Other Solar Blogs from Ontario

I like to see what other people are sharing about their own solar project experiences. Here are a couple blogs I'll share with you. I don't endorse them.

• http://www.solarontarioblog.ca/ 
• opps, that's it! I searched for some blogs on solar and found that 80% were companies, 19% were organisations, and 1% were political (or some similar breakdown). So, enjoy solarontarioblog.ca and feel free to read all the other blogs. 

Little Snow Means Better Solar Production in 2011-2012

Spring is already here but our 2011-2012 winter ended a long time ago. There has been very little snow - I didn't have to shovel much since Christmas. The sky seems to have been clearer too and this has enabled our solar array to generate more power than last winter. It means a lot too, financially. Last August was our 1 year anniversary and on a $30k investment after 10-year loan payments, we netted $460 - not a great return on investment so hopefully 2012 will be better. So far, so good. Here is our kWhr generated by month in Table 1.

Sum - Daily kWhr	Years
Date	2010	2011	2012	Total Result
Jan		169.7	255.8	425.5
Feb		275.0	322.5	597.5
Mar		560.8		560.8
Apr		492.9		492.9
May		534.3		534.3
Jun		707.2		707.2
Jul		769.0		769.0
Aug	164.0	658.5		822.5
Sep	438.0	528.0		966.0
Oct	450.0	391.1		841.1
Nov	355.4	316.3		671.7
Dec	78.2	219.8		298.1
Total Result	1485.6	5622.7	578.4	7686.7

If I use Dec-Feb to define winter, then we yielded 523 kW in 2010-2011 and this year 798 kW. That is a 275 kW difference or $220.55 difference in revenue. We'll see what this March brings to be able to compare two full winters. December 2010 and 2011 were especially different because Dec '10 was dark, dreery, and frequent intermittent snow that accumulated on the panels and seldom fully melted off or slid off.
The system didn't get connected until 25 August, so ignoring that we can see that most months are better than the year before, other than Oct and Nov 2011. We had a "dark" fall, but otherwise, I see it is all going well.
As you may read in this blog, I focus on the numbers, kW, dollars, and cents of our solar system. I am interested in these results today as it shows that you can't use a single year to determine if production data. Or any coefficients either. In an earlier posting I calculated the typical coefficients people use to estimate the power generation for our first year. I look forward to calculating this year's coefficients, plus to calculate the values for the duration of the system - that way we'll get the general values to expect for a multi-year estimation of coefficients.
So far, so good.
Oh, a little note about how I analyse these data. I use OpenOffice Calc to store and analyse the data. I use the Data Pilot tool [Pivot Tables in Excel] to summarize the data very quickly and easily.

Fronius Datalogger Data Processing

This posting is really for the benefit of me. I have a Datalogger Pro datalogger on our PV system. I download the data every week or so, though I am currently installing some networking cable so it is a little easier and i'd then download it more frequently.
When I download the data, I can export it into an Excel spreadsheet file, it looks like this:

The date is in DD/MM/YYYY format. I was having problems when I opened the file up in Excel or OpenOffice Calc [what i use at home]. The dates were all in "text" format. If I tried to plot the date and kW the chart wouldn't work because the X axis would be text and not numbers. Hummm, what to do. Google, of course.

Solution 1.

1. Click a blank cell formatted as a number cell and enter 1 in the cell.
2. Go to Edit | Copy.
3. Select the cells that contain the text values that you want to convert.
4. Go to Edit | Paste Special.
5. In the Operation section, click Multiply.
6. Click OK

This worked on my work computer, but not on my PC at home. It is a good way to convert text to numbers (or dates) but it just wasn't working. More Google.

Solution 2.

In the Control Panel, I have my region set to Canada, and therefore the date format is day/month/year [DD/MM/YYYY].  But in OpenOffice Calc, there were several date formats, shown to the right.

But since the data in the Fronius logger file was DD/MM/YYYY but there was not a corresponding format in Calc, the dates were being saved in the spreadsheet as text because Calc did not recognise the format. Perhaps if the format in the datalogger spreadsheet file was saved as 2012-02-23 it would import as a number/date, but that was not the case. Therefore, I created a new format in the form of DD/MM/YYYY as follows:

• Format → Cells → Numbers → Category → Date dialog

Then enter the custom date that I needed. Presto, next time I opened up the spreadsheet and copied-pasted the dates, they were recognised as dates and not as text.

Whew, now I finally get to update my big spreadsheet of all the solar data. That will be my next posting.

Data Catch-up!

Several months have gone by without me posting my data - sorry about that. Actually the last posting was 1 September - shame on me. Sorry again!
Our system has now been running for almost 1.5 years and we can now compare data between two months of different years to begin to see how variable the solar energy received is. Since our system was commissioned August 2010, we can now compare September to December (and in a few days January). We know that weather and solar energy will be different between the years, but I didn't know by how much. Also, the effects of weather will affect the solar generation - I'm primarily referring of snow and its persistence. So, on to the data...

Daily Power Generation

The data is downloaded from my Fronius datalogger and creates two M$ excel files: a daily summary file and a instantaneous (15 min average) file. The files report the kWhr, AC and DC voltage, and error messages (never had any error messages. I'll have to do a posting on the AC power but I don't know enough about it to say anything intellegent about it (yet). I add the daily data to a spreadsheet file where I do calculations and the figures.
The annual trend in solar radiation is clearly visible now that we have more than a full year cycle in Figure 1. There is considerable daily variability - as much as 30 kWhr for the system or 6 kWhr per kW per day. The highest variability is during the spring months of March and April. In August and September the variability ranges about 20-25 kWhr or 5 kWhr per kW per day. One reason for the larger daily variability in the spring months is because the overall potential output is highest (35 kWhr) and there is still the good chance that snow covers the panels or there is a very dark overcast day. The days are also still a little short therefore the total accumulated solar radiation will be less than the longer summer days. This is why we see the lowest generation days in mid-summer still seldom being less than 10 kWhr. This means the variability per kW to be closer to 5 kWhr/kW/day and not 6 kWhr/kW/day.
December was an interesting month to compare between the two years. December 2010 received a quite a few snow days and this resulted in many days with very little power generation (see all the points clustered around the x-axis during the second week in Dec with virtually no days over 10-15 kWhr until mid-January. I've (begrudgingly) reported this in an early posting. Even though we love the snow and winter, the good news for December 2011 was that there was virtually no snow fall this year and there were many days where the system generated over 10 kWhr. Several good days over the month makes a big impact on monthly revenue.

Figure 1. Daily Power Generation, 4.9 kW DC PV System

One Year Anniversary - how did the system perform?

There are many ways to answer the question "How did it go? Was it worth it?". Our system was online one year as of 4pm 24 August. Our system is a 4.9 kW panel array and 5.1 kW string inverter. We are located on Farley Ave, Guelph and our roof faces south east, 40 deg slope. We have 20 SolarWorld panels that are 240 watts (two strings of 10 panels into the inverter). I have downloaded the data from the inverter data logger and can now say the following:

• Total annual output was 5509 kWhr
• $4418 gross revenue (HST not included)
• Our loan payments (2nd mortgage on the house so we are only paying 2.6% interest) have been $3,921 which started being paid July 2010
• Total payout from Guelph Hydro was $2,942, which means we should be getting a nice cheque any day now 
• Total output per kW of installed capacity is 1124.2kWhr/kW capacity

I have not had time to to do much more analysis on the data, but I shall over September. For example, I'd be interested to know what type of production does the system acheive during the longer sunny days, but the hotter temperatures. 
I also want to discuss my experience with claiming back the HST, and what you have to do when you collect the HST on behalf of Revenue Canada (hint - cheque book). I would also like to compare the annual production with what I modelled to see how RETSCREEN matched our system. 
Tonight I went to a solar coop meeting here in Guelph at Harcourt Church. It had about 30 people attend and they talked about the two proposed solar coop projects. I'll talk about those soon too. But for now, I just wanted to get the annual results out.

Taxation of Properties with Solar PV System

The question of property tax changes after a PV systems in installed on your house has never really been clarified by the local or provincial governments. Adding a PV system to your home increases the value of it [assets and potential revenue]. Of course, some may disagree and prefer not to buy a house with panels.
I have not heard of any homeowner facing a property tax re-assessment. But there is good news, released 2 August 2011. The Ministry of Finance has released a proposed regulatory amendment to the Assessment Act to provide greater clarity and certainty to property owners, energy generators, municipalities and the Municipal Property Assessment Corporation regarding the property tax treatment of renewable energy facilities. The proposed policy would apply to electricity generation installations that utilize solar, wind, or anaerobic digestion.
In summary, for roof-top and ground-mounted small scale solar systems:

• Roof-top: The assessment and tax classification of property would not change due to the addition of a rooftop energy generation installation.
• Ground-mounted installations: the property tax treatment will depend upon the size of the facility as well as the entity who is doing the generation - Small-size ground installations (up to 10 kW) would not result in assessment increase or change in tax classification.
• Medium-size ground installations, with generation capacity over 10 kW up to 500 kW, would be taxed based on the surrounding land use (e.g. residential, farm, multi-residential, commercial).

Essentially, a house with a microFIT project would continue to be taxed as a house and not as a business. Also, the house would not be assessed to a higher tax rate due to an increased value.
This is great news - we had wondered all along if our property tax would increase due to our PV system. It would be disappointing if the government paid you to generate renewable energy then turn around and increase your taxes to claw back a part of that revenue. On a small PV system, even a couple hundred dollars would have a large impact on the financial viability of the project [see my recent post]. Secondly, this would act as a disincentive to produce renewable energy - something that is socially beneficial. Thirdly, I have never seen any information from the Ontario Power Authority to say the $0.802/kWhr accounted for increased taxation.
There is more details on wind and larger solar projects that I won't get into here. On Farm anaerobic digestion systems (even systems over 500 kW) are taxed at the farm rate.

July 2011 PV Revenue Results

In my previous post I show that all but one day had very high PV generation for our system over July 2011. I don't complain about the one lower output day as we desperately needed the rain. On the 20 June 2011 we broke even since the winter where our cumulative revenue exceeded our cumulative loan payments. We had a very sunny June and we continued to add to our surplus so that by 1 July we started the month with $58.60 surplus. Don't forget, this is a surplus on a PV system that was over $31,000 and we had less than 2 more months to earn a little on our investment.
July was a very good month, adding to June's very strong output [and therefore revenue]. My chart below shows the cumulative revenue, loan payments, and microFIT payments we received.

Cumulative revenue, microFIT payments, and loan payments to 31 July 2011, 4.9 kW PV system.

We see the following:

• Revenue has exceeded loan payments by $341 by the end of July
• Return to date is 1.08% [profit over loan value]
• microFIT payments are a little irregular [number of days for each payment has been 49, 70, 68, 43, and 63]. I suspect that microFIT payments are manually processed at Guelph Hydro with "flexible" schedule
• Slope of cumulative revenue is greater during May-July vs. Aug-Nov [clearly showing the tendency of longer days in the summer, less cloud cover]. This trend should continue for the rest of the summer given the long range forecasts, though some rain is forecasted over next 2 weeks. 

I did do a boo-boo in some previous charts. I was showing earlier versions of the figure above with the microFIT payments including HST. The payments from Guelph Hydro includes HST. I must submit this to Revenue Canada so I incorrectly was including that tax as part of my revenue. The chart above is corrected and does not include HST. I shall talk about taxes in a forthcoming blog post.