Feeding solar power back into municipal grid: Issues and finger-pointing

Page 9 of 9  
g wrote:

I'm not arguing that the grid can't or won't take any, the majority, or all of the generated power.
The question here is - what exactly must the invertors do in order to get as much current as the PV system can supply into the grid.
If our analogy is pipes, water, and water pressure, then we have some pipes sitting at 120 PSI and we have a pump that must generate at least 121 PSI in order to push water into the already pressurized pipes. So the local pipe system now has a pressure of 121 PSI. If you measure the pressure far away from your pump, it will be 120 psi.

Not sure I understand what you're trying to say there.

No, I don't agree.
Hypothetically speaking, let's assume the local grid load is just a bunch of incandecent lights. A typical residential PV system might be, say, 5 kw. At 120 volts, that's about 42 amps. How are you going to push out 42 amps out to the grid? You're not going to do it by matching the grid voltage. You have to raise the grid voltage (at least as measured at your service connection) by lets say 1 volt. So all those incandescent bulbs being powered by the local grid will now see 121 volts instead of 120 volts. They're going to burn a little brighter - they're going to use all of the current that the local grid was already supplying to them, plus they're going to use your current as well.
Doesn't matter if we're talking about incandescent bulbs or AC motors. Switching power supplies - different story - but they're not a big part of the load anyways.

I don't see how - not at the level of the neighborhood step-down transformer. I don't see any mechanism for "balancing" to happen there.

If you're getting paid for every kwh of juice you're feeding into some revenue load, then the concept of "efficiency" doesn't apply. What does apply is ergonomics and practicality. I agree that a small-scale PV system can't be counted on to supply a reliable amount of power 24/7 to a revenue load customer (or even a dedicated branch circuit of a revenue load customer) to make such an effort workable - but I still stand by my assertion that the extra current a small PV system injects into the local low-voltage grid will not result in a current reduction from the utility's sub station to the local step-down transformer.
The extra current injected by the PV system will result in a small increase in the local grid voltage which in turn will be 100% consumed by local grid loads (motors, lights) and converted into waste heat with no additional useful work done by those load devices.
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Bad analogy. The 1V will be lost in the internal resistance of the inverter connection, which is much higher than that of the grid. Think of pouring water from a bucket into a lake. There's NO measurable rise in the lake level.
jsw
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Jim Wilkins wrote:

If that were the case, then your 42 amps would be converted into a tremendous amount of heat as it burns up that internal resistance, and there would be no measurable current for your revenue meter to measure.

For me to pour water into a lake, I have to raise it higher than the lake level.
Think of height as eqivalent to voltage potential.

Unless water is compressible, there has to be a change in lake level. The fact that I may not have a meter sensitive enough to measure it doesn't mean there's no change in the level.
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harry wrote:

I doubt that the regional sub-station is going to do that.

I didn't say that it couldn't be handled.
I'm saying that a small-scale PV system is going to raise the local grid voltage for the homes connected to the same step-down distribution transformer. All the linear loads on the local grid will consume the extra power (probably about 250 to 500 watts per home, including the house with the PV system on the roof). The extra 250 to 500 watts will be divided up between the various AC motors (AC and fridge compressors, vent fans) and lights. They don't need the extra volt or two rise on their power line supply - the motors won't turn any faster and the lights will just convert those extra watts into heat more than light output.
The home owner with the PV system will get paid 80 cents / kwh for the 40-odd amps he's pushing out into the grid, but that energy will be wasted as it's converted disproportionately into heat - not useful work - by the linear loads on the local grid.

I don't see a rabbit around here.
I'm not claiming that pushing current into the local grid by way of raising the local grid voltage doesn't work.
I'm claiming that there won't be a corresponding voltage down-regulation at the level of the neighborhood distribution transformer to make the effort worth while for all stake holders.
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On 13/04/2011 17:59, Home Guy wrote:

From Wikipedia: "In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line."
Obviously when a local area is supplying power to the grid, power generation elsewhere will be reduced. And any voltage changes that results from that will be adjusted with line voltage regulators, if necessary.

How do you get the value 250-500W?
Motors will only increase their energy drain by raising the frequency, Plus a small loss due to internal resistance in the windings.
As for a resistive load, increasing the voltage from 120 to 125 volt will result in a power drain increase of about 8.5% or 8.5 W for a 100W light bulb, assuming 120V is the nominal voltage.
Remember though that the voltage increase on the step-down side of the transformer due to homeowners PV arrays will be less than 5 volt pretty much guaranteed. Local codes state a maximum voltage drop (7V in BC) over the lines to a house, at 80% load of service panel capacity.
Most households have a 200A service panel. A 10kW PV array is well below the service panel capacity.
And you cannot just look at the PV array output. You must take into account the local energy consumers as well. That will reduce the current going into the grid, and thus the voltage increase.

You claims are pretty vague, please explain what you mean by wasted.
By the way, there is some "waste" by just using the grid only as well. Losses everywhere in the grid.

What is your definition of worth while? And what do you know about the utility's voltage regulation policies?
The utilities _have_ to use voltage regulation due to demand changes.
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Wikipedia is not a source of information (by their own definition). Do not use it for quotes. Now your information is a fourth hand paraphrasing, lower than a rumour level.
------- "g" wrote in message
On 13/04/2011 17:59, Home Guy wrote:

From Wikipedia: "In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line."
Obviously when a local area is supplying power to the grid, power generation elsewhere will be reduced. And any voltage changes that results from that will be adjusted with line voltage regulators, if necessary.

How do you get the value 250-500W?
Motors will only increase their energy drain by raising the frequency, Plus a small loss due to internal resistance in the windings.
As for a resistive load, increasing the voltage from 120 to 125 volt will result in a power drain increase of about 8.5% or 8.5 W for a 100W light bulb, assuming 120V is the nominal voltage.
Remember though that the voltage increase on the step-down side of the transformer due to homeowners PV arrays will be less than 5 volt pretty much guaranteed. Local codes state a maximum voltage drop (7V in BC) over the lines to a house, at 80% load of service panel capacity.
Most households have a 200A service panel. A 10kW PV array is well below the service panel capacity.
And you cannot just look at the PV array output. You must take into account the local energy consumers as well. That will reduce the current going into the grid, and thus the voltage increase.

You claims are pretty vague, please explain what you mean by wasted.
By the way, there is some "waste" by just using the grid only as well. Losses everywhere in the grid.

What is your definition of worth while? And what do you know about the utility's voltage regulation policies?
The utilities _have_ to use voltage regulation due to demand changes.
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-- X-No-Archive: Yes On 6/2/2012 7:11 AM, m II wrote:

Okay mom.
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Oh but there is. Look around and you will see an occasional unit that looks like a pole pig (transformer) with no low voltage wires attached, just the high voltage ones. This is either a line reactor of some kind (inductor or capacitor) or an on-load tap changer, which is an autotransformer that automatically changes winding taps as needed to maintain the output voltage within the 5 or 10% of spec.
If the load on it is say 50KVA and you switch on a GTI with a perfect 1.0 power factor and outputting 25KW the load on that transformer will drop to 25KVA, since all wiring has some resistance this will cause the voltage to rise the same as if half of the load were switched off, the tap changer responds after a delay period by changing taps which lowers the output voltage back down.
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EFFECTS OF PHOTOVOLTAICS ON DISTRIBUTION SYSTEM VOLTAGE REGULATION
Peter McNute, Josh Hambrick, and Mike Keesee
National Renewable Energy Laboratory, Golden, Colorado Sacramento Municipal Utility District, Sacramento, California
ABSTRACT
As grid-integrated photovoltaic (PV) systems become more prevalent, utilities want to determine if, and at what point, PV systems might begin to negatively impact the voltage regulation of their distribution systems. This paper will briefly describe voltage regulation methods in a utility distribution system. It will also take a preliminary look at the distribution impacts of high penetrations of grid-integrated PV systems being installed and operated in a Sacramento Municipal Utility District community. In particular, the issue of excessive service voltage and excessive substation voltage due to the reverse power flow from exporting PV systems will be examined. We will also compare measured data against modeled data.
Index Terms - Photovoltaic (PV), Distribution System, Voltage Regulation
INTRODUCTION
A three-year, joint project between the National Renewable Energy Laboratory (NREL) and Sacramento Municipal Utility District (SMUD) began in March 2008 to analyze the distribution impacts of high penetrations of grid-integrated renewable energy systems, specifically PV-equipped SolarSmartSM Homes found in the Anatolia III Residential Community (hereafter referred to as Anatolia) in Rancho Cordova, California. SolarSmart Homes combine high-efficiency features along with rooftop-integrated 2.0-kWac PV systems with no energy storage. When completely built out, Anatolia will have 795 homes, 600 of which will be SolarSmart, eventually amounting to 1.2 MWac potential generation. (So far, only 115 homes have been built for 238 kWac potential generation.) In particular we are investigating if there will be excessive service voltage or substation voltage due to reverse power flow from exporting PV systems.
VOLTAGE REGULATION METHODS
The primary distribution voltage needs to remain within ANSI C84.1 limits: 114 V to 126 V or 11.4 kV to 12.6 kV, over the length of the feeder. The service voltage is provided to the customer meter and includes any voltage drop from the primary service through the distribution transformer and service conductors. The electric supply system is designed so that the voltage is within the 110 V to 126 V range (Range A) most of the time and infrequently within the 106 V to 127 V range (Range B). The utilization voltage is the operating voltage system and loads are designed to operate within. During heavy loading, SMUD may adjust the substation voltage as high as 12.75 kV to account for the voltage drop at the end of the feeder.
Load Tap Changer
A load tap changer (LTC) effectively varies the transformer turns ratio to maintain the transformer secondary voltage at the substation as primary-voltage changes occur due to changes in loading of the transmission system, or as the load on the transformer itself varies. The Anatolia substation voltage is automatically controlled by a LTC on the secondary of the substation transformer, managed by a voltage regulating relay. The band center is 123 V (12.3 kV lineto- line at the substation). The bandwidth is +/- 1.5 V (or 3.0 V) total. The time delay for adjustments is 60 seconds. The LTC compensates for added load by increasing the band center linearly from 123 volts at no load to 126 volts at full load (about 20 MVA or 1,200 A).
Capacitors
Capacitors are reactive power sources that affect the voltage by supplying leading reactive current that compensates for the lagging reactive current of the load. The Anatolia substation has six three-phase, 1,800kVAR capacitor banks (hereafter referred to as capacitors). The capacitors are computer controlled using an algorithm developed by SMUD called Capcon. During normal operations, one capacitor is turned on each time the VAR flow exceeds 900 kVAR (from the substation bank), and a capacitor is switched off each time the VAR flow exceeds -1,200 kVAR. These set points are modified on days hotter than 100oF, but this setting can be manually overridden depending upon weather forecasts. These settings automatically adjust for abnormally high or low bulk system voltages.
SMUD ANATOLIA III OVERVIEW
Distribution System Description
Anatolia is a residential community served by individual single-phase lateral circuits from a three-phase primary feeder which connects to a 20 MVA, 69 kV/12.47 kV delta-wye transformer at the Anatolia-Chrysanthy Substation (hereafter referred to as Anatolia-Chrysanthy or substation). The feeder has several points along the line that allow for switching. The length of the feeder to the switching cubicle furthest from the substation is about 18,895 feet and the furthest distribution transformer, 5K7, is about 22,360 feet from the substation. In Anatolia, there are a total of 85 singlephase pad-mounted distribution transformers: 23 are 75 kVA and 62 are 50 kVA. Also connected to the same substation feeder is a rendering plant fed by two 1,500kVA transformers, consuming between 20 and 200 kW, a water storage plant, and a residential community with an estimated 1,000 homes between the substation and Anatolia. There are two additional feeders that also connect to the 20-MVA transformer that have an additional estimated 1,000 customer loads each.
SolarSmart Homes Description
SolarSmart Homes are advertised as able to reduce annual residential electric bills by 60%. They combine cost-effective, energy-efficient features and a rooftop PV system. Typical SolarSmart Home features include: radiant barriers to reflect summer heat that would otherwise enter the attic and cause greater need for air conditioning; 90%-efficient furnaces; 14 SEER / 12 EER HVAC systems; compact-fluorescent lighting; ENERGY STAR-qualified windows; and independent third-party verification, required to confirm all energy-efficiency measures are installed and operate correctly.
A 2.0-kWac PV system can generate a major portion of the electrical energy consumed in the home. The majority of the Anatolia PV systems comprise 36 SunPower 63-watt SunTile roof-integrated modules feeding into a SunPower SPR-2800x positive-ground, grid-connected inverter. The inverter can be remotely accessed by SunPower if the homeowner elects to connect it via the internet. The orientation of the PV systems ranges from southeast to southwest.
MONITORING
The distribution system is monitored at the substation feeder using a DAQ Electronics ART-073-79-0 Supervisory Control and Data Acquisition (SCADA). The SCADA is ANSI-class high-accuracy, better than 0.5%. The sampling rate is every two seconds with an average recorded every five minutes. Four distribution transformers are monitored using PMI Eagle 440 monitors having an accuracy better than 1.0%. The sampling rate is 256 samples per cycle with an average recorded every five minutes. Four homes are monitored at the service panel using PMI iVS-2SX+ power monitors having an accuracy better than 1.0%. The sampling rate is 128 samples per cycle with an average recorded every five minutes.
Solar and metrological data are also collected from a solar/meteorological station installed at the substation. One-minute-interval data from the solar/meteorological station are collected automatically daily.
ANATOLIA RESULTS
SMUD wanted to investigate what effect reverse power flow from exporting PV systems would have on service and substation voltage regulation. Figure 1 shows the Home-to-Substation voltage difference (top) and solar irradiance (bottom) on a clear, cool day, Saturday, March 7, 2009, representative of a day with relatively low load and high local PV penetration. Penetration is defined as the amount of PV output divided by the load at a particular point in time.
At night the substation voltage ranged between 0.4 V to 0.7 V higher than the home voltage. This is representative of a typical circuit with voltage drops through the line and transformer impedances. During daylight hours, this reversed and the home voltage rose as high as 0.7 V, or 0.6%, greater than the substation voltage. The voltage amplitude was 124.5 V at its peak, so it remained well within ANSI C84.1 limits. Due to heavy home loads in the morning, the PV system did not begin to export to the distribution system until almost noon. In March 2009, there was a 2.0-kWac PV system on the home, 30.1 kWac of PV on the transformer (twelve SolarSmart Homes), and 238 kWac of PV on the distribution system (115 SolarSmart Homes). Preliminary estimates of PV penetration levels on the feeder were 11% to 13% under lightly-loaded conditions (2.0 MW) and around 4.0% of the total substation transformer load. Since the PV penetration levels are still relatively low, there were no adverse effects on voltage regulation.
Modelling Anatolia
To measure the effects of PV on voltage regulation, a Distributed Engineering Workstation (DEW) model was created that included the distribution transformers, secondary, and service connections. Once validated using measured field data, the model will be used to determine acceptable levels of PV penetration.
The feeder contains significant loads which are not part of the system under evaluation including a rendering plant, water storage facility and approximately 1,000 residential customers. Additionally, the substation transformer and LTC are shared by two unmonitored feeders.
For initial testing and model verification, the unknown residential loads were represented as a lumped spot load. Eventually, the residential loads will either be calculated from load research statistics or distributed based on distribution transformer size. The rendering plant load was represented as a spot load based on recorded data.
The load on the other feeders was modeled using a spot load placed immediately after the LTC. Since the additional feeders share the LTC, the load on those feeders will affect the position of the tap as well as the regulation set-point. While the load on the other feeders will not greatly affect the voltage profile of the system under study, these loads may affect the voltage regulation.
To verify the topology of the model and to ensure the switching devices are represented in their correct states, the electrical distances from the substation of the measurement points were compared against the values estimated from a GIS map. Table 1 describes this comparison. All modeled electrical distances are within 3.5% of the estimated distances as determined from GIS drawings.
Next, the behavior of the secondary-side of the distribution transformer was validated against real data. The voltage rise measured between the secondary of the distribution transformers and the service entry to the homes will be affected by the loads and generation of the other, unmonitored homes that share the secondary connection.
Figure 2 shows the simulated and measured voltage rise from Home 3 to the secondary of Transformer 3 (8K6). The data reflects roughly a month of data where Home 3 is net exporting real power with an inductive load between 0.18 kVAR and 0.22 kVAR. The secondary system was simulated assuming uniform generation from all customers connected to the secondary of the transformer. The generation from the homes was increased while maintaining a constant inductive load of 0.2 kVAR. The homes were modeled as constant current loads.
The variation in measured voltage rise data is largely due to uncertainties with the other customers sharing the secondary connection as well as the resolution of the voltage measurement device at the home. Figure 2 indicates that the model reasonably reflects the behavior of the actual system. With improved monitoring and meter accuracy, the model could be better validated and, if necessary, adjusted to more accurately reflect the system.
Currently, there are too many uncertainties on the circuit to perform any meaningful whole system validation. Efforts are under way to increase the monitoring on the system so that the overall model may be better validated. This includes adding meters at critical points to eliminate many of the unknown loads described above.
CONCLUSIONS
After one year of monitoring the Anatolia SolarSmart Homes Community, there was no excessive service or substation voltage due to reverse power flow from exporting PV systems. Preliminary estimates of PV penetration levels on the feeder were 11% to 13% under lightly-loaded conditions (2.0 MW) and around 4.0% of the total substation transformer load. Since the PV penetration levels were relatively low, there were no adverse effects on voltage regulation. It was possible to see the effects of the PV systems on the voltage at the individual homes and the distribution transformers. This slight voltage rise was approximately 0.6% on clear days in comparison to the normal drop of -0.6% without the PV exporting. The DEW model that has been developed reasonably reflects the behavior of the actual system. The model will be used to determine acceptable levels of PV penetration.
=============== Photovoltaic Specialists Conference (PVSC) 2009 34th IEEE Issue Date: 7-12 June 2009 On page(s): 001914 - 001917 Date of Current Version: 17 February 2010
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They have stated that the servo-loop stability of grid voltage regulation -may- become questionable at over 20% uncontrolled solar input.
http://eioc.pnnl.gov/research/gridstability.stm
jsw
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Plug a Kill-A-Watt (etc) voltmeter into an outlet and then switch on a load, like a heater or iron. See what the voltage drop is for that current. You can measure the drop at the breaker box by metering an outlet on a different breaker on the same side of the line. This will show you approximately how much your grid voltage changes with current, from or to the grid.
jsw
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You are claiming that any electricity produced by PV arrays that goes onto the local grid just gets wasted because putting it on the grid raises the voltage a tiny amount. I think that's what he meant by saying "it doesn't work". That is you're saying that PV arrays that have net current flowing into the grid don't work, because the energy somehow just gets dissapears.
There is SO much wrong in your analysis, that I don't know where to begin. But here's a start. You claim that with a slightly higher voltage, an AC motor in an HVAC compressor won't turn any faster and hence the additional power is wasted. What you've completely overlooked is that power is P=VI, or power is voltage times current. Give that motor an extra half a volt and I'll bet it's current decreases by a corresponding amount.

As Bud said a while back, you're new analysis must be devastating to all the power companies in the world.
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" snipped-for-privacy@optonline.net" unnecessarily full-quoted:

I'm not saying that it dissapears.
I'm saying that if your local grid is sitting at 120V and your panels come on and raise it to 121V, and if the utility company doesn't down-regulate their side to bring the local grid back to 120V, then the current that your panels are injecting is wasted. It's wasted because all the linear loads on the grid that are designed for 120V will not operate any better at 121 volts. Motors won't turn faster, lights won't really burn brighter. They will just give off a little more heat thanks to the extra current the panels are supplying to the grid.
But sure - electric heaters will get hotter. They're the only devices on the grid that are intended to convert electrical energy into heat.

So why not run a 120V motor with 240 volts then?
AC Motors are not simple loads like a resistor, but they will still "consume" power (V x I) as a function of their supply voltage.

All the power companies in the world are in the business of generating electricity in the thousands of volts and sending it out over high-tension wires. That's what they'd rather do if they weren't being hamstrung by crazy ideas and new rules / laws made by politicians about small-scale co-generation.
Look at the microFIT program in Ontario. When the rules were changed to allow local utilities to veto hookups based on "network capacity" or "substation insufficiency", they were only too happy to start swinging their veto left and right. They don't want to see this small-scale shit coming on-line if they have a choice.
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On 4/14/2011 11:47 PM, Home Guy wrote:

(Which is why I didn't try.)

Duh...
A motor running at a constant RPM creates a fixed amount of mechanical power for a given load. RPM of induction motors is not very sensitive to voltage. The electrical power used is tied to the mechanical power consumed. Raising the voltage a little lowers the current a little.
--
bud--

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Wrong.
Motors won't turn faster, but they will take less current. They're doing the same work so will take (roughly) the same power to do it.

Wrong, not that the higher intensity is always useful.

Wrong.
You're batting 1000.

Put the windings in series and it'll run better.

Wrong. You're still batting 1000.

"Co-generation"?
They have to *pay* for that energy, not to mention manage the complexity of the mess and lose money at the same time. Of course they'll opt out, if given the chance. It shouldn't be done, but certainly not for the reasons you suggest.
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On Apr 15, 7:46pm, " snipped-for-privacy@att.bizzzzzzzzzzzz"

Ok, subsitute the words "gets wasted and performs no useful work". That is what you are saying.

That sure must be news to all the power companies that are paying people for having PV arrays generate power to the grid.

Actually, they do turn very slightly faster when supplied by a slightly higher voltage. Heres' a good reference that covers HVAC compressors:
http://www.hvactroubleshootingguides.com/the-effects-of-voltage-variations-on-ac-motors.html
Take a look at the graph, which shows slip, which is the variation between shaft speed and the sychronous magnetic field which is determined by the line freq. It shows that slip is also a function of voltage, that when voltage increases, RPMs increase slightly.

Agreed. At higher voltage they do burn a tiny bit brighter. And that would appear to be an example of what you could consider wasted energy. Unless you want to factor in that in winter at least, in some cases, it adds to the available heat.

Because 240V is out of the range of operation for a 120V AC motor. Stick to the case at hand. We're talking about running an AC motor at 120V or 121V. I say running it at 121V means the current will be slightly less, resulting in the motor operating at the same HP output, but at slightly higher voltage and slightly lower current. And/or part of the voltage increase will result in more power being delivered by the motor to the AC comptressor. You say what? The motor justs takes that extra volt and turns it into pure heat? How does it know to do that?

Well they do consume power in relation to their voltage and current. Take a look at these formulas:
Look at the one "To find horsepower." Clearly I can get the same HP output by raising the voltage slightly while the current gets reduced. Also take a look at the previous graph, which clearly shows that full load current DECREASES if you increase voltage slightly.

Again, you'd think that if most or all of that net energy that is put onto the grid by PV arrays is being wasted, we'd have heard about it from someone long before this.
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On 12/04/2011 16:50, Home Guy wrote:

The inverter must ensure that it transforms the DC from PV to the frequency and voltage of the grid. To ensure flow of current into the grid the voltage must be attempted to be raised. Because there are losses between the inverter and the grid, the voltage will be higher than the grid.

Fairly good analogy, and due to internal resistance in the pipe then that must be overcome by having a higher pressure. Don't forget that somewhere someone else has to reduce the water flow into the pipe system in order to avoid pressure buildup. Because the water in the pipe system is used up as it is supplied, at the same rate.

See the pipe analogy above, the power lines from the inverter has some resistance, which results in a voltage drop. Therefore the voltage measured at the inverter will be slightly higher than measured a distance away.

Why? take a hypothetical grid with 1 megawatt consumption. Generating machinery produce that energy at a set voltage. Mr Homeowner connects to the grid with a 10kW PV array. If no power utility adjustment took place then the overall voltage of the grid will increase. OK for small fluctuations, but if enough PV arrays came online, somewhere energy production has to decrease or bad things will happen due to high grid voltage.

You cannot unless your local load is zero. You must subtract the local load from the generated PV array power if the house load is lower. If the house load is higher than the PV array output then you will use all the PV array power with the difference supplied from the grid.

Correct, due to a slightly raised voltage if there is a voltage drop between the inverter and the grid. (There is some drop)

Not possible, the current is controlled by the internal resistance in the lamp. They will draw a current by the formula volt/resistance. So when the PV array produces current, grid current is reduced.
The voltage increase you will see at the output of the inverter is very small, but it does depend on the cables used.
An example: I have a 300 feet underground cable to the nearest utility transformer and a 100A service panel.
If I max out the power, I will have a voltage drop over the cable of about 6 Volts. Much higher than normal households.
When your PV array is producing full power, and your house load matches that, then the voltage difference between the grid and inverter is zero.
at any other house load, current will flow in the power utility lines, and the inverter voltage increase is a function of the loss in those lines.
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wrote:

A lot of them were sold for mountain vacation homes. Thieves steal them often for the copper though there is not that much copper in them.
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On 04/04/2011 03:08 AM, Home Guy wrote:

http://microfit.powerauthority.on.ca/Program-updates/2010-December-8-microFIT-Connection-Rule.php
The bark may be worse than the bite. The company who did my PV installation also did the entire beaurocratic paperchase for me. They sent me a whole pile of application forms to fill in, and I sent them all back with a limited power of attorney to let them get on with it.
I can understand that the grid operators need to know how many PV installations there are and how they are all connected.
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