# Excess capacity in the power grid

My question concerns capacity in the power grid. I am an attorney trying to understand whether excess capacity runs in a power grid to avoid brown outs and how long can the excess capacity exist within the grid before it is dissapated or used? Also, is power generation produced to keep demand below total generation of power at any given time such that demand could be described as operating at a percentage of capacity in the power grid, say for example 98% of capacity? Or does power generation always equal demand exactly? thanks for any insights, I am helping a client recover payments to a municipal electric company for excess electricity he was billed but never used since it dissapated through the meter box due to a faulty lug clip damaged when the meter was installed. I am basing recovery on the theory of unjust enrichment to the power company for electricity paid for by the customer that in essence was produced at zero marginal cost to the end user because the billed power would have been present within the excess capacity generated as a matter of due course because power companies do not operate exactly to the demand. So I am trying to understand if my theory of recovery is accurate. My client was billed over $100,000 for excess electricity over a 30 year period. response to comments and answers Thx every one for helping me understand my erroneous thinking and ignorance on the matter. I understand that power is used immediately and no excess is in the line. Voltage and frequency are also variables in the equation. Marginal costs also increase in the industry for peak periods. To clarify, I believe the crushed lug clip must have been on the load side which is why the meter registered it. One electrician who inspected the crush lug clip said the clip and wire were discolored which meant in all likelihood it was glowing extremely hot which caused it to pull the extra current through the meter. • Power generation always equals demand. Any 'excess capacity' in supply is fuel not used, or water not run through a turbine, but ready to be used if needed. If the lug in the meter case got hot (ie was dissipating power) then this power would have had to have been generated by burning extra fuel, at a cost to the supplier. 30 years? Isn't there some sort of statute of limitations on this? If the lug was not getting hot, then the meter should not have recorded any extra use. Mucilage? – Neil_UK Feb 11 '17 at 17:32 • I think your hope would have to lie in finding a particularly ignorant judge and/or a fairly ignorant jury. – Spehro Pefhany Feb 11 '17 at 17:55 • And just as a nitpick, if you're really going to be a credible lawyer, you'll need to learn the difference between mucilage and municipal. I can't begin to tell you the bizarre images conjured up by the phrase, "mucilage electric company". – WhatRoughBeast Feb 11 '17 at 22:39 • This seems EXACTLY analogous to a water leak where the water goes down the drain. – mkeith Feb 11 '17 at 23:16 • I think what you need to do is argue that the utility created the fault, or should have recognized the fault was there, or find a precedent where a utility refunded money that was due to a fault. I don't think your zero marginal cost theory is going to persuade anyone. That is like saying "our usage is just small potatos to the utility, so it should be free." – mkeith Feb 11 '17 at 23:21 ## 7 Answers The short answer is no. There is not "potential" electrical energy present on a power line. Instead, the power company generators are always being tweaked to produce the power needed. Think of your car doing 55 on a level highway. Now think what happens when you reach a hill and start climbing. With the throttle at a fixed setting, the engine speed will slow down and the vehicle speed as well. In order to maintain a constant speed (and constant motor rpm) you must increase the throttle, and in the process will burn more gas. Similarly, a generator being driven by a turbine will put out a certain amount of power. If the load increases, either the generator must be driven harder, which takes more fuel, or the output voltage and line frequency will drop. Neither of the latter is considered a good thing. The power grid is obligated to work at a certain voltage (within an acceptable range) and at a certain frequency (50 or 60 Hz). To do this, the generators on the grid are constantly being adjusted. The good news on this front is that, with a large number of customers, the law of averages suggests that for the most part the total load doesn't change very quickly, so maintaining constant voltage and frequency is usually possible. Just as your car does not usually put out its rated power, so a power grid is not usually driven at full power, and this is where the percentage of capacity comes in. if the grid is running at 50% of capacity, there is not another 50% magically available. Rather, if the load demand doubles, the generators will be able to be cranked up to 100% of their rated output to meet the demand, but this is not instantaneous, and if the power company does not increase the throttle setting on the generators the line voltage and frequency will drop. If the demand gets too great, such as can happen in hot weather due to air conditioners being used, it can be necessary to reduce line voltage ("brown out") or even cut of power to part of the grid, as happens in a rolling blackout. • "Neither of these is considered a good thing" - letting the voltage or frequency drop is bad, but burning more fuel isn't necessarily bad, it's a normal condition. – immibis Feb 11 '17 at 22:47 • @immibis - Oops, you're right. I was unclear. I've edited. Thanks. – WhatRoughBeast Feb 11 '17 at 23:19 • Thanks. I appreciate the response. In this situation the marginal costs would increase or be rising with output and I was mistaken. I understand your example. – Lawbit Feb 12 '17 at 4:08 I would argue that your theory of marginal cost is backwards. Power production is managed so that the base load, the amount of power that is produced all of the time, is produced by the lowest-cost method of generation. Additional power that is required during peak usage times, is produced using smaller generators that can be started up quickly. Those generators, called peaking generators, are generally less efficient and often use the most expensive fuel. You have the additional problem of the unrealistic estimate of the amount of power dissipated as heat in the meter that is described in another answer. You also need to prove that the bad connection was on the load side of the meter. Any power lost on the line side of the meter would not be registered by the meter. Of course, any hint that any part of your case is based on information that you got from the internet will result in you being laughed out of court. That is why expert witnesses are well paid. • Yes, I did not understand. Marginal cost increases as I understand it now. Thanks. – Lawbit Feb 12 '17 at 4:10 • Expert witness is a definite must. – Lawbit Feb 12 '17 at 4:10 From a legal standpoint the court argument would be who owns the equipment where the power was dissipated? Speaking for residential customers in the United States: 1.) The power company owns the meter 2.) The Residential customer owns the Meter socket. Now you are going to argue that$3,300 of annual electricity was dissipated at the meter socket? If the bad connection was on the load side of the meter socket lug clip - the attorneys for the power company will most likely argue that any energy dissipated on the load side does not make the metering inaccurate and the dissipated energy was at the point of use (being on the load side).

I would expect that the experts on the power company side, such as Engineers and field service technicians, will argue that it is suspect that the customer didn't require or request service due to this fault which existed over a 30 year period.

• He did argue but it was not discovered for some reason. I stand corrected on my ignorance of electricity usage. – Lawbit Feb 12 '17 at 4:21

Disclaimer: you are the lawyer here, and I am not. This is not legal advice.

It just does not add up. Regardless of which party is responsible for the lost energy, the information you have provided simply does not work.

If you say your customer was billed in excess of $100,000 over the course of 30 years, using an average cost of$0.15 per kWh, it would result in an average power consumption of 2500W, which is a whole lot. A whole lot. Equal to a fairly large space heater. Or two and a half electric kettles. Were the lugs on the meter to dissipate that much energy, the metal would get red hot in a minute or so.

Should you attempt to convince the judge of this, the utility company's experts will destroy you. Assuming the meter is not faulty, you should instead locate the actual energy losses. Has a heater been running at full power for 30 years, in the ceiling or some other place that is very infrequently visited? Is a neighbor stealing energy using a rogue extension cord? Is the meter accurate at all?

• I understand better now how electricity is produced and consumed, but I spoke to an electrical inspector yesterday and he believed that the discoloration of the clip and wire showed the clip was red red hot. Anyway, after the lug assembly or socket was replaced, the electricity usuage dramatically dropped. The repair seems to speak for itself as showing what the cause of the usuage was. But to be more exact, I will compile the meter readings and get back to you with the differences. – Lawbit Feb 12 '17 at 4:47
• @Lawbit Red hot is one thing. But 2.5kW is nearly an oven, with the thermostat stuck on and no insulation. The whole meterbox would be red hot. – Someone Somewhere Feb 12 '17 at 11:32
• @Lawbit Agreed sleblanc, what needs to happen here is to determine the power consumption average difference before and after the repair. 100k/(30years*12months) is $278 a month which doesn't seem like an unheard of electric bill depending upon the house size. It's still high and there likely was significant wasted energy, but 100k sounds like the entire electric bill, not the excess electricity wasted bill. – horta Feb 13 '17 at 5:03 • @Lawbit, the clip might have been red hot, which the discoloration would hint at, but it cannot have been that hot for 30 ongoing years. At that temperature, metals start oxidizing very quickly, and that part would have either melted or oxidized so much that it would have eventually snapped. And to reaffirm my position: I am sure that the meter did not dissipate that much energy. Maybe it is worth investigating the accuracy of the meter itself… – sleblanc Feb 15 '17 at 15:37 trying to understand whether excess capacity runs in a power grid to avoid brown outs and how long can the excess capacity exist within the grid before it is dissapated or used? You are confusing yourself by being loose with the definition of "power grid". The grid itself stores no power. All power dumped onto it by generators is immediately consumed. Most of that goes to power customers, and some fraction is lost in the transmission process. However, there is usually more generating capacity than demand. In this case, generating capacity means extra power that could be generated, but isn't. This can come from, for example, running more water thru turbines at a dam, bringing more costly "peaking" plants on line that are normally idle, etc. These all come down to the modern equivalent of shoveling more coal into the boiler. Also, is power generation produced to keep demand below total generation of power at any given time such that demand could be described as operating at a percentage of capacity in the power grid, No. Again, the grid doesn't store power. However, power generation is adjusted to match demand in real time. Or does power generation always equal demand exactly? Yes. I am helping a client recover payments to a mucilage electric company for excess electricity he was billed but never used since it dissapated through the meter box due to a faulty lug clip damaged when the meter was installed. The electricity was certainly "used" from the power companies standpoint. Someone somewhere had to shovel more provebial coal into the boiler to cover the extra power that was dissipated due to the faulty lug clip. Real expense was incurred in producing that power, whether it did anything useful for your client or not. This case hinges around who owned the faulty equipment and who did the faulty work. Generally, up to the output of the power meter is the utilities responsibility. After that it's the customer's responsibility. However, specifics vary. You need to find out who owned, operated, and did the work on the faulty equipment, and authorized that work. If the power company did the work and owns the equipment, and if it's all in a cabinet they control, then you may have a case. If your client installed the equipment or did the repairs, it's likely on him. Here is a analogy. You fill up your car at a gas station. There is a leak in the hose by the gas pump, so you are charged for more gas than got into your car. That's on the gas station. It cost the gas station money to provide the gas that leaked out, but in this case it is their expense to bear since their equipment is at fault and you did nothing wrong. However, if there is a leak in your gas tank, it still cost the gas station the same amount to provide all the gas. But this time, the responsibility is yours. The gas station sold you the gas, and it was your fault, not theirs, that you didn't get to use all of it as you intended. The problem here is deciding who exactly had responsibility for the "leak". Who owns the equipment, who worked on it, who approved it, etc, probably all have bearing. But, that's your end of things. Those are not electrical issues. for electricity paid for by the customer that in essence was produced at zero marginal cost No. Just no. It doesn't work that way. It did cost the power company incrementally to produce that electricity, just like it cost the gas station for the leaked gas, regardless of whos fault it was that it got leaked. because the billed power would have been present within the excess capacity generated No. It doesn't work that way. If this were the case, then why couldn't I and everyone else claim a fraction of their power bill was invalid because only free excess was being used? There is nothing special about your client's "leaked" power versus anyone else's successfully used power. It doesn't work this way. It could never be allowed to work this way, else the whole system of buying and selling electrical power would be invalid. • To be pedantic, the answer to "does the power generation always equal demand exactly" is no. If more power is being generated, the excess will be used in speeding up not only the generators in the power station that is producing too much energy, but every other generator in every power station connected to the same grid - and also every synchronous electric motor that happens to be running. Of course this means the speed-up is slow enough to be automatically corrected, in normal circumstances. – alephzero Feb 12 '17 at 0:00 • @aleph: OK, there is a tiny amount of temporary energy storage in the grid in the rotation of the generator shafts. But, as you say, this is pedantic and will only confuse more those who are already hazy with the concepts. It also doesn't help the OP's case at all. Please don't add confusion when there is already plenty. This is not the right context for bringing up nits like this. – Olin Lathrop Feb 12 '17 at 0:06 • Alright, I stand corrected on my ignorance. To clarify, the municipal electric company installed their meter into the customer's electrical box which came with the components for the meter to plug into. Then the company sealed the box so the customer could not access it. Unfortunately, when the meter was installed, the city electrician crush the lug clip and caused the clip to over heat. – Lawbit Feb 12 '17 at 4:18 • @Law: If that crushed clip was inside the box sealed by the electric company, you probably have a good case. The less your client had anything to do with causing the problem, the better off he is. – Olin Lathrop Feb 12 '17 at 13:29 The power supplied on the grid equals demand. If demand exceeds supply then you have a brownout or loss of power. If your client has been billed for power he did not consume, then I'd imagine that you need to question the accuracy of the power measurement meter. 1. Your client did get power, and we could assume he got all the power he needed through those 30 years. 2. I'd think there is a reasonable customer expectation that the power billed is accurate as measured by the utility meter. If the meter did not register any power usage, would the customer now be being sued by the utility based on 'expected' usage once they discovered the fault? I'd bet they would sue to get the money. You'd be the one to decide if in the inverse case the client could sue. • FWIW, on my (Toronto, Ontario, Canada) monthly electricity bill, there is an explicit increase (around 3%) on the energy usage measured by the meter. This allows for line losses, marijuana grow-op theft of electricity, utility in-house usage, etc... The bill uses this increased energy consumption for all the calculations in the bill... – DJohnM Feb 12 '17 at 1:19 • Ok, I understand better. Thx – Lawbit Feb 12 '17 at 4:18 how long can the excess capacity exist within the grid before it is dissapated or used? Your question reflects a misunderstanding of the function of "the grid". The grid does not retain any (electrical) energy, but merely carries it from the generators to the consumers. At any given moment whatever amount of energy is being drawn from the grid is being fed into the grid by generators. As a simple analogy think of the grid as a wire connecting a light bulb to a battery. While it is connected to the battery, the light bulb draws a certain amount of energy (power) from the battery. If the wire is disconnected from the battery the light bulb immediately loses its power source since there is no (substantial) energy stored in the wire. Also, is power generation produced to keep demand below total generation of power at any given time such that demand could be described as operating at a percentage of capacity in the power grid, say for example 98% of capacity? Or does power generation always equal demand exactly? As above, power generation always equals demand exactly. There is potential for confusion since the generators need to be capable of adapting to varying demand very quickly, so the generators must collectively have an "excess capacity" readily available to respond to an increase in demand. As others have explained this is tied in to the source energy used to produce the generation, and is essentially fuel, heat, steam, etc. The key point is that this "excess" does not exist on the grid itself, but purely at the generation sites. excess electricity he was billed but never used since it dissapated through the meter box due to a faulty lug clip damaged when the meter was installed. ... My client was billed over$100,000 for excess electricity over a 30 year period.

$100k over 30 years equates to an average of (100000 / 30 / 365.25 / 24)$0.38 per hour, so depending on the average tariff charged this amounts to a substantial average power usage, i.e. an average of $0.38 per kWh equates to an average power of 1kW,$0.19 = 2kW, $0.127 = 3kW etc. and as others have expressed it doesn't seem feasible for such a large amount of power to have been dissipating in what is presumably a relatively small space without it being noticed in some way. Having said that there are many details that we don't know and are therefore making assumptions about. The most prominent one being that the$100,000 "excess" that is being claimed is valid, particularly since you did not provide any information about how that figure was arrived at.