Jason's system

[koputai]

Like a lot of people, I've looked at getting solar installed a few times over the past fifteen years. Up until recently, the payback wasn't there in a timeframe I was happy with. Last November, I thought it was about time to get it done, before the providers started refusing installs as they are in some areas.

 

I looked at both string and micro-inverter systems, and as my roof is north facing (points 9 degrees east of north, inclined at 23 degrees), and totally unshaded, a string system was a good option.

In late November 2019 I had a 8.58kW system installed using:

26x QCells Q.PEAK DUO-G5+ 330 Watt

Fronius Primo 8.2 inverter

Fronius Smart Meter

 

The 26 panels are in two strings of 13 panels each. The Fronius Smart Meter is installed at the feed-in point, which gives some very useful data in relation to consumption, feed-in to the grid, usage from the grid, self consumption from the solar, as well as other data. This is all logged in five minute intervals on SolarWeb (the Fronius cloud), and I also have custom reports set up to give me all the data I need for my rather comprehensive spreadsheet. As of today, in the seven months since it was connected, it has produced an average of 33.6 kWh/day, and paid back 14.7% of the total installed price. 100% payback should be less than four years.

 

I've also bought another three Fronius Smart Meters, which will be installed on several power circuits so I can do further analysis. These were bought unused on an auction site for about $150 each, instead of the $700 the cost through an electrician, or $300 from a supplier.

1. Climate - Daikin 16kW Inverter aircon, plus underfloor heating in two bathrooms.

2. Flat - The basemant flat that has a separate circuit

3. I have this wired on 3-pin leads so I can monitor any plug-in device I like. Currently it's on my rack.

 

Another device bought through the auction site was a Fronius Sensor Box. This box interfaces directly with the inverter and to SolarWeb, and gives more channels of data like temperature, wind speed, and more. I'm going to use one channel to count pulses from my gas meter, so I can analyse my total energy usage.

 

Here's a shot of the array on the roof, taken using a GoPro on a long stick. The array is about 11 metres above ground level.

 

Thanks for looking.

Jason.

 

 

Edited July 13, 2020 by koputai

[Marc]

Thanks for sharing Jason.  How's your power bill looking since the PV was installed?

I'll have to start documenting my setup - all part of a home extension and retrofit smart home.

[koputai]

The first bill which was over Dec-Feb was $236. Without the solar it would have been $953, saving $717. The solar wasn't even connected for the first three weeks of the billing period.

The second bill, Mar-May was $135. Without solar it would have been $792, saving $657.

 

Cheers,

Jason.

 

[koputai]

4 hours ago, Marc said:

I'll have to start documenting my setup - all part of a home extension and retrofit smart home.

 

Marc, elsewhere you said you have two Fronius Primo's. Are they hooked up to appear as the same system in SolarWeb, or are they two separate pages?

 

Cheers,

Jason.

 

[Marc]

On 7/16/2020 at 1:06 PM, koputai said:

 

Marc, elsewhere you said you have two Fronius Primo's. Are they hooked up to appear as the same system in SolarWeb, or are they two separate pages?

 

Cheers,

Jason.

 

Having done my research before the PV system was installed, I was aware they could be linked with an Ethernet cable. This allows you to combine the total readings etc, or drill down and single them out via Solarweb. I asked my installed to link them and they had no clue what I was talking about. I ended up having to do it myself post-install, and after loads of conflicting info on the web (from older models), found it really was as simple as using a standard Cat6 cable and plugging into both units. Done after the install unfortunately it hangs between the two units rather than going internal into the walls and back out into the inverters which I would have preferred.

Sorry, long answer to your simple question. Yes, they both appear in the one instance of SolarWeb.

[koputai]

Cool, so you can get total combined data in your energy balance.

 

Cheers,

 Jason.

 

[koputai]

Our electricity bill for the 3rd quarter is in.

Over winter, 28 May to 27th August, our breakdown was as follows.

 

Solar Production was 2,725 kWh at an average of 29.6 kWh per day. Our usage of the solar production was 1,400 kWh, which is 51% own usage.

Our usage from the grid was 2,216 kWh at a cost of $732.52, and we fed 1,325 kWh back to the grid (after own usage) for a return of $279.26. Our net bill was $453.26

 

Taking in to account our own usage, the total saving for the quarter due to the solar was $564.57

 

Effectively, our bill was reduced from $1,017.83 to $453.26 which is pretty good over a few pretty crappy months of weather.

Our usage is quite high, averaging just over 39 kWh per day. The main culprits over winter being the resistive underfloor heating in two bathrooms using around 12 kWh per day, and an old fashioned oil heater in a part of the house where this is the only option for the moment using around 10 kWh per day.

 

Since install last December, the system has produced 9.15 MWh of electricity, and has paid back 18.3% of it's installation cost.

 

Cheers,

Jason.

 

[koputai]

Analysis for August 2020

 

Daily Averages -

Production: 37.3 kWh

Consumption: 40.9 kWh

Own Consumption: 17.3 kWh

Export: 20.0 kWh

Import: 23.6 kWh

Cost: $3.35

Yield: 4.3 kWh/kW

 

August was sunnier than predicted, as production was 1,156 kWh against a predicted 913 kWh (27% over predicted).

The best day was August 23rd with 48.8 kWh produced. The worst day was August 7th with just 3.3 kWh produced.

 

In August we had 15 'Green Days', where we exported more than we imported, but overall the month was not a 'Green Month'.

 

Cheers,

Jason.

 

[koputai]

Analysis for September 2020

 

Daily Averages -

Production: 40.6 kWh

Consumption: 30.3 kWh

Own Consumption: 15.8 kWh

Export: 24.7 kWh

Import: 14.4 kWh

Cost: - $1.29 (ie. earned $1.29 per day)

Yield: 4.7 kWh/kW

 

September was sunnier than predicted, as production was 1,218 kWh against a predicted 1093 kWh (11% over predicted).

The best day was September 26th with 56.9 kWh produced. The worst day was September 18th with just 6.0 kWh produced.

 

In September we had 25 'Green Days', where we exported more than we imported, our best yet. September was also a 'Green Month' exporting 742 kWh to the grid, against 432 kWh drawn from the grid.

 

Cheers,

Jason.

[koputai]

Analysis for October 2020

 

Daily Averages -

Production: 39.1 kWh

Consumption: 33.6 kWh

Own Consumption: 17.6 kWh

Export: 21.5 kWh

Import: 16.0 kWh

Cost: - $0.21 (ie. earned $0.21 per day)

Yield: 4.6 kWh/kW

 

October was almost exactly as predicted, with production of 1,211 kWh against a predicted 1223 kWh.

The best day was October 21st with 57.7 kWh produced, our third best day since install. The worst day was October 25th with just 7.2 kWh produced.

 

In October we had 20 'Green Days', where we exported more than we imported. October was also a 'Green Month' exporting 665 kWh to the grid, against 495 kWh drawn from the grid.

 

Since install last December, the system has produced 11.7 MWh of electricity, and has paid back 23.3% of it's installation cost.

 

Cheers,

Jason.

[koputai]

We have just passed our first year since our system was hooked up. The vital stats are:

 

Total Solar Production: 12.96 MWh

Total Household Consumption: 12.66 MWh

Energy Exported to Grid: 6.96 MWh

Energy Imported from Grid: 6.66 MWh

Total value of power produced: $2,766

 

Highest 5-minute output: 8.35 kW (14 October)

Highest daily production: 60.604 kWh (28 December)

Highest daily consumption: 90.427 kWh (28 November, the last day of the first year, which was a stinking hot day, and the longest we've ever run the air-con)

Highest daily export: 49.631 kWh (12 November)

Highest daily import: 46.516 kWh (30 April)

Highest daily cost: $15.32 (15 July)

Lowest daily cost: (-$6.71) (28 December)

 

So, we produced more than we used, and exported more than we imported. I'd count that as a success on the greenie scale.

It has paid back 26% of the installation cost, not bad for one year. I doubt the next year will be nearly as good, as our electricity plan won't be as beneficial, and the next years solar forecast is not as good, what with the La Nina and all.

 

Cheers,

Jason.

 

[koputai]

Analysis for November 2020

 

Daily Averages -

Production: 44.5 kWh

Consumption: 37.6 kWh

Own Consumption: 20.6 kWh

Export: 23.9 kWh

Import: 17.0 kWh

Cost:  $0.23

Yield: 5.2 kWh/kW

 

November was 13% better than predicted, with production of 1,336 kWh against a predicted 1187 kWh.

The best day was November 11th with 59.3 kWh produced, our second best day since install. The worst day was November 5th with just 6.7 kWh produced.

 

In November we had 25 'Green Days', where we exported more than we imported. November was also a 'Green Month' exporting 718 kWh to the grid, against 509 kWh drawn from the grid.

 

Since install last December, the system has produced 13.0 MWh of electricity, and has paid back 26.1% of it's installation cost.

 

Cheers,

Jason.

[koputai]

Analysis for December 2020

 

Daily Averages -

Production: 36.0 kWh

Consumption: 34.7 kWh

Own Consumption: 18.0 kWh

Export: 18.0 kWh

Import: 16.7 kWh

Cost:  $1.71

Yield: 4.2 kWh/kW

 

December was a pretty cruddy month weather-wise, with only 90% of predicted production, 1,115 kWh against a predicted 1241 kWh.

The best day was December 7th with 58.3 kWh produced. The worst day was December 19th with just 11.1 kWh produced.

 

In December we had 15 'Green Days', where we exported more than we imported. Despite the relatively poor production this month, December was also a 'Green Month' exporting 557 kWh to the grid, against 517 kWh drawn from the grid.

 

Since install last December, the system has produced 14.1 MWh of electricity, and has paid back 28.4% of it's installation cost.

 

Cheers,

Jason.

[koputai]

Analysis for the full year of 2020

 

Total Production: 12.882 MWh

Total Consumption: 12.931 MWh

Highest Production Day: 59.3 kWh on 11th November

Lowest Production Day: 1.9 kWh on 26th July

 

Daily Averages -

Production: 35.2 kWh

Consumption: 35.3 kWh

Own Consumption: 16.6 kWh

Export: 18.6 kWh

Import: 18.7 kWh

Cost:  $1.88

Yield: 4.1 kWh/kW

 

We had 195 'Green Days' where we exported more than we imported, but as you can see above, we just dipped out on having a 'Green Year' by a tiny amount, we basically broke even energy-wise.

Over 2020 the system paid back 26.6% of it's installation cost.

 

Cheers,

Jason.