The Myth of “Baseload” Power

By Tyson Cook, Staff Scientist

For those of us looking forward to a day when we’re less reliant on dirty, fossil fuel-based power plants, it’s important to know the role they serve in the electricity system, and just what we have to do to replace them. One argument that is starting to be used against renewable energy revolves around that very idea: The claim that renewables may not be able to provide the “baseload” power like large fossil-fuel plants.

Which begs the question, what is this “baseload” power, and why does it matter?

The first thing to realize is that so-called “baseload” is not actually a different kind of power; it’s simply part of an engineering concept to visualize electrical demand. Imagine a line graph of the amount of total electricity used in a region over time. The plot would look like a series of waves, with peaks in the afternoon and early evening when everything is running on high, and dips at night and on the weekends when people are sleeping and offices are closed.

You could divide the line graph a lot of ways, but the idea of “baseload” comes from drawing a horizontal line to represent the minimum amount of electricity that is being used, no matter what time or day. The areas above that line are then labeled “intermediate” and “peak” loads. Kind of like this:

Graph explaining baseload power

From Understanding Base Load Power, October 2008, New York Affordable Reliable Electricity Alliance

In this way of thinking, the “baseload” power demand is met with big generators like old coal and nuclear plants that don’t turn on and off very well. To accommodate electrical needs above the “baseload,” smaller, more responsive plants are used that can more easily follow the demand. Makes sense, right?

The problem with this idea is that it’s not how the electrical grid actually works. In reality, the grid isn’t one uniform pool of power demand, but a huge, sprawling, interconnected web of transmission lines of various sizes and capacities, dotted with producers and users of power. More like this:

From Atlanta Journal-Constitution

The whole thing is controlled by an “independent system operator,” whose job is to make sure the system works right and everyone gets the power they need as cheaply and reliably as possible. This means constantly turning production up and down at various plants and using various mechanisms to manage flow.

So the idea of “baseload” power? Yes, there is always some minimum level of power being used in a particular region of the grid, but it’s certainly not as simple as that old line graph would indicate. And when trying to meet electrical demand, the power can come from any number of facilities at any time of day. For the system operator, the solution to which plants should be running when (and how much) is clear: Whatever makes electricity cheapest at any given time, considering the constraints of the grid. If that happens to be a large coal plant, so be it. If it’s a wind farm or small solar installation, that’s just as good. Even better.

Meet the Staff: Tyson Cook

Today we begin a new weekly blog series simply called “Meet the Staff.”

Now, this isn’t your typical biography that rehashes work experience and education history. Instead, we’ve asked staffers to write an autobiography with plenty of personality. Because we have a lot of that around Clean Wisconsin.

Without further ado, we kick off the lamely named Meet the Staff series with a not-so-lame autobiography by one of our newest staffers, Tyson Cook, staff scientist.

***

I remember one day, as part of a class project in early elementary school, writing my dream job on a construction-paper star: I wanted to be a naturalist. Actually, I think it was something to the effect of “½ football star, ½ naturalist.” The first half didn’t pan out; I ended up playing hockey instead of football. But I’ve always loved being in the great outdoors.

Later on in life, a couple less-than-thrilling biology courses in high school caused me to lose that direction a bit. I spent my time in college bouncing around the physics department studying everything that seemed interesting: industrial engineering, computational neuroscience, plasma fusion, complex systems. It wasn’t until my senior year that I took an “Environmental Science” course and got back on track; I went on to get a master’s in civil and environmental engineering from Stanford University.

After finishing school, I headed to an energy efficiency consulting firm, where I worked to increase the production of solar electricity through the statewide California Solar Initiative and pushed for advancements in efficient LED lighting. After some other career twists and turns that included a summer in rural Tanzania installing a solar water system, I landed as the staff scientist here at Clean Wisconsin.

You won’t see me in the Monday Night Football line-up, but I’ve finally found my dream job — working across Clean Wisconsin’s wide range of programs to protect the clean air and clean water we all rely on, and to help move us toward clean energy that will keep them that way for generations to come.