What is Peak Demand?

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What time of day do you use the most electricity? Most of us have never wondered about that. But the utility company is necessarily very aware of when the community is using the most energy, because they have to make sure that they can supply all the energy we need at any moment. There are specific times when the energy demand is highest, and supplying enough energy during those times is challenging. We can help meet this challenge by becoming aware of when we use energy and reducing our energy use during those peak times.

What is Peak Demand?The demand for electricity fluctuates over twenty-four hours, and the utility company has to buy enough power – hour by hour - from their suppliers to make sure there is sufficient electricity available whenever we want it. The time of day when the demand is typically greatest is from about 2:00pm to about 8:00pm. Those are the hours when businesses are still calling for a lot of power, and workers are just getting home and starting to call for more power. These hours are called “peak demand.” This is the time when utility companies have the biggest challenge in making sure there is enough electricity for everyone.

Electricity is more expensive when there is more demand, so if we use a lot of energy during those hours we drive the price up and that is reflected in our electricity bill.

Managing peak times was traditionally handled by building new power plants, to make sure that utility companies had extra capacity in case they needed it.This is expensive. Another possible way to make sure there is enough electricity during peak times would be to create a lot of storage capacity, but that is also expensive, and it’s not clear how best to do that. Utilities also make use of what are called “stand-by” plants, which are only used to provide electricity a few days of the year when demand is particularly high, but are run and maintained year-round.They stand ready to deliver the extra electricity that is needed during peak times on especially hot or cold days, usually not more than a couple of weeks a year. This is extremely expensive.It’s like keeping a second car in your driveway, running 24/7, just in case someone in your family might need it.

By far the easiest and least expensive way to manage times of peak electric demand is for us to reduce our energy use during those hours and on those days.If enough of us – families and businesses – can reduce our energy use between 2:00pm and 8:00pm on weekdays we can solve the peak demand problem. Without building new plants, and without using stand-by plants. Just by not flicking a lot of switches in the late afternoon and early evening.

What are Time of Use rates?Our utility company, NYSEG, will try to provide some incentive for us to avoid using electricity at peak times by offering “Time of Use” rates that any of its customers can opt in to. We are all charged a certain amount of money for every kilowatt-hour of energy that we use. If we opt in to a Time of Use rate, that kilowatt-hour charge will be reduced for any energy that we use from 6:00pm in the evening to 4:00pm the next day. And in exchange for that, we will try to not use electricity from 4:00-6:00pm. To encourage us to remember, NYSEG will get to charge us A LOT more money per kilowatt-hour during those peak hours from 4:00-6:00pm. For businesses, the same offer applies, but the peak hours are from 2:00pm to 8:00pm.

Should I do it?So, it’s a risk.If we can pay attention we can save money. If we can wait until after 6pm to run the dishwasher, or do laundry, or have a lot of electronics running, or run the air conditioner then we will save money on the electricity we use during all the other non-peak hours. This will work for some people and not for others. Some people do not have a lot of flexibility to decide when to use electricity. Or have too many other urgent things on their mind every day to be able to juggle when electricity gets used. If you can arrange your life to avoid energy use during peak times, then a Time of Use rate may benefit you. NYSEG will help people figure out, based on your past electric usage data, whether the time of use rates will work in your advantage.

How do I know what not to turn on from 4-6pm? There are some things that use electricity on and off all day and night but you don’t want to turn them off – like the refrigerator, the water heater, or the water pump. But there are some things that use a lot of electricity and you could postpone using them until after 6:00pm.Besides the clothes washer and dryer, and the dish washer, you could make sure to turn off extra lights, unplug chargers, turn down the heat or turn up the air conditioner, and not watch TV.Each of these actions will reduce the amount of electricity needed on the grid, and save you and everyone else a substantial amount of money.

If you have solar panels on your home, you should definitely NOT sign up for Time of Use rates, because signing up will change the nature of your contract with NYSEG for the electricity beyond what you use that you may be generating from the panels. Your net metering agreement will change, and it will not be as beneficial for you. You can call NYSEG or Cornell Cooperative Extension to find out more about this.

Reducing our energy use is a good idea for many reasons – it reduces our greenhouse gas footprint and saves us money.And it also helps to manage the electric grid, helping to prevent the building of expensive new power plants, and reducing the risk of blackouts or brownouts. So think about it. When DO you use the most energy? Are there ways of shifting your use? Whether or not we opt in to Time of Use rates, we can all try to avoid peak times, and be more conscious of how much energy we are using and when we are using it. If we all think a little more about this we can have a big impact!

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Last updated August 16, 2018