News comes today of disruptions to life in Detroit. But before we see this story spun up into an argument for one type of power plant or another, let’s get the facts. The local utility, Detroit’s Public Lighting Department is saying that a cable failure caused the outage around 10:30 am local time.
Wires are usually what break
Tree falls in the city. Credit: M. Jacobs
To keep the electricity on, we depend on an electric grid that has wires, cables, transmission lines. These lines go everywhere, and they are vulnerable to just about everything. Almost every power outage in the U.S. is caused by broken wires. To help make this clear, I assembled a summary of 13 largest power outages, describing how they happened. The average consumer sees small, local power outages maybe once a year, typically caused by small, local damage to wires. Major storms can make a bigger impact, no doubt. The bigger the impact, the more attention that power outage will get. Whether a storm or a squirrel that breaks the wires, these are unexpected and sudden outages.
Not about the coal plants
The traditional debate about adequate electricity looks at the long-term projections of supply and demand. The $600 million (or $6 billion) question is posed: “Will we have sufficient generating capacity for the summer 5 or 8 years from now?” This is the way the traditional debate has been framed, and we still see some of that kind of talk. The problem with this frame is that most of the country does not rely on a central planning, top-down approach to investment in new power supplies. Federal law opened this former monopoly 30 – 40 years ago, allowing new power supplies of all sizes and ownership models. The deregulation of the power business invited industrial facilities to combine steam process needs with cogeneration. Then nimble developers worked out the “independent power producer” concept to build plants, usually gas-fired, without a requirement to sell the steam. And on and on, until today.
What are we building now?
In the past few years, new gas-fired power plants are feeling the heat of competition from renewable energy generation. Windfarms, solar farms, and solar rooftop installations are being added more quickly than the traditionalists ever imagined. Looming large on the horizon are new forms of installing energy storage and energy efficiency in commercial buildings. The time required to build new energy supplies, especially efficiency, renewables and storage, is much shorter than the 7+ years assumed for the traditional large central plants. And that is why so many of the announcements about the need for new power plants are exaggerating the situation.
Back to Detroit
At the hospitals and fire stations of Detroit, emergency generators are allowing vital services to continue. These are now often called micro-grids, and that idea is likely to grow. Combining a set of energy supplies, and reducing the wasted energy, are great ideas (whether we call that a micro-grid or not). But just like the wires that go everywhere, the micro-grid idea will need to reach everywhere if everyone is going to have a back-up power supply. Making sense of this idea requires thinking about the scale of the service. We can use batteries to keep lights on in hallways, and just as new LED bulbs mean flashlights require less batteries, we will soon see emergency lights using more efficient lightbulbs. Now, come to think of it, if we used LED bulbs everywhere, we would require less energy supplies for our lighting all year. In Detroit, the cable failed in the middle of the morning, when temperatures were about average for early December, 29 degrees. Those are not the most stressful conditions.
Next time?
It would be possible to reduce energy waste, replace enough light bulbs, and design for spare cables and switches so as to avoid a city suffering a blackout caused by one cable failure. The details are not yet known about how the design and the conditions in Detroit combined to lead to this outage. I do know that budgets for reliability and the improvement of infrastructure are never as popular as other needs. Detroit has been through too many budget cuts, and seen too much decline to suggest that the most reliable power grid would be found there. In reality, more of American infrastructure is older than it should be to remain reliable. Our budgets are only starting to grow for electric wires, and too little of that is being used to encourage more supplies at the customers’ locations. We could be planning for more flexibility, more grid-support from distributed generation, and more benefits from smart meters. Maybe the utility decision-makers will ask for these non-traditional, faster-responding improvements as we rebuild the wires all around us.