I saw this problem cominga couple of years ago

[PhilipA]

Rooftop solar panels overloading electricity grid | The Australian (http://www.theaustralian.com.au/national-affairs/carbon-plan/rooftop-solar-panels-overloading-electricity-grid/story-fn99tjf2-1226165360822)

Is there no end to the stupidity and short sightedness of governments and the management of utilities?

Regards Philip A

[djam1]

Rooftop solar panels overloading electricity grid | The Australian (http://www.theaustralian.com.au/national-affairs/carbon-plan/rooftop-solar-panels-overloading-electricity-grid/story-fn99tjf2-1226165360822)

Is there no end to the stupidity and short sightedness of governments and the management of utilities?

Regards Philip A

Put simply NO and its just not utilities

[slug_burner]

"If you get a very, very hot night and there's obviously no solar, the mains voltage is going to drop a lot," he said. "If your wires aren't up to it, you've got a problem."

Not really a PV electricity problem.

[p38arover]

Not really a PV electricity problem.

I didn't understand that comment either. Dion, where are you?!

[Tombie]

Same issue occurs here on a windy day!

The Onesteel Powerhouse (yes we have our own) shuts production down as the nearby wind farms ramp up in the wind because it overloads the grid.

We just need providers to extract their profit making fingers and upgrade infrastructure to a Smart Grid

[JDNSW]

The problem is not so much a problem of PV power on rooftops as one of inadequate distribution network capacity (largely, I suspect, because of the widespread adoption of airconditioning plus large screen TV in the last decade). You can hide the shortcomings of the network by upping the voltage (and wasting energy on heating the air) - but this only works if the power is coming from a single source. And is only financially viable while the extra wasted power remains cheaper than upgrading the network (or where you can simply increase prices to the consumer to cover it).

I think the increase in the domestic power consumption may have taken the supply companies by surprise, as well as the bill recipients.

John

[bee utey]

Both population/consumption growth and green energy feeds require the grid to be strengthened instead of raising the pay of power industry CEO's. Surprising, innit.

Back when Starfish Hill wind farm (Cape Jervis SA) was new I was in a small group who got a guided tour with the chief engineer. One of the things the company had to do was to upgrade the power lines to the nearest major substation south of Adelaide. The bonus was the improvement of supply stability for the whole peninsula and Kangaroo Island as well. So in this case the wind farm was a benefit for a whole bunch of people.

So domestic solar installs have outstripped the ability of some of the grid to cope? No surprise as you say, but excessive consumption on hot cloudy days used to do the same in reverse. With the future roll out of electric cars there will be ready made solutions to better grid management available.

[PhilipA]

The problem I see is more on a micro basis and I have asked techs about it and they just shake their heads.

Each residential street or area has a step down transformer to go from High voltage to 240 volts.
What happens in the 240volt area when solar output exceeds demand by a big amount. Can the excess power then reverse through the step down transformer back up into the high voltage grid or is it isolated into the local area?
I see this scenario as quite probable as most solar power will be generated between 10AM and 2PM and AFAIK, demand is quite low at these times in residentail areas. How can the distributor control these voltages? By resistor banks? How can a smart grid control it?
Whatever way, it is going to cost a lot of money and I doubt whether the government will make the uptakers of the solar subsidies pay it,as IMHO they should.

Regards Philip A

[Tombie]

Whatever way, it is going to cost a lot of money and I doubt whether the government will make the uptakers of the solar subsidies pay it,as IMHO they should.

Regards Philip A

WHY?

Why should I have to pay for infrastructure issues?

My PV system is reducing requirements to build more and more power stations - Which all of us have to pay for if they are built...

No different to when a huge wind blow comes up and the Wind farms fire off... Traditional generators then have to ramp down or divert excess power.

Smart Grids can divert and utilise power efficiently and quickly, routing excess to meet damands of heavier consuming areas. Combined with smarter power stations themselves they can ramp requirements better.

And as for the "poor me, i didnt take advantage of the solar rebates (for whatever reason) and those who did should pay more"..

What a load of Dogs Bollocks :mad:

I know lots of people paying taxes and who don't have children who are essentially contributing to family benefits to those who choose to breed...

And I know a lot of people driving nice new D4s etc...
Just because they could afford them and they are marginally heavier than earlier models, does that mean they should pay more in rego to use the roads because they have a new vehicle?

Our power distribution and generation network in the country is a disgrace... Instigate upgrades to work with the PV systems..

But they wont of course, because they no longer make money from people like myself - in fact - I provide enough power per day (on average) to run my house and those of my 2 neighbours...

If they jerk me around I will pull completely off the grid - something which now will only cost me a few thousand.

[rovercare]

The problem I see is more on a micro basis and I have asked techs about it and they just shake their heads.

Each residential street or area has a step down transformer to go from High voltage to 240 volts.
What happens in the 240volt area when solar output exceeds demand by a big amount. Can the excess power then reverse through the step down transformer back up into the high voltage grid or is it isolated into the local area?
I see this scenario as quite probable as most solar power will be generated between 10AM and 2PM and AFAIK, demand is quite low at these times in residentail areas. How can the distributor control these voltages? By resistor banks? How can a smart grid control it?
Whatever way, it is going to cost a lot of money and I doubt whether the government will make the uptakers of the solar subsidies pay it,as IMHO they should.

Regards Philip A

Yes, iron core transformers in distribution, work both ways

The joys of privatization, sec had massive plans for future infrastructure, now we are 2.5 brown coal stations and lots of network upgrades behind, that's just Vic

None the less my additional 4kw will be going on in a couple weeks while system extensions are eligible for the pfit, followed by an additional 4.6 when parity to the feed in tariff is looming, 9.6 kw total

Currently stepping a system upto 15kw from 5 at Phillip island

[clubagreenie]

Tombie, lets see who can afford to "take advantage of solar rebates".

I'm a single parent of 3, mortagage and usual bills. Now yes there's been a rebate but on the basis of you front up the cash first and then we'll get around to giving it back when we see fit.

Now that Origin are being realistic and offering interest free and claiming the rebate for you and you just get to pay it off I might consider it.

But I'll concentrate on feeding us, using less power to start with (compared to the in-laws who run a gas heater to keep warm and the A/C to stop the associated condensation) and just trying to get by.

[Warb]

Now yes there's been a rebate but on the basis of you front up the cash first and then we'll get around to giving it back when we see fit.

If you're talking about the REC's installation rebate, almost every installer will simply deduct it from the installation fee, so there is never a requirement to pay and then claim it back - but you can if you want to! This rebate has been reduced this year, in that the first 1.5kW of installed capacity used to qualify for 5 times the "normal" rebate, but now qualifies for 3 times. The process, however, has not changed and the normal course of events is that the (reduced) rebate is simply deducted from the installation cost.

If you're talking about the feed in tariff, then that was paid as you generate the power, and used either to reduce your electricity bill or give you a refund if you generate more than you make. If you did generate more than you used (from a $ perspective), it took about a week (from my experience) to get a cheque from the electricity company.

When all the rebates were at their height (60C/kWh and 5 times REC rebate) it was possible to get a 1.5kW system installed for about $2500 in Sydney ($0 in Dubbo where 60%+ of houses now have PV system, apparently). Such a system would have produced about $1500/year of electricity for the next 6 years......

The article quoted is quite amusing. The voltage rises due to PV systems "may cause damage to.." etc. Funny that all PV inverters have a 10 minute maximum average voltage of 254V, and a spike voltage of about 263V from memory. Anything above that and they automatically shut down to prevent damage to the grid. The Australian standard voltage is 230V, with +10% allowed (253V), and this is the standard to which inverters have to adhere. The issue here is that the grid runs at an overly high voltage as standard, because it's cheaper than upgrading it (as was stated above).

So what actually happens is that the PV systems remove load from the grid, causing the already overly high voltage to increase, and the PV inverters shut down, but only when the grid is at 254V average. The power companies blame the PV systems (which remove their profit, so they don't like them!) for a problem that is basically (again, as was stated above) caused by their own lack of investment in a grid that will supply the required power and still remain in spec.!

When I installed my first PV system it shut itself down every few minutes. My "230V" grid was (without PV) running at a 10 minute average of anything up to 257V, and spiking above 267V. My transformer had to be retapped (after much "discussion"), with an off-the-record admission that really the entire 11KV line needed to be reset but that was not possible because all the low voltage transformers along the line had been adjusted too high to allow for the voltage drops.......

The system is basically out of control, and any excuse is grabbed to remove the blame from where it deserves to go.

[Tombie]

Tombie, lets see who can afford to "take advantage of solar rebates".

I'm a single parent of 3, mortagage and usual bills. Now yes there's been a rebate but on the basis of you front up the cash first and then we'll get around to giving it back when we see fit.

Now that Origin are being realistic and offering interest free and claiming the rebate for you and you just get to pay it off I might consider it.

But I'll concentrate on feeding us, using less power to start with (compared to the in-laws who run a gas heater to keep warm and the A/C to stop the associated condensation) and just trying to get by.

Firstly I dont mean to offend, and those who are doing it tough are missing out on lots more than just Solar... Theres new vehicles, tv's etc so they do it tough all over...

And being unaware of how you ended up in your personal situation I do not wish to judge you in any way shape or form.. 1 kid on your own is enough (done it) so 3 must be 'entertaining' (and tiring)...;)

In SA at least (although I went through a Vic company) I paid nothing of the rebate component - as mentioned it was deducted from the purchase price.
I then went on the Interest free plan which allows me to pay my 5Kw system off at $150.00 per fortnight. Note-> 5kW system.... For a 3kW system payments were about $70.00

I then get approximately $4000.00 from the feed in tariff p.a back in my pocket and not a single power bill all year.:cool:

Besides actively reducing power consumption - we have dropped our quarterly bill 40% this year... And its amazing how aware of waste we now are :D we now produce more than the repayments on the system above and beyond our consumption.

Entry level in SA was 1.5kw and could be had for as low as $1100.00... Even these systems pull down a family bill...

Friend in a tight financial situation has gone the largest inverter they can afford and a small system of panels.. In SA you are only paid feed in on the approved maximum size of the system (so on the high feed in which has now expired they can increase system as funds come avail - a panel at a go) and up to the 4kw inverter limit.

At the moment they buy about 2 panels a year.... They started at ~2kw and are now around 2.4kw.


In the case of the solar - short term financial pain has produced long term gains - less than 2 weeks after my PV went in the SA providers (AGL and Origin) increase prices by a huge jump......

In the mean time, I will continue to enjoy the benefits of my PV system, much like my Father does (and how unfair is that, he has a shiny new Discovery TDV6) :angel:

[clubagreenie]

So a few questions, Whats the "Optimum" size system (I know thats the how longs a piece of string question), basically, I realise that unless I have on site storage I can only benefit if I'm at home and using power, but I have a ****e load of IT stuff that has to be connected 24/7 for study/work use. I was looking at min but probably 2.0 to try to get a better benefit from feeding back in.

Given we don't have gas in the street, would we reap better benefits from getting a couple of bottles and a gas heater for over the winter vs air con?

The monthly cost is just below with what I'm paying at the moment per month, given I'm home 50/50 what sort of returns should be expected on usage (again a striung question)

[bee utey]

So a few questions, Whats the "Optimum" size system (I know thats the how longs a piece of string question), basically, I realise that unless I have on site storage I can only benefit if I'm at home and using power, but I have a ****e load of IT stuff that has to be connected 24/7 for study/work use. I was looking at min but probably 2.0 to try to get a better benefit from feeding back in.

Given we don't have gas in the street, would we reap better benefits from getting a couple of bottles and a gas heater for over the winter vs air con?

The monthly cost is just below with what I'm paying at the moment per month, given I'm home 50/50 what sort of returns should be expected on usage (again a striung question)

2kW is a minimum if you want feed in tarriffs to cover bills, 3kW would be better. Gas bottles are ****loads dear nowadays, I wouldn't use them for heating anymore. We have bottles for the cooker cos power failures are bad news without food. Reverse cycle heating isn't bad so long as you have an efficient unit and only use it where needed.

I work from home, me and the missus and the lad aren't hard on power and our 1.5kW system with sun tracker just covers our electricity bills, including a heat pump hot water. We have mainly wood heating and evap cooling with a small reverse cycle a/c that gets some use, especially between dinner time and bed time in from of the TV.

Oh and I reckon our solar earns about $800 to $1000 p.a.

[Tombie]

So a few questions, Whats the "Optimum" size system (I know thats the how longs a piece of string question), basically, I realise that unless I have on site storage I can only benefit if I'm at home and using power, but I have a ****e load of IT stuff that has to be connected 24/7 for study/work use. I was looking at min but probably 2.0 to try to get a better benefit from feeding back in.

Given we don't have gas in the street, would we reap better benefits from getting a couple of bottles and a gas heater for over the winter vs air con?

The monthly cost is just below with what I'm paying at the moment per month, given I'm home 50/50 what sort of returns should be expected on usage (again a striung question)

Excellent questions and you are thinking in the right direction for sure.

Air Cons - Make sure they are efficient, inverter style units.. We ended up with 4 individual units that use very little power once to temperature. It also allows us to shut down areas (bedrooms etc).

Ceiling fans are more efficient and often all thats needed to make a room comfy in all but the worst weather.

Home IT - What exactly are you running? My new router uses less power by 70% than my previous unit. It also can be set to turn down / off WiFi during certain times to reduce power use. I have mine set to drop WiFi power to 15% until someone connects, then it ramps up as required.
Run laptops only - they are usually 90w PSU so much less than a monitor+box
Printers can be turned off, doesnt take long to boot them up as needed.


LED globes everywhere you can!

Turn everything off - every time you leave the room, turn the light off...

Kids - No TV & Laptop, its one or the other... Music on the computer is fine. Lights off when not needed, desk lamps (LED)....

Check your fridge - you'd be amazed how much they chew... Electrolux are the most efficient you'll find in normal stores.
Smaller, full fridges are more efficient than a huge half empty fridge - if you have a large fridge, lots of bottles of drinking water to fill the spaces...

TVs & Home Theatre - The News doesnt need a full Pro Logic system, so just use the built in speakers... Movies - Now they NEED DTSHD ;) so turn the gear on, only when justified!


These are just some things to think about...

This link has a great tool to help decide system size:
Grid Connect Solar Power Electricity Calculator (http://www.energymatters.com.au/climate-data/grid-electricity-usage.php)


Ring me if you want to discuss...... More than happy - (Reverse) 5399591040

[Warb]

Excellent questions indeed. However I am sad to say that you have missed the boat for solar. At this point in time (and this may change in the future) there is NO feed in tariff in NSW - and I'm judging from your profile that you are in Sydney.

I'll repeat that, because it is different from state to state, but for NSW there is no compulsion for your energy retailer to pay you anything for any excess power you produce. They may choose to pay you the wholesale rate (about 4c/kwh), and there is currently an IPART review in progress to evaluate a "fair rate", but as of this point in time it is very unlikely you'll get more than a few cents for your power, if that. As a result, to be honest there is little point in buying a system much above 1.5kW at present, because you will not be rewarded for generating more power than you use at any point in time - most energy retailers these days install meters that read "instantaneous" usage, or at least in small time blocks, so generating 3kW at 1.00pm will not offset using 3kW at 1.30pm, if you see what I mean.

OK, so what else? Tombie has made some good points, but to add more details:

Air conditioners - be aware that some (not all) have crankcase heaters to maintain the oil at a suitable temperature for use. These are thermostatically controlled, but can still chew 100W almost continuously, especially through the winter EVEN WHEN THE AIRCON IS NOT ON. The only way to prevent this is to switch the AC off at the circuit breaker, with the downside that it will then take 24hours after power-up to reheat the crankcase before the unit can be safely used (or theoretically risk premature failure). The government energy rating website lists which units have crankcase heaters.

The government energy rating website is also good for fridges, freezers etc., but note that the "star" rating has been altered many times, so older units in the shops may have more stars even when less efficient. Also note that the star rating allows for amount of work done - so a large 4 star freezer will use more power than a small 4 star freezer, both have 4 stars because they use similar amounts of power per unit of food they store. Also note that chest freezers are inherently more efficient than uprights, but may get the same number of stars per unit of food because the government assumes that everybody knows they are better (bizarre, but that's what they told me!). So in all cases it pays to check the "kwh used per year" column as well as the stars!

LED lights. Personally I'm less than totally convinced. The power savings are there when compared to 50W halogens, but less so when compared to 20W energy saving halogens, or linear (or circular) fluoros. If the 20W halogen costs $7 and the LED costs $20 (which is a cheap LED), it has to last a long time to payoff the difference in capital cost. The sellers will compare 50W halogens running for 7 hours a day to show a saving, and assume the LED will last for 50,000 hours. The reality is that most cheap LED's don't last more than a year or two, so the capital cost kills any savings they may offers. Also be aware that they still produce far less light than a 50W halogen, and also less than a 20W Osram energy saver.....They may give 100lumen/watt (75 is more likely, but lets go with the hype), but for a 6W LED that's still only 600lm - compare to a 50W MR16 halogen at 20lm/watt (so 1000lm), or a T8 linear fluoro at 90lm/watt (3000lm+). Reality is that at a more believable 75lm/watt, the LED saves power but produces far less light - OK if you're overlit to start with, but if the halogen lighting was designed to be correct, when replaced with LED's it will now be dark!

Basically the best advice is to use what you have until it dies, then replace it with the best option (best, not "most hyped"). And most important of all is to switch it off when not in use. Whatever "it" is!

[timbo]

Can't they reduce the load by installing large underground storage cells, for use when it's overcast for significant periods of time?

[clubagreenie]

If they poured some development money into research for new/inproved battery tech (for large scale storage) it might be an option. However from experience with friends on properties without main power (still exisits in NSW) They used both solar and generator with 12v storage (a huge bank of truck batteries) just for residential use. Storage had to be in it's own enclosure well ventilated as you'd imagine.

[PhilipA]

In my research on the subject, the most promising storage solutions appear to be "water pumping" where water is pumped to a high reservoir to generate hydro power at times of high demand. This is already used in Australia by SMEC, by buying off peak power and then selling the hydro power at peak.

The other technology is spinning flywheels. This is currently used in Coral Bay with very small units to even out wind power fluctuations, as well as 6 diesel generators LOL. The theroy is to spin up a VERY large flywheel which spins on superconducting bearings to use the power later. Similar to no break Airport systems.

I reckon they could put units in old coal pits in the Hunter, then if one went out of control it would bounce around in there rather than destroy a city.
In Spain they use molten sodium to store heat in the very large solar station they have there . There was a "scandal" recently when it was disclosed they were selling power at peak rates when the sun didn't shine but I don't see anything wrong with that.

All of these things are experimental , and do not seem to have any real funds being spent on them certainly in Australia, yet to me the storage issue is the major one facing solar and wind power, in order ot makje them viable base and peak load.

Regards Philip A

[Bigbjorn]

Re the above post concerning gas appliances. I once worked at a major gas company. The accepted wisdom of staff experience was that gas stoves were good. Gas bath and sink heaters also but not convenient. Few on staff would contemplate having a gas hot water system or room heater (gas fire) as they are so bloody expensive to run. Before solar systems became readily available, the cheapest hot water systems were electric off-peak storage units. Instananeous electric HWS were very expensive to run and the internal heating filament seemed to have a quite short life.

Regarding air conditioners, about 2004 the NWQEB had a promotion on air conditioners. Buy one and get free installation. Now the north west Qld. summers have weeks on end where the ambient temperature never drops below 40 even in the evenings. Every item inside your house becomes warm to the touch. People ran their brand new air conditioners hard and long. Bloody marvellous, aren't they, a pleasure to come home to a cool house. Then the accounts started to come in. $2,000-$3,000 not uncommon. Up from maybe $200 if you had hot bore water reticulated. Many have not switched the a/c on since, and many had to make arrangements to pay off the unexpected accounts.

[PhilipA]

Before solar systems became readily available, the cheapest hot water systems were electric off-peak storage units

They still are.
Met a bloke the other night who had ditched his solar for a storage as he had mechanical problems with the solar and also the local distributor would not allow him to run the booster on off peak!!!


Both neighbours across the road have recently fitted storage, as we live in a very treed area. I note one neighbour has recently fitted a solar and his solar is shaded for 60% of the day. I wonder what his booster bill will be?

However NSW is rumoured to be following SA in banning storage replacement, as AFAIK already banned for new houses.

This is crazy policy as the coal fired power stations have to be run all night. That is why they offer off peak rates,so there is no additional greenhouse gas emission.
I was pondering whether to buy a Hardie Dux and store it under the house to replace mine when it dies hopefully in 23 years like the previous one , but I will probably be dead by then.
Regards Philip A

[clubagreenie]

Mine takes a standard element used in a variety of other applications as well and is a stainless steel tank so should hopefully keep going for a while.

[Ivan]

I use off peak electric water heating. Looking at my bills it costs me about $10 a month for water heating. It's going to take a while for solar heating to be paid off. Consequently I'll stick with my electric off peak until it goes wrong.

Ivan

[p38arover]

I use off peak electric water heating. Looking at my bills it costs me about $10 a month for water heating. It's going to take a while for solar heating to be paid off. Consequently I'll stick with my electric off peak until it goes wrong.

Ivan

I note a NSW govt website says "If you have an electric hot water system, it'll be responsible for up to one third of your household's power use. "

Ref payback period, exactly, Ivan. Too many don't look at payback period, etc.

We went to a new gas instantaneous hot water system even though our off-peak hot water system was still working because (a) it was gravity feed and didn't give us sufficient water pressure, (b) we regularly ran out of hot water when the kids were still home, (c) we were installing a new kitchen with gas appliances so gas was being laid on, and we also wanted flick mixers (d) in preparation for the bathroom and laundry upgrade.

[Hymie]

What I want to know is if they cut power to an area to work on the lines, surely the houses with Solar panels would be pumping power into the system as well.Do they have to go around and isolate every house and then reconnect it when they've finished?

[mick88]

I use off peak electric water heating. Looking at my bills it costs me about $10 a month for water heating. It's going to take a while for solar heating to be paid off. Consequently I'll stick with my electric off peak until it goes wrong.

Ivan


I agree,
off peak power usage for hot water is extremely cheap.
By the time the solar system is paid off you would be looking at replacing it.
One thing that extends the life of electric storage units is replacing the "sacrificial anode" at regular service intervals. I have done ours every five years and so far so good. The unit, a steel/ceramic one, is 21 years old. When the time comes, the replacement one will be a stainless steel unit.

Cheers, Mick.

[p38arover]

What I want to know is if they cut power to an area to work on the lines, surely the houses with Solar panels would be pumping power into the system as well.Do they have to go around and isolate every house and then reconnect it when they've finished?

No, they shut off when they lose grid supply.

[p38arover]

When the time comes, the replacement one will be a stainless steel unit.

You may not be able to buy one if the new regs come into force this year.

[PhilipA]

No, they shut off when they lose grid supply.
__________________


Actually I had a talk about this to the foreman of the linesmen who recently replaced my cable in to the house from the street.

He told me that they all have had to be retrained to look for power on the "wrong" side of the fault due to the presence of solar panels, I guess to be failsafe .
Another instance he mentioned is where a neighbour runs an extension cord to a house on the wrong side of the fault. he told me they had lost some linesmen that way.
Regards Philip A