North facing mountainside - is solar worth it?

[KWeirich]

I have a property on a mountainside where the meadow (for a potential ground mount array) faces somewhere between NW and North. While I would really like to move towards at least a partial solar battery system I am not sure if it is worth it. The cabin on the property is small - less than 800sqft, and uses on average less than 500KW of electricity per month (highest month - 800, lowest month - 300). Heat and cooking comes from propane, and it is occupied year-round by two people.

What factors should I be considering when evaluating the feasibility of solar? Are there any tools and websites I can use in my analysis? What is the experience of others in this forum who have looked at similar projects?

Thanks!
Kurt

 

[pvgirl]

PVwatts can generate an estimate of solar production for your site: https://pvwatts.nrel.gov/ although that estimate may not include effects of local shading from other mountains, trees, etc That direction won't be as productive, but some estimates I've run show even north facing panels can still produce 65-70% of south facing ones.

Very important to the design is knowing what purpose you want for your solar? Do you want to reduce electric bills? Handle grid outages? Get a grid tied system for netmetering with local utility if available? Go off grid? Also do you plan on moving any propane appliances to electric?

Biggest consideration is going to be budget. Local electric rates, will determine how quickly you will make back your investment in solar. If you are able to DIY you can save a good bit of money on an install.

 

[BentleyJ]

Look up sunshine_eggo in the By Member: search bar. Click on one of his posts, There are several resources in his footer that will allow you to estimate solar production based on panel azimuth and tilt.

 

[chrisski]

If you have access to your property, recommend getting a phone app that will allow you to stand on your property and point your phone at obstructions to see if they will block your panels. Set this for the shortest day of the year, December 21, or the shortest day you’ll be on your property

Sites like PV Watts and the calculator I have in my signature block take into account weather, but not obstruction of trees.

It’s important you get the height of the panels and measure both sides of the array. A single tree in the way ruins obstructions.

I can’t name a good app, but sunseeker or sun tracker may be good. There’s been some postings recently with good shots.

 

[Zapper77]

I have a property on a mountainside where the meadow (for a potential ground mount array) faces somewhere between NW and North. While I would really like to move towards at least a partial solar battery system I am not sure if it is worth it. The cabin on the property is small - less than 800sqft, and uses on average less than 500KW of electricity per month (highest month - 800, lowest month - 300). Heat and cooking comes from propane, and it is occupied year-round by two people.

What factors should I be considering when evaluating the feasibility of solar? Are there any tools and websites I can use in my analysis? What is the experience of others in this forum who have looked at similar projects?

Thanks!
Kurt

Assuming you live in the southern hemisphere...yes

 

[ChrisG]

If you have access to your property, recommend getting a phone app that will allow you to stand on your property and point your phone at obstructions to see if they will block your panels. Set this for the shortest day of the year, December 21, or the shortest day you’ll be on your property

Sites like PV Watts and the calculator I have in my signature block take into account weather, but not obstruction of trees.

It’s important you get the height of the panels and measure both sides of the array. A single tree in the way ruins obstructions.

I can’t name a good app, but sunseeker or sun tracker may be good. There’s been some postings recently with good shots.

This app is excellent. The Augmented Reality capability is spot on: https://apps.apple.com/us/app/sunontrack-sun-path-shadows/id1610305853

 

[KWeirich]

PVwatts can generate an estimate of solar production for your site: https://pvwatts.nrel.gov/ although that estimate may not include effects of local shading from other mountains, trees, etc That direction won't be as productive, but some estimates I've run show even north facing panels can still produce 65-70% of south facing ones.

Very important to the design is knowing what purpose you want for your solar? Do you want to reduce electric bills? Handle grid outages? Get a grid tied system for netmetering with local utility if available? Go off grid? Also do you plan on moving any propane appliances to electric?

Biggest consideration is going to be budget. Local electric rates, will determine how quickly you will make back your investment in solar. If you are able to DIY you can save a good bit of money on an install.

Good Morning,

Thank you for the reply and the link to the PVwatts website - I will incorporate that into my analysis. If the numbers line up then the goal is to take the cabin completely off-grid. If that isn't feasible then the goal will be to build out a system that can provide backup power for when the utility goes down. That would be likely be a smaller installation as it would only have to power a couple of circuits.

-Kurt

 

[KWeirich]

Look up sunshine_eggo in the By Member: search bar. Click on one of his posts, There are several resources in his footer that will allow you to estimate solar production based on panel azimuth and tilt.

Thank you, I will look up sunshine_eggo!

-Kurt

 

[KWeirich]

If you have access to your property, recommend getting a phone app that will allow you to stand on your property and point your phone at obstructions to see if they will block your panels. Set this for the shortest day of the year, December 21, or the shortest day you’ll be on your property

Sites like PV Watts and the calculator I have in my signature block take into account weather, but not obstruction of trees.

It’s important you get the height of the panels and measure both sides of the array. A single tree in the way ruins obstructions.

I can’t name a good app, but sunseeker or sun tracker may be good. There’s been some postings recently with good shots.

Good Morning and thank you for the suggestions, especially the idea of checking obstructions. The affect of partial shading on solar production is something I am learning about through this forum. It may be that I will have to use solar optimizers on the panels - what are your thoughts?

One of the many challenges is that the meadow is surrounded by trees, and the owner won't likely want any of them trimmed or removed. I am hopeful there is enough open space, for long enough, to at least handle a partial off-grid solution.

-Kurt

 

[KWeirich]

Assuming you live in the southern hemisphere...yes

LOL - Nope, the property is in WV

 

[KWeirich]

This app is excellent. The Augmented Reality capability is spot on: https://apps.apple.com/us/app/sunontrack-sun-path-shadows/id1610305853

Good Morning,

Thank you for the recommendation! Do you know if there is an android version of the app?

-Kurt

 

[chrisski]

Good Morning and thank you for the suggestions, especially the idea of checking obstructions. The affect of partial shading on solar production is something I am learning about through this forum. It may be that I will have to use solar optimizers on the panels - what are your thoughts?

If shading is a huge issue, I’d consider scrapping the project.

When I lived in North Carolina, we used trees grow at the rate of 1’ to 2’ per year. I’d be concerned without a lot of planning that you’d get a meager return the first year and it would quickly go down from there as the trees grew up.

 

[ChrisG]

Good Morning,

Thank you for the recommendation! Do you know if there is an android version of the app?

-Kurt

No idea, we only have iPhones. Search the Google play store for SunOnTrack

 

[Madcodger]

Much will depend on the slope of the property and the height of obstructions to the south of it. We own a gently sloping property in Maine that faces north but has no tall mountains or hills to the south, and the field is large enough that we can move far enough into it to get away from the trees on the south border. The result is a perfect solar location, even for a ground array, with no daytime shading. A south-sloping location in the northern hemisphere is moderately easier to work with, but as long as the panels themselves can face south and get direct sunlight, all should be well. As others have noted, PVWatts and other tools are a huge help. If it's a steep slope, I'd be concerned.

I do remain skeptical of arrays that face actually face north producing 2/3 the power of a south-facing array, though, as some are noting here. I'd like to see that happen in the real world, but am skeptical. I don't get 2/3 production in winter just because of the tilt of the panels, so facing the wrong way, with no direct sunlight, seems to me a much bigger issue.

 

[Solarcabin Channel]

How is the wind there?

Sounds like one situation where a wind turbine might be more productive than solar.

If the power use is minimal a small propane or gas genny will recharge a battery bank or power station pretty fast.

Portable solar panels or tracker that can be moved to face the best sun might be an option.

 

[KWeirich]

If shading is a huge issue, I’d consider scrapping the project.

When I lived in North Carolina, we used trees grow at the rate of 1’ to 2’ per year. I’d be concerned without a lot of planning that you’d get a meager return the first year and it would quickly go down from there as the trees grew up.

That's a good point to consider. It may be I have to wait until the owners are able acquire the neighboring property, which both situated more towards the south and has more open space.

 

[KWeirich]

Much will depend on the slope of the property and the height of obstructions to the south of it. We own a gently sloping property in Maine that faces north but has no tall mountains or hills to the south, and the field is large enough that we can move far enough into it to get away from the trees on the south border. The result is a perfect solar location, even for a ground array, with no daytime shading. A south-sloping location in the northern hemisphere is moderately easier to work with, but as long as the panels themselves can face south and get direct sunlight, all should be well. As others have noted, PVWatts and other tools are a huge help. If it's a steep slope, I'd be concerned.

I do remain skeptical of arrays that face actually face north producing 2/3 the power of a south-facing array, though, as some are noting here. I'd like to see that happen in the real world, but am skeptical. I don't get 2/3 production in winter just because of the tilt of the panels, so facing the wrong way, with no direct sunlight, seems to me a much bigger issue.

Hmmm, interesting point about the slope and panels facing south. Something that I need to consider.

-Kurt

 

[KWeirich]

How is the wind there?

Sounds like one situation where a wind turbine might be more productive than solar.

If the power use is minimal a small propane or gas genny will recharge a battery bank or power station pretty fast.

Portable solar panels or tracker that can be moved to face the best sun might be an option.

Where the cabin is located they get some wind but it is not steady, nor is it smooth due to the trees. I have thought about using the wind, and there are some new technologies that appear to be promising, but I have not done much detailed research.

If I go with just having a battery backup system then a generator is a viable option. And that may be the solution, as much as I would like to get them completely independent. And yes, portable panels are another option for an backup system.

Thanks!

 

[Solarcabin Channel]

Where the cabin is located they get some wind but it is not steady, nor is it smooth due to the trees. I have thought about using the wind, and there are some new technologies that appear to be promising, but I have not done much detailed research.

If I go with just having a battery backup system then a generator is a viable option. And that may be the solution, as much as I would like to get them completely independent. And yes, portable panels are another option for an backup system.

Thanks!

You need about 15mph winds for smaller turbines like the 400 watt but they can charge a battery really fast in a short time.

Can be mounted to a tall pine close to the cabin. Get one with a built in controller.

Best to you!

 

[Hedges]

North slope is worthwhile if you want electricity in the summer. So long has you have enough area completely unshaded for enough hours.
Maybe one long row of panels tilted South, uphill.

I plan to put PV panels on a north facing roof slope. At my latitude, sun goes well past overhead in Summer.

Cost of PV panels and MPPT SCC channel is not high, compared to balance of system. An inverter/charger with batteries and generator would provide power in winter, more pleasant than operating generator 24/7, and PV saves you running generator when there is sun.

Is there flowing water? Even seasonal?