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Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 01:29
by gttool
Hi Everyone,
In the market for a pv grid connect system does anyone have anything good or bad to say about different panels or inverters ?
Are peoples systems producing the output that you expected ?
Will most probably get a 2kw CMS system but would hopefully end up with 4kw that would supply enough to balance our power bill !
Open to suggestions, i am aware that the Sunny Boys are very reliable but not available at the moment

Thanks Geoff

Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 03:24
by lithbattboss
Hey Geoff,

Last week I dropped off a dozen LiFePO4 battery packs to a customer in Lane Cove as part of his solar system for his house. The owner is retired from the CSIRO and has worked out a complete solar system for his home. Recently he had 1kW of solar panels installed and then added another 1.7Kw of extra panels. He has two Sunnyboy grid connect inverters connected to the panels so they are set up as two separate systems.
He plans on charging the lithium batteries not from the solar panels but from off peak grid power at night and feeding this power back to the grid along with any excess power from the solar panels during the day. That way he buys the power cheaply during the night at off peak rates and gets paid the maximum amount for feeding back to grid at peak demand times during the day.
He has been very happy with the system so far and it is still a work in progress. Below is a photo of the owner after I delivered his LiFePO4 battery packs. As you can see his "Solar Lithium" grin is almost as good as an EV grin!!

Image

Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 18:17
by voicecoils
What are his metering arrangements and does he plan to pump that stored power back in at the 60c/kWh gross feed in tariff rate? Image

Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 19:05
by moemoke
gttool, I have a 1.4kw Grid connect solar system which produces nearly all of our power over the summer, and about half in winter.
We have 8 175 watt BP panel (Aust made, BP have now shifted to India)
with a 2500 watt Sunny Boy inverter, we hope to add 4 more panels to give us 2.1kw which will be great as long as the Govt keeps the FIT
and Origin pay us 66 cents for exported power.
We have had the system for nearly 2 years with no problems. the power does drop of a bit on hot days but it has put out the 1400 max watts
at various times. I have a Sunny Beam data logger which has a daily graph. If I can work out how to post photos I'll post a graph.
The output does vary a lot, on a good sunny day we put out about 8 to 8.5kw over summer, a bad summers day (rain or heavy cloud all day) we put out around 2-3kw. My panels face a couple of degrees east of north
Have a look on these forums for more comments.
http://forums.energymatters.com.au/
http://www.ata.org.au/forums/

Lithbattboss. Is what the CSIRO man plans to do allowable, does he get the FIT for the power from the batteries?
I guess he has done his sums so it could work out quite profitable.


Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 19:13
by Johny
Let's say you store 10kw/hr per night and feed it back during the day. Let's also say you make 60c per kw/hr - that's $6 a day. After 4 years (assuming EVERY day you got the 10kw/hr) you would have earned $8760 and your cells would have cycled 1460 times - probably fairly deeply.
You would want to hope the the Govt. didn't plug that loophole during that time - nor changed the tarrif rules.

Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 19:14
by evric
Yeah, but what did the cells cost?

Grid Connect PV systems

Posted: Mon, 22 Feb 2010, 19:55
by antiscab
when the solar panels heat up, their output falls from specification.
some don't fall as much as others (kaneka modules come to mind, they don't drop output as much).

the solar panels output varies with orthogonal light intensity.
this means, for a fixed array, output will depend upon sun location, as well as how "sunny" it is.

fronius inverters are also fairly good, and more than a few of their inverters have voltage input ranges handy for capacity testing traction batteries.

Matt

Grid Connect PV systems

Posted: Wed, 24 Feb 2010, 02:09
by lithbattboss
voicecoils wrote: What are his metering arrangements and does he plan to pump that stored power back in at the 60c/kWh gross feed in tariff rate? Image


Yes the plan is to feed as much power back to the grid and be paid the max rate of 60c/kWh.
I was told that Energy Australia need to replace his meter shortly.

Grid Connect PV systems

Posted: Wed, 24 Feb 2010, 02:28
by photomac
I have had Solar Shop's Kaneka/Sunnyboy system for just on 14month.
Brilliant system, brilliant service. (No - I have no connection with Solar Shop - just a very content customer)
First rule - look at their warranty periods. Inverters in particular. Indication of a proven model. A good system will have 5years on the inverter and 20 to 25years on the panels.
Be aware of ratings - many are optimistic.
Poly and Mono crystalline panels will use half the area of Amorphous but will be same dollar per watt.
Poly and Mono panels will rate their power at 20 or 25 degrees - not ambient but panel temperature. Their efficiencies DECREASE at approximately 1% per degree above 25degrees. In summer the panel surface can be 55degrees celsius.
Amorphous efficiencies will INCREASE up to about 45 degrees celsius.
Another advantage of a larger area is the benefit of a "tropical" roof cooling effect. The roof is shadowed decreasing heating of the roof space.
Yes- you do need an appropriate size roof - then Mono/Poly panels are appropriate.
look at the Sanyo Hybrid HIT panels (now owned by Panasonic) which combine the best of both worlds.

I estimated an annual generation of 45% of consumption - it has achieved 56%.
Unfortunately I have a salt pool which pretty much takes up the energy.
It is rated as a 2.14kW array with an inverter for 4kW for expansion (immminant).
In summer I typically generate 16 to 17kW per day with a regular 2.3kW peak generation. After a cold front with a cleared and clean sky I have observed a generation capacity 2.6kW.
In Winter, on a clear day it would typically generate 7kW per day.
It generates about 250W from ambient light before the sun's rays have line of sight - hence it has generated 3kW in Off-Peak.
It is north facing on a 20degree slope.

Also - be aware of the "carbon" footprint of manufacture. Kaneka's is one of the lowest.
Good luck - look out for the ATA website   http://www.ata.org.au/    and their latest magazine "ReNew" has full comparison of panels.
Matthew

Grid Connect PV systems

Posted: Thu, 25 Feb 2010, 01:13
by gttool
Thanks for the responses,
after some discussion would like to go with a SMA 4000TL if i can get one and possibly Kaneka panels i have 72sqm to fit them on
Was going to partly finance them through the green loans program, now it is in a bit of trouble had an assesment 3 weeks ago but has taken up to 6 months for some assesments to be receive ??
Has anyone financed their electric vehicles with this loan ?
Geoff

Grid Connect PV systems

Posted: Fri, 26 Feb 2010, 05:16
by BjBlaster
I have a Latronics Inverter. I love it because it's made from "real" Australian stuff (acquirable), in Australia. Tough as nails.

Image

and some kyocera panels

Image

they seems to work well!

live stats

Grid Connect PV systems

Posted: Fri, 05 Mar 2010, 15:52
by Thalass
I've discussed this with the guys at work quite a bit, and the general consensus is that solar panels still aren't worth it financially. In Europe they pay less than half what we pay over here for the panels, and get very large FIT. Though they have improved in energy output - so they should generate more energy over their life than what was used to build them. haha.

We've come to the conclusion that a solar array is good, but ought to be supplimented with a wind turbine or two. They're cheaper to purchase (or, if you go to www.otherpower.com/ you can build your own) and in Perth at least, the wind is usually blowing, even at night! haha.

You can get a "windyboy" from the same company as the sunnyboy inverter, which can handle both solar and wind (and, I believe, other sources) inputs with all the features of the sunnyboy.

Grid Connect PV systems

Posted: Fri, 05 Mar 2010, 20:49
by BjBlaster
I suppose it depends where you live, as most councils won't let you have wind as it is classed as noise pollution! Also the safety aspect of a 5m pole in your backyard has to be questioned. That was why I built a VAWT and put it straight on top of my shed. It works, but does it discretely.. I think HAWT are just to noisy for urban areas that is why I took mine down before the neighbours/council made me :(

Grid Connect PV systems

Posted: Fri, 05 Mar 2010, 21:45
by Thalass
Yeah, especially in Ellenbrook where you're not allowed to sneeze unless the covenants let you. Image I think technically nothing is allowed to be seen from the road: Aircon, hot water systems, solar panels. Antennas aren't even allowed in my area at all!

I don't know about the noise factor. A small house-scale turbine wouldn't be much noisier than the big rooftop aircon units, i think. Depends on the design, though. i'd like to try it, though. The last thing i want to do is call in sick because my bike isn't charged. Image

Grid Connect PV systems

Posted: Fri, 12 Mar 2010, 17:34
by Peter C in Canberra
Whether PV is financially worthwhile or not depends on where you live. In the ACT or NSW it is worthwhile due to the gross rather than net feed in tariff. That is, all your productions goes into the grid, is metered and paid for. All your consumption comes from the grid and is metered separately and paid for. Your consumption and production are independent, you just produce as much as you have roof for and can afford to buy the panels for. Any reduction in your consumption saves you money just the same as if you had no PVs. You can get a cheque if your sales exceed your purchases of electricity.
PV efficiency declines with increasing temperature but there are more photons in summer. Winter output is less than in summer but not by as much as you would expect because the cooler temp give a small increase in efficiency.
I got 2000KWh in a year from a 1.44KW system in Canberra. Roof angles are slightly off ideal and there was some minor end of the day shading reducing the output from what it could have been. At 50.05c/KWh in Canberra that means $1000/year for the first 20 years. NSW is 60c/KWh for the first 7 years and only up to a cap of some number of installed MWs so get in early! The amorphous panels are suited to locations with tons of area because they are less efficient in W/area. Most houses are limited in suitable roof area so you would probably prefer crystaline or polycrystaline.
The discount on purchase is through the RECs scheme and this was not the ideal way to give an upfront discount. That means that others might be purchasing those RECs as greenpower. The deepest green is to keep the RECs or not claim them. I sold my RECs but then I purchase greenpower for all my consumption. I view my contribution with the panels as adding to the renewable energy total but all the output is effectively sold to others. I am well paid for that and use the money to purchase greenpower for all my consumption, including the car.
There are lots of changes happening just now. There are unintended consequences whereby the small renewables were perversely squeezing out large scale renewables. The proposed spliting of the Renewable Energy Targets into capped large scale and uncapped small scale is a good step and the sooner the Solar Credits mechanism is replaced by a rebate that doesn't involve perverting RECs the better. In spite of the flaws of various schemes there is real movement to improve and I think it is still better to do PVs than not.
Peter.

Grid Connect PV systems

Posted: Sat, 13 Mar 2010, 19:43
by mjcrow
I had a 1.44kW system installed in October 08 by the Solar Shop. It is made up of 24 Kaneka panels (25 year warranty) with the Sunnyboy sb-1700 inverter.
Image

As you can see it takes up quite a large area of the roof but if you consider all the things on this list (linked from http://www.solarshop.com.au/resource-ce ... echnology/)
Image
and you have the available space then the thin film panels are the go imho.

I was very happy with the Solar Shop and would gladly recommend them. Their guide as to how much power I would produce was a very surprising underestimate Image and I usually produce 1 to 1.5KWh per day more than their estimate. My electricity bill last year cost a total of $360.00 and the panels have now made back the energy used to manufacture them.

Michael

Grid Connect PV systems

Posted: Sat, 13 Mar 2010, 19:51
by antiscab
those kaneka's are't silicon cells (gallium arsenide IIRC, far less energy required in production, also much cheaper, i have seen them for sale for US$0.90/Wp)
their peak efficiency is at around 45 deg C, perfect for Australian climate.

It is probable the solar shop used the silicon based cell data to predict energy output.

Matt

Grid Connect PV systems

Posted: Sat, 13 Mar 2010, 21:13
by coulomb
antiscab wrote: those kaneka's are't silicon cells ...

They're thin film amorphous (silicon) solar panels, according to
http://www.solarshop.com.au/resource-ce ... echnology/.

I would think that GaAs would be dearer than silicon.

Grid Connect PV systems

Posted: Sat, 13 Mar 2010, 21:27
by Electrocycle
yes, Gallium Arsenide cells are much more expensive (and efficient) than Silicon.
All the top solar car racers use them.

Grid Connect PV systems

Posted: Sat, 13 Mar 2010, 21:33
by gttool
I think i will end up with Kaneka cells due to their heat tolerance ,64 of them close to 50sqm and a Sb3800



Grid Connect PV systems

Posted: Sat, 13 Mar 2010, 23:44
by antiscab
oops, you're right,
kaneka are a-Si modules.

still cheap and heat tolerant :D

Matt

Grid Connect PV systems

Posted: Fri, 26 Mar 2010, 16:22
by bga
Hi Geoff,

Inverter makers like SMA (sunnyboy), Kaco, Latronics all have a good and reliable product. When I looked about a year ago, the sunnyboy inverters were very slightly more efficient.

There has been some talk about kaneka panels. If the ultimate plan is to have a substantial amount of capacity, the panel efficiency will be important because of the area the panels will need. What Matt says is correct, the (kaneka) thin film amorphous panels are less heat affected than the more common monocrystalline panels, which lose approximately 0.5% per deg.C. On a hot day, this amounts to about 20% losses in the panels.

Moncrystalline 175 watt : ~14.5% efficiency   (7.5 sq.m per kW)
Amorphous (kaneka)      : ~6.5% efficiency    (15 sq.m per kW)

I have a two brands of chinese moncrystalline panels that perform well. These are both 170-5 watt 808x1600mm panels, using 54 x 125mm wafers.

As for price, I would expect a supply only price for 175 watt monocrystalline panels (808x1600mm) should be no more than $650 each, or 3.70 per watt. (I have been quoted 575+GST) More than this and your suppier is ripping you off.
Amorphous and thin film panels are cheaper per kW. I would expect $3 per watt to be achievable in AUS today.
look at solarbuzz.com for current market trends.

There are a lot more suppliers of mono panels so the prices are going to be more honest.

One way of looking at the temperature coefficients of mono panels is that the losses are mostly in the summer peak, when the system is collecting a lot more sun.

The big retailers in AUS are mostly very poor value and should be avoided.

I would not over size the inverter greatly. It will be more efficient if near to its capacity and cheaper. I would expect that 1.5 or 2KW inverters will become the commodity items and be proportionally cheaper than other sizes. They can be paralleled or put on different phases.
It may be worthwhile looking at two inverters.

It's important to do a roof plan that accomodates the future panels, as the installer will put their first set right in the middle and it may complicate extension later.

[edit:added]
Ultimately, thin film will be the winner because of the construction costs of the panels. One newcomer worth following is nanosolar. They are using a printed seliconductor ink technology on aluminium foil. They currently achieve ~7% efficiency and have built test cells up to 14% efficient, indicating that they will likely be a better option than moncrystalline panels before too long.


Grid Connect PV systems

Posted: Fri, 26 Mar 2010, 18:05
by Johny
Thanks for that info. bga. We plan on going into a deal with Eco-Kinetics in the next couple of weeks. I hadn't thought about leaving (usable) space on the roof for more panels - excellent point - thanks again.

Grid Connect PV systems

Posted: Thu, 01 Apr 2010, 05:47
by acmotor
Some info on FITs in Oz

In WA we are still waiting for an FIT (July 2010 ?)
Net and limited to 5kW (drat !) is likely.

Ok, Questions....
Is the 5kW the 'nominal peak system capacity' although you can have a bigger system or export more. How will the authority know if you increase the system capacity ? Or will there be a maximum daily feed in of kWh ? It seems wind power is done that way as it can blow 24/7 in places.

It seems a safe option for govt having net FIT rather than gross as many PV systems will export little if any power in a 'normal ?' household of 20kWh+ per day. (10+ in the EV)

If you have 3 phases and you feed all you grid connect power out one phase at 60c/kWh FIT and draw your house power off the other two phases at 7 to 37c/kWh then does that help to get near a gross tarrif ? Image
Mind you the weekends are the only sunny off peak times.

Grid Connect PV systems

Posted: Fri, 02 Apr 2010, 00:32
by antiscab
i was wondering how they were going to enforce the 5kw rule aswell.

the TOU meters we have now sure can't do it.

Matt