Solar - Legality

That would be a question for CR3, the legal forum....

What is your locale? The laws might be different from those in some U.S. jurisdictions where power companies may be required to accept reverse power. There are some issues, though. If the grid goes down, but unaccounted-for users are backfeeding it, some poor lineman might get zapped.

I suppose reverse power could be prevented by a breaker.

Apart from that, I don't see how the power company could distinguish between generating some of your own power, and just switching off a few appliances. Though I appreciate the contract might be set up to forbid it.

Cheers.......Codey

Those inverters are equipped with a circuit that stops the inverter if no grid voltage is sensed. When the grid is off no power is being generated.

The issue is if someone can prove reverse power to the grid when you only produce a fraction of what you need? Here in the example: you use 1000 watts - you produce 250 watts with solar/grid inverter - and the meter counts for the difference as 1000-250=750 watts. One should think only when producing more than the 1000 watts, you should start feeding the grid?

but 1000 watt may be an average, your peak maybe 1500W , and your lowest is 175 W

Of course. With inclement weather.

The hypothesis "Your regular used Power for your household is always more than 1000 Watts continuous" immediately demotes this discussion to the level of counting angels. There is no way that the hypothesis could be guaranteed 100% -- stuff happens.

Sounds "always more than you supply" better? Or the supply from the panels is inferior to the load? I just don't want to make it happen that the power, produced by the panels and connected through the inverter exceeds the load. The power supplier is a monopolist and the sole source for the grid. With prices like between 40 to 50 cents/kWh, he makes it a rough living for us all. The first objection was against Solar Water heaters, officially because they look ugly om a house (unofficially: each house with a water heater on Solar was $100.00 or more less power bill).

I have a 4 KW PV system with a Perfect tie Grid Inverter, clearly a sensible way to go if local politics are friendly to solar power. Before it could be tied to their grid, everything was inspected by my Power company. In my case, they were friendly and helpful.

If your "service" is dead set on being uncooperative and control the political climate, they can drag it out for a long time and provide you with a lot of frustration and some serious legal bills. Adding the blood pressure medication and expected legal costs into your cost-benefit analysis, I suspect that you will find that the scales tip towards a stand-alone system, partial or total.

went through it already for the water and won the battle. That is why I need strong arguments pro and con.. to weigh my defense, against, all common sense.

Is there a Public Utilities Commission they have to answer to?

I think the problem comes down to the local grid, considering any power generation scheme to be an unapproved appliance.

Do they have regulations about reactive load balancing?

nothing of all that - pure private monopolists with a lot of political backing

tell us more about the "Perfect tie Grid Inverter"

Are there precedents you can cite from other jurisdictions about the suitability of your control system?

PS, CR3 changed his name to Texas Charlie & I don't think He's a lawyer

They have CE approval. Each power company that allows grid tie - allows this type. The question is not more hypothetical than the inverter with avg. 90 to 94% efficiency. But here is basically how it works: A phase locked inverter couples a direct coupled amplifier. A fast microprocessor checks: 1. if there is grid voltage and how much 2. If the panels provide enough output 3. The phase 4. When 1 and 2 are conform, it produces a go for the inverter and a amplification factor to the amplifier, this providing a higher output to the grid. The inverter produces a nearly perfect sine. 5. If no grid is sensed, it switches off the unit. So in case of power outage it just doesn't work. Power can be produced for 16 cents/kWh with a write off of 10 years.

My interpretation of your hypothetical question. For what it's worth. The company has a policy not to buy power from you. You would have to generate more power than you use in order for them to have to buy it from you. As someone stated in an earlier post, in the U.S. there are a bunch of requirements on power companies to allow grid tie power generation. Check with your power companies engineering department regarding back feeding power to the grid. One could use battery systems which would allow you to turn off your main breaker and use as much of your self generated power as you can muster without back feeding or grid tie inverters. Gary

Thanks Gary, problem is that batteries are not environmental friendly, and more, not small pocket friendly - it adds up to the costs and the profit is too small. I have several tests running with all kind of configurations.

Sorry, but the rules are made by the supply authorities. What they say is legal, is what is allowed.

There are other potential complication as well as them loosing revenue. What if a linesman is working outside your house on an "Isolated" section of the line and your inverter starts up?

Grid tie inverters have Auto shutdown if they cannot see the supply voltage, mentioned before.

If your usage is allways 1000 Watts then you will never feed back into the grid because your panels will never produce 1000 Watts due to efficiancy losses.

You should have the installation approved and tested by the power Company or you could be in trouble for not allowing for Murphy.

Thanks for making me happy. I would like to present it in a graphic understandable way for judges.

I agree that the grid-tie inverter should protect against power to the grid in the event of a "black-out" on the grid, but what happens in the event of a "brown-out" if the power company is only producing a small fraction of the normal power and you are now producing more than them?

Good question. I will need to check the lower voltage threshold. But under 90 volts it doesn't work anymore.

The first thing I would do is contact your Secretary of State and ask them if the power company can sue you for giving power back to them regardless of how much.

That being said, in my own opinion for what it is worth is that I don't think or feel that they would be able to sue you and win, I would think that they would be worried that you would sue them for money for power that your giving them, but since they have it in their information that they will not pay for power pumped back into the grid that you would be the one losing in that situation as well because it wouldn't matter if it is 250 watts of power or 250,000 watts of power they could gain benefit and never have to give you a cent for it because you willingly put that power out for their use.

Problem here is that they sell for avg. 45 cents to me with a big smile and making them live comfortable. If they win in proving I deliver power back to them, I am actually selling also, and considering the circumstances, for the same high price, because stopping my load make the meter spin backwards.

I have 7.56 KW of solar PV installed on my house. I finally got to turn it on roughly 2 weeks ago following the "final inspection". Before I could turn on the system it had to be inspected by the local Building Inspector, an independent electrical inspector and the inspector from out local power company. Also, we're required to have a "Reverse Meter" installed before our main breaker panel and grounds. BY New York Sate law, the power company must buy from me or credit me my excess power that my panels produce and send to the grid.

My MSA inverters will automatic trip off if they sense the power company's grid going down. That way no lineman gets accidentally juiced by my solar PV system.

I also had installed a MSA Data Logger to keep track of the power produced by the system, which will be providing invaluable evidence to perspective buyers of this house in the future......just like implementing an automotive repair and maintenance log!

I'll be doing the same with a future SCADA system that'll be monitoring my up and coming Solar Thermal Heating and DHW system that will be recording the BTU's generated and consumed......that plus it will monitoring my already- installed weather station (wireless transmitter). simultaneously.

Thank you for a note from civilization. Here in the Caribbean it should be a capital sin in all religions to not use solar power. Doesn't it come straight from ?.... God? The nation I live in is still registered as 2,5 th development country with IMF. Things take time... here,

I have a question, if you go off the grid, and the PV is still producing, what are the issues or are there none?

p911

Off the grid systems are slightly different. Your solar charges batteries and the battery power is inverted to a grid value. Here is no connection of these loads to the regular grid. If a grid- tie system is off the grid, normally the inverter stops producing with disconnecting the solar source.

If you use a reasonably powerful UPS (residential grade- about $US 150) powered by the solar system and batteries as the reference power for the inverter, you should be able to go fully OFF-GRID because your UPS will be giving the inverter the reference power signal.

A small, gasoline-driven generator (100-200 Watts) could back-up the solar system to be sure that there is power available for the UPS during potential disruption of solar.

I'm sorry but I want to complete the answer to your question. The type of inverter I use is very well suited also to top off batteries.

They can guard the battery for overload, when there is grid, sending the energy to the grid.

If the batteries have no switched on load they can be overcharged in this case, why I consider also to run some load on them.

Our country is as small as 3 streets in NY. Law - some - the technical inspection does the education here, but has not really a legal backup yet. The power company has the say, but nothing of it is in the contracts. We started up a solar company- $10.000 anual lic. fee - 3 weeks later new restrictions: only allowed when not visible? That was the political end. Now everyone who can afford it installed solar water heaters and there is no law or enforcement on that part.

Your country is bucking the trend for the power company to reduce its carbon footprint , the more solar panels the smaller the CO2 production. which is good for the world environment if you believe the hype. They should be shown up to the world as polluters and shamed!

Of course like most governments they don't mind others making sacrifices but don't like their own income to be reduced. The fact is people with large incomes have a larger carbon footprint than the people who are toiling with low incomes to produce the profits and large incomes for these people. In a fair world they should be penalised for excessive consumption but it will never happen, politician's are myopic a $1000.00 to a politician is equal to a $1,00.

One more simple suggestion-

Pick one or more devices that are "normally" operating that could use the power from your PV system and wire them directly to the PV output using a simple transfer switch- powered by the PV.

If there is not enough power from the PV to activate the transfer switch, then the switch will return to "normal" position which isolates the PV from your devices and puts them on "the grid". Whenever the sun is shining enough, those devices will be powered by the PV.

Install a properly sized UPS upstream of the loads and downstream of the power supplies to assure uninterrupted power feed to the devices.

Your condition is no different than if you bought devices with higher electrical efficiency or simply decided to turn off some devices. Unless your power supply agreement has a provision for some minimal power purchase- not likely, and you would know if it did- then the utility cannot force you through any legal arrangement to buy more power than you want to buy.

Isolating your PV from the grid totally will eliminate ANY of zapping a line worker or causing any damage to any grid component.

Practically, the inverter works when the panels have 14 volts available. Only then it generates power. Problem for your suggestion is that the sensor AND the output go over the same cable. I have other configurations standby too: I use this inverter, combined with a small bank of storage batteries (440 Ah)- here when the batteries are not fully charged, even with panel outputs, lower than 14 volts, I still charge the batteries. The 14 volts is pretty comfortable, because once the batteries are at that threshold, the inverter operates towards the distribution panel. From the batteries I also work towards a group of loads that or require 12 or 24 VDC or through a cheap inverter I make 120 or 240 VAC of it. This group is apart from the main distributor panel. But the goal is to have enough arguments PRO to convince all parties when it coms to a court case. It avoids the use of a expensive inverter and a solar power battery charger- controller.

Be careful, with a digital electric company power meter, programmed incorrectly, you will be charged for KW used AND KW generated. It happened to me! Their excuse was the meter's default program is no generated power on site.

We are decades away from it. Only big consumers - industry - hotels get one.

This may be oversimplifying this issue, but for our own interconnect of our 4 megawatt generation facility into the utility grid, we were furnished with protective relay settings by the local utility for use specifically while we were in parallel with the utility. The settings for the reverse power relays are governed by that agreement. In the even of a loss of utility power, or in the rare event that we might lose contol of an engine and over generate, the protective relays will trip the breaker open and disconnect us from the utility grid within a predetermined amount of time preventing us from ever backfeeding power into the grid. I will be honest and say that I do not know what the "perfect tie grid inverter" uses to prevent reverse power but that should be easy to find out and test. Compare that to the published requirement from your utility (yes, they are required to publish them), be sure you meet or exceed those requirements, maintain periodic testing results as outlined in your agreement, and you would be in a much better position in the event something did malfunction. It's one thing to do everything possible as required to prevent an injury and something still go wrong, and quite another to have done nothing and that same injury take place.

I need to move to your place. In Europe they promote people who exploit these systems and give money back for the power they 'buy" from them. I have seen many combinations: some one the same meter- others have e reverse power meter at the same or different tariff. The principle of the grid tie inverter I tried to describe in earlier posts. The sampling time of the microprocessor is 20 micro seconds- 50 kHZ. Response time typical 100 microsecond, max 1 millisecond. Way to fast to get somebody electrocuted.

Something else to consider is whether your self-generated power will actually leave your house. Your 250W generator is a weak power source compared to the utility. In order for your self-generated current to flow out past your meter and feed your neighbors, it has to overcome the resistance of the wires conducting it, which would reduce the voltage available from your generator outside your home. Since the wire runs are much shorter to the loads in your house than the loads in your neighbors house, and since the utility is able to supply constant voltage and current (from their stronger source) to your neighbors, you will not be simultaneously running all your loads from the utility and supplying power back to the grid. Just take precautions to prevent backfeeding the grid during grid outages.

Regards,

Stilicho