sector consumes 25.1 percent of the total energy of the country and electricity generates about 12.6 of the total.