Guelph Solar

01 September 2011

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.

03 August 2011

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.

July 2011 PV Results

A hot July ends and it has been a good month for our PV system. The very hot weather has had a very real decrease in our output, but the sunny long days has still been good for overall production. I counted 7 days that were either "pure blue" skies, or virtually cloud free other than the odd passing cloud. Many more had occasional cloud passage. However, we had many days that were 30 deg C and this hot weather reduced the peak output levels. I'll post examples of those soon.
Below I am providing the raw daily totals for July. The days with 30 or more kWhrs were virtually cloud-free, and you can see the number of days over 25 kWhr is also high. Only 1 day [28 July] was low - a cloudy day with even a bit of rain which was much needed.

July 2011 daily kWhr PV production, 243 Farley Dr., Guelph, Ontario.

The next figure shows the total daily production since we started. Despite the longer days in July compared to March, total daily output is trending down to 30 kWhr from March's 35 kWhr.

Daily kWhr PV production up to July 2011, 243 Farley Dr., Guelph, Ontario.

20 July 2011

Solar Production on Hot Summer Days

Today in July Guelph should be getting about a theoretical 5.8 kWh/m2/day compared to 4.5 kWh/m2/day in March. Cloud and atmospheric conditions affect the amount of energy of course. But our nice long days of 14.5 hours vs. March's 12 hours should be yielding more peak and cumulative power on any given day.
My SolarWorld 240 W mono panels are rated at 14.3% efficiency. And the extra energy striking the panels - where does it go? It is converted into heat. And heat decreases the efficiency of energy conversion. Essentially, the voltage decreases. The figure below shows three curves where the panel temperature is 25C, 45C, and 60C. This is an often borrowed image, I shall calculate it for my panel myself one day.

Effect of temperature on solar panel current
http://www.solarpower2day.net/solar-cells/efficiency/

This chart only goes to 60C, but my panels will be reaching over 70C on these hot July days. The current [amps] decreases and power output decreases [P = V.I]. I've read on websites a general rule of thumb [which means it is wrong] is a 0.5% decrease in efficiency for every 1C increase. They don't specifiy if it is a 0.5% decrease of the overall efficiency or of the 14.3%, not do they specifiy for mono/poly crystalline or for amorphous panels. Many good general descriptions of panels and output exist on the web. However, I found a great tool to calculate the panel derating effects by temperature where you can put your own panel data in. The temperature coefficient of my panels is -0.45 %/ºC.
What this all means is the long summer days of July provide a lot of sunshine, but the total accumulated output is lower than the best days in March. Fortunately for my solar revenue and unfortunate for the farmers and plants and animals, there has been a lot of clear sunny days, albeit our grass is very brown.
I show our cumulative daily output chart as of 19 July 2011 below.

Daily power output [kW.hrs] to 2011-07-19.

Our average revenue from 1-19 July has been $21.23. This is pleasing as we've been averaging about $10.50 above our loan costs. We are now above our cumulative loan payments by about $250. We have just over a month to go until we can get a full year tally. I was also pleased that we received out first cheque over $1000 the other day from Guelph Hydro! Our cumulative loan, revenue, and MicroFIT payments are shown below.

Cumulative loan, revenue, and MicroFIT payments to date.

05 July 2011

Solar Energy Information Sessions Across Ontario in July 2011

Considering OR Getting Started in Solar?

Four solar sessions are planned for Ontario in July. These will provide information to those who are recent solar generators or to those considering solar installations. Back by popular demand, Thomas Boehni, a Swiss pioneer in solar energy with over 16 years experience in solar systems will share his expertise and tips. Invited speakers to join Mr. Boehni include: OMAFRA and Hydro One.

Fees

Pre registration fee is $35.00, at the door fee is $45.00 Pre register to secure your spot at this special information session. Deadline for pre registration is June 30 for Southwestern Ontario locations and July 4 for Kingston location.

Schedule of Dates:

All Sessions begin at 7PM

Tuesday, July 5: Ridgetown
Wednesday, July 6: Woodstock
Thursday, July 7: Guelph
Monday, July 11: Kingston