Introduction
When we moved to our new home in Lakeshore, Ontario, (near Windsor) in Southern Ontario in August 2012. I looked at putting solar energy harvesting equipment (AKA solar panels) on our roof. I based my analysis on 12 cents per Watt and not on the higher 54.9 cent rate. When I found out that the Ontario microFit tariff or contract rate was much higher, I started to investigate the feasibility of a Solar Panel Roof mounted system or program for our home. As an engineer, I used the internet to quickly accumulate a vast amount of information on design, local solar radiance, equipment types, solar panel specifications, component analysis, failure rates, etc.
Caution:
You must be approved for your electrical feed line and gain approval with an offer to connect from the microFit Power Authority BEFORE you spend any money.
Maximum microFit Size is 10 kW DC.
Your 10 kW AC Inverters will automatically limit you so I don't understand why they have the DC limit if they want to protect the environment.
Educate yourself about Solar before signing anything. This is a good place to start and maybe all that you need. Help us and others to reach the safe CO2 levels of 350 ppm. Every little thing helps. Harvesting energy to meet your electrical consumption is a good first step. We expect to harvest more energy than we use, at least on good days. We currently are at 395 ppm on this planet.
The Conservatives have stated that they will stop this microFit Program and keep funding big business paying in some cases for them NOT to produce energy. That tells me that it most likely is a good idea for the average home owner.
Installing Solar panels in our case will mean never again having to pay for our electrical consumption even after the 20 year microFit contract. After the contract, we remain grid tied and they will pay us the current electrical consumption rate. Current forecasts is for a 40% increase in your electrical bill over the next 3 years.
The first thing that I noticed during my review of the solar panel installers in Windsor Ontario were the
horrible sales people in the "Solar energy equipment and suppliers field" (Yellow Pages listing) who's main plan was to lock you into them with a huge $20,000 down payment or much more. I contacted as many people as I could find to submit a proposal for our home. We missed out on the 54.9 cent tariff rate and were horrified at the new 39.6 cent rate and the added restrictions of a maximum 10 kW DC versus the original unlimited DC with limitations at the inverters only (10kW AC). Hydro One still wanted their $1500 connection fee + HST, building permits are still $11 per panel, other fixed cost still up there. Some equipment costs have significantly decreased. Be aware of poor quality, hard to maintain equipment.
We found out that Flexible Solar in Windsor, Ontario are one of the best microfit solar panel installers serving Southern Ontario.
Again, for example; Mike Holmes says that we need good structure for our houses and solar panel systems also need a good structure (railing system) plus a well built Tier one solar panel. Be careful not to buy cheap products. We used Schletter Rails which is the best Rail System that we know of.
Your key result areas are:
Reliability, long life, maintainability, optimization, maximum ROI, Tier 1 Manufacturing, Safety
Beware of these type of DC to AC Inverter Systems:
1. Micro Inverters - Limit panel power output and IMHO may fail after 10-12 years due to the use of Electrolylic Capacitors which have a shorter life span. Cost of all of those connections is very high. Low 240 V lines cause higher current loses. Located under every panel. They however do not need optimizers, just larger capacity units and elimination of the electrolytic capacitors that they use that will shorten the life span of the unit to around 12 years estimate like all other similar capacitors. Line voltages at panel even while turned off will be 240 V I understand. Not good for Firemen working on roof.
A horrible labor cost to maintain.
2. Straight String Inverters without optimizers. Maximum output of the string is limited to the minimum output of a panel. Read further down about how fouling/shading does effect your panel output. Strongly not recommended. Cheapest system to install. High 600V lines at panels when shutoff.
3.String Inverter Systems that do not turn off power to panels when switched off. Most systems will maintain 600 V at each panel when turned off. Not good for Firemen and when changing out panels. SolarEdge reduces voltage at panels to 1 V when turned off.
You will lose $20,000 over the life of the project.
Current MicroFit Program - 39.6 cents per KW - Maximum 10 kW DC side.
Current rate is lower but still such a contract can net you $6-7k+ per year added income which is taxable IF you get the right people to work with you to optimize the program for your particular house.
Why settle for $5k per year ($100,000 gross) when you can get an additional $20-40,000 (up to $140,000) over the 20 year project life.
You Don't Need to have any Money?
Remember you can get a HST refund. Roof orientation and shading by trees or other structures can and do limit the return on your investment. You can get a home based loan at around 3.5%-4% interest rate. The cost of the system can be written off over 5-7 years meaning you pay little or no taxes. Any long term upgrades after 15 years can be written off before your contract ends. It is not very often that we as home owners can get a win/win situation like this. Like any investment, we want to get the maximum ROI (Return on Investment) that we can get. If that interests you also, then keep reading. In a good month, we expect to harvest around $900+, in a bad month $160 or enough to cover the interest payment. You add considerable value to you home. If you have to sell, you will most likely get multiple offers due to the hassle free monthly income.
NOTE: If the Conservatives get into power they want to stop this green energy program.
Our System
We are very fortunate to have a large truss roof that faces north and south. Our garage is also a blessing as it faces east and west. We opted to put 80% of our panels on the south roof. After some convincing, my wife allowed me to put 4 panels (8 in total) in landscape position along the west/east roof peak. She didn't want them on the street side (west) at first but she is happy with the final installation. We did the same with the east peak. But I wanted more output from these panels. I didn't like the fact that the west panels did nothing until around noon time. At or about the same time the east panel harvesting would begin to tapper off. So I did something about this. With help from FlexibleSolar, I designed what I call my dynamic positioning system. I used electric actuators to raise and lower both the east and west arrays. Now when the sun rises at the crack of dawn, my west 4 panels start screaming out power as they are facing the sun. As the day progresses, I lower the west panels and automatically raise the east panels. Panels sticking up in the air will be a lot cooler on a hot summer's day as the cooling breeze wraps around them. The same thing reverses it self in the late afternoon. It is all controlled by a PLC (programmable logic controller) which I programmed to raise and lower the panels relative to the time of day and the month of the year. My experience as a Microsoft Certified Trainer (MCT) and MCSD, MCDBA, MCSE and 3 years of electrical engineering, retired P.Eng. and a lot of Ontario Hydro's system training all helped with programming the PLC and designing a maintainable system.
UPDATED JUNE 2014:
Our 22.5 degree pitch garage roof was in fact a bit of a blessing. The lower pitch angle allows the sun to hit the east panels up until 5:30 pm or 3 hours after solar noon. That is a real good thing making our harvesting curve much fatter. The array results: The east/west array produces or harvests 25% more than south facing panels from April to Sept or 45% more than static east facing panels. Putting the panels into any type of cooling wind also helps it to produce more power.
System Optimization - Maximize Your ROI and Gross Income
NOTE: In Solar Harvesting in Fixed Roof mounted systems, South Facing Panels are considered the best orientation to have. Therefore any optimization will compare the results to our South Facing panels.
Understanding Solar:
Because the Earth is tilted on it's axis, we get seasons as we orbit around the sun. We are actually closer to the sun in the winter than the summer. On Jan 3 the solar radiance is 7% higher than on 3 July. The sun moves across the sky in what is called a "great circle". The Earth's rotation stays the same so movement in time from solar noon is about the same all year round. Solar noon in Windsor during daylight savings time is 1:34 PM. That is one hour for DLST and 34 min for time zones. The tropic of cancer occurs at 23 degrees 26 min north of the Equator and reverses in winter. For summer with a 22.5 degree roof, your panels should be latitude minus the sun's latitude or 42 -23.5 or 18.5 degrees. We have a 22.5 degree roof. That means on the 21 June the sun is about 4 degrees past optimum. That is good. It means that we will get more intense sunlight as it moves during the summer months on our panels. With the longer summer days, the sun rises at around 6:10 AM and sets around 9:10 PM.
Compare that to the winter months in December sun rises 9 AM and sets 6 PM on daylight time for comparison. With standard time that equates to rise at 8 AM and sets at 5 PM in December with a real time effective sun at 9 AM and setting at 4 PM. So summer gives us up to 7 hours more sunlight to harvest or almost double the Winter hours. Because the angle in winter is so bad, we don't get a good concentrated sunlight on our panels and we get less sunlight all amounts to much less harvesting.
You will find on the internet that the best orientation of your panels is considered to be on the angle equal to the latitude for a yearly average. Here in Windsor that is around 42 degrees (see Feedback note below: most likely 30-34 degrees or around a 7:12 pitch). That will look terrible on a 22.5 degree roof (5/12 pitch) so mount on the same angle as your roof or in my case you would NOT have a happy wife. Don't worry too much about your roof pitch as there is little that we can do about it.
What is the effect of Not having the Perfect Angle of Attack?
If the Perfect Angle for Winter is 65 Degrees (42 + 23.5) you would get 100% solar input for your Panel
If that angle is reduced to 60 Degrees, then you would get 99.6% or the cosine of 5 degrees
In Winter, my 22.5 Degree roof is off by 43 or 73 % of maximum
with about 7 hours of usable sunlight (took away 2 hours)
For March 21 the sun is over head at the equator so you have 42 -22.5 or 19.5 degrees = 94.3%
with 10.5 hours of usable sunlight
For June 21 you have 42-23.5=18.5 -22.5= -4 or 99.7 %
with about 13 hours of usable sunlight
*I took away two hours from sun rise to sun set until we get good light on our roof.
Spring and summer hours might be 1/2 hour more sunlight.
You got to love the Spring, Fall & Summer for Solar Panels.
NOTE: I had some good feedback on what is the best angle for fixed roof mounted solar panels. On December 21 the best angle is 65.5 Degrees: On 21 March that becomes 42 Degrees: On 21 June that become 18.5 Degrees. I did not go further on this as I have a fixed 22.5 Degree roof and anything else is a Moot point. It did occur to me and others that the ideal is most likely less than 42 Degrees because of the longer days. One reader believes 30 Degrees is the optimum value. I can not disagree with this nor agree 100%. I would like to have that 7:12 pitch roof but I don't.
I do however have some real world inputs. Another location has 20% more DC installed than we do (they have a higher tariff rate and are permitted to have more DC generation). The angle of their roof is around the 42 Degree mark. On the 24 December they had a peak output of 9 kW (outstanding as you will be limited to 10 kW from your inverters). Ours was 7 kW with one south panel not producing maximum and 8 panels on east and west total. They have mono and we have poly panels. Mono can produce a bit better in the cold and poly in the hot days. If we had 20% more DC then we would have produced around 8.4 kW peak output. Now account for the poor angle that we have and we did excellent. It is also reported to me that that person does very well in the summer as expected. Remember, the sun rises SE at this time of year and NOT due east. That makes south facing panels extremely desirable from October to March. South facing panels do well all year round. When we have the optimum solar angle of 22.5 Degrees that person will still be at 42 Degrees. Our East and West panels produced double of normally statically mounted panels, but still only about 75% of the south panels in December. They are optimized for the period from March to October when we have longer days and the sun rises and sets a lot more from the east and west. I expect to slightly out produce this person in May and June because of our roof angle is better suited for the spring and summer and fall.
I wanted some East and West facing panels to widen my histogram or in plain terms harvest the solar energy as early as possible in the morning and as late as possible during the evening.
I STRONGLY DO NOT RECOMMEND NORTH FACING PANELS
You may be laughing. Some one put them on a house in Windsor.
Again, some horrible people in this business.
Even with 6 panels being shaded by two tree trunks and 3 panels being shaded by the garage roof until noon, we produced just under 40 kW for the day. One tree is now 9 feet lower and the other will also be lowered shortly (removal is a Work in progress). I expect that all shading issues will vanish as the sun rises higher in the sky in January through March as we gain on average 7 degrees per month. We started to produce 2 kW at 9 am and 5 kW just after 10 am and peak around noon. The curve is below. All in all, the 24th of December was a great solar day with only intermittent clouds. The wind gusts required that I lower the West panels earlier than I wanted to. Just after noon time, I happened to notice that a solar tracking array had to lay flat because of the wind. I was able to keep the East panels up as the wind was from the NW and our main house roof sheltered the panels from the wind. The panels automatically lowered after 5 PM when we were gone.
UPDATE: Both Tree trunks now lowered to prevent shading.- 26 December 2013- May 2014 both tree trunks are now making great garden supports for our veggies: ie they both have been cut down.
Any shading will significantly reduce the panel's output. See below.
Solar Edge Optimizers Saves the Day:
NOTE_2: Seeing is believing. I had to strain my eyes to see the very faint shadow cast from these two remaining tree trunks located some 35+ feet from the roof. The reduced panel output was horrible. The optimizers prevented the entire string from producing 50% less. You could see the progression of decreased output as the shadow moved across that part of the roof in the morning finally ending just before noon.
In Winter, the sun rises from the South-East and sets South West. That means both East and South panels see the sun as it rises.
In the summer as the sun rises from the East, our South facing roof has a delay before the sun hit the panels. At that time of the year, the East and West have a big advantage. The angle of attack is very good, the duration of solar harvesting is great. Temperature is your biggest nemesis.
The Sun Does NOT reduce its energy output in the Winter.
We are actually Closer to the sun in the Winter. The problem with solar panels in Winter is the shorter days, cloudy skies and the low angle of the sun in the sky. Here is a graph of our actual solar output on a relatively good sunny day on 24 December 2013. Net harvesting was just under 40 kW and should have been about 45 kW except for some unexpected shading from two tree trunks located 35 feet away from the roof in the process of being removed. One cut back, one left to remove. The tree has to be cut in small sections and lowered to the ground by rope. The sections are very heavy. Always remember safety first. Tie off your ladder, go slowly and have a ground person to steady the ladder. The base of our trees are 18" in diameter. We bought a 16" electric chain saw to help with the larger sections. For the branches, I used a $5. bow saw on sale from Princess Auto. See my tree cutting post.
The 5 kW value was reached at around 10:15 AM. The data is gathered every 15 min. The drop to 4 kW was not for more than 5 min and should be ignored. The above histogram is great. Power rapidly rises from 9 AM to noon and maintains good output until 4 PM. This is mainly because of our south facing panels and the fact that the sun rises in the South of East and sets in the South of West. The East and West panels did very well because they were moved throughout the day. They produced 75% of the value of a south panel. Normally that would be about 33% of South if the panels were not moved.
To summarize:
Assume we have a 2 square feet of solar panel. In the summer, the sun will cover that panel. In the Winter, the sun because of its low angle will cover say 27% less, thus fixed panels lose out if the angle is not around 42 degrees. If we tilt that panel to say 65 degrees, then it is the same as summer and we harvest even more energy because the cells work better in the cold. The solar radiance is more better than summer (we are in fact closer to the sun in winter and the radiance is 7% more on 3 Jan than on 3 July in the summer). It is the angle of attack we need to address. Besides that, a much bigger winter time problem is cloud cover which happens about 80% or so of the time. We still produce some power, just not as much as we would like.
Temperature Effects:
Temperature is your next nemesis. East panels out produce west panels in the summer, simply because they are cooler in the morning. The heat coming off of your roof will reduce the output. I had the top panels positioned to maximize wind air draw from under the panels. We also improved the air flow around the array panels to optimize the cooling of the panels. Being a Mechanical Engineer helps with understand fluid flow, heating and cooling. The best month is May. It should be June but temperature play a big part here.
Panel Selection:
Poly-crystalline panels are better in hotter climates than monocrystalline. Panel type selection is not a simple thing. Poly also does have some small advantages in low light conditions (1-3%) and angled light sources. Mono panels can also produce the largest output up to 310 W for 60 cell units. Manufactures advertise that their poly panels have the best - 96% low light radiance and indirect light performance.
The best panels out there are the SunPower mono panels.
FORGET about using them in Canada.
You can't get them, and they are not CSA approved.
They must be installed by a registered SunPower installer in the USA.
But you can learn a lot from their site so go follow the link. Take a real close look at Solar Reliability and watch the videos. See what happens when your panel has a small amount of fouling, like a couple of leaves or some dirty bird. In a normal panel you loose 1/3 of the panels output. Using string inverters without optimizers means that you just lost 1/3 of your strings output. That is why monitoring is so important and having optimizers is so important. You may even get a squirrel to chew up one of your wires. It recently happened in Windsor solar panel installation.
We used a Tier One panel manufacture and selected a panel that gives us more output than regular panels with a Tedlar backing.
DC to AC Inverters:
Not all things are created equal. Straight String Inverter System are widely used for Solar Panel Systems. They are the cheapest but not the best system to use. The main problem with String Inverters is if one panel starts producing low power output due to fouling, leaves, bird droppings, shading, etc; THEN all of the panels on that string also reduce their output. The higher voltage lines also help to reduce your energy loses on the roof. Make sure you buy a system where the voltage at the panels drops to 1 V when turned off. The Firemen are aware of this hazard and we should be good citizens and install equipment that will protect them. The Solar Edge inverters/optimizer system reduces voltage at the panels to 1 V when turned off.
A 350 V DC system is much better than a 240 V AC system. That reduces your transmission line loses.
Micro Inverters look like a good alternative but they are not IMHO. Add in the expected early failure rate (IMHO), extremely poor maintainability (they are located under the panels on the roof), and the 240 V lines, plus the huge cost for all of the parts required to put them together. Micro Inverters do include a system monitoring program.
I recommend that you AVOID, AVOID, straight string inverters and micro inverter systems.
What are Optimizers?
Optimizers are used only on string inverter systems. They look at the panel output from their panel (you need one per panel) and add it to the string output without lowering the output from the string. Thus eliminating a major flaw when using string inverters. They also "talk" to the inverter. They are a MUST HAVE component of any solar panel system that uses string inverters. They also give a panel monitoring system.
How do Optimizers Work?
This is my best guess only. Every solar panel output power at around 37 Volts and for 250 W the amps will be 6.75 A. The bus or line voltage is maintained at around 350 V in a SolarEdge system and not the normal 600 V that others use. Power is the product of Voltage times Amps. If you electronically increase the voltage from the panel to this 350 V value, then the amps must decrease accordingly. For a 250 W input the amps will be 250/350 = 0.71 A Now add a second panel and you will double the amps. If the panel is producing half power, then half the amps will be added. With no power it is like a short and like the panel is not in the circuit. Now knowing the power from every panel in every optimizer, you can monitor your complete system.
Remember, Optimizer DO NOT produce AC power, or any DC power and NO inversion of the power occurs at the optimizer. Thus NO APPRECIABLE HEAT is produce in the units. DC power is one continuous straight line pulse. AC power is a sine wave. Capacitors are needed to convert the DC to AC power when connecting to the Electrical Power Grid -AC. The best ones to use are electrolytic caps but the down side is that they have a shorter life. Big Inverters like Solar Edge can use larger capacitors which have a longer life span. The String Inverter companies have operating history and know that their caps will not last much over 12 years or so. That is one of the reasons IMHO that smaller micro inverters will also experience similar failure rates. Do NOT confuse mean time to failure with life expectancy. MTTF is totally NOT applicable here. They will try to BS you as they did me. It is also why a it is a good reason in this case to buy the extended warranty from SolarEdge for about $400 per inverter.
When I taught my students programming, database and computer repair I would tell them to watch for these two rules:
1. Common sense is not so common.
2. Good advice is seldom followed.
When something went wrong, I would ask the adult class, well which one was it? It always brought a good laugh.
Your can achieve all of the benefits of a Micro Inverter System with elimination of most of the problems by using a String Inverter System with Optimizers. Although not really known, they must add at least 10% to your system income alone (some say 24%). Sometimes a lot more. They also give you a monitoring system so you can see if a single panel get fouled or is not working properly. The main draw back is cost but lower than a micro inverter system. They do not however generate heat and the capacitors used have a much longer life (ceramic capacitors) making claims of 25+ year life seem realistic.
Most Micro Inverters use Electrolytic Capacitors (with
8000 hour life capacitors NOT the 100,000 hour life needed here) which have a much shorter life span. So string inverters with optimizers is your first optimization step. It add a huge flexibility in panel orientation and design.
You can't mix east, west, south panels with normal string systems.
You can with a String System that has optimizers like SolarEdge.
The SolarEdge engineers are smart enough to give you 300 W (60 cell), 350 W (72 cell) , 400 W (96) and 600 W options not like others who started at 190 W and then 215 W maximum power output. Considering panels today can produce 250 W, 310 W and 400 W + what are they thinking? Why limit your system output in you inverter if you don't have to? The SolarEdge optimizer selection is also based on the number of cells in the panel, so make sure you get the correct optimizer.
UPDATE APRIL 2014: Go with the new 400 W optimizers
Place your SolarEdge Inverters in a protected area that is easily accessible for future replacement of the Electrolytic Capacitors. Buy the twenty year warranty for around $400 per inverter. Beware of over charges.
A Closer Look:
Let's look at that a bit closer. Let's say our 10 kW install will bring in $5500+ gross per year (SolarEdge) It will gross $110,000 over twenty years. At the end of that period you tie to the Power Grid and still make money but pay no electric bill. A straight string inverter system with out optimizers would bring in a lot less money($10,000+ less). In fact our system just will not work with that type of system as we load balance each inverter with the east, west and south facing panels.
We are very fortunate to have a large truss roof that faces north and south. Our roof pitch is 5/12, where a 7/12 would be much better. We have what we have and that is it. Our garage is also a blessing as it faces east and west. After orientation, temperature is you next nemesis. East panels out produce west panels in the summer, simply because they are cooler in the morning. The heat coming off of your roof will reduce the output. Poly-crystalline panels are better in hotter climates than mono. But panel type is not a simple selection. Poly also does have some small advantages in low light conditions (possible 1-3%). The best panels out there are the
SunPower mono panels. But, forget about using them in Canada. You can't get them, and they are not CSA approved. Some mono panels also have much higher efficient silica giving you more power for a limited area. This is changing yearly.
Now optimize the system a bit more and increase your harvesting by +10%. That equates to $121,000 over twenty year. Your ROI just rose $11000 with a small increase in your capital investment (about $1200). This was achieved though proper panel selection. We used a Tier One manufactured panel that simply out produces all other panels. In this case what you see is what you get.
A word on panel selection. There is a test facility in
Kortright that some manufactures use the results to show that they have the best panels. This should be a good thing but it is open to abuse or manipulation by smart marketing managers. The purpose of this site was to demonstrate that ALL Tier 1 Manufacturers produce good quality panels which they do. An error was made during the flashing of the 72 cell panel. The flashing equipment was not calibrated for 72 cell panels. You will see that most mono panels produce the same amount of power. Their is no real difference here. What has happened, is that some manufactures have increased their prices based on this site, claiming to be the best. A closer analysis would show something different. Panels lose up to 3% of their output after 1-7 days of burn in. A smart marketing manager would select their best panels, burn them in and then rate them and then send them in for testing. Rating panels for Ontario is a whole other discussion that I will not go into at this moment. Mono offers higher outputs at times and may be the best choice if you don't have enough roof area. That is the case of my garage array and mono would be a good choice for it. Mono panels at the time had a cost factor exceeding 40% over our poly panels with very, very little improvement in output. It all comes down to ROI and cost per Watt. I hate to pay more money per Watt than I need too. Panel efficiency keeps improving so we may see some good things in the near future. Most of these panels produce the same output. All are good. There is only one panel with a 72 cell configuration. Apparently, it was not properly flash tested with a 72 cell standard and a 60 cell standard calibration unit was used. Again, these panels are still high quality equaling all of the other manufacturer's in Ontario. Heliene Canada also make the highest efficient cells and the largest panels available at 440 W. When people use high quality silica like this, they normally don't cut back on other parts of their panel design. They also have an amazing 335 W 72 cell with 17.7% panel efficiency. The biggest problem we currently are facing is low efficiency solar panels at or below 15.% or so. I love the approach that Heliene ans Silfab are taking with their 17.7% efficient panels. Using their 72 cell 335 W panels mean fewer optimizers to buy and more room for more panels.
I am waiting for the day that 20%+ efficient panels are available. That means a 60 cell panel will give us around 300 W. and not your typical 225-240 W. I understand that they are working on a 40% efficient solar cell. Cost will be a factor. We don't have the $300,000,000. spent of the solar panels for the Space Station.
IMHO every 60 cell or 72 or 96 cell manufacturer with a Tier 1 facility like:
Heliene Photovoltaic Modules
Eclipsall Energy Corp.
OSM Solar Corp.
Silfab Ontario
Solgate
and others should all produce good quality panels. With cut backs in pricing, you do have to watch that all of the panels components will last your 25-50 years. Speak with the guys from Flexible Solar , they will tell you what you should buy. We shouldn't have to pay more for the illusion that you may see on this site. Pay attention to the panel's efficiency, construction materials and performance. A lot of manufacturers use the same silica waffers. Some use better quality silica and that is we we should focus on as long as the panel is build to a high standard. Beware of none Tier One manufactures. Tier One is fully automated with clean rooms and a robot to do the work. All panels need people to attach the box at the back of the panel. Some may have difference in design that you may like. To me, it breaks down to ROI. Other factors like minimum roof area will benefit from higher efficiency panels. There is always a variation from one panel to the next. Some people separate the better panels out and charge you more for them. Some don't do this.
UPDATE April 2014: We installed 5 Heliene 72 cell panels with excellent results. After a 2 week burn in the panels are producing 23 % more than similar 60 cell panels. So the test facility results are lower than we are seeing. We are very, very happy with these polycrystalline panels. Again, most panels are similar. I choose poly for the best ROI and low light performance.
A word on Panel Backing Materials
In this era of cutting corners, make sure that the panels all use good quality frames and backing. We recommend using Tedlar backing most likely in a T-PET-T sandwich. Tedlar is proven to last 25+ years. The purpose of the backing and encapsulation is to hold every thing together and seal if from any moisture or oxygen penetration that will corrode the junctions. Historically Tedlar (PVF) from Dupont was the standard backing material. It is very pricey and some people are using alternatives. One of these is Kynar (PVDF) which apparently has been used in Germany for over 25 years. It appears to be a good replacement for Tedlar. Another solution is to use a Tedlar-PET-Tedlar sandwich which is also good. Straight PET was found to be cracking in Spain after 4 years (see references below). It has become the old "buyer beware".
Exposure or Daily Harvesting Optimization
I recommend that you install the maximum amount of panels that you can. More panels normally have a lower cost as you have to over come the fixed system installation costs. Now take 20+% of you harvesting equipment and make it work from sunrise to sunset if you can.
South Facing panels will work better in year round simply because the location of the sun. they even turn on earlier from October to March because the sun rises from the South East and not due east.
East and West will have more time of exposure provided there isn't any clouds in the summer.
Clouds are a huge penalty in late fall and in Winter. January is normally much sunnier than December.
In the Winter months we get about 8 hours of total sunlight, 7 good hours after we clear the neighbors houses. Our 80% South facing panels will produce for much of this 7 hours. It is fun to watch how much more the ridge line panels harvest due to longer exposure times. All this time the sun is low on the horizon so the concentration of sunlight is much less than in the summer. There are no racking systems that you can adjust seasonally to make harvesting more efficient. Besides, most people would forget to adjust them anyway. At the same time our east/west panels are lying flat they harvest about 1/3 as much energy as the south panels. So by automating the movement of your east and west facing panels though out the day, you increase the direct exposure on the panels by at least 2 times in winter and possibly over 3 time in the summer compared to south facing panels. Testing in the winter has shown east/ west panel output to be about 75% of south with our positioning array. This will improve after 21 December as we get closer to March 21.
That means that our 2 kW panels will act like 4kW (winter) (Proven) and most likely 6kW (summer not proven yet) of installed panels as compared to your fixed south facing panels. We are limited by the peak of 10 kW at the inverter. We want to widen the harvesting time as much as possible. That means more East/West harvesting.
We want to optimize the system for Summer when the days are longer and the sunlight is more concentrated.
South facing panels have long been thought to be the best orientation. Here we are just being a bit creative. We are limited to installing 10 kW DC unlike the original people who could install any amount on the DC and they also got 85 cents per watt.
Remember, your inverters are limited to 10 kW. So why the DC limit then if you are a 10 kW microFit system? With so few people installing solar panels and the need to lower our CO2 levels is so great there should be no limitations other than the 10 kW which would be better at 20 kW DC.
When I worked in Ontario Hydro's Nuclear operations as an Engineer, all we heard was Solar and Wind energy should be used. Now, people complain about Wind Turbines and Solar Panels, go figure. We always thought that there was nothing wrong with a little "Nukie" (humor). This was long before CO2 levels were considered to be an issue. We can produce more energy than we use. Solar and Wind Energy harvesting does not produce any of the harmful by products of conventional electrical generation.
Cost of panels has significantly decreased from over $800 for some to around $200 per panel. Greed by the utility, local governments and ridiculous regulations in some cases significantly increase the cost of the system. Your inverter costs have also significantly been reduced. We have a manual shutdown switch for the arrays on windy days and are playing with adding an automatic wind speed shutdown switch plugged into the PLC.
Optimization of the 8 East and West Solar Panels
A closer look at our East/West dynamic positioning system gives us a morning peak perpendicular to the sun, a noon orientation and afternoon orientation that again moves the panels to the best harvesting position based on our roof.
That is 3 peaks per panel every day verse one and all day harvesting.
I could design the system to give me 3 more peaks per day but that makes things a bit more complicated. I will how ever look at the benefits of doing that later. It means a lot more control equipment.
Another factor to consider is that the sun rises and sets at different times of the year and changes on a daily basis. I programmed the PLC to correct for this on a monthly basis. I could have programmed it on a daily basis but deemed it not worth the trouble.
So in summary, our $6000 income can be increased by a minimum of $1000 per year conservatively by moving the panels though out the day in order to maximize the solar harvesting. The ROI of the added cost is around 7:1 in our favor. That should upset the utility who openly hate this green energy program by evidence of their actions. They only want to support big business wind turbine or solar panels Fit programs. This is not the $12,000 +per year for the original contracts but we do win a lot more.
Enough to pay for the entire system.
Based on the conservative $7000 per year gives us a gross income of $140,000. ($7k times 20 years).
This is not like winning the Lotto or becoming a Senator but we can maintain our honesty and still have a nice living.
It pays for a big part of our living expenses.
It is a much better option than some of those "deals out there" that offer up to $100,000 gross income. Go figure.
What did we just learn?
Going cheap we lose big time in the long run.
That the cookie cutter systems sold by most companies end up costing us $40000 over the life of the contract. That approach seems wrong to me. Does it to you also? You must get an installation company that is willing to work with and for you.
MicroFit Roof Mounted Solar Panel Optimization Summary With Flexible Solar
1.0 Use SolarEdge Inverters with SolarEdge Optimizers (click blue to see comparision with straight string inverters and micro inverters)
-I estimate +10% annual savings. Adds a panel monitoring system.
Independent testing has shown significant savings with optimizers - up to 24%
. Expect $12,000 life time savings (10%).
2.0 Choose a select Tier 1 Panel Manufacturer (details via FlexibleSolar only) +10-15%
Initial Testing Results show 15%+ or $18,000 maximum
3.0 Dynamic Array System -estimate up to +20% (add 2 kW to 10 kW). We have a 2 kW array that has good exposure to the sun from dawn to dusk. I estimate 2 to 3 times more power generation than straight south, east or west exposure because of this. It is like adding 2 -4 kW's on solar panels more to your system which you are not permitted to do. Standard East or West mounted fixed panels do poorly between October and March. On a test day on 24 Dec the array produced twice as much harvesting as statically mounted panels but 25% less than south panels. This will change as we get out of the winter conditions.
Initial Testing Results Show 2x's Static Panels for December -
This gives a minimum 2kW+ of installed capacity for East and West Panels
Summer 3x's not determined yet. Proof of concept is working perfectly.
On Target for $24,000 pay back or more.
You can do this.
4.0 Apply all of the above and put money in your pocket before program is ended and you miss out on getting your 20 year contract.
NOTE: The SolarEdge Optimizer system IMHO is much, much more flexible than micro inverters. Both contain Electrolytic Capacitors used to create AC power from DC. Both should start to fail after 10-12 years. Having them easily accessible reduces this cost by $1,000's of dollars. No one wants to go up on the roof and start removing panels every few weeks. It could take months to get some one to do that and you will be losing money. The micro inverters also are normally limited to 250 Watts where the SolarEdge give you a much better range and thus don't limit your design to low Watt panels. For example if I take Heliene's 335 W 72 cell panel on a 250 W micro inverter the max that I can get is around 250 Watts. Using a 350 Watt optimizer, I don't lose anything. Plus the Optimizers use Ceramic Capacitors which have a much longer life span. We also opted for the 20 year warranty extension with SolarEdge. Having a 25 year micro inverter warranty is not much good if you have to pay $200 + to have them replaced. Also the connectors for the micro inverters are so expensive that it costs you more to install that type of system.
Act NOW! ..................Before it's Too Late.
If the Conservatives get into power they want to stop this green energy program. They only want to help big business Fit Programs.
Engineering Installation Specification
I wrote an engineering specification which you can use with your supplier. That is what Mike Holmes would tell you to do.
Experience with Local Installers
After speaking with half a dozen or more people locally, we saw immediately that the FlexibleSolar people were the only ones interested in getting us the maximum return on our investment while maintaining the high equipment standards necessary for a 25+ year investment. It was a breath of fresh air working with Steve and Glen. I was working closely with a local PV manufacturer until they decided to ignore my engineering specification. It was a "bait and switch" operation that failed. Another supplier tried to put me down at one of my recommendations that will make us over $12,000 over the twenty year contract. Clearly these people are not customer focused. Another customer told me to stay away from Tigo optimizers as he had a poor experience with them. Perhaps they are better today. That leaves you thank God with at least one good company. Another big name string inverter manufacturer developed micro inverters verse optimizers. Again, 10 year warranty and a horrible location to maintain under the panel. They might have optimizers in about 2 years. Poor choice IMHO.
IMHO if you see one lie, run from those people. Mike Holmes says that 80% of contractors are in it strictly for the money and not for the customer. I am sure that Mike would like my ideal of an engineering specification to layout the quality of the work to be performed, and the payment method. We worked closely, and at time, correcting or adjusting my specification when warranted.
Discussion:
Beware of large down payments. I prefer a small 10% down and an immediate give a check for the equipment as soon as it is delivered to your house. This prevents people from grabbing and running away with your money. One guy suckered 15+ people into giving him $30,000 and he was gone. Another local company has over 300 home installed but not connected . Both the customer and installer should equally benefit from the payment specification. IMHO as soon as you get the equipment, pay them from you LOC. It will help to keep the costs down. All solar panel manufactures and I am sure all equipment suppliers want to be paid before releasing the goods. You simply want to prevent your self from paying large amounts of money and getting nothing in return. By the way, if that does happen, contact the RCMP as several of these cases can quickly turn from civil law to criminal law.
Get your offer to connect first from the Ontario Power Authority and then give out your money on the agreed schedule.
I hate to see thieves stealing from people and in many times retired people who can least afford the loss.
Hold back 20% until your are connected and your monitoring system is working. Then pay them.
Beware of hidden costs which your installer may or may not cover. Things like the building permit, engineering assessment of your roof, engineering review of the project, Hydro One's huge $1500. connection fee. Make sure that the MicroFit 22-26% Ontario content, CSA approved equipment, etc. FlexibleSolar are totally up front about any of these costs with you.
We went with Tier One manufactured solar panels, the best panel railing system, SolarEdge string inverters with optimizer to maximize the output of each panel and to give the ability to monitor each panel's output. We also have SS flashing over each attachment to the roof which will be a god send when the roof has to be re-shingled in 20+ years as they can be easily unbolted and re-used. Panel selection is very, very important. The good guys at Flexible Solar will make sure that you get the best panels with the best components built in.
A word about Inverters. You need to change the DC voltage from the panels to match the 240 V AC supply from Hydro. We went with string inverters with optimizers. We wanted to monitor each panel. String inverters IMHO must have optimizers on each panel. If a bird leaves it's droppings on one of your panels, it effects each panel in the string and lowers each panel to the lowest amount. Not a good thing. For a beautiful review of what happens when just a few leaves fall on one panel go to this SunPower mono link and see what they say. It is an eye opener. String inverters will need replacement or maintenance after 10-12 years. We went with the low cost additional 20 year warranty. We positioned the inverters in a semi protected area on the north side of our house next to the Hydro meter. I must add, IMHO all inverters using electrolytic capacitor will need replacement in 10-12 years and that includes the popular Micro-Inverters which in the end, cost a lot more money to install and maintain. I am NOT alone in this line of thinking. My system design and philosophy does reflect what I learnt as a Professional Engineer working for the local power company in operations.
IMHO my system will result in up to 20-30%
+ higher returns on our investment. This is not BS but the simple application of proven engineering principles when designing your system. I designed and built a simple dynamic sun following array of 8 solar panels, 4 each on the east and west roof of our garage. Each array is powered by two actuators that automatically raise and lower the 4 panels to best collect the sun's energy though out the day. I estimate that this will result in harvesting 2 to 3 times more energy than a static roof mounted panel system. It has a PLC (programmable logic controller) that is used to make the system work. Think about it. Our south exposure panels are calculated to collect energy for 4 hours per day at peak rate. Now point the panels from sunrise to sunset to follow the sun and you get up to 7 hours a day in Winter and 14 hours per day in Summer. Remember that the system is self limiting because you only have 10 kW DC/AC inverters. This unique design can be fitted to your system to maximize your ROI (return on your investment).
We went with the SolarEdge string inverter system with optimizer I researched micro Inverters and at the time IMHO believed that their 8000 hour capacitors would not last 100,000 hours as indicated by the failure rates posted by the string inverter manufacturer's who should know best. Remember, the maintainability is extremely important for a system that will last you a life time. It is the customer who must pay someone to replace the micro Inverter when they all fail after 12 years regardless of the posted 25 year warranty. We put the SolarEdge Inverters in a sheltered north side of our building next to the power meter. It keeps them in the shade all year long and parts can be quickly replaced when required. We opted for the 20 year warranty extension. It was a no brainier to me. Almost anyone can turn off the system and replace the capacitors or boards that simply pop in and out. Remember to wait 20 minutes after you shut the system down. There are all kinds of isolation switches: one on each inverter, a breaker for each inverter, a main disconnect switch from the grid.
If you have any questions, please contact me at KW Masters Photography and I will put you in touch with Steve or Glen at FlexibleSolar. Our contact information is above via the menu bar or click on our link. Pictures and stat's will follow as soon as they are available. You can even have our dynamic solar positioning system installed at your home. This extra is not cheap but the ROI is significant. I am a customer and not associated with FlexibleSolar. I assist them because I hate the sales practices of other people that I have seen in this business. We were careful and did not get ripped off. I do offer the dynamic positioning system to FlexibleSolar Only that I designed, coded and built so that you too can benefit from my research and work.
Thanks for dropping by. Give us a call if you like to talk about this (use CONTACT at top of page), or by drop in to discuss your project. Seeing is believing. An educated consumer is the best customer. We will have a monitoring system with this install. Drop us a line and tell us if you like what you see! Remember to tell Steve or Glen about this post if it helped you to make your decision to go with Flexible Solar.
NOTICE: We are on track to earning over $140,000 on our 20 year contract.
After the 20 years we will Grid Tie and sell power at going rates:
Author: Kirk Masters B.Eng, MCT, MCSD, MCDBA
Reference: Here is a comparison with Tigo and Solar Edge
One of the First People to go Solar with Ontario's MicroFit:
Cost of Solar Power verse others - Good INFO Here
Getting the Panels with the Best Backing
Solar Panel Construction Component Studies
Dupont's Tedlar Backing
Alternatives to Tedlar Backing
More Alternative from Dupont for PV Panel Backing
Government Testing 15 year exposure of Backing
Another Backing Study
