Why are we having rolling blackouts? There seems to be a lot of confusion about what is happening in many utilities in the US right now. Since I worked as an electrical engineer at an utility for 5 years, I thought I might shed some light on the issue. Yes that’s a pun. Get over it.
So, I did what a good engineer would do. Research. I put together a few common questions that I’ve seen online:
Question #1: Why are we having rolling blackouts?
A- Utility companies are performing rotating outages, also known as rolling blackouts in order to keep the electric grid stable. There’s very little actual energy storage in the grid. So, the power generated at generation plants has to match the amount of power used. Otherwise, the system becomes unstable. To protect the system from instability, the grid operators have different levels of energy conservation. For example, in the Southwest Power Pool, the grid operator in the midwest, has 3 energy emergency levels.
EEA1 – It means that there’s enough power available to meet the demand. The power to some large industrial companies may be shut off. This is the least serious of the 3 levels.
EEA2 – The grid operator tells the electric companies to notify the public and request them to lower their power usage. For example, in the winter, lowering their thermostat and reducing the usage of big appliances like ovens and clothes dryers.
EEA3 – This is the most critical energy alert level, in which the grid operator tells the utilities to perform rolling blackouts.
Question #2: How exactly will shutting off the power at someone’s home saves energy? Won’t the heater have to work harder to warm it back up again?
A – the heat loss through a home’s walls is less as the temperature difference decreases. It’s true that your furnace will have to work a little harder when power comes back on, but the energy savings happens when the inside temperature is temporarily lower.
Also, other devices like lighting, TV, etc. don’t have to consume extra energy after a power loss, so there is more energy savings.
Question #3: Why are rolling blackouts needed?
A- We’re in this situation for three reasons: 1) tight gas supplies; 2) unprecedented energy demand; and 3) low wind conditions across the Midwest.
Question #4: Why the tight natural gas supplies? And why does it matter in my home?
A- Natural gas comes from natural gas wells, which bring the natural gas from underground to the surface so that it can be refined and delivered to your house. So, Natural gas from the ground typically has water vapor in it. When this water vapor comes to the surface in extremely cold temperatures, it condenses and turns into ice. When this happens, enough ice can build up and can clog the pipe. This is called a freeze off.
Natural gas can be used in homes to cook, as a fuel for the home’s furnace, which provides the heater and also to heat the water. What many people don’t know is that natural gas is used as a fuel to generate electricity in many power plants.
The cold temperatures have caused many people’s furnaces to use natural gas to keep the house warm.
Question #5: Why are people picking on wind generation so much when there are other energy generation sources?
A- Wind is not the only issue. The problem is deeper than that. As I said before, the grid doesn’t store much energy, so the energy produced has to be equal to the energy used at that time. There are different energy resources that can respond to the power needs. The quickest responding power generation comes from natural gas units. These are typically called peaking units because they typically respond to the highest energy demands, and the power output can be rapidly changed to respond to rapid changes in power demands to maintain the balance.
Generation such as coal and nuclear generation can be controlled but it takes considerably longer to change the power output. And renewables such as wind power and solar power cannot be increased to meet demands, but can only decrease their output. So, when fluctuations occur in the wind or solar power outputs, natural gas peaking units must be used to balance the grid.
This relationship between wind and natural gas is very important. Wind generation has been extremely low this week (around 3% of capacity). Part of this is because there hasn’t been a lot of wind in the midwest. So, natural gas generation has to pick up the slack, which is an issue because as I said before, natural gas reserves are currently stressed.
I hope I answered the questions you have. If you have any other questions, please comment below. Politically charged comments will almost certainly be ignored.
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