When the Lights Go Out
As I write this, 600 million people in India – approximately twice the population of the United States – are in the midst of the most extensive power outage in the history of the world. Take a moment and consider the chaos that would occur here in the U.S. if the entire country lost power for the day. As I have been reading the news accounts about this crisis, I have been trying to investigate how this could have happened and whether it could happen here.
As usual, lets start with some background. Electrical power grids have three main components: generation, transmission, and distribution. I previously covered the basics of generation in “Electricity Production 101.” Transmission is carried out through the overhead wires you see everywhere as well as in underground cables. The electricity in these wires is delivered from the power plants at a higher voltage than is required by the end user. Distribution is managed by transformers located near to the end user, which reduce the voltage to the appropriate level. In your house this is typically 220 volts for electric clothes dryers or ovens and 120 volts for everything else.
For an electric power grid to operate in a stable way the supply from power plants and the demand from end users needs to stay extraordinarily well balanced. When supply and demand get out of balance, the grid fails either due to equipment failure such as a burned out transformer, or a more difficult to describe scenario during which the voltages in the grid fall out of equilibrium. In the latter scenario imagine that the grid needs to go through the equivalent of a “reset” in order to resume normal function. Most electric power grid failures occur when an unanticipated increase in demand exceeds either the generation or the transmission capacity, thus leading to an imbalance.
The modern electric power industry in the U.S. came into being with the passage of the Public Utility Holding Company Act of 1934 which defined electricity as a public good. These types of public electric companies managed U.S. electric needs from 1934 until the industry was deregulated in 1992. Since the beginning of deregulation, the rate of blackouts in the U.S. has increased by over 120%. The primary reason for this increase in blackouts is a reduction in reserve transmission capacity in the system. In a regulated environment, the design and operating capacity of the system is determined by the electrical engineers who ensure operational stability of the grid by including extra transmission capacity. For example he or she might specify that the system be designed to run at 80% capacity to allow for room to ramp up during a heat wave. In a deregulated environment, where companies are more focused on generating returns for shareholders rather than preventing service interruptions, monies for installing excess capacity for unexpected demand increases are generally cut out of the budget. As a result, much of the electric grid in the U.S. runs close to capacity at all times, making it increasingly vulnerable to blackouts.
While the investigation of the current outage in India is ongoing, it appears that the failure stems from supply dropping below demand rather than from a transmission capacity problem. As in the U.S., the summer is a time of high electricity consumption in India, stemming from consumption for air conditioning as well as from water pumps tapping increasingly deep underground aquifers. (For more on this topic see “When the Well Runs Dry”.) Coincident with this high summer time electricity demand, India’s coal-fired power plants have been generating less-than-expected amounts of electricity due to reduced supplies of coal, and production from water-powered hydro-electric plants has been reduced due to lower-than-expected rains from the spring monsoon. While this drop in electricity supply is considered to be the root cause of the power grid failure, its massive extent seems to be exacerbated by years of under-spending on maintenance and upgrades.
As our electric grid infrastructure in the U.S. continues to age, the risk for an India-like system-failure continues to grow. Former Vice President Al Gore and others are increasingly calling for a transition of our power system to what has come to be called a “smart grid”. In essence the smart grid involves the installation of digital meters throughout the system which allow for improved balancing of power supply and demand, thereby reducing both the possibility of the system falling out of equilibrium and also reducing power loss due to inefficient routing of electricity. Converting to a smart grid system would reduce the need to build more fossil-fueled power plants and allow some of the older, more polluting power plants to be taking out of service. An additional, and rather important advantage of a smart grid is that it would make it much easier to connect to small-scale solar and wind power units. Envision houses, schools and other public building all topped with solar panels.
Conversion to a smart grid is a cornerstone feature of converting to a more environmentally benign energy system and to ensuring that we don’t slip into darkness due to massive network failures. Constructing the smart grid would create just the sort of green-energy jobs we are seeking. Bear in mind that smart grid technology is not a pie-in-the-sky sort of a notion as the often cutting-edge nation of Denmark is well on the way to creating a smart grid already. My concern is that the current fragmented, deregulated power utility system we have is not amenable to this sort of coordinated public action and investment which would be required for a massive national project like this. In the post World War II era we routinely embarked on these types of national infrastructure projects such as the interstate highway system which we call use and benefit from on a regular basis. I hope we can come together as a country and embark on another important national effort and build a smart grid.
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