Photo by Arthur Lambillotte on Unsplash
This article was first published in Castanet Dec 12, 2023 / 6:00 pm
It’s not easy being an electrical utility. Electric utilities have to be able to meet the demand every minute of the day, no matter how much electricity we use. To make sure electricity is available around the clock utilities have peaking generators (often a natural gas plant) that they can fire up when demand is really high. As you might expect, building a “just in case” power plant and leaving it idle most of the time is expensive and those expenses are passed on to consumers. Rather than unendingly increasing electricity, we could reduce power during peak times. That is called “demand side management.”
A dramatic example of demand side management was the emergency alert California sent to 27 million cell phones on September 6, 2022. The message read “Conserve energy now to protect public health and safety. Extreme heat is straining the state energy grid. Power interruptions may occur unless you take action. Turn off or reduce nonessential power if health allows, now until 9pm.” The text went out at 5:45 PM and within 15 minutes electricity usage dropped by 2000 megawatts, averting rolling blackouts.
A more sophisticated demand side management system leverages the power of large numbers. In the worst case scenario high demand can trigger blackouts where a small number of customers get zero electricity. Utilities can achieve the same reduction by making small (often unnoticeable) adjustments for hundreds of thousands of customers. BC Hydro has a “Peak Rewards” program and Fortis BC is running a pilot program called “Peak Saver.” Customers can voluntarily join these plans by installing a special thermostat. During peak periods the utility can make small adjustments to your heating or cooling. Customers can opt-out on any day by simply going to the thermostat and adjusting the temperature. “Peak” programs in California, where peak usage is tied to summer air conditioning, are more sophisticated. They pre-cool the house, then turn the AC on and off in short bursts.
Let’s look at two appliances -- your dishwasher and your home EV charging station. Your dishwasher already has a four hour delay setting. Since most people run their dishwasher after dinner, using the delay insures you have hot water (for the kids’ bath), puts off the dishwasher noise and moves electricity use from peak (4pm-9pm) to off peak (after 9pm).
Home EV charging puts new pressure on the electrical grid. It’s natural to come home from work around 6pm, pull your car into the garage and plug it in. If you do that, you are drawing a lot of electricity during peak demand. Delaying the start time can be done by the user (some charging stations offer a dishwasher-like delay) or the BC Hydro and Fortis BC “Peak” programs can communicate with your EV charger.
As battery storage gets less expensive, home battery storage systems can play a part in demand side management. One of the more popular home battery systems is the Tesla Powerwall. The Powerwall was originally a solution for homeowners with solar systems that produced excess power during daylight hours. Saving that electricity during the day and discharging it overnight allowed people to make maximum use of their solar capability. Conveniently, having a home battery system also provides power during an outage. With a utility-connected smart thermostat a collection of home battery systems can create a virtual power plant, replacing a fossil fuel peaking plant.
Where does demand side management fit into your life? First, be aware that peak electrical use happens between 4pm and 9pm. Electricity used during this time is more expensive and generates more carbon emissions as natural gas peaking plants are brought into use. You can help avoid dirty energy by doubling down on normal conservation measures (putting on a sweater, turning off lights) and by shifting your energy intensive activities (like running the dishwasher and drying clothes) outside the 4pm-9pm window. If you install a home EV charger, choose a brand that has a delay setting. Consider participating in your utility’s new tariff plans: either a smart thermostat on a “Peaking” tariff or a time of use tariff. What matters is not just how much electricity you use, it’s also what time it is when you flip the switch.
Comments
Post a Comment