Wednesday, September 26, 2012

Do it yourself microFit Solar Panels

One home owners experience with microFit

***a posting and project in progress***

microFit is an Ontario program under which the government will pay you a premium for any electricity you generate back to the grid through renewable sources. It started in 2009 and offered an amazing 80.2¢/kWh for electricity generated by rooftop photovoltaic panels. The demand was so high that to keep the program balanced in 2012 the rate was lowered to 54.9¢/kWh - 31.5% lower and I would bet the rate will continue to declined as the program is now under yearly review. Assuming an average 13¢/kWh electricity cost in Ontario the rate is still appealing and makes the investment worthwhile financially and of course environmentally.

It must be said that if you yourself are considering microFit then do not wait - apply yourself or have it done by a company on your behalf - once you get a approved your rate is locked in for 20 years and you have 6 months to complete the project. Furthermore, because these contracts are against specific locations, a property with one could become very desirable in the future as electricity costs continue to rise.

Quick Rule of Thumb Return Mulipler

To get your yearly dollar revenue (for microFit at 54.9¢/kWh) multiply your faceplate in KW capacity by 572. That is a 10KW system would generate $5720 a year. A local Kingston renewable energy company did a microFit package for me and using their numbers the multipler conversion rate works out to 635.

Determining your brake even point

One way to decide on the size of your solar panels photovoltaic system is to analyze your yearly electricity costs and work backwards form that. This will determine the estimated minimum system size needed to brake even - at the end of the year have a net electricity costs of zero; let's dive in using numbers from my projects numbers except my target is to cover almost all our utility costs:

Yearly total utilites: $5000
Rebate per kWh:        $0.549
--------------------------------------
kWh Needed:            $5000 / $0.549
                      =9107

Based on the above 9107kWh in a year must be generated to result in $5000 revenue which would offset our utility costs.

Converting required kWh into kW faceplate capacity

This step is a little tricky as the total kWh produced is based on location, system setup - inclination, azimuth, static or one that tracks the sun - and faceplate kW capacity. The best resource to assist with this is PVWATTS a US resource with data point for some Canadian locations.

Once you find your location click the 'Send to PWatts'. On the next screen enter your roof angle and direction [link to some android iPhone app for this] then click 'Calculate' button. On the following page locate yearly kWh and divide it by 4000 (or whatever value you entered for faceplate capacity) to how many kWh you can produce per 1kW; for our home's Kingston, Ontario location the numbers are as follows:

DC Rating (kW):          4.0
DC to AC Derate Factor:  0.77  
Array Type:              Fixed Tilt 
Array Tilt (degrees):    45
Array Azimuth (degrees): 180
-----------------------------------
Yearly kWh Production:   4165
kWh to kW Conversion:   4165/4000
                        =1.04125

Now to get faceplate kW we divide 9107kWh by our rate:

Required Faceplate kWh:  9107/1.04125
                        =8746

Calculating the number of Solar panels and surface area required

Monoycrystalline photovoltaic cells are the most efficient type – followed by polycrystalline then thin-film panels - and a panel like the microFit qualified Sharp panels average between 230-240W per panel. Calculating number of panels required is easy:

Required Faceplate kWh : 8746 
Wattage per Panel  : 234W
Panels Needed  : 8746 / 234
           =  37.21 or 38 panels

And now to get the rough surface area required:

Panel Dimensions:  64.6 x 39.1 x 1.8”
Panel Area:  2525.86 inches square = 16295.8 cm2 = 1.62958 m2
All Panels Area: 1.62958 x 38
   = 61.92m2

Will it fit on the roof? Surface area required.

One can use Google Earth to estimate the surface area of the roof – do keep in mind that the slope of the roof won't be taken into consideration hence your actual size would be a little bigger. If you can see the roof from the street a more accurate way would be to count the number of shingles width and length wise and time it by dimensions of one shingle, in my case the calculations were as follows:

Shingles width wise: 24
Shingles height wise: 34
Number of Shingles: 24x34
   = 816
Shingle width:  33cm
Shingle height: 14cm
Shingle Area:  33 x 14
  = 462 cm2
Total Roof Area:  462 x 816
   376992 cm2 = 37.70 m2

Based on that my roof area is insufficient for the required faceplate capacity. It can roughly support 37.70 / 1.63 = 23 panels. The good news is one can use the garage's roof area but in my case I there is plenty of roof 'on the other side' to utilize altough at a much more flatter angle.

How much will it cost?

Do it yourself installation there are microFit kits 5KW at around $11,000 and 10KW at $21,000 as long as you do the work yourself. Now this potentially could mean you don't qualify for the microFit content requirements. There is also the cost of the extra meter hook up.

more to follow eventually – contact me or comment if you have questions

Further Reading

Found this excelent guide by our Kingston Hydro LDC worth a read as part of the planning process: Guide for Distributed Generators. On that page one call also find the required forms to fill out for a Connection Offer.

The linked guide is absolutley worth a read to learn things such as:

Hourly Ontario Energy Price – The Wholesale Market 
In Ontario, there is an open wholesale market for electricity administered by the Independent 
Electricity System Operator (IESO). Throughout the day and night, Ontario electricity suppliers 
submit offers to sell electricity and wholesale buyers submit bids to buy electricity. The IESO then 
uses these offers and bids to match electricity supply with demand, establishing the Hourly Ontario 
Energy Price (HOEP) paid by wholesale customers. This spot market energy price changes from 
hour to hour, day to night, from season to season, and for short periods in response to high levels 
of demand or sudden changes on the IESO-controlled grid. Every five minutes, the IESO calculates 
a new spot market price by balancing the supply of electricity with demand. As demand increases, 
more expensive offers from generators are accepted, which raises the price of electricity. As 
demand drops, only the less expensive offers are accepted, which reduces the price.  

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