949 kwh per year

[mchunman]

Hey guys,

Just collecting some thoughts on whether it's even feasible to build an off-grid solar system to run 6.0kwh/day worth of greenhouse equipment in the cloudiness place in Canada.

According to the Feds - this place only generates 950 kwh per year.

Utilities are charging 12.6 cents per kwh projected to increase to 22.0 cents per kwh when the new electric facility is operational.

No real budget in mind yet.

 

[snoobler]

Welcome to the forum.

What Feds? In what context does "this place only generates 950kWh per year" apply?

6kWh is a modest amount of power, but your northern location, possible terrain issues and weather may make it challenging.

Link #5 in my signature or link #6, if you can't find a nearby city, for your available solar hours.

Once you see what's available, you can formulate a plan or abandon all hope.

 

[mchunman]

Welcome to the forum.

What Feds? In what context does "this place only generates 950kWh per year" apply?

6kWh is a modest amount of power, but your northern location, possible terrain issues and weather may make it challenging.

Link #5 in my signature or link #6, if you can't find a nearby city, for your available solar hours.

Once you see what's available, you can formulate a plan or abandon all hope.

My bad - Feds - Federal Government Agency. Link to the 949kwh per year value: https://www.energyhub.org/newfoundland-and-labrador/
It may appear I'm using the incorrect solar terminology - sorry.

These are the values I get when I plug it into Link 5.

 

[curiouscarbon]

Need at least 4000W of panels in december to hit around 6kWh/day

 

[snoobler]

Yep. Provided you have good solar exposure where the terrain and trees do NOT significantly shade the array between sunrise and sunset.

 

[snoobler]

Ah... now I see:

"According to data from Natural Resources Canada, the average solar system in Newfoundland and Labrador can produce 949kWh of electricity per kW of solar panels per year."

So for every 1000W of solar, you will get 949kWh total per year.

6kWh/day = 2190kWh/year, so on average, you would need only 2190/949 = 2.3kW of solar, but you will fall short in the winter months.

4000W * 1.77h = 7.1kWh/day

How windy is it?

 

[snoobler]

Hmmm....



38kWh/kW of panels...

4 * 38kWh = 152kWh/month in Dec.

153kWh/month / 31 days = 4.9kWh/day

Using that data point, even 4000W isn't enough.

6kWh/day * 31 day = 186kWh/month

186kWh/38 = 4.89kW of solar.

So... to be safe...

5000W of solar.

 

[Roswell Bob]

Great analysis Honey Badger. Nothing needs to be added. I am curious as to what kind of gear you plan on running.

 

[snoobler]

Okay. I can't let this go. Averages are for suckers.

A simple 5kW array will not cut it.

I used PV Watts to simulate a 5kWh array at 60° (winter angle year round). I downloaded the hourly data which incorporates production numbers by the hour based on the "average" day's weather over the last few decades.

Weather is the driving factor by far.

In January, in 11 of 31 days, 5kW of solar at 60° tilt FAILED to produce 6kWh of energy. Of those 11, 4 were consecutive yielding a total of 14.4kWh over the four days where 24kWh was needed.

In December, 10 of 31 days, again with 4 consecutive. Over those 4 days, only 7.9kWh total were produced out of the needed 24kWh.

What this emphasizes is that you also need at least 4 days of no-sun power storage to make sure you can get through the ugly weather. You still need the big array to "catch up" on sunny days, but you might be able to downsize it.

This is still a gross analysis that does not take into account inefficiencies in conversion to AC, etc.

I have attached a zipped spreadsheet containing the hourly data.

 

[snoobler]

P.S. I am so spoiled here in AZ.

 

[Roswell Bob]

Okay. I can't let this go. Averages are for suckers.

A simple 5kW array will not cut it.

I used PV Watts to simulate a 5kWh array at 60° (winter angle year round). I downloaded the hourly data which incorporates production numbers by the hour based on the "average" day's weather over the last few decades.

Weather is the driving factor by far.

In January, in 11 of 31 days, 5kW of solar at 60° tilt FAILED to produce 6kWh of energy. Of those 11, 4 were consecutive yielding a total of 14.4kWh over the four days where 24kWh was needed.

In December, 10 of 31 days, again with 4 consecutive. Over those 4 days, only 7.9kWh total were produced out of the needed 24kWh.

What this emphasizes is that you also need at least 4 days of no-sun power storage to make sure you can get through the ugly weather. You still need the big array to "catch up" on sunny days, but you might be able to downsize it.

This is still a gross analysis that does not take into account inefficiencies in conversion to AC, etc.

I have attached a zipped spreadsheet containing the hourly data.

Cool. What did you use for solar panel efficiency? The data said 2kWh of sun falling per square meter. Solar panels are near 20-25 percent efficient to maybe need 12 square meters of panel. Is that about right. I have 4kW array so sounds about right size. A good generator and a 10kW cell array would work good I think

P.S. I am so spoiled here in AZ.

Where are you in AZ? I think you told me once.

 

[Diysolar123]

P.S. I am so spoiled here in AZ.

yuma arizona is the siniest(edit: ok not siniest but sunniest, I mean the words are close, right) city in america, 90%...

hey, I bet solar would work there you should look into it

so often people forget to include the actual number of cloudless days when thinking about solar.
Do people in cold bay alaska know what the sun is???

Location Days a Year With Cloud cover
Cold Bay, Alaska 354
St. Paul Island, Alaska 348
Hilo, Hawaii 329
Annette, Alaska 325
Yakutat, Alaska 324
Juneau, Alaska 321
Mt. Washington New Hampshire 321
Astoria, Oregon 315
Elkins, West Virginia 315
King Salmon, Alaska 314
Quillayute, Washington 314
Binghamton, New York 314
Olympia, Washington 312
Buffalo, New York 311

 

[Roswell Bob]

yuma arizona is the siniest(edit: ok not siniest but sunniest, I mean the words are close, right) city in america, 90%...

hey, I bet solar would work there you should look into it

so often people forget to include the actual number of cloudless days when thinking about solar.
Do people in cold bay alaska know what the sun is???

Location Days a Year With Cloud cover
Cold Bay, Alaska 354
St. Paul Island, Alaska 348
Hilo, Hawaii 329
Annette, Alaska 325
Yakutat, Alaska 324
Juneau, Alaska 321
Mt. Washington New Hampshire 321
Astoria, Oregon 315
Elkins, West Virginia 315
King Salmon, Alaska 314
Quillayute, Washington 314
Binghamton, New York 314
Olympia, Washington 312
Buffalo, New York 311

Are you in Yuma?

 

[snoobler]

Cool. What did you use for solar panel efficiency? The data said 2kWh of sun falling per square meter. Solar panels are near 20-25 percent efficient to maybe need 12 square meters of panel. Is that about right. I have 4kW array so sounds about right size. A good generator and a 10kW cell array would work good I think

Where are you in AZ? I think you told me once.

I just accepted the defaults.

Home is in Mesa. Honey Badger Ranch is near Concho Valley (between Show Low and St. Johns).