Winter and Solar Panels???

[drozwood90]

So, who here has a Solar Array (or experience with them)? Raise your hands.

OK, now, of this group, how many have dealt with Solar Panels in Winter / Snow, etc.?

What do you do for maintenance? Did you have to get on the roof and sweep the panels off?

Any other comments?

--Dan

 

[mdiehl]

So, who here has a Solar Array (or experience with them)? Raise your hands.

OK, now, of this group, how many have dealt with Solar Panels in Winter / Snow, etc.?

What do you do for maintenance? Did you have to get on the roof and sweep the panels off?

Any other comments?

--Dan

Panel maintenance is usually pretty low, I usually do a "paper towel and mild detergent cleaning" once or twice a year. My panels are "top-of-pole" mounts with the center of the "rack" at about 10' above ground level.

As for snow accumulation (and removal...), that depends on local conditions. In Ohio, and depending on the local forecast, I can go out and use a "long handled broom" etc. to clear most of the snow. If it is going to get above freezing the next day, sometimes I'll just let it clear naturally, since once the air temp gets above freezing, the panels will usually clear fairly quickly; an if the sun manages to come out the panels (since of a dark color) will absorb sunlight and heat fairly quickly even if just a small section is exposed.

If you're in a high snow, long cold period region, the long-handled broom variation should be good, just put together something that is easy on the panel surfaces.

Not sure how others with "roof mount" installations go about it, maybe one will chime in here

 

[drozwood90]

Can you post a few pictures?

I've also been debating a pole mounted or a roof mounted system.

Also, what kind of inverter do you use and what panels are you using? Does this affect your automation switches? What kind of automation are you using?

Thanks!

--Dan

 

[mdiehl]

Can you post a few pictures?

I've also been debating a pole mounted or a roof mounted system.

Also, what kind of inverter do you use and what panels are you using? Does this affect your automation switches? What kind of automation are you using?

Thanks!

--Dan

I'll post a pic or two in the next couple of weeks Dan. I'm currently in progress on a 1KW "grid-tie" system, consisting of 5 (eventually a sixth...) 200w Sanyo Panels, on a 6 place DP&W Top-of-pole mount. This array will be feeding a Magnetek Aurora 3.6KW inverter for grid connection. Array voltage will be in the neighborhood of 250vdc with the 5 panels and in the 300v range with a sixth panel added later. I'm getting ready right now to get a 14', schedule 40, 6" pipe in the ground and then get the concrete poured next week, so I can get the rack up...

The system I've had in place for the last 7 years or so consists of 4 panels(two Solarex MSX-60s, and two OLD Arco 48watts, wired for 24volts which yield in the 6-8 amp output range), which feed a Morningstar 20 amp, 24 volt controller. I'm charging 4 concorde AGM batteries(24v, 510ah total), and have a Prosine 3kw(very clean sinewave output) inverter which is wired to a "home brew" transfer box to be able to switch to a couple of "critical" upstairs AC outlets. This combination has worked well for me for "back up" power in event of failure of the local grid, for backup of the furnace(gas), computer, TV etc., and about a month ago had to plug in the basement sump-pump when I lost power during a 4.77" rain event, and stayed dry...

I'm using Z-Wave controls here because two years or so ago, I started using a T.E.D. (the energy detective) to monitor power use, and the unit transmits on the ac line at a frequency just between X-10 and Insteon (which screwed both of them up...), so I switched to Z-Wave(happy with the Z-Wave).

For me the Top-of-Pole mount has two advantages, which are that you don't have to worry about any roof penetration, and the electrical code requirements aren't(usually) as stringent as no electrical equipment is connected directly to the house structure. The other item is that Top-of-Pole mounts usually allow for better ventilation of the panels, which allows them to operate at lower temperatures.

 

[drozwood90]

Can you post a few pictures?

I've also been debating a pole mounted or a roof mounted system.

Also, what kind of inverter do you use and what panels are you using? Does this affect your automation switches? What kind of automation are you using?

Thanks!

--Dan

I'll post a pic or two in the next couple of weeks Dan. I'm currently in progress on a 1KW "grid-tie" system, consisting of 5 (eventually a sixth...) 200w Sanyo Panels, on a 6 place DP&W Top-of-pole mount. This array will be feeding a Magnetek Aurora 3.6KW inverter for grid connection. Array voltage will be in the neighborhood of 250vdc with the 5 panels and in the 300v range with a sixth panel added later. I'm getting ready right now to get a 14', schedule 40, 6" pipe in the ground and then get the concrete poured next week, so I can get the rack up...

The system I've had in place for the last 7 years or so consists of 4 panels(two Solarex MSX-60s, and two OLD Arco 48watts, wired for 24volts which yield in the 6-8 amp output range), which feed a Morningstar 20 amp, 24 volt controller. I'm charging 4 concorde AGM batteries(24v, 510ah total), and have a Prosine 3kw(very clean sinewave output) inverter which is wired to a "home brew" transfer box to be able to switch to a couple of "critical" upstairs AC outlets. This combination has worked well for me for "back up" power in event of failure of the local grid, for backup of the furnace(gas), computer, TV etc., and about a month ago had to plug in the basement sump-pump when I lost power during a 4.77" rain event, and stayed dry...

I'm using Z-Wave controls here because two years or so ago, I started using a T.E.D. (the energy detective) to monitor power use, and the unit transmits on the ac line at a frequency just between X-10 and Insteon (which screwed both of them up...), so I switched to Z-Wave(happy with the Z-Wave).

For me the Top-of-Pole mount has two advantages, which are that you don't have to worry about any roof penetration, and the electrical code requirements aren't(usually) as stringent as no electrical equipment is connected directly to the house structure. The other item is that Top-of-Pole mounts usually allow for better ventilation of the panels, which allows them to operate at lower temperatures.

Thanks for the insightful information! Any idea (schedules pending of course) about the pictures? I'm only posting as a reminder...as I know sometimes we all loose track of threads we were part of (I had a PM once from a guy, it took me searching for a combination of that guy's username and my username until I could find what the heck he was talking about!

Thanks again!

--Dan

 

[Waynedb]

Can you post a few pictures?

I've also been debating a pole mounted or a roof mounted system.

Also, what kind of inverter do you use and what panels are you using? Does this affect your automation switches? What kind of automation are you using?

Thanks!

--Dan

I think the best reason to use a pole mounted array is so you can use a tracking mount and follow the sun.
http://store.solar-electric.com/zotrmoforsoe.html

I gave my brother a couple of C-band Satellite mounts I found and he welded up a frame for the panels and designed his own controlller to move the panels.

 

[BraveSirRobbin]

Curious how much more efficient the solar tracking offers vs. just tilting the panels based on season (winter vs summer). I'm doing a solar project (for work) right now as described HERE.

 

[mdiehl]

Can you post a few pictures?

I've also been debating a pole mounted or a roof mounted system.

Also, what kind of inverter do you use and what panels are you using? Does this affect your automation switches? What kind of automation are you using?

Thanks!

--Dan

I'll post a pic or two in the next couple of weeks Dan. I'm currently in progress on a 1KW "grid-tie" system, consisting of 5 (eventually a sixth...) 200w Sanyo Panels, on a 6 place DP&W Top-of-pole mount. This array will be feeding a Magnetek Aurora 3.6KW inverter for grid connection. Array voltage will be in the neighborhood of 250vdc with the 5 panels and in the 300v range with a sixth panel added later. I'm getting ready right now to get a 14', schedule 40, 6" pipe in the ground and then get the concrete poured next week, so I can get the rack up...

The system I've had in place for the last 7 years or so consists of 4 panels(two Solarex MSX-60s, and two OLD Arco 48watts, wired for 24volts which yield in the 6-8 amp output range), which feed a Morningstar 20 amp, 24 volt controller. I'm charging 4 concorde AGM batteries(24v, 510ah total), and have a Prosine 3kw(very clean sinewave output) inverter which is wired to a "home brew" transfer box to be able to switch to a couple of "critical" upstairs AC outlets. This combination has worked well for me for "back up" power in event of failure of the local grid, for backup of the furnace(gas), computer, TV etc., and about a month ago had to plug in the basement sump-pump when I lost power during a 4.77" rain event, and stayed dry...

I'm using Z-Wave controls here because two years or so ago, I started using a T.E.D. (the energy detective) to monitor power use, and the unit transmits on the ac line at a frequency just between X-10 and Insteon (which screwed both of them up...), so I switched to Z-Wave(happy with the Z-Wave).

For me the Top-of-Pole mount has two advantages, which are that you don't have to worry about any roof penetration, and the electrical code requirements aren't(usually) as stringent as no electrical equipment is connected directly to the house structure. The other item is that Top-of-Pole mounts usually allow for better ventilation of the panels, which allows them to operate at lower temperatures.

Thanks for the insightful information! Any idea (schedules pending of course) about the pictures? I'm only posting as a reminder...as I know sometimes we all loose track of threads we were part of (I had a PM once from a guy, it took me searching for a combination of that guy's username and my username until I could find what the heck he was talking about!

Thanks again!

--Dan

Haven't forgotten you Dan.

Projects like this always take longer than expected, but I should be done by this weekend. Thanks to the efforts of two volunteers, the Panels were placed on the rack (well, five of em' on a six panel rated rack, which will of course bother me until I save my pennies to install a sixth...). The hole for the 6" support pole was really fun at the required 4' depth and 28-30" diameter...but after much perseverence and the making up of new words that Carlin would be proud of..., it got done!

The Inverter and AC part is connected and I'm waiting for the UPS truck to deliver cable and a DC Disconnect for the Panel side of it. Should be ready for a system test in a couple of days.

I'll post some pics then, along with the actual "real world" performance data (which the inverter logs daily etc.).

Stay tuned

 

[drozwood90]

Haven't forgotten you Dan.

Projects like this always take longer than expected, but I should be done by this weekend. Thanks to the efforts of two volunteers, the Panels were placed on the rack (well, five of em' on a six panel rated rack, which will of course bother me until I save my pennies to install a sixth...). The hole for the 6" support pole was really fun at the required 4' depth and 28-30" diameter...but after much perseverence and the making up of new words that Carlin would be proud of..., it got done!

The Inverter and AC part is connected and I'm waiting for the UPS truck to deliver cable and a DC Disconnect for the Panel side of it. Should be ready for a system test in a couple of days.

I'll post some pics then, along with the actual "real world" performance data (which the inverter logs daily etc.).

Stay tuned

Fantastic! Thanks again for taking time to help me understand some of this stuff. I've been so Solar dumb, and thank all that have helped through relaying their experiences (especially those that are up in the Northern parts of the US (i.e. People that see all 4 seasons such as myself)).

--Dan

 

[Waynedb]

Curious how much more efficient the solar tracking offers vs. just tilting the panels based on season (winter vs summer). I'm doing a solar project (for work) right now as described HERE.

I usually see claims of 25%-30% for a single axis mount and about 5% more for adual axis mount.
For people who want to make their own D.I.Y. tracking mount from an old C-band mount, here is
a page with controllers you can make. http://www.redrok.com/electron.htm#led3

 

[mdiehl]

Curious how much more efficient the solar tracking offers vs. just tilting the panels based on season (winter vs summer). I'm doing a solar project (for work) right now as described HERE.

I usually see claims of 25%-30% for a single axis mount and about 5% more for adual axis mount.
For people who want to make their own D.I.Y. tracking mount from an old C-band mount, here is
a page with controllers you can make. http://www.redrok.com/electron.htm#led3

The best "sage" advice on tracking (may not hold true for "home brew" trackers, with minimal dollars invested...), but usually Tracking gives the best return (can't remember exactly, but 20-30% gain), if you have a clear horizon from sunup/sundown (or at least reasonably so).

Here's first pic of the Rack and Panels(will save for a 6th to fill the rack). I'm in a valley and the panels are just getting the first wisps of sun from the East, still peeking thru the trees. Inverter output is approx. 40 watts right now, but will be increasing soon. Just how much throughout the day, I'll find out soon , keep you posted.

 

[mdiehl]

Curious how much more efficient the solar tracking offers vs. just tilting the panels based on season (winter vs summer). I'm doing a solar project (for work) right now as described HERE.

I usually see claims of 25%-30% for a single axis mount and about 5% more for a dual axis mount.
For people who want to make their own D.I.Y. tracking mount from an old C-band mount, here is
a page with controllers you can make. http://www.redrok.com/electron.htm#led3

The best "sage" advice on tracking (may not hold true for "home brew" trackers, with minimal dollars invested...), but usually Tracking gives the best return (can't remember exactly, but 20-30% gain), if you have a clear horizon from sunup/sundown (or at least reasonably so).

Here's first pic of the Rack and Panels(will save for a 6th to fill the rack). I'm in a valley and the panels are just getting the first wisps of sun from the East, still peeking thru the trees. Inverter output is approx. 40 watts right now, but will be increasing soon. Just how much throughout the day, I'll find out soon , keep you posted.

Haven't received my DC Disconnect yet so I can't finish (and take a GOOD pic) of the Grid-Tie inverter and mount.
The system has been running normally since (but only a half day last Friday...needed to change some panel cable routing), and even with "Hazy, Hot & Humid" here in Ohio, I've generated 28.5 KWHs to date.

Here's a current "snapshot" of system performance at "full sun" and "Solar Irradiation" levels as measured with an Apogee Instruments Pyranometer.

Solar Radiation at 919 watts/sq. Meter
Array output 1011 watts
AC Output 936 watts (about 91% inverter efficiency).
Array Voltage approx. 260VDC.

Under the "Cloudy" part of today's "partly cloudy" skies the output is as follows.

Solar Radiation at 129 watts (dark cloud)
103 AC Watts from Inverter and 137 watts from the array approximately.

I'll post a pic of the Inverter Setup as soon as "Mr. UPS" gets my Disconnect here and its nicely wired.

 

[kgingerich]

About how much for your 1KW system if you don't mind me asking?

 

[mdiehl]

About how much for your 1KW system if you don't mind me asking?

"Core System" (panels and inverter)approx. 7K, although the Sanyo "hi efficiency" panels tend to be more expensive than most (I'm pleased with their performance so far though).

Other system components such as panel mounting system (whether top-of-pole, roof mount etc.), cabling, AC & DC Disconnects will be added to that but some will depend on local requirements.

There are still Federal Tax incentives of up to $2000 in "Tax credits" for the remainder of the year, and some states have additional incentives that help defray costs.

The "new" system here is a pure "Grid-tie" and does not work if the "Grid" is down. I've had a "back-up" system in place for a few years, which consists of 4 small panels which charge about 500amp hours of storage batteries (24v), and another "sine-wave" inverter for use during power failiures. Probably by next year, I hope to install a switching system at the new array (plus adding a 6th panel to fill up "the hole"). This would allow me to "parallel" the panels so I could feed a lower voltage, higher current to a charge controller and substantially "boost" my charging capability to the "standby" system.

There is something new out that would have been of interest to me before planning the current system, and that is a new company (Enphase) that is marketing a small Grid-Tie inverter that is designed to attach at the panel. A Dutch company had produced a product called the OK4(100watt, 24v input), but they haven't been produced for years now.

The new inverter seems to be rated at 150-200watts, 24v input and you can(I think..) use these singly or parallel quite a few of them, along with a system monitor to keep an eye on the system. Pricing seems to be around $200.00 per inverter which is quite a bit cheaper than the older OK4's. Using one of these with a properly sized panel could get you started with a Grid-Tie system for about $1000.00, and your results are promising, you could "scale up" a panel and inverter at a time...

Probably a bit "wordy", but I tend to ramble a bit in my old age...

 

[kgingerich]

I'm not sure if I'm calculating this right but I'm trying to decide whether solar is really worth it. A 1KW system puts off 1kW per hour right? maybe i have that wrong.

If it's 1kWH for $7,000 and i'm paying my electric coop on average 6.5 cents per kWH then the way I see it I would have to get the full power out of that panel 24 hours a day 7 days a week for 12 years to just break even. That doesn't account for the system breaking down and needing repairs and replacements.

Short of the "going green" reason, I'm hard pressed to find a reason to go with a solar system at this point.

Of course, 90% of the HA stuff I've done in my home doesn't give me any return on my investment at all but I did it anyway. It's just cool!