Hunting Solutions for the Duck Curve
“Huh, that kind of looks like a duck.”
This line was most likely uttered sometime in 2012, as people at the California Independent System Operator were huddled around a table making a chart about renewable energy. The point of the chart was straightforward: to show the contrast between electricity demand and renewable energy production throughout the day. The chart did, indeed, look like a duck:
Adapted from CAISO.
This is the duck curve: one of the most important charts in energy.
What does the duck curve actually represent?
The duck curve chart measures “net load”, which is what you get when you subtract the amount of energy being produced by renewables (like solar) from the total demand for electricity.
Net Load = Total Demand – Renewable Energy Production
Net load tell us how much electricity needs to be generated at any given time from non-renewable sources in order to meet demand. When the curve swings low, renewables are meeting a lot of the demand. When it’s high, renewables aren’t generating as much energy as people need.
What does it mean, though? Two big ideas.
1: Overproduction of energy is inefficient — and possible with renewables. Having an oversupply of energy, while not as bad as an undersupply, can cause a bunch of logistical issues. For the most part, you can’t just ‘park’ electricity somewhere until it’s ready to be used, at least not on a large scale. Otherwise we wouldn’t need to worry about this in the first place.
2: Renewables often don’t produce much energy during peak demand. Peak demand tends to be in the evening, when solar energy production is already starting to wane and the wind is starting to die down.
This mismatch is renewable energy generation and peak energy demand means that renewables often can’t meet our daily energy needs. This leads to spikes in non-renewable energy, like natural gas.
It also fuels arguments against the transition to renewable energy, with arguments like “The sun doesn’t always shine,” or “the wind doesn’t always blow.” While that’s true, it’d be foolish to treat the duck curve like a reason we shouldn’t use renewables — or a problem without solutions.
Solutions to our duck-sized renewable energy problem
Like most problems in energy, the duck curve is solvable. There are two clear paths to solve it so we can depend more on renewables: one is on the energy production side, and the other is on the energy consumption side.
On the production side, there are a number of actions that utilities and generators can take to avoid the potential downsides of the duck curve. Some ideas outlined by the people who made the duck curve chart are:
Connect power grids across more states
Add more batteries to store extra energy
Encourage people to use power when it's plentiful
Build power plants that can quickly change output level
Better predict sun and wind power availability
Transition more people to electric cars for more daytime demand
Reward power plants that can easily adjust to demand
But this list, while interesting, isn’t particularly actionable if you’re not working in the government, or for a utility (other than buying an electric car). Fortunately, making renewable energy more viable isn’t just something that executives at utilities can make happen.
The easiest, highest-leverage way for you to help flatten the duck curve is simple: appliances with integrated batteries. The appliances in your home, including your heating and air conditioning, account for at least ~74% of your total energy consumption. These appliances are a big reason for the duck curve — you want to use your AC during the heat of the day like everyone else, you want to cook dinner in the evening like everyone else, and so on.
Battery-integrated appliances, though, offer an alternative. What if your appliances automatically and intelligently charged during the times of the day when renewables produce the most energy (usually midday) — and then use that power during the times when renewables produce less and the grid is closer to being overloaded?
That’s the future we’re building at Impulse. Our product is a powerful battery-powered induction cooking that plugs into a 120V outlet (the standard in American kitchens). To learn more about the stove, head here. Or, if you’d like to learn more about electrification via battery-powered appliances and see some options for other products, head here.
Lyn Stoler is the Climate and Policy Lead at Impulse Labs. In addition to writing (and illustrating!) our electrification blog posts, she manages our policy and energy partnerships. She is also an enthusiastic (if amateur-ish) cook. If you want to talk energy, electrification, and more, you can reach out to her at enterprise@impulselabs.com.