diy solar

diy solar

Meeting with a solar installer this week

petee_c

New Member
Joined
Feb 20, 2021
Messages
64
Location
just outside Waterloo, ON Canada
Hey all,

I'm meeting with a Solar installer via Google meets this Thursday to begin preliminary discussions on getting a solar array installed on my home. I am in SW Ontario, Canada. at approximately 43.5degrees N Latitude.

roof.jpg
My southern facing roof is about 185-190degrees... I have large trees on the neighbors properties to the south. This is clipped from google maps the image must have been from a couple years ago Looks to be mid summer?. There have been some changes that I'll list in the below picture.

solarsuervey1.jpg

The 3 red X's mark 3 ash trees that are now gone. Orange X is a blue spruce that is gone. Purple X is play structure that has been removed. The purple circle is the neigbors Maple that will shade part of my southern roof during the afternoon....

In 2021, we used 13386kwh (cost $1876 cdn) of electricity throughout the year. In late 2022, I am hopefully going to be driving a EV which will use about 3900kwh of electricity per year (20,000km/yr). I want the system to pay for itself within 10 yrs. We have net metering in Ontario, and no other incentives that I can find. I can pay cash for the system, unless there are some really good financing somewhere, but my municipality doesn't over anything at the moment....

My rough guesstimates are I can put about a
4.7kw array on the South roof
2.7kw array on the East Roof
3.4kw array on the West roof (the west roof is angled about 280degrees, so a touch to the North) I can fit more panels on the West roof, but not sure where the most cost effective number is.)

I estimate the roof to have about a 30deg pitch all around, though I am just eyeballing it from the street.

PVWatts estimates that this should get me about 12500kwh/yr of solar if I can place them in spots that minimize effects of the shading.... I am a little worried about the blue spruce remaining in the front of the house. (Seen near the SE corner of the house), but I went out yesterday morning (Feb 12 @ 1034am) and it didn't shade the roof too much; so maybe I can better put panels on the East roof (~100 degrees)
front-house-bluespruce shadow.jpg

Picture of South roof at 1030am on Feb 12.
southroof from street.jpg

Any thoughts?
 
Are you attempting to max out the solar? For best value I believe providing around 80% is best depending on the rate tiers or TOU charges.
 
I don't understand your reply.

80% of what?

One question would be would you place a panel on a spot on a southern roof that might be shaded part of the day or on a western roof that is not likely to be shaded in the afternoon, but not get sun in the morning?

Peter
 
Do you have a sliding scare of rate tiers? Such as the more usage is charged at a higher rate? The idea for best value is to mostly just avoid the higher rate tier. Maybe post a recent electric bill.

Shading is tough. Your own intuition and the sales person will have better insight. Best to avoid shade. Maybe even trim or remove the tree if it turns out worse than expected.

Does the area have morning clouds or fag as a weather pattern? If so these would favor the panels getting afternoon sun.

If you have time of use rates (TOU) with higher rates in the afternoon, this again will create more value for the west panels getting evening sun.
 
...3900kwh of electricity per year (20,000km/yr)...
The average EV is about .17 kWh/km (ref), so 20,000 km x .17 kWh/km / 90% charging efficiency = 3700 kWh. ✅


In 2021, we used 13386kwh (cost $1876 cdn) of electricity throughout the year. ... going to be driving a EV which will use about 3900kwh of electricity per year
So, yearly usage 13,386 + 3,900 = 17286 kWh/y
For a net-zero, you'd want 17,286 kWh of power consumed. Assume 92% inverter efficiency you'd need to generate 18,789 kWh.

Southwest? Let's assume Dryden and grid-tied so you can optimize for year-round.
That's about an average insolation of ~3.9.
1644847495565.png


4.7kw array on the South roof, 2.7kw array on the East Roof, 3.4kw array on the West roof
4.7 + 2.7 + 3.4 = 10.8 kW

You used PV watts, so your numbers are probably more accurate, but with an average daily insolation of 3.9, then to achieve net-zero the array size should: 18,789 kWh / 365 / 3.9 = 13.2 kW

...I am a little worried about the blue spruce ...

The sun is pretty low that far north...

SAM (the full free version of PVWatts) has a shadow tool built-in. See the
tutorial videos for how to use it.

I'm at 25° and it's amazing how far the trees south of me cast shadows
onto my roof during the winter solstice. Microinverters are a lot better than
string inverters for shade issues.

You might also want to check to see if anyone can recommend panels made
for snow coverage (e.g., some panels are split, so the bottom half being
covered only gives a proportional power reduction).
From sunpath3D, you can zoom and reorient...
1644848805800.png

Any thoughts?
Nice looking place! Hope that's of some help!
 
Assuming your permit to generate net metering contract pays the retail rates.... keep in mind much of the solar produced will get paid at 17 cents and overnight charging of the vehicle will cost 8 cents per kWh. This allows you to produce less than your annual usage and still come out ahead on the economic side. Assuming more loads can be shifted to off-peak hours the system may only need to produce 60% to 80% of the annual consumption to zero out the annual billing. For example if you can cool the house overnight in the summer at the low rate and mostly keep the air off during the day... your cost of cooling the house will be greatly reduced. Other items like consistently running the dishwasher overnight will reduce costs by shifting the load to off-peak rates.

A smaller system will allow break even much faster because there is less capital to recover. Don't let the salesman talk about producing 100% of the usage unless there is some intrinsic value to be net zero usage.

My system paid for itself in five years due to favorable TOU rates and shifting loads to off-peak. My system produces about 60% of my usage and reduced my annual bill from $2500 to $100.
 
Off peak $0.082 / kWh
Mid Peak $0.113 / kWh
On Peak $0.17 /kWh

$136 for 1322 kWh, so the blended rate is ~$0.10287/kWh
$47 in other charges

So, the questions are:

Is a battery-only system to cover the peak rate worthwhile?
On-peak is 240 kWh over 32 days and represented 30% of your bill. 240/32 = 7.5 kWh/d for July.
Assuming you charge off-peak and discharge on-peak, that's a value of $0.17 - $0.082 = $0.088/kWh, or 240 kWh x $0.088/Kwh=$21/m

Assuming 2% inflation over 10 years and that all months have the same consumption year-round (most likely a very bad assumption) that's a value of $2759 over 10 years.

At 90% DoD an LFP would last 10 years (ref). Assuming 92% inverter efficiency, 7.5 / .90 / .92 = 9 kWh of storage. At DIY prices cells are around $160/kWh and add 10% to be installed, so 9 kWh x 160$/kWh x 1.1 = $1584. A 5 kW Fronius inverter would be about $1600 U.S., so at $3100 > $2759 it doesn't seem worth it. Be aware I'm mixing your Canadian costs with U.S. inverter prices, so it might be very different. Also, storage prices are always falling.

Is a solar PV system worthwhile?
It will depend on your net-metering agreement and installation costs. Peak rates usually don't overlap with prime time solar. Usually, you'll export the most power around 10 to 2, which is probably your mid-tier, so you might only get 11¢/kWh.

If your array generates 12500kwh/yr as per PV watts, then at 11¢/kWh over 20 years that's a value of $27,500 ($33,408 at 2% inflation). So, for a 10 year payback period the installed system must cost under $13,750 (or $16,500 for 2% inflation). Australians pay from $0.50 to $1.00/W installed, so that's a good deal. U.S. DIY prices are around a $1/W so again possible. It'll be interesting to hear what you get quoted.

Solar with Battery?
If solar is recharging the battery, then the value goes to the full $0.17/kWh. 240 kWh/month at peak rates x 12 months (again, a bad assumption) x $0.17/kWh = $489.60 / year. At 2% inflation over 10 years is $5,385.

Since you'll probably already have a hybrid grid-tied inverter in the solar costs, then the battery costs are $1584. Since $1584 < $5385 it seems like it might be a good deal (depends on the actual year-round consumption).
 
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I'll trade you my solar installation for your house.;)
Your house is so attractive you might consider not putting any panels on the east side. I've never seen a solar roof install that didn't detract from the appearance of a home. Can you use the west facing side of the garage, or is that shaded by the house? The north facing side of the garage might produce more than you think, it doesn't appear that it's ever in the shade.
 
I'll trade you my solar installation for your house.;)
Your house is so attractive you might consider not putting any panels on the east side. I've never seen a solar roof install that didn't detract from the appearance of a home. Can you use the west facing side of the garage, or is that shaded by the house? The north facing side of the garage might produce more than you think, it doesn't appear that it's ever in the shade.
thanks for the complement... it's just barely an average house for our street... lots of people here do a lot of landscaping and such. We just did our 1st big landscaping a couple years ago after being here for 15 yrs. We ripped out a bunch of overgrown shrubs at the front.

I am a little hesitant about putting panels on the front of the house, but will see what plans they come up with and decide from that.

I'll see what the installer says about panels on the garage roof. It is a lower roof than the main house. I'm thinking maximizing the west side even though it's a touch WNW may be the best option....

I was also wondering about maybe a ground array in the vicinity of the yellow rectangle in pic2 of the original post might be something to consider. it looks to be shaded by the neighbors tree, but I know he wants to take that tree down... plus the canopy is high enough that the shade it throws is barely on my side of the fence. If a ground array is not permitted, then a future shed build there with a south facing roof might be in the works at that location. I should time lapse that location during the day and measure how much sun that spot gets during the day.
 
I was also wondering about maybe a ground array...
I have a ground mount, it adds a fair bit of cost to the install compared to roof. And you have deep frost so piers need to be deep. Problem with roof mount is if you ever have roof leak it can get expensive. No easy answer.
 
Power's been down for about 5hrs total in the past 8 yrs.... I have a 3 yr old 3500w gas generator with less than 1hr runtime on it. Power here has been pretty stable.
I've been introduced to an interesting panel which can attach to the solar panel. They may cool the solar panel, which produces more power, and heat the fluid so you can get some energy there too.

Food for thought in this post.
 
Had the google meet with the 1st solar company today.... going to get a few quotes I decided. He explained the Net Metering to me, and he believes my utility does it based on TOU and kwH produced. So if I make good power in the afternoon, then I can get creditted power at a premium, and then can use those $ for the cheaper power that I would use in the evening when the sun is down...

I played around with tinkercad and took some pictures of the back of the house today too... (just had a big 24h thaw, so you can see the roofline better) I'm just a beginner at tinkercad, so don't laugh.

Here's the back of the house, and my southern neighbors trees at the property line.

1645159536569.png



I think I can only make any noticeable PV power from Mar 21- September 21st (EDIT: March 10th - Oct 1st) ?

March 21st at 10am
1645158819149.png

March 21st at noon
1645158974268.png

March 21st at 3pm
1645158907875.png

June 21st @0900h
1645159059162.png

June 21 @ noon
1645159125392.png

June 21@ 1500h
1645159225167.png
 
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OK, I have got 3 quotes.... They are all around $30K cdn after a $5K rebate. The quotes range from 14-16kW arrays paired to 10Kw inverters

At today's rates, it'll take me 15 yrs to pay off.... Of course, the solar companies all say hydro rates are going up, but I can't confirm this. I've reached out to OPG (Ontario Power Generation) and will see what they have to say....

I will likely have to replace my roof too, as I have '40yr' shingles, but they've been on the roof for 15yrs already.

There is supposed to be an interest free loan of up to $40K available - announced in 2019, but not running yet. https://www.cbc.ca/news/politics/liberal-climate-change-plan-home-retrofits-1.5296400

I'm getting a home energy audit done to qualify for the $5k grant.
 
Hey all,

I'm meeting with a Solar installer via Google meets this Thursday to begin preliminary discussions on getting a solar array installed on my home. I am in SW Ontario, Canada. at approximately 43.5degrees N Latitude.

View attachment 83660
My southern facing roof is about 185-190degrees... I have large trees on the neighbors properties to the south. This is clipped from google maps the image must have been from a couple years ago Looks to be mid summer?. There have been some changes that I'll list in the below picture.

View attachment 83661

The 3 red X's mark 3 ash trees that are now gone. Orange X is a blue spruce that is gone. Purple X is play structure that has been removed. The purple circle is the neigbors Maple that will shade part of my southern roof during the afternoon....

In 2021, we used 13386kwh (cost $1876 cdn) of electricity throughout the year. In late 2022, I am hopefully going to be driving a EV which will use about 3900kwh of electricity per year (20,000km/yr). I want the system to pay for itself within 10 yrs. We have net metering in Ontario, and no other incentives that I can find. I can pay cash for the system, unless there are some really good financing somewhere, but my municipality doesn't over anything at the moment....

My rough guesstimates are I can put about a
4.7kw array on the South roof
2.7kw array on the East Roof
3.4kw array on the West roof (the west roof is angled about 280degrees, so a touch to the North) I can fit more panels on the West roof, but not sure where the most cost effective number is.)

I estimate the roof to have about a 30deg pitch all around, though I am just eyeballing it from the street.

PVWatts estimates that this should get me about 12500kwh/yr of solar if I can place them in spots that minimize effects of the shading.... I am a little worried about the blue spruce remaining in the front of the house. (Seen near the SE corner of the house), but I went out yesterday morning (Feb 12 @ 1034am) and it didn't shade the roof too much; so maybe I can better put panels on the East roof (~100 degrees)
View attachment 83662

Picture of South roof at 1030am on Feb 12.
View attachment 83663

Any thoughts?
I know that any snow on my panels kills the power output. I would not count on much power in the winter unless you can remove the snow.
 
I will likely have to replace my roof too, as I have '40yr' shingles, but they've been on the roof for 15yrs already.

I installed 40yr shingles in 2010 and solar in 2019. As part of their service, the installer included in the contract 1 free removal and reinstallation of the panels if I ever need to reroof.

See if any of your installers offered or can include this perk in the contract. Then you won’t feel the need to reroof so soon.
 
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