Production Update to March 2016

Time for me to post a new update of the production from my solar array. In October 2013 I installed some new equipment, including Tigo Energy optimisers [www.tigoenergy.com]. I was not anticipating a significant increase in the overall array efficiency because the array is not facing any shading. It should increase the output and efficiency during the winter when there is partial coverage due to snow and ice.
Table below shows the production to date as well as the efficiencies for each month.

Updated:	04/02/16
		Years
Date	Data	2010	2011	2012	2013	2014	2015	2016	Total Result
Jan	Sum - Daily kWhr		170	256	243	216	281	210	1374
	Average - Efficiency [kWhr/kW]		0.9	1.3	1.2	1.1	1.4	1.1	1.2
Feb	Sum - Daily kWhr		275	323	214	197	333	312	1652
	Average - Efficiency [kWhr/kW]		1.5	1.7	1.2	1.1	1.9	1.7	1.5
Mar	Sum - Daily kWhr		561	569	499	577	663	483	3352
	Average - Efficiency [kWhr/kW]		2.8	2.9	2.5	2.9	3.3	2.4	2.8
Apr	Sum - Daily kWhr		493	626	574	615	656		2962
	Average - Efficiency [kWhr/kW]		2.6	3.3	3.0	3.2	3.4		3.1
May	Sum - Daily kWhr		534	758	768	699	745		3504
	Average - Efficiency [kWhr/kW]		2.7	3.8	3.9	3.5	3.8		3.5
Jun	Sum - Daily kWhr		707	715	633	757	687		3499
	Average - Efficiency [kWhr/kW]		3.7	3.7	3.3	3.9	3.6		3.6
Jul	Sum - Daily kWhr		769	762	693	735	821		3780
	Average - Efficiency [kWhr/kW]		3.9	3.8	3.5	3.7	4.1		3.8
Aug	Sum - Daily kWhr	164	658	720	711	694	693		3640
	Average - Efficiency [kWhr/kW]	3.2	3.3	3.6	3.7	3.5	3.5		3.5
Sep	Sum - Daily kWhr	438	528	600		626	625		2817
	Average - Efficiency [kWhr/kW]	2.3	2.8	3.1		3.3	3.3		2.9
Oct	Sum - Daily kWhr	450	391	338	79	381	455		2093
	Average - Efficiency [kWhr/kW]	2.3	1.9	1.7	1.8	1.9	2.3		2.0
Nov	Sum - Daily kWhr	355	316	286	296	177	334		1765
	Average - Efficiency [kWhr/kW]	1.9	1.6	1.5	1.5	0.9	1.7		1.5
Dec	Sum - Daily kWhr	78	220	144	119	169	148		877
	Average - Efficiency [kWhr/kW]	0.4	1.1	0.7	0.6	0.8	0.7		0.7
Total Sum - Daily kWhr		1486	5623	6096	4828	5841	6439	1005	31317
Total Average - Efficiency [kWhr/kW]		1.8	2.4	2.6	2.4	2.5	2.8	1.7	2.5

You'll see that of course the efficiency is different for each month from winter to summer to winter again - there is much less sun energy coming in so the panels generate less. The same pattern for total energy output. The summation in the right column doesn't mean too much given that part way through October 2013 the equipment changed. The sum and averages at the bottom are interesting. Disregard 2013 again due to partial data and a change in the equipment. 

Comparing 2011 and 2012 with 2014 and 2015 we see the following:

• lowest output was 2011 [range between 2014-2011 = 218 kWhr]
• highest was 2015 [range between 2015-2012 = 343 kWhr]
• average efficiency 2011-2012 = 2.5, post upgrade = 2.65]

These statistics, if anything, show that there is quite a lot of annual and intra-annual variability in energy production. There was 600 kWhr difference between 2014 and 2015, or about 10%. 

So? Was the equipment upgrades worth it? Let's look at more statistics.

Variables kWhr Dollars

Mean 15.90 $13.03

Mean post upgrade 15.50 $12.43

Per 1 kW 3.24 $2.66

Per 1 kW post upgrade 2.42 $1.94

Min 0.05 $0.04

Min post upgrade 0.08 $0.07

Max 35.44 $28.42

Max post upgrade 36.49 $29.26

Pre and post upgrade, the data show an underwhelming result despite an extra 1.5 kW of capacity:

• mean kWhr was actually higher before the upgrade
• efficiency was lower by 0.8 kWhr/kW installed post upgrade
• maximum daily output on the best day pre and post upgrade increased from 35.4 to 36.5 kWhr

The maximum daily output and other values of course can vary by year, but really, the max daily output should be at least 1.5 kW x 3 hours = 4.5 kWhr. I'll state this because I think that over any given 2 year period, there will be at least one amazing, sunny, clear, long, cold day.

I shall investigate this much more indepth using RETScreen soon and share these results with you.

Net Zero Home in Guelph

I have been meaning to do a write-up about a new home built in my subdivision in the south end of Guelph. It was built by Reid’s Heritage Homes and is a net-zero home. I'll still do my write-up, but in the mean time you can read this good article about it : http://www.greenenergyfutures.ca/episode/net-zero-spreading-across-canada.
These writers are quite supportive of this project. Reid's was one of 5 selected builders in Ontario to do this. It was funded in part by the previous federal government. Owens Corning was hired by Natural Resources Canada to deliver the program. Me, I was a little skeptical of several aspects of the home and the true commitment of the program and builder, but it is a good start. I'll write soon with my own observations.

Update to end of Nov 2014

It seems like it has been a fairly grey, mild, and somewhat overcast 2014 so far. And December is looking to be much of the same. It has been a while since I have updated this blog with data from our solar panels. My last blog post was about the TigoEnergy systems. I am really happy with the online monitoring system.
To see our system information, go ahead and check it out! [http://www.tigoenergy.com/site.php?guelphsolar_blogspot_com].
Below is my summary table of solar revenue and generation.

Sum - Revenue, daily	Years
Date	2010	2011	2012	2013	2014	Total Result	CV
Jan		$136.10	$205.18	$194.58	$171.78	$707.65	0.21
Feb		$220.57	$258.66	$171.45	$157.93	$808.60	0.22
Mar		$449.77	$456.57	$400.57	$462.50	$1,769.40	0.07
Apr		$395.30	$501.84	$459.99	$491.71	$1,848.83	0.12
May		$428.51	$607.72	$615.85	$560.35	$2,212.43	0.19
Jun		$567.19	$573.10	$507.35	$607.37	$2,255.01	0.06
Jul		$616.75	$611.45	$555.82	$589.13	$2,373.14	0.06
Aug	$131.53	$528.09	$577.23	$582.20	$555.32	$2,374.37	0.05
Sep	$351.28	$423.49	$480.85	$459.41	$500.03	$2,215.06	0.13
Oct	$360.90	$313.65	$270.70	$133.86	$305.43	$1,384.53	0.14
Nov	$285.03	$253.69	$229.61	$237.50	$141.75	$1,147.58	0.05
Dec	$62.74	$176.31	$115.73	$171.78		$526.57	0.43
Total Result	$1,191.47	$4,509.43	$4,888.65	$4,490.35	$4,543.29	$19,623.19

You can see that there is quite a bit of variability between the months. I also added the coefficient of variation so you can see how much revenue varies from year to year for each month. December, January, and February have quite a bit of variation, particularily December. That is snow-induced shading. There is certainly snow shading in January and February - but is much more consistantly shaded in Jan and Feb. The high CV in December shows that some years snow is more and some Decembers it is less. Really, it is the very snowy December 2010 and 2012 that really reduced the output. We'll see what this December 2014 brings us, but the long range forecast is not too much snow and somewhat mild.
I highlighted October 2013 because that is the month that I did a system upgrade to increase the efficiency of my system. I still just have a 5 kW inverter. The Tigo Energy power optimizers were a big part of the efficiency upgrades.
Below is the kWhr of generation our system has produced.

Sum - Daily kWhr	Years
Date	2010	2011	2012	2013	2014	Total Result	CV
Jan		169.7	255.8	242.6	214.2	882.4	0.21
Feb		275.0	322.5	213.8	196.9	1008.2	0.22
Mar		560.8	569.3	499.5	576.7	2206.2	0.07
Apr		492.9	625.7	573.5	613.1	2305.3	0.12
May		534.3	757.8	767.9	698.7	2758.6	0.19
Jun		707.2	714.6	632.6	757.3	2811.7	0.06
Jul		769.0	762.4	693.0	734.6	2959.0	0.06
Aug	164.0	658.5	719.7	725.9	692.4	2960.6	0.05
Sep	438.0	528.0	599.6	572.8	623.5	2761.9	0.13
Oct	450.0	391.1	337.5	166.9	380.8	1726.4	0.14
Nov	355.4	316.3	286.3	296.1	176.8	1430.9	0.05
Dec	78.2	219.8	144.3	214.2		656.6	0.43
Total Result	1485.6	5622.7	6095.6	5598.9	5665.0	24467.8
as of:	2014-12-08

See the Solar Output in Real-Time with TigoEnergy System

We recently had Merlyn Power install additional equipment on our 5 kW system. The panels now have TigoEnergy power optimizers on them. I had the old Fronius data logger pro taken out and now the Tigo website provides the online monitoring and data logging. I have not tried out download the data yet. I'll try that later and let you know.
Click the link to see the public access link to our solar panels. http://www.tigoenergy.com/site.php?guelphsolar_blogspot_com

Solar Costs in Germany and USA

I found this interesting article that analyses the differences in costs of solar PV systems in Germany versus USA. I don't have a similar analysis of Ontario costs, but I am looking - let me know if you have seen any research on Ontario solar PV costs.
http://cleantechnica.com/2013/02/17/why-german-solar-is-so-much-cheaper-than-u-s-solar-updated-study/

Solar Generation Results to Sept 2013

I am updating the results of the solar PV system, below. It is now 3 years and a month since the system was installed [well, and a little bit of October too and the few days in August 2010]. This is giving me a good range to see what good and bad months are, as well as how the system is faring relative to what i hope was to be the rate of return.
First, I have my set of important variables : mean daily total kilowatts, mean kilowatts per watt installed, minimum and maximum output days. And the same is in dollars, as calculated from my data. However, what my datalogger calculates as output and revenue is less than what my Guelph Hydro meter shows. This is what I hear from others - what their system reports seems to be less than their utility's meter.  I haven't heard of anyone producing more than what their meter is reporting.

Variables	kW	Dollars
Mean	15.96	$12.80
Per 1 kW	3.26	$2.61
Min	0.05	$0.04
Max	35.44	$28.42
Sum - Daily kWhr	Years
Date	2010	2011	2012	2013	Total Result
Jan		169.7	255.8	242.6	668.2
Feb		275.0	322.5	213.8	811.3
Mar		560.8	569.3	499.5	1629.6
Apr		492.9	625.7	573.5	1692.2
May		534.3	757.8	767.9	2060.0
Jun		707.2	714.6	632.6	2054.4
Jul		769.0	762.4	693.0	2224.5
Aug	164.0	658.5	719.7	725.9	2268.1
Sep	438.0	528.0	599.6	572.8	2138.4
Oct	450.0	391.1	337.5	87.8	1266.4
Nov	355.4	316.3	286.3		958.0
Dec	78.2	219.8	144.3		442.4
Total Result	1485.6	5622.7	6095.6	5009.5	18213.4
as of:	2013-10-08

And you are likely asking, well, just how variable is it by month? Are the summer months consistently bright and the winter consistently dull? I know, you wanted to know the coefficient of variation, and now that i have 3 months (4 Septembers), i have done the calculations for you:

Month	CV
Jan	0.21
Feb	0.20
Mar	0.07
Apr	0.12
May	0.19
Jun	0.07
Jul	0.06
Aug	0.05
Sep	0.13
Oct	0.14
Nov	0.07
Dec	0.48

What it shows, for this limited dataset is that June, July, and August are fairly consistent between the years, with only 5 to 7% variation, whereas Jan, Feb, and esp Dec are quite variable between the years.