After my solar panels are installed, and connected to a gross meter, is it legal to pay an electrician to "hack" or "mod" the install so that the power generated goes to my house only, if I wanted? Just out of curiosity. I don't see why not, as a man's home is his castle and he can do whatever he wants to it.
"Hacking" my solar install?
(38 posts) (15 voices)-
I like the idea but have to ask, to what end? If you just use more electricity the end result will be that all power produced will occur at your home.
You could buy a battery bank and inverter/charger to store excess power for use at night or in blackouts that will be a little inefficient. Or buy an electric car to charge during the day. I have an electric bike and a standalone solar system for that purpose.
Posted Saturday 31 Jul 2010 @ 4:17:50 am from IP # -
Emuu
MemberWhen the cost of power from a supplier exceeds the feed-in tariff (and at current rates that won't be too far down the track) you may want to do it, until then, the only reason to do it would be so that they don't know about the crop of plants you are growing in your hydroponics garden.
Posted Sunday 1 Aug 2010 @ 2:43:18 am from IP # -
swanning_it
MemberI'd hardly call it "hacking" unless you intend to steal electricity. Whether you can or can't have a sparky rewire to supply your house alone from your solar power system will probably depend on the contract you signed with the supply authority. I haven't read the NSW FIT agreement, so have a read and see if you have agreed to sell them power for a minimum contractural period.
Posted Sunday 1 Aug 2010 @ 3:50:46 am from IP # -
SJ2571
MemberWhen I say "hacking", I don't mean in a theft context. I just mean so I could use the power as I see fit, rather than just send it to the grid to get credits on my electricity bill. Because who knows, in 5 years time the Govt may drop the payments from 60c per kW to 10c or something awful like that. If that happens, I want to be able to use the panel electricity for myself FIRST.
Posted Sunday 1 Aug 2010 @ 7:46:20 am from IP # -
SJ2571
Member@Guy: Your last bill was $20 for 91 days? Sounds great, but can you please tell me a little more about yourself. Do you live alone? What devices do you use (PC, Plasma TV, etc)? I have a wife and 3 kids at home fulltime, so I doubt my bill would ever be that low.
Posted Sunday 1 Aug 2010 @ 7:47:54 am from IP # -
Benny
MemberWhat you're asking still doesn't seem to make sense. If you have a need for power, then the power from your system will be used to supply it. If you don't have a need then the excess will be exported. Whats the point in wiring the system so that "only you" get the power ? That means the system will just shut down and the potential power generation will be wasted.
If you want to sue the power "as you see fit", then just use it. If you know how much is being generated and how much you are using, just turn on whatever extra gadgets you have until you're using all the generation and none will be exported. Your attitude doesn't seem to fit in with the general attitude on this site though, where most are glad to be exporting power and helping reduce the need for more power stations.
Also be very careful with the provisions made for the system to shut down if there is a power cut. Its frustrating that in a power cut we can't use our solar power but understandable given the safety issues.Posted Sunday 1 Aug 2010 @ 10:51:56 am from IP # -
SJ2571
MemberBenny, you said that if I need power, then the power from my panels will supply it. But from what I understand about net/gross, that's incorrect: the power from my panels will go to the GRID and not TO ME. Then I will get a rebate from what I've sent to the grid. So, using it "as I see fit" is not an option at all, UNLESS I get an electrician to re-wire it to NOT go to the grid but to me alone. That's what I meant.
As for my attitude, what the heck is with that comment? By using solar power to myself first, I'm still negating the need to draw power from the stations. If everyone did that, then stations wouldn't need to exist at all! Quite frankly I think that is very much in line with the attitudes of the people here.
Posted Monday 2 Aug 2010 @ 3:49:30 am from IP # -
LanceTurner
Key MasterSJ2571, when you say 'to me' not to the grid, what is it you are imagining there? You have no energy storage in a grid interactive system so if you are not using in your house the same amount of power being generated, any excess is sent to the grid, otherwise it would simply be wasted. It's impossible for a GI system to only power the house, if you want to do that you need to take the house off the grid and have a different system, one with batteries and stand-alone inverter. Alternatively, a hybrid system which is both GI and has battery backup, but the average GI inverter doesn't allow for that, hybrid inverters are much more expensive.
The GI inverter should be wired to the solar input on the meter but how the metering is done depends on whether you are gross or net metered. Or have things changed regarding how inverters are wired to meters nowadays and I'm just behind the times (perfectly possible, I don't have the time to keep up with all the policy BS that floats around in this industry)...
Posted Monday 2 Aug 2010 @ 5:15:25 am from IP # -
SJ2571
Member@LanceTurner: I'm still a newbie to all this so maybe I have my wires crossed about it all. I've seen diagrams on the net where the solar panels are shown to be connected to the house's power, and then on to the grid after that. That's what I meant by "to me and not the grid", eg. imagine "unclipping" the cable from the house to the grid, and leaving only the panels connected to the inverter to the house. Isn't that correct?
Posted Monday 2 Aug 2010 @ 1:23:45 pm from IP # -
SJ: You can't disconnect the modules/inverter from the grid. The grid interactive inverter requires the grid to be connected or it shuts down to protect other grid users and power company workers during power outages. Put simply this means that if you switch off the circuit breakers that connect your system to the grid your system will shut down immediately for safety reasons.
As you have IT skills why not look into accessing the data that almost all grid interactive inverters produce so you can observe how your system is working on a real time basis.
Posted Monday 2 Aug 2010 @ 9:46:52 pm from IP # -
Benny
MemberSorry if I offended you SJ - but your questions do sound odd to me and to others if you look at their replies - I hope we can explain the situation to you better.
Your power will not go to the grid if you are using it all. Just because you are connected to the grid doesn't mean all your solar power goes there. If you generate 1.5kW and you are using 1.5kW then nothing will go to the grid. There will be no nett export. If you are generating 1.5kW and using 500W, then 1kW will be exported. There's no point disconnecting from the grid and stopping that power going to the grid i.e "going to your house only". If you did this you'd just be wasting the extra 1kW - it wouldn't go anywhere. You wouldn't be "using at you see fit" as you wouldn't be using it at all. The panels + inverter would just adjust to only output 500W. As Lance said if you had batteries you would dump the extra 1kW in to the battery array but you can't do that with a grid connect system.
It can be confusing reading a power bill - like we get here in WA - because it only shows power imported from the grid and nett power exported to the grid (and even more confusing refers to that as Renewable Energy Consumption). It doesn't show the power generated and immediately/directly consumed on site.
You always have control over how your generated power is used. If you have a need for power and turn something on, you will use the solar power if it is being generated. If you don't have any need for it, then it will be exported.Posted Tuesday 3 Aug 2010 @ 2:12:32 am from IP # -
SJ2571
Member@Benny: Now I'm REALLY confused.
You said: "If you generate 1.5kW and you are using 1.5kW then nothing will go to the grid. There will be no nett export." I'm in NSW. I was under the impression that all generated solar power goes to the grid, and not to my house. But you're saying my house will use what I generate first and THEN send the surplus to the grid? Isn't that a net metering situation? NSW is gross metering only. Confused now.
Posted Tuesday 3 Aug 2010 @ 3:27:16 am from IP # -
termite
MemberNow I'm confused - but then I don't have a PV system (yet).
I think that the power you generate actually (physically) goes to you first, but for the purposes of paying you a different, higher, rate for the renewable energy you produce versus the price of the power you use, the meter logs separately how much is produced and how much is used. This is the advantage of the gross metering over the net metering.
Of course, the meter may be separately recording only (1) the excess power added to the grid and (2) the amount taken from the grid at other times when your usage exceeds your production. Either way, it's for costing only, not the physical state of affairs.In the physical sense, it is more efficient to generate power close to where it is used, as the longer the wire, the greater the power loss. This is why nuclear power stations can't be sited in the middle of nowhere - they would waste too much power.
Now that may be good for user costs (for those whose PV system is just a means to lower power bills), but it isn't right by me - I wouldn't want to be 'using' power at the cheaper rate for non-renewables. Any power that I drew out of the grid I would want to be produced by other renewable sources.
Posted Tuesday 3 Aug 2010 @ 4:35:43 am from IP # -
Jeffbloggs
MemberSJ: If your metering is gross in NSW the feed in tariff (FIT) should be applied as follows:
- Any solar power generated (regardless of who uses it!) will be paid at the FIT rate
- Disconnecting a solar system from the grid will result in you no longer getting the FIT at all which in most cases is counter-productive anyway, as grid dependent systems rely on the grid for synchronization (ie 50hz)and will not operate in islanding mode.Dual system inverters (parallel and islanding)are available from Xantrex, Selectronic etc however are normally considerably more expensive as a system especially so if including batteries. However these dual mode systems will allow you to do the following (and this might just be the "hack" you're really looking for!!):
- Use the solar/inverter/battery setup as a UPS (uninterrupted power supply) for when the grid goes down
- Allow you to specify the period in which to import/export power to the grid according to the best on/off-peak rates should they apply with your retailer
- and if so; Allow you to charge your batteries from the grid off-peak and resupply this power back to the grid on-peak for a profit. Now I say profit, because economically it can make sense to do so, especially if you can buy at 10ckWh and sell at 60ckWh. Efficiency wise you will obviously not gain anything, and expect to lose 15-30% through the conversion process, but economically this works out to a cost of 13ckWh including the loss vs 60ckWh, so a net gain of 47ckWh. It is also clear that this energy resupply will most likely not be renewable (unless you happen to be a wind farm) but the inventors of the scheme tend to lend a blind eye to this method as it is costly (but still viable if you have the right system and cost) and they only accommodate small generators up to 5kW which means that nearly nobody will try it anyway. The trick here is that the FIT generally applies to anytime of the day, whereis the off-peak rate is at night, so you can have quite a small battery pack as you can quite literally import one hour at 7ckWh and export at 60ckWh the next. Get some LiFePo4 batteries with high charge/discharge rates to do this.
- however possibly the best part is that you can install more that the rated 5kW in solar, as the amount you export to the grid from a 5kW solar is typically only 20kWh per day (40kWh max) but your connection point will accept 120kWh per day under the scheme if you can spread the energy export over 24hours via the batteries. Economically, a decision would have to be made on which combination of PV/batteries is most effective to achieve the desired outcome. But keep in mind your max return per year per 5kW connection point is about $26k, compared to a $4.4k return achieved by a single mode, parallel export solar inverter.
- BTW check with your retailer/regs etc before connecting any equipment/batteries.To all "tree huggers" out there: Do not confuse the "green feeling" you get by installing solar system on your roof with being environmentally friendly, solar PV take up to 7 years in Australia (12years in EU)just to recoup the energy that was necessary to make the PV cell in the first place, any other system components will add to this. Even commercial wind takes 3-4 years. The fact is that with the current pricing of fossils, renewables can nearly never afford to produce renewables, only fossil fuels can do this economically. (this is possibly why BP is one of the biggest produces of PV!) So any solar should be considered a "solar activated battery" which will give its energy back in the first 7 years if you leave it lying in the sun, and should it survive past then, it will start reducing emissions. A recent EU report calculated the CO2 emissions produced by each energy source over its lifetime and the outcome was that solar produced 101g/kWh an natural gas 148g/kWh, using CHP natural gas was only 49g/kWh. On top of that, producing renewables with fossils is bringing the fossil emissions of the future to now, instead of leaving them in the future.
So take your pick which you think is greener...The irony is that we are nearly exclusively relying on the climate to combat climate change...
Posted Tuesday 3 Aug 2010 @ 5:55:47 am from IP # -
gully
MemberI've hesitated writing in this post because of the senseless nature of the question, but time to jump in ...
Whether you are on a NET or GROSS tariff, physically, any energy usage in your house will use power generated by your PV panels before it is physically exported (electricity follows the path of least resistance).
In NET tariff, the export counter only clicks over if you use LESS than you generate.
In GROSS tariff, the export counter ticks over for whatever power your PV panels generate - REGARDLESS of your own energy usage inside your house.Clear 'nuff?
Posted Tuesday 3 Aug 2010 @ 6:56:13 am from IP # -
cool at home
MemberJeffblogs, re your comment that PV panels take up to 7 years to repay their embodied energy, there are a sea of comments in this and other forums, and of late I've never seen figures anything like 7 years - more like 2 years.
Posted Tuesday 3 Aug 2010 @ 11:17:21 am from IP # -
guy
MemberAfter my solar panels are installed, and connected to a gross meter, is it legal to pay an electrician to "hack" or "mod" the install so that the power generated goes to my house only, if I wanted? Just out of curiosity. I don't see why not, as a man's home is his castle and he can do whatever he wants to it.
Guy: Your last bill was $20 for 91 days? Sounds great, but can you please tell me a little more about yourself. Do you live alone? What devices do you use (PC, Plasma TV, etc)? I have a wife and 3 kids at home fulltime, so I doubt my bill would ever be that low.
.....
theres a problem! no electrician will "hack" a solar system because the law says you can't. an inverter needs a system frequency, you might be able to hook up a signal frequency generator to spoof the 50hz supplied to you but this will make the government very sad and you'll be slugged with fines and a court appearance if you try doing this.
the thing is this, the laws that surround electrical work came about because people were being shocked or killed, pets etc or houses were being burnt to the ground, its very important that stuff is wired safely or you start creating incredibly dangerous situations.
just get the system wired up as per normal it will save you money and grief in the short and long term (i am an electrician)
house details
2 people
pets
lcd tv (big)
laptops (not desktops - they suck power)
heat pump hot water system
new fridge more efficient than old one
1 kw solar system (sunpower solar cells, sunnyboy inverter 4600 after rebates)
there's a reason i chose this set up, the company making the equipment has been around for a long time and they are not made in china, it is my opinion that like most chinese stuff most of it will be dead in ten years whilst mine will still be working.the cells normally make around 125 dollars a quarter so you are looking at 500 dollars credit a year. ten years from now the system will have paid for itself in queensland.
if you want to save money you must turn off all standby stuff, don't allow anything to be left on when you aren't using it. try lcd tvs not plasmas. laptops use a lot less power than desktops, those things are like running a 150W bulb - then imagine them on most of the evening.
air con - we only ever use it in summer (north queensland) in the bedroom and of a night, the doors are sealed up.
we have fans on during the day only where we are sitting etc.
if i can get my act together i should have some extractors to suck any hot air out of the house. i am trying to grow some bushes to shade the house during the day. i have been mulling over getting some insultech to coat the roof to stop the roof turning into a griddle and heat the house up.
a few years ago we were living at the gfs parents a few years ago, in that time their powerbills fell!! i used to go around switching stuff off!!
Posted Tuesday 3 Aug 2010 @ 11:54:38 am from IP # -
Jeffbloggs
Member@ cool at home
about the 7 year PV LCA
It all depends on who you ask. The common misrepresentation is that the majority of studies don't include the energy used to produce the actual silicone, as the silicone used in PV comes predominately from waste micro-electronics parts. The few that do, have no firm standardized methodology to calculate this. It's like comparing apples to pears and every manufacturer will have different assumptions and procedures. Chk out this link showing various studies to make up your own mind: http://energybulletin.net/node/17219 There are some on there that claim up to 25 years.Don't get me wrong I am not claiming that solar PV is bad for the environment, just not the best renewable resource.
I always say "Nobody on the planet uses electricity directly, they all only use the effects thereof"...so unless someone figures out how to plug a human into a PV cell I can only recommend looking for an alternative, preferably one that tastes better
@ guy
Which law would that be in breach of??
- The Electrical Safety Act are Regulations to make sure Electricians like yourself act responsibly and safely. It also provides consumer protection by requiring electricians to be registered, licensed and educated. It should not be construed to invoke fear and terror in forum participants to conform to normality....:)
- The only reason why you need an electrician is because of the electrical network's low 50Hz frequency. Would the system run on 1kHz or above, instead of the 50Hz frequency our bodies operate at and are susceptible to, we wouldn't have to be worried about electrocution, because the electrical current at 1kHz and above would produce a corona around our body and go straight to earth. I agree that 50Hz and below is a killer, but the only reason we have it is because our AC father Nicolai Tesla, who built the first AC transmission lines was limited to running the Hydro generation at Niagara falls at 1800 revs (which is 60Hz), otherwise the bearings on the geny would go. The European system we have hear in Aus went to 1500 rev or 50Hz, just so the manufacturers could control the generator/appliance market independently from the one in the USA.
- SJ clearly said it was not meant to be an illegal hack, rather a way to improve what he wanted to get out of his system. BTW there are inverters that allow this as per my post further up. All I can say there is, good on him and keep on trying to make things better. Be safe;)Posted Tuesday 3 Aug 2010 @ 5:24:11 pm from IP # -
guy
Memberit is illegal to do electrical work without training and hold an appropriate licence
anyone with training would see a problem with the original idea, i'm all for original thinking but he'll only cause himself problems in every way.
a normal solar system will power the house during the day anyway, if you are using less or equal to the power generated by the cells you are not using any power from the grid!!!
if you are generating power and some of it is going out on the grid then you are also being paid for it its a win win situation.
as a point of interest we use AC because when power was first generated they found that AC was the best way to do it with the technology of those times. its easier to modify the voltage of the system from generation to load using transformers (the big humming blocks of steel and copper you see in the streets in green boxes or on the side of power poles).
nowadays we have better technology and over distances of 100km i think DC is actually the better way of transporting power. (no coronal effects or skin effects or induction/ capacitive issues)
Posted Wednesday 4 Aug 2010 @ 11:01:34 am from IP # -
Jeffbloggs
MemberGuy what the??
Do you really hold an electricians licence or are you pulling our leg?
DC is better over 100km?? You sitting a potential copper mine site or something?Quick question to test your knowledge of AC: where abouts do you think the neutral from the fuse box goes down the mains? Generator, transformer, or earth?
Posted Wednesday 4 Aug 2010 @ 11:45:45 am from IP # -
RoBo
MemberSeems to me there is a way around the problem of supplying your own house with your own electricity and even avoiding the use of an electrician.
Wire the house for a 12 volt supply. No electrician required if there is no connection to the AC system. Most panels can deliver 12 volts regulated DC. You will need a couple of 12 volt batteries preferably high capacity/longlife variety. Something like that which is used in mobility vehicles would be suitable. Now you can buy 12 volt light bulbs (used for caravans etc) that are the low energy variety and simply have all your house lighting running off DC. Wire up the house with a new set of sockets and 12 Volt bulbs. You could run in tandem with your AC lights so that you could use your 240 volt lights if you had a week or two of overcast weather with no recharge of your batteries. It wouldnt be too difficult to hook your cars alternator 12 volt charging system to the battery as well and then you could use petrol/ethanol to charge up your battery when the sun doesnt get out of bed....Posted Wednesday 4 Aug 2010 @ 12:35:47 pm from IP # -
Jeffbloggs
MemberYou can do this up to 50V in WA. In fact if you want to, according to the regs you can use a step-down and step-up transformers to go mains 240V - 50V - 240V or even 10Kv if you want without breaking the regs. CHK out what this guy does with it down in Busselton WA: http://tesladownunder.com/Misc.htm
Posted Wednesday 4 Aug 2010 @ 12:44:58 pm from IP # -
Benny
MemberJeffBloggs - calm down re Guy the electrician. He's sort of right re using DC for long distance transmission but the distance is more like 500km and not just 100km. There are long distance dc transmission lines in operation everywhere - e.g. Vic - Tasmania. They still use very high voltage dc to get over the IsquareR losses. The reason for using dc is not that its necessarily more efficient, but over long distances there are problems with transmission line effects even with low frequencies like 50Hz.
And I fully agree with Guy re "hacking" the grid connect solar system. You could be in serious trouble if you tried to get around the safety measures built in to the systems currently used, principally to make the solar inverter shut down if the mains is ever cut off. The electricity supplier workers fixing problems out on the main lines don't want your solar system keeping the lines active. There are apparently solar inverters/systems that can be set up to keep operating when the grid goes down but these are much more expensive than the standard grid connect inverter. It sounds like it should be easy to keep your inverter running if the grid goes down - and disconnected from the grid - but someone more knowledgable than me ( I hope) has decided its not safe.Also JeffB have you got any more info' on this idea that solar PV cells are made from recycled silicon? (not silicone thats the sticky stuff for sealing gaps). I've never heard of any attempts to recycle chips. The chip in an IC is usually only 1-2mm in size and completely polluted with dopants etc to make it work. I can't imagine anyone going to all the trouble to break open the packaging to get out that small chip and then have to refine it back to pure Silicon. Much easier to start from scratch with SiO2 especially for the big amounts of Si used in solar cells.
Finally regarding electrical safety, I think the principal reason that you need to be licensed is the voltage not the frequency. Thats why you can work with 12V whatever frequency it is. Over 100V you start to get problems with the bodies resistance, where that voltage can cause currents of about 20mA which is just the right amount to cause fibrillation. I don't think I'd be willing to handle a circuit of 250V just because it was 1kHz.
Posted Thursday 5 Aug 2010 @ 1:54:29 am from IP # -
Jeffbloggs
MemberBenny
This Australian University study explains the recycled silicon further (aye no sticky stuff this time, what a difference a single letter makes!). They also claim 7 years for PV and 8-11 for total system if installed in Sydney. http://www.ecotopia.com/apollo2/pvepbtoz.htm
It is an older though, but it should point you in the right direction to find out more about the silicone recycling process. I believe it is the low grade reject ingot that is purified and recycled, and this would happen long before they would be "chipped" and packaged in plastic to be sold as ICs. As I tried to explain further up specific manufacturing data is hard to come by, as this is generally not available from companies interested in selling PV.In regards to the electrical safety I would like to make some general comments about electrical networks, island and parallel modes:
- in a parallel network type arrangement (the most common PV installation method) the inverter physically needs to read the 50Hz from the network side, in order to produce a synchronized AC current with the grid. The inverter has no "own" oscillator to drive the inverter in sync with the grid, hence it is not possible to run such a parallel inverter without the 50Hz pulse. This is similar to old LED clock radios that always lose their time when theres a power failure or you unplug them. This type of clock does nothing else than count up to 50 AC cycles and then add a 1 second increase on the display. It then just keeps on counting for minutes and hours. Try plugging a US one in via a step down transformer and you will find that time slows down..this is the easiest time machine I know of
BTW this is also were the old style TV sync comes from.
Another way to look at synchronization on the network is to imagine marking every generator armature and stator whilst stationary, and then start up the network. You will find that all alternators are rotating at exactly the same speed ie the marks will pass each other in synchronization with all other alternator marks(if they have the same pole configuration). A inverter needs this "mark" to synchronize to the grid otherwise it is impossible to export to the grid. Trying to feed in out of sync is the equivalent of electro-mechanically trying to force the other generators to speed up/slow down and will result in spectacular failure of the tiny inverter. Commercial non-inverter and gearboxed Wind Turbines display this effect of synchronization clearly. It is one of the reasons Enercon decided to use inverters, without any gearboxes to fully utilize the power of the wind. The ones with gearboxes generally have two alternators that they switch between for different speeds, and will only operate at either speed regardless of the wind. My point is it will not work to mod such an inverter to make SJ's original proposal work without serious interference with the inverter itself. That is why I did not in any way promote it, I did however proceed to recommend how he could achieve the desired effect, as I described further up in this thread.- The islanding/parallel system, that I proposed, uses both internal and external timing for synronising to either the grid or to operate itself in islanding mode, isolated from the grid. This system even includes some benefits that no-one seemed to have an opinion at all, which I find a bit disappointing. But a dual islanding/parallel system can be profitable if some intelligent manipulation of the system is used. Remember the return on investment is a function of money, not of energy. A FIT is designed to provide an economic stimulus to consumers to install renewables, I see no harm in making use of such stimulus to the fullest extent in order to provide more power to the network from RE. In regard to using storage to take advantage of the off-on-peak periods, this is not counterproductive if alternating between tariffs. For further info on this chk out the plans of Shai Agassi and his electric car buffered, movable capacity network.
In regards to the DC transmission, these are primarily used for long undersea and out of sync connections. AC will only go 30km or so underwater. BTW I'm generally opposed to centralized generation and distribution. A locally sourced, distributed generation system requires little long distance interconnectivity. But now I'm beating my own drum...chk out Biogas systems in Germany, they achieve exactly that, with many more benefits than any other renewable I know of.
Defibrillation usually uses around 1000V and once used a single Lown waveform before they introduced Biphasic defibrillation. The original 50Hz power point versions only had very limited success, and only managed to cause serious burns and muscle damage in most patients. Frequency is key when dealing with high potentials, check out some history and achievements on Tesla the inventor of AC.
Posted Thursday 5 Aug 2010 @ 12:12:43 pm from IP # -
Benny
MemberThanks for the references on PV energy payback time. I see the conclusion of the big review and investigation was "about 4years" and as they said - thats without the improvements in panel assembly and mounting requirements we've seen recently.
I was confused by your original statement "silicone used in PV comes predominately from waste micro-electronics parts" but after reading the papers you referenced I now understand. It seems to be that there are "under-spec" silicon wafers produced by the standard processes ie not good enough for the IC industry. These can be re-treated to produce PV cells but some are good enough to use as is. So in a way its good that PV systems are so popular now as they will make use of a product that maybe was being rejected completely before ? I suspect though that manufacture of pV cells is so large scale now that its comparable to the IC industry requirements and so they can't just use reject wafers - anyone know anything about that ?Posted Thursday 5 Aug 2010 @ 12:37:03 pm from IP #
