How are those handled by the inverter, that's more than the usual two strings.

neb:

 

How are those handled by the inverter, that's more than the usual two strings.

 

The North facing panels are grouped as a 5Kw set and is one of the 2 inputs to the inverter, I call them a string.  There is a joining Box, had a special name, gets the input of the 7+3 East facing and the 7+3 West facing panels. That group of 20 panels , due to the 15deg roof pitch, become a peak of 8kwh string.  The inverter is a DC input and 3 phase output. The inverter is  Fronius Symo 15Kw Inverter.  

Sorry I do not know enough about the technical side of things, but they have done a few upgrades with the software and have been improving the efficiency with regards to shaded panels. 

We do the history check of what it makes in a month and I have a spreadsheet that I download the data from Meridian, and I download the data from Fronius and compare that they are closely related. As long as they are within 10kwh per month I am happy. But they did change both of my meters in the main meter box, as the numbers from the Fronius system data, was a long way different to the Meridian  data. It turned out that Meridian  were not reading all 3 phases correctly. But it is all sorted now and all is working very well.

The inverter can also handle  34% over its rated 15kw, and can handle a peak of 20kw, but we have only seen a peak of 18000 Watts in December.

LightbulbNeil:

 

This is the layout we used. Inverter is on the outside wall by the back door to the cloths line.

 

They are quite noisy during the day, and being outside , does not effect us. The sound level at the fence is lower than the noise of the neighbours heat pump unit when it is going. So was happy about that. East and West facing panels are in 7 and 3 split arrangements. The group of 8 and then 2 below, are North facing. At 4pm today it is only making 1kw with no clouds, but is being shaded by the house next door. The centre set of 10 panels, could have been elevated to being at 35deg with a 20 deg frame, but I was more concerned about what would happen in a rare very high wind situation.  The installation went very well and was installed in 1 day. Everything was done very neat and tidily as well.

 

 

 

 

Hopefully the picture is available for all to see.

 

Jealous of these incentives being offered in NSW for battery installation. https://www.solarquotes.com.au/blog/nsw-battery-subsidy-mb2928/

It would be great to have a government here that actually realised the potential of getting distributed generation onboard for addressing grid demand. 

HarmLessSolutions:

 

Jealous of these incentives being offered in NSW for battery installation. https://www.solarquotes.com.au/blog/nsw-battery-subsidy-mb2928/

 

It would be great to have a government here that actually realised the potential of getting distributed generation onboard for addressing grid demand.

Our government's focus is almost entirely of expenditure reduction so that it can afford the tax cuts it promised to give, so a scheme to pay householders to have batteries for their PV systems is a low priority. The proportion of NZ houses with PV systems is much less than in NSW - I believe it's something like 30% of houses in NSW, so this would be less generally useful, and I'd guess that having PV panels might be seen as a dangerous sign of Green Party sympathies too.

More importantly, the whole Australian electricity grid from Victoria & SA through to Queensland is in desperate straits.
Their big coal-fired stations are at or past the end of their economic lives, and since they were all privatised their owners see no commercial reason to keep them going: most will be shut as soon as 2030.
They also privatised their high-voltage grid in piecemeal fashion, so that there's less coordination and less ability to build lots of new interstate links which would enable switching of renewables around from places with lots to places with less.

NSW really needs household batteries, NZ doesn't have the same urgency

So first month with solar and its done what it said on the tin.

We consumed a total of 1316kWh of power in May
of that, we directly consumed 361kWh from the solar, so we used 978kWh from the power company.
We exported 374kWh to the grid. This is at 12c/kWh

We imported 640kWh during the day (7am-9pm, @24.34c) and imported 337kWh at night (9pm to 7am @11.06c). So our exported power completely covered our night power, which included all the car charging.

I estimated the bill would have been about $340 without the solar, so we are down to about $210 so about a 40% saving off the bat.

Not bad considering it's almost the winter solstice.

@Jase2985, Interested in what your total generation for May was so as to compare with our similar sized PV system.

Jase2985:

 

We imported 640kWh during the day (7am-9pm, @24.34c) and imported 337kWh at night (9pm to 7am @11.06c). So our exported power completely covered our night power, which included all the car charging.

 

Oh I'm jellious of those rates.  11c night rate is half my 'half price nights' rate on Octopus (20.54c).  Is it really half price?  More like normal price nights and double price peaks.  Guess you are on standard user and ev tariff? which provider if you don't mind?

HarmLessSolutions:

 

@Jase2985, Interested in what your total generation for May was so as to compare with our similar sized PV system.

 

Exported + directly consumed in the previous post

734kWh, the east facing panels (117 degrees) on my setup are not contributing much at all, its the west facing panels that are doing all the heavy lifting

dantheperson:

 

Oh I'm jellious of those rates.  11c night rate is half my 'half price nights' rate on Octopus (20.54c).  Is it really half price?  More like normal price nights and double price peaks.  Guess you are on standard user and ev tariff? which provider if you don't mind?

 

Im with Meridian in South Auckland. My night rate is half of the day rate, and the decent sell back means I can use the grid as a battery.

If you have a battery back up,  What size battery did you go for ?  What do you have connected to that phase that the battery is working on?

I am looking into some battery back up options , as there was a fairly long power cut last night and into today.

I am thinking of the refrigerator, house lights, and power for the gas hot water to light. 

What are thoughts about the battery back up so far?  

Through facebook I am getting adds all the time promoting solar with a battery backup, and not seeing much about the cost and the actual lifespan of the batteries. 

There was talk 3 years ago about the hybrid battery super capacitor, but again no prices of those either seem to show up in searches.

On an overcast day like today, it looks like the east west group of panels produced a little more than the North facing array, but they matched very closely together their time of starting to make power and when the slowed down during the day etc, which was not something that I had looked closely at until this evening.

Any info and opinions will be appreciated.

Neil

LightbulbNeil:

 

If you have a battery back up,  What size battery did you go for ?What are thoughts about the battery back up so far?  

 

Any info and opinions will be appreciated.

 

Jase mentioned he was using the grid as a battery, but seen as you asked for opinions....

Commercially available home batteries aren't viable from a financial perspective, and the prices need to about half i reckon to make it worthwhile.  Even on a Time of Use plan, say Octopus Low User, you are gonna save max $40c/kw on peak by either self consuming which just isnt gong to pay itself back over the life of the battery.

So it's a question of how much do you value that backup in a powercut function?  And what are the alternatives, like a small generator with a few extension cords for those rare power cuts.  Depends how often it happens at your place, and depends what you need to keep running.

I've been following Dala battery emulator project, where you can take a worn out Leaf battery or crashed Telsa battery and hook it into a hyrbid inverter.  On trademe you're looking at $2.5K for a 24kw leaf battery at 70% health from the wreckers, or $10K for a 60kwh Tesla near new.  So that's about $150/kwh of storage.  Best case, say you cycled that 80% a day for ten years.  1kwh*0.8*365*10 = 2920 kwh.  $150/2920kwh = 5cents/kwh charge to store.

But I figure that will void your warrenty on the inverter, from the installer, and probably your house insurance too.  If someone ever comes out with a certificed device that allows you to clip in used EV packs they will make a small fortune i recon.

Thanks for the reply. A generator for the small time frame may well be the answer. Some cars do allow for them to power a circuit in a house to 3 kw, but not buying an ev just for the convenience. 

Jase2985:

 

So first month with solar and its done what it said on the tin.

 

We consumed a total of 1316kWh of power in May
of that, we directly consumed 361kWh from the solar, so we used 978kWh from the power company.
We exported 374kWh to the grid. This is at 12c/kWh

 

We imported 640kWh during the day (7am-9pm, @24.34c) and imported 337kWh at night (9pm to 7am @11.06c). So our exported power completely covered our night power, which included all the car charging.

 

I estimated the bill would have been about $340 without the solar, so we are down to about $210 so about a 40% saving off the bat.

 

Not bad considering it's almost the winter solstice.

 

Generation 784 kWh

Total consumption 935 kWh

Self consumption 604 kWh (77%)

Import from grid 330 kWh

May invoice ~$95 (incl. $32 daily supply charge) Our Octopus account runs from 16th month so this is from Solar Analytics but within a $1 or 2.

We're charging a Leaf and a Polestar2, house water is pumped, we have a logfire for home heating and our HWC is controlled by a Paladin diverter.

We're missing some early morning sun recently due to tree shading but otherwise 9.5kW of PV north facing with 39 degree slope feeding an 8.2kW Fronius single phase inverter limited to 5kW export. Best day's production we've seen so far was 63 kWh in early January.

HarmLessSolutions:

 

For side by side comparison of our similar sized systems, both without battery storage our data for May was:

 

Generation 784 kWh

 

Total consumption 935 kWh

 

Self consumption 604 kWh (77%)

 

Import from grid 330 kWh

 

May invoice ~$95 (incl. $32 daily supply charge) Our Octopus account runs from 16th month so this is from Solar Analytics but within a $1 or 2.

 

We're charging a Leaf and a Polestar2, house water is pumped, we have a logfire for home heating and our HWC is controlled by a Paladin diverter.

 

We're missing some early morning sun recently due to tree shading but otherwise 9.5kW of PV north facing with 39 degree slope feeding an 8.2kW Fronius single phase inverter limited to 5kW export. Best day's production we've seen so far was 63 kWh in early January.

 

You are making about 50kWh over the month more than me, 1.6kWh per day. 

On my east facing array (3.3kw panels) im seeing a max of about 1.4kWh at 1030am, but i dont think its adding more than about 3-4kWh on a good day due to the low sun and the direction of the panels. I think they will come into their own in summer and really broaden my power curve, but they aren't doing much going into winter.

We are a fully electric house. We have just had to upgrade our dryer, which was 15+ years old, and got one with a timer which will help move some power round, next thing will be installing a hot water cylinder timer to have that heat at night.

dantheperson:

 

I've been following Dala battery emulator project, where you can take a worn out Leaf battery or crashed Telsa battery and hook it into a hyrbid inverter.  On trademe you're looking at $2.5K for a 24kw leaf battery at 70% health from the wreckers, or $10K for a 60kwh Tesla near new.  So that's about $150/kwh of storage.  Best case, say you cycled that 80% a day for ten years.  1kwh*0.8*365*10 = 2920 kwh.  $150/2920kwh = 5cents/kwh charge to store.

 

But I figure that will void your warrenty on the inverter, from the installer, and probably your house insurance too.  If someone ever comes out with a certificed device that allows you to clip in used EV packs they will make a small fortune i recon.

 

That is interesting, haven't seen that one before but looks good with some of the BMS stuff out there for the batteries it seems like there are some viable solutions out there for a decent sized homemade battery.