What if your washing machine could help fight asthma? Or your electric car could stabilize the power grid? It's not science fiction—it's the power of timing. While we often focus on how much electricity we use, a quiet revolution is happening around when we use it. As solar arrays proliferate on farms, blanket parking lots, and cover rooftops, our electricity grid is facing an unexpected challenge with a quirky name: the “duck curve.” Understand this concept, and you can turn your vehicles and everyday appliances into powerful tools for sustainability—while potentially slashing your utility bills in the process.

Understanding the Duck Curve

The "duck curve" represents the daily pattern of electricity demand from the power grid after accounting for solar generation. This curve gets its name because, when graphed, it resembles the silhouette of a sitting duck, with a belly-like dip during midday solar production and a steep neck-like rise in the evening as solar power drops off but electricity demand increases.

Why is this important? As more solar capacity comes online, conventional power plants are used less during midday, creating a deeper “belly” in the curve. This creates two key challenges: grid stress and economic inefficiency. In the evening, when solar generation drops but demand remains high, grid operators must rapidly ramp up conventional power plants to meet consumer demand, making it difficult to balance supply in real-time.

Why Time-Shifting Matters

The traditional utility model was built around massive hydroelectric turbines and pumps and coal and nuclear power plants running continuously, with fluctuating output to match demand throughout the day. Now, with abundant solar generation everywhere during daylight hours, we face a new reality:

  1. Mid-day surplus: Solar often generates more electricity than needed during peak daylight hours

  2. Evening shortage: When the sun sets, solar generation stops just as many people return home and increase electricity use

  3. Wasted potential: Without proper timing, renewable energy may be curtailed (shut off) because it can't be used immediately

One Simple Step: Shift Your Usage

The solution? Adjust when you use electricity to match generation patterns. Here are practical ways to shift your electricity consumption:

Tasks to Move to Mid-day (10 am-3 pm):

  • Charge electric vehicles when solar generation is abundant

  • Heat water using timer-controlled water heaters

  • Run major appliances like dishwashers, washing machines, and dryers

  • Pre-cool your home by lowering thermostat settings slightly before peak evening hours

  • Charge batteries for power tools, electronics, and home energy storage

Tasks to Avoid During Peak Hours (5 pm-9 pm):

  • Simultaneous use of multiple high-draw appliances

  • Non-essential cooking with electric ranges or ovens

  • Heating or cooling beyond necessary comfort levels

Benefits of Time-Shifting

Electricity produced by rooftop solar, used locally during the day and stored locally for evening use, avoids generation, transmission, and distribution losses and effectively replaces much more energy that would be required from the grid. Benefits include:

  • Lower bills: Many utilities offer time-of-use plans with cheaper rates during solar-abundant hours

  • Reduced emissions: When you use electricity during solar peak hours, less fossil fuel generation is needed

  • Grid stability: By flattening the duck curve, we help prevent blackouts and reduce infrastructure costs

  • Better renewable integration: More consistent demand patterns allow higher renewable penetration

Going Further: Storage Solutions

If you want to maximize your impact, consider energy storage options:

  1. Home batteries allow you to shift up to 100% of your usage daily—or even shift usage to different days of the week (charge on a sunny day, soaking up excess solar electricity, and discharge on a cloudy day, supporting the grid)—depending on the storage capacity you install.

  2. Thermal storage through pre-heating water or pre-cooling living spaces

  3. EV batteries as temporary home energy storage with “bidirectional” charging. Note: not every model of EV can send power both ways through its charging port—check your owner’s manual to see if yours offers vehicle-to-home (V2H), vehicle-to-grid (V2G), or vehicle-to-everything (V2X) technology.

Simple Automation Tips

You don't need to manually adjust your schedule every day:

  • Smart plugs and outlets can be programmed to run devices during optimal hours

  • Programmable thermostats can pre-cool homes before peak hours

  • EV charging timers can ensure vehicles charge during solar-abundant times

The Bigger Picture

The duck curve isn't just a California phenomenon—although that’s where it first emerged as a serious problem in the United States—it's emerging worldwide as solar adoption increases. By adopting time-shifting habits now, you're participating in an essential transition toward a more flexible, renewable-powered grid that can eliminate the need for fossil fuel “peaker plants” that run only during high demand.

Remember, you don't need solar panels to participate in this energy shift. Whether you have rooftop solar or not, everyone who adjusts their electricity usage patterns helps create a more sustainable energy system. Even small changes, when adopted by many households, help us paddle smoothly to a more sustainable energy future.