I'm specifically talking about Duke's EnergyWise program, but I'm fairly sure utilities everywhere are adopting similar programs. The idea is that they tie into your major appliances (i.e., heatpump and hot water heater) - during high demand they can temporarily shut off your appliances (maximum of like 16m at a time) and in return you get a credit of up to ~$150 on your power bill over the course of a year.

What are the gotchas for this kind of program? Assuming I'm ok with them occasionally turning off my heat pump and hot water heater for a few minutes every now and then, should I be concerned with anything else?

  • I don’t have quite as much conspiracy theory as the currently existing answer, BUT Nest is the “partner” in most of these programs. Nest is Alphabet... i.e Google... I do have a problem with Google and how they collect and sell data.
    – Tyson
    Nov 17, 2017 at 0:57
  • 3
    So far these answers have all been from the mentality of tinfoil hat, prepper, ammo-hoarding, wing-nut, "I'm all right Jack keep your hands offa my stack" greedy, regressive, "citizenship is all benefits to me, I don't have any social responsibility" man-child thinking. Ironically, what they accuse the utility of! When I have the time tonight I'll go into depth about what's really going on, and how it's about a magnificent future which actually puts more control in YOUR hands. Nov 17, 2017 at 21:21

4 Answers 4


"What fresh hell is this?" Dorothy Parker

It must be for electric appliances only? It sounds like the biggest pitfall is having no energy when you want it... A one-time $150 credit sounds like a terrible deal. Even $150 every year is small change compared to most yearly utility bills, and the annoyance this could cause.

Here's their image of when you could get your power "cycled" off. Approximately 45% of your possible heat anywhere from 6AM to 11AM, and 6PM to 11PM, and 45% of your possible cooling from 1PM to 11PM. Basically anytime most people are at home and awake:

enter image description here

You might not even get any credits either, it says "To earn credits, customers must meet minimum energy requirements. Customers with lower energy usage may not qualify." I don't see the minimum energy requirements specified anywhere, other than the "exceeding 600KWh/month you'll get credits even with no cycles" below.

enter image description here

Some problems I found in their own FAQs on their page for Florida:

Will cycles ever occur outside peak usage periods?
Possibly, but only in the case of critical capacity conditions in the Duke Energy system.

So you could be "cycled off" at anytime, really. Not just "peak usage periods."

How long can I expect to have hot water when the program is being used?
This depends on the size of the water heater tank. A water heater tank is nothing more than a large thermos bottle. The more you conserve, the longer the hot water will last.

So basically you could end up with no hot water during your shower, especially if it's right after you put in a load of laundry using hot water.

Can EnergyWise Home cause damage to my air conditioning or heating system
No. EnergyWise Home cycles your unit the same way as your thermostat. The minimum off time is 10 minutes; therefore, no short cycling damage can occur to the compressor.

Their page is unclear, but if there is an external "EnergyWise Home box" that controls power going to the whole appliance, and if it's red light is on then the appliance has no power. With everything being computer-controlled now, just pulling the plug on an appliance is NOT how the thermostat works. Pulling the plug on any computer isn't usually a good idea, so I don't 100% believe their "no damage" claim.

And with the whole heat/AC system off, that probably includes the basic blower fan, so not only is there no heat/AC but there's not even a breeze to move the air around.

But, elsewhere it says you must have "equipment compatible with EnergyWise Home program technology" so it's possible their box really does just turn off the thermostat, keeping the other power/fan going, so that would sound ok.

When EnergyWise Home cycles my heating or air conditioning unit for 16.5 minutes out of 30 minutes, my unit should run the balance of 13.5 minutes. Is that correct?
Yes. However, there may be exceptions. Electronic thermostats and time delays built into your system can extend the off time, even if the power is back on.

So you'll only have heat/AC for 13.5 x 2 = 27 minutes an hour at the absolute maximum. So about 45% "power" of what you could have. For an extremely cold/hot day it would take twice as long to heat/cool, or you'll just stay colder/hotter than you like.

Will my pool pump freeze if it is interrupted five hours in extremely cold weather?
No. EnergyWise Home allows the pool equipment to operate for five minutes each hour. Customers with solar pool heaters should drain them per the manufacturer's instructions.

I would disagree here, if it's well below zero (maybe not very applicable to Florida, but it could happen, more to other states) then 5 minutes an hour sounds inadequate to prevent freezing. Even if the whole pool would take hours to freeze, once the small pump itself freezes it's game over.

What if I am using a timer on my water heater or swimming pool pump?
If you are using a timer on your water heater or on your swimming pool pump:

  • Set the timer to allow the water heater or pool pump to operate at different times from the peak usage periods for the EnergyWise Home program.
  • Adjust the timer in November and again in April when the EnergyWise Home schedule is switched from winter to summer.
  • Adjust the timer for daylight saving time.
  • Check the timer periodically for proper clock time.

This sounds excruciatingly annoying, I'd rather pay $150 than fiddle with changing a timer 4+ times a year and checking/adjusting it's clock every month.

Maybe if you've got mainly gas appliances (furnace / pool heater / water heater) then just one being forced off sometimes might not affect you much at all, a pool would probably take the longest to cool down & notice. But then you won't get the full credits anyway.

If you never notice hot vs warm water & air, and meet their "minimum energy [usage] requirements" then maybe it's for you. I'd say switching to gas might be a better idea, depending on your local electricity vs gas prices. Or even propane & your own tank if that's possible.

  • 1
    "Critical capacity conditions" basically means that they'll be using this in the event of a power-plant failure or other major loss of supply as an alternative to rolling blackouts.
    – Mark
    Nov 17, 2017 at 2:49
  • @Mark Is there an official / legal definition? I get the impression it's still "whenever we want to, but we'll really really want to, trust us"
    – Xen2050
    Nov 17, 2017 at 3:01

This is actually a very good thing for the future of the grid. It's just off to an awkward start (and a very late one).

This particular awkward start could do this during peak power-demand times, mainly the hottest afternoons when everybody is running their A/C:

  • Reduce the duty-cycle on A/C and electric heat to about 50%, which only matters if its duty cycle is over 50%. That would be an issue if the day is very hot/cold, or you program your thermostat to chill/warm the house an hour before you get home. (in that case make it 2 hours). They say 16.5 minutes worst case out of 30, they are allowing for propagation time for the "cycle" signal - transmitting data over power lines is very slow and very narrow-bandwidth.
  • You have hot water, but as you use it up, your water heater can't replace it, for up to 5 hours. But who takes long hot showers on hot days? Tanked heaters hold hot water just fine for hours, but when you use it, it'll be gone. It will extend runtime if you use anti-scald faucets and bump your heater temp as high as possible (also helps for legionella). You may be able to exclude this from the program, but you'll make less money if you do.

You can beat the water situation with a gas water heater or with solar collectors (which heat water) - they will be at peak performance right when the cycling happens. If your HVAC is running >50% duty cycle, insulation can fix that.

Let's talk about why.

How the grid dispatches

The power grid was designed as a one-way service: a central authority generates and delivers, and consumers only consume. "Alternative electric companies" like Enron only exist on paper, it's still the same grid run by the same authority.

The grid architecture is currently has "open demand": consumers can draw any load, and the generators must either provide it, shed load (in a gruesome way), or the grid collapses.

Load varies dramatically through the day, so you must add and remove generating plants. Except some plants aren't made to cycle daily - nuke, coal, geothermal, any steam plant. Others make power when they make it (solar, wind). The top of your capacity that you only use 20 days a year for 6 hours, are called peakers.

You also need to cover second-by-second changes in load. This is done with "spinning reserve" - part of your capacity that is spun up and on the line, but doing no useful work. Steam plants hate this, and it's wasteful with "all capital expense" plants like nuke, solar or wind. Back to peakers.

Peakers are traditionally Cat/EMD/GE diesels, or of late, jet engines driving a generator. They are "highly" dispatchable - meaning the central authority which controls the grid can push a button and get them online in a 10-15 minutes. (That doesn't sound very "highly", does it?) This is only good for replacing lost spinning reserve, it can't fill an instant need for load. And because of this, quite a bit of spinning reserve must be kept up. And peakers are ex.pen.sive!

If only they could dispatch instantly.

If only peakers were cheaper.

If only power could be stored somehow.

Power storage

Electricity does not store, even for 1 second. It regularly drives the spot market price to zero. That's especially a problem if your region is heavy in baseload (coal, nuke, wind) like Ukraine, France or North Carolina.

Pretty much your only storage options are hydro backpumping or batteries.

However, that says nothing about storing the work product of electricity, e.g. You can certainly store hot water for a few hours or a chilled house for a few minutes.

The impossible dream: dispatching load

A 10MW deficit in the grid can be made up either by dispatching 10MW of generators or "dispatching" 10MW of load. The gruesome act of rolling blackouts can hardly be called dispatching, but there was no other way to cut load in a controlled way. Now, with the computer/network revolution, there is.

And load dispatching (or the industry term, demand-side management) dovetails very nicely with that thermal energy storage I mentioned in water heaters, whole house A/C and heat, pools, and other loads you can reasonably afford to pause, like washers, dryers, dishwashing, charging electric cars, etc.

Potentially they could also dispatch your generating capacity. Not your solar; it's already the perfect peaker. I'm talking about having your Tesla PowerWall, EV or home generator backfeed onto the grid, for which you would be decently paid.

From the grid's perspective, demand-side management that is instant greatly reduces the need for spinning reserve. It also reduces the need for peakers generally, at a time when solar is coming on gangbusters, and solar is an inherent peaker. It's possible if demand-side management is widely adopted, peaking plants could cease to exist - a literal breath of fresh air to the minorities in whose neighborhoods most are built.

Your duties as a citizen in a great society

I don't believe America should be a nation of leeches greedily grabbing what they can, in a national-scale "tragedy of the commons". I think each of us owes something to the social contract that gives us our freedom and prosperity.

Provided, of course, they pay us. Part of our social contract is capitalism: wealth should go to its creator. Fair enough.

These technologies stand to make a much stronger, more robust electrical grid, with less pollution and much lower costs. Which should come back to the consumer, preferably in proportion to their participation.

Another part is independency. It is an affront to individualism to depend mouth-to-teat on the power grid. While load dispatching/demand-side management does nothing for this, the enabling technology will enable other stuff that help individuals achieve energy independency, or at least choose the terms of their relationship with the grid.

Consumer demand-side management, version 1.0

Obviously from their literature, the implementation is rather cheesy... grafted on and hacked. They aim to operate heavy contactors on your water heater or pool, and interrupt your thermostat wiring to regulate your A/C or aux heat.

Of course since all this stuff moves at the speed of government regulatory authorities, it's only now reaching the consumer. And it's a rough-hewn and awkward shadow of what the technology and business practices could and should be.

Others have gone through the plan in the most critical light possible, with an aim to reject it out of hand. So I'll say that the power company is being conservative (in their favor) because this has never been done before, and nobody has any earthly idea how the economics will end up working out, and they don't want to lose their shirt. There's another factor: "I don't have to outrun the bear". For a limited rollout, they don't need everyone - suckers will suffice. So it's no surprise their initial offerings will be... lowball.

Consumer demand-side management, version 2.0

As it proves itself and matures, I'm confident the value of demand-side management and backfed home power dispatching will become more appreciated, and become priced correctly. Remember most delivering power companies are profit-regulated, excessive profits can't go anywhere else but back to the ratepayer.

The real beauty of this tech will arrive when it becomes integrated with the appliances. Now your water heater knows exactly what to do when it hears Code Orange groups 1-9 on the power line signaling: let itself cool off from 160 (legionella temp) to 120 (still usable temp) which will take hours. And when you use enough that the whole tank drops to 110, fire back up anyway. Now you're not impacted at all, and really, neither is the grid, since draining a tank during outage time is rare enough not to matter.

Your furnace haggles with the grid: "the house is worryingly cold, I need power." and the grid goes "run in heat pump mode if able, otherwise aux heat authorized to 50%".

Your washer, dryer and EV charger have an "urgent" button you can push for when the job can't wait.

It empowers off-grid living too. The tech can be easily extended so appliances know how to behave on generator or solar/battery. For instance the generator manager goes "Dryer, suspend because heat pump needs to run". The solar controller knows batteries are topped up and it's about to start wasting power, so it says "dishwasher GO" or "air conditioner please overcool" etc. No one would ever build this tech just for solar, but it's an easy add-on to demand-side management tech.

Now it becomes easier to build a more robust off-grid solar home, and cut the big cord entirely.


Some people are really, really worried about the Gub'Mint knowing they have a clothes dryer.

Okay, maybe you don't want them knowing you did a marathon washer-dryer run an hour after the coroner's time-of-death :)

Seriously though, smart meters are a big ooga-booga privacy-scare issue, especially in light of just how much data can be divined by home power monitors like Curb. You have to be politically active to deal with that, both with your legislators and with your utility regulators.

I can tell you this: The utility doesn't care. They need load dispatching for the reasons I describe, period. It will suffice for them to clump you anonymously into a large group at random, say group 7, so they can command everyone in group 7 to go to reduction level Yellow. Other than that, they only need to know if you signed up and are cheating. But there can be ways to figure that out without invading your privacy.

And as I said, the power company simply lacks the bandwidth to spy on you. Their communication network is the power line and it can't handle Big Data. As mentioned, it takes 90 seconds to broadcast a simple demand-side management SCADA control. It is adequate to remotely read and shut off meters and broadcast demand-side dispatching signals, but that's about it. If they wanted to spy, they would put cell phone modules/antennas on smart meters. Watch for that.


Technical perspective:

The device used for AC is called a digital cycling unit, if you want to look it up. I found this document that details how it's installed (page 6). Note that it basically goes between the thermostat and the AC. So, the only time it's going to do anything is when the thermostat decides it's too hot in the house, and activates the AC. The DCU will block this signal in some cases. (This is why it's only for central AC/heatpump installations; there needs to be a wire from the thermostat to the AC that can be intercepted.)

So, what does this feel like? Well, the program says that it won't activate on weekends or holidays. This is under the assumption that you're at work then. If you happen to be home at the time, it will be a couple degrees warmer. This is because it can only do anything when the thermostat notices that it's above the set temperature. This means that if you work a regular 9-5, you probably won't even notice a difference. If you (or someone else who lives with you) is usually home during this time, you (or they) will be a little warmer, but not by much. I don't see any damage this could cause to your equipment from a technical perspective; it's exactly the same signals that your thermostat is sending.

Side note: Duke Energy also offers a free home energy assessment. There's a reason this is prominently displayed on their site, and there's a reason it's free. Energy that never needs to be generated is the cheapest of all, and I suggest taking them up on their offer if you haven't already. (This goes double for an older house.)

EDIT: two more notes.

First, saying "a few degrees warmer" relies on you having an well-working and appropriately sized AC, and a reasonably-insulated house. If your AC needs to constantly run in order to maintain a reasonable environment, it will not be able to maintain that if given a restricted duty cycle. If this is the case, you have different issues.

Second, you can withdraw from the plan at any time. The only downside is a slight decrease in comfort on really hot days. If this turns out to be unacceptable, you can just call up your utility company and have them turn the box off.


Some of us believe that this is a program that lays the ground work for the government to further and further control our lives. (And don't doubt the government is behind this.) It is estimated that soon every water heater made will include this control feature. Someone will be able to, from a remote location, turn your water heater off without your knowledge or consent. It will be against the law to disconnect this feature. And they will be able to monitor whether the feature is working or not. Instead of releasing the private sector to develop energy sources as they see fit, (it has worked pretty good up until now) they think the answer is to control and to restrict.

In the novel Animal Farm the horse willingly gave the rest of his natural life to the benefit of the movement while the pigs just sat around, got fat, and rode the movement to their benefit. The government could do a lot to encourage growth and expansion of our energy resources. But right now, that is not considered friendly to the environment.

  • 1
    That doesn't really make sense. This can be entirely explained from the economics of the power companies, without involving the government. The power company wants to have control over high power devices during peak times so that they can save on peak load. Having a system to deal with a highly variable consumption is a lot more expensive than "base load" energy that stays near constant. This system allows the power company to have more control over the extent of the load variations; therefore they can save money on fuel or new plants.
    – JMac
    Nov 17, 2017 at 15:12
  • 1
    Well said, JMac however, I will remain a bit more skeptical. Since when did boards of power company's make sense. The company's primary and nearly only goal is to sell more electricity. It has always been that. Now this sophisticated game of push and pull. There is something rotten in Denmark.
    – Paul Logan
    Nov 17, 2017 at 16:33
  • Skeptical about what? I don't see anyone saying they are trying to do anything besides make more money with this. Motivating consumers to avoid high consumption during peak hours is common practice anyways in the power industry, and there are perfectly logical reasons why it's the case. Depending on the provider and your contract with them, it's entirely possible to have deals where you pay less for electricity between 1 AM and 5 AM (as an arbitrary example). It doesn't make as much economic sense to force this onto people. Just the social issues involved would be staggering.
    – JMac
    Nov 17, 2017 at 21:04
  • @JMac is correct. That’s why we have “Demand Meters” to encourage users to use electricity in low-demand hours. Power plants are designed for peak usage. By distributing the peak loads out they can avoid building new plants, and in the northwest that means not building a new dam or two, which has obvious environmental considerations.
    – Lee Sam
    Nov 18, 2017 at 20:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.