Gotta Go Green Energy Solutions

Factual Questions
1

I was at a business of a friend of mine yesterday and saw a panel next to the circuit breaker box labeled “Gotta Go Green Energy Saver 3200”. An employee there told me it saves them money on their electric bill.

I went home and googled the company and came up with this:

http:// gottagogreenenergysolutions.com/ (break included to remove direct link).

It claims to cut electricity usage by 8-25% (the FOX news video states 30%, but hey, it’s FOX).

I was initially thinking it was just some sort of capacitor (which the video also alludes to).

Of course I’m skeptic; it seems to be along the lines of magnets on fuel lines to cut your gas usage. Also, having a company with “Gotta” in the name doesn’t sound that promising, either.

So, Dopers, what say you? Would it be helpful or hooey?

2

I don’t quite understand but 3 phase induction motors want to pull the electric current off cycle. It is called reactance. Connecting a capacitor to the line would reduce the power used or at least what they called the power factor. The electric company measured the power factor and multiplied it times the kilowatts to calculate the bill. Synchronous drive motors also reduced the power factor. Many companies would use them with large air compressors which ran constantly. The capacitors were something you could calculate a pay back from your reduced bill. My experience with them goes back 30 years. Use of them goes back much longer than that.

Reactance also develops in single phase system where you have transformers and other inductive loads. In a more energy sensitive world, maybe capacitors would help there.

3

Does it perform PF correction? If so, I doubt it would be worthwhile in a whole-house application for the typical home. By contrast, PF correction can be beneficial for some industries that utilize many motors and (as a consequence) represent a strong inductive load to the power company. In such instances, installing PF correction can be beneficial for the company and the utility provider.

Here is a study performed by Brandeis University on a similar system:

http://alignment.hep.brandeis.edu/Lab/KVAR/

4

Very interesting link. In the early 80’s I was managing a factory with a lot of big machinery, a 600 hp motor; but not that many people. It was part of a complex big enough to have their own substation. There was only one watt meter for the whole place. There was also a power factor meter and maybe one other type of meter. The electric company also tracked our peak power usage and used all the data to calculate our bill. We had capacitors both on my incoming 4160 V and at some of the motors. Our peak came at 2 PM. I was pressured into only running the one machine with a 200 HP motor after 3 PM. When times were good, everything else ran 24 hours a day. Since we were billed based on the power factor. controlling it saved the company money.

It doesn’t look like the residential power factor has much potential for savings. Of the big common residential resistance loads, range, hot water, drier, and space heating, we only have the range. We do have some other resistance stuff, toaster, coffee maker, hairdrier, etc.; but small intermittent use. Most of our inductive loads are small and intermittent too. I once calculated the furnace, fridge, freezer, and pump only totaled 4,000 watts if all were running at once. The biggie is the A/C, but the compressor sets almost under our meter, a very short run of #10 wire and I think running, a maximum of 14 amps.

Now, our fridge and freezer only draw about 5 amps, but are also wired with #10 wire. So if the capacitor only reduces the power dissipated in the wires, does this leave me even less possible savings? Would heavier wire be more cost effective then capacitors?

Oh, the #10 wire wire was free, an unofficial benefit of working for a wire company.

5

My understanding is that residential users are only billed for real power, so power factor correction doesn’t save you any money, although you might get a gold star from your utility, since it saves them money.

6

I think that for typical home users, the power company typically does power factor correction on their end (based on the assumption of some given proportion of residential loads being inductive at any given time).

7

It looks as if the web site is selling a box of capacitors to ignorant homeowners.

There’s definitely a need for power factor correction in some industries but the typical homeowner isn’t going to save much nor would they need this type of application.

It’s also interesting to note that this “Green” company doesn’t appear to have any renewable energy products like they state.

The local fox news stations that provided videos must have some real morons in their reporting ranks. One obviously did their study at the end of the summer and even admitted that the savings weren’t occurring in the summer months (I bet the be “before” period included some cooling load which made the “after” period look like a big savings.)

And the demo with the refrigerator motor bordered on criminal. Most refrigerators and AC units have start up capacitors which already provide power factor correction. Their demo of a bare frig motor with and without capacitor assistance was almost comical.

No self respecting honest electrician would try to push this product on an unsuspecting homeowner.

8

I have been thinking about changing residential loads, resistive vs. reactive. I am sure the biggest factor is the big stuff, space heating, water heating, clothes drying, and the cook stove. Is gas or electric gaining on those applications? Are people letting the gas range set and using the toaster oven or microwave?

I think most of the newer stuff, electronics is reactive, all going through a transformer in the power supply. Also, we have replaced most of our lighting with fluorescents. That replaces resistive loads with reactive. So how much can I save by by adding a capacitor to my 13 watt CFL? Even at the switch for the 5 in the bathroom?

I don’t think we have been told if the bussiness in the OP was using 3 phase.

9

No, this is a small mom n pop, not anything requiring a substation or 3 phase power; Other than heating and cooling, I can’t think of anything that would cause a large load on the system.

I didn’t think I’d see a gain here @ my place of business; we have heating and cooling obviously, but other than that, no heavy loads here either.

In my mind, it appeared to be one of those situations where you think, “if this is such a great product, how come it’s not mainstream by now?” On their own website, they state it’s because of previously low electricity rates - but if that were the case, then solar panels / windmills wouldn’t have been popular either - but their initial startup cost is much higher than this panel of capacitors.

It seems like a load of bunk to me. I’m sure other people swear by it, but I don’t think I’ll become one of those people anytime soon. I could see sweating at it, however…

10

Total scam. Those ‘Reports’ are also as true as any from Blacklightpower.

If you are being billed based on a unity power factor (as a factory usually is), then power factor correction is important. Even there though, where it IS important, a box with capacitors is useless. Plants that control power factor do it with devices that monitor and switch in and out active components (capacitance primarily) as required. For severe cases, where there are extremely heavy out of phase loads, an active system with an overexcited (and controlled) large synchronous motor are used.

For residential use, the only ‘observable effect’ is the placebo effect of the user after spending money on a product like that.

You want to save more power per day then any of those residential PFC devices will save in a month? Turn off one light bulb. Unplug one wall-wart type power transformer that isn’t connected to anything.

11

All of those devices are purely resistive, and have no effect on the phase relationship between voltage and current, so would derive absolutely nothing from power factor correction.

Now, Air conditioner units, heat pumps, they might be slightly affected, but again, not enough to make any difference in your bill, even if left on 24/7.

12

The NIST further explains why power factor correction wouldn’t make a difference for home users. Here’s probably the most concise quote:

13

If such a device can reduce (or eliminate) the “circulating currents” in the wires due to reactance, doesn’t that mean the copper wires inside your walls will dissipate slightly less real power in the form of heat? If so, then I would think such a device would decrease the amount of real power your home is using (and thus being charged for), albeit a slight amount. Not worth it, obviously. But I’m not sure I would say it makes no difference whatsoever.

14

I checked the web page in the OP. There wasn’t much technical info there, even under the specifications section, so that makes it difficult to say for certain whether the device in the OP is a worthless piece of junk or not.

Residential power factor correction devices are completely worthless. Power is made up of watts and vars. Most folks have heard of watts, but not vars (var = volt-amp reactive). Watts are the power that is actually used, like for example the electricity in a light bulb that goes into making light and heat. Vars are a bit harder to explain, but if you have a simple coil of wire (an inductor), if you run current through it, a magnetic field develops which stores energy. Remove the electricity, and the magnetic field collapses, releasing the stored energy in the form of electricity again. Since residential power is an alternating sine wave (hence alternating current, or AC) any inductors will be constantly charging and discharging. The energy isn’t doing anything useful. It’s just being temporarily stored and released. However, it does take current to charge up the device, and hence some “power” is used to charge the inductors, even though this energy is later released.

Capacitors do the same thing. A really simple capacitor is just two metal plates placed close to each other. Instead of storing energy in a magnetic field like an inductor does, a capacitor stores energy in an electric field, but it’s the same basic idea. Energy is stored and then released later in the AC cycle.

Inductors and capacitors are “reactors”, which is where vars (volt-amps reactive) comes from. In an AC system, inductors and capacitors work kinda opposite of each other, since while one is charging the other is discharging, and vice-versa.

Most residential loads tend to be slightly inductive, due to things like motors in your refrigerator, washing machine, dryer, vacuum cleaner, hair dryer, etc. You can balance these out by adding capacitance to the line, which is what these power factor correction devices claim to do (but don’t, which I’ll explain in a moment). Power to your home is most efficient when you get capacitors to perfectly balance out the inductors. That way, the capacitors supply power to charge the inductors during part of the AC cycle, and the inductors supply power to the capacitors later in the AC cycle. The reactive power just ends up bounding back and forth between the inductors and capacitors, and the power company only has to supply the real power (the watts). When everything is perfectly balanced like this, it is said to have a power factor of 1 (or unity). If it is not balanced, the power factor will either be leading or lagging, depending on whether the load is more capacitive or inductive.

This all sounds good in theory, but the problem is that the devices sold for home use are just capacitors in a box. They don’t monitor the power factor at all, and aren’t switched on and off of the line as needed. Instead, they constantly adjust the reactance of the house load whether it needs adjustment or not. This is why they don’t work. And, they can’t possibly save you money because all they affect are the vars, which you aren’t charged for anyway. The old fashioned spinny wheel type power meter only measures watts, so the power company can’t even tell how many vars you are using even if they wanted to (unless they hook some measuring equipment up to your line). The newer digital meters can measure vars, but even then you aren’t charged for them. If your power factor is far enough out of whack the power company may pay you a visit and tell you to fix it, but it would be very difficult using standard residential type stuff to get your power factor that far out of whack. Let’s face it, not very many people have 1,000 hp motors running in their basement.

If you are a business owner, though, things are different, and it’s important to note that the unit in the OP was installed in a business. Business and manufacturing customers have different types of meters installed, and these do measure power factor, and the power company charges them for the vars. In fact, the power company often charges them out the wazoo for vars, giving them a really good incentive to hook a power factor correction device up to their heavily inductive loads. A proper power factor correction device will monitor the line and will switch capacitors on the line as needed, or if you have a big machine that is very inductive it may have a power factor capacitor added to it which is switched onto the line whenever that specific machine is turned on.

It’s not clear from the web site in the OP if their device switches or not, so it may be just as useless as your typical residential unswitched capacitor boxes, which are just a waste of money.

Most businesses that need power factor correction also get three phase service, but that’s not strictly required for power factor correction to be important.

Power factor correction is generally done at the substation. I’m sure there are older systems out there that just assume a constant power factor and correct for that, but it is my impression that most of the power companies these days monitor the lines and switch the capacitors on and off the line as needed.

15

BOLDING MINE

I agreed with you to that point. While some power factor correction is done at distribution substations it is many times more cost effective to place the correction as close to the load as possible.
A common application for capacitor banks is to hang them on a pole about 2/3 the load distance from the substation on a heavily loaded distribution line. Many of them are switched and operate both seasonally, daily, and/or via voltage sensing.

In fact some rural people are unknowingly notified that their distribution circuit’s capacitor banks have come on when they have to change a number of their incandescent bulbs which suddenly “for no reason” burn out all in the same week(usually late spring or early summer). Incandescent filaments weaken over time and, while the customer may not realize that his house voltage has gone up 3%-5%, the light bulbs end their lives a few weeks sooner due to the increase.

16

My point was that although everybody else and I are adding electronics and fluorescent light, if the large resistive appliances were gaining market share, it would keep the ratio of resistive to reactive loads about the same for the total load. If gas appliances are replacing resistive loads, then the fraction that is reactive would go up.

Oh, a correction, space heating can be reactive instead of resistive if it is a heat pump. I think they are gaining in central systems over resistance heating.