Sun hours

[organic farmer]

When I was making the cables to fit between the batteries of my bank. I considered the wattage rating of the cables. Some of them needed to be bent into weird shapes. But it was all done during summer weather. and those cables will never be bent to a different shape ever again. What are you doing with wire that requires it to be bendy flexible in negative temps?

[jflorey2]

A lot of wire insulation loses too much of its flexibility at -20F to be reliable. Finding an insulation with the right combination of sunlight resistance and flexibility could be interesting

I got a spool of 10ga wire labeled "locomotive cable" years back that had insulation that was supposedly flexible down to very low temperatures, sunlight and oil resistant and good to 600 volts. It's hard to find though.

[bcroe]

So it was 17 F below zero this morning, a tour revealed the 6 heat pumps
were keeping up and performing as intended in 2 buildings. I believe
heating capacity at best is about 9 tons, that is degraded quite a bit at
this temp. The "just right sizing" people would say I have way too much,
but I say this allows a couple things. First I never need to switch to
auxiliary heating, although it still exists here. Second no single failure
(like a furnace blower motor) can cause a desperate situation, spare
capacity will carry me through till I get around to repairs in summer.
Cost was quite minimal when bought on the internet and DIY installed.

Well into the 11th winter things are quite stable, system repairs amount
to 3 burned out electrical connections and one panel hit by a tree. And
I did have to scrape sap off some panels till that tree was removed. So
it may be the coldest day of the year, but the spinning disc shows with
sun the cold panels are collecting more energy than I am using. I see
about 4200 kWh energy still in reserve, but days will soon be here when
I can make as much as I uses again.

One thing the extra energy has made possible, is running the big
electronic air filter nearly a third of every hour. Looking at the particles
(or rather the lack of them) in a beam of sunlight shows a drastic
reduction in solid stuff floating int the air. Of course the particle charging
method used works no matter how small the particle, not just the ones
bigger than a mechanical screen. And maintenance ia way less as well.
Wish I had done this much earlier in life.

I am realizing the E-W array design has more advantages than I first
planned. It takes an absolutely minimum of snow cleaning effort, often
none while I am clearing the S facing panels. It basically operates all
year with no need to worry about changing tilt. I can collect a better
ratio of energy to unshaded space. And the cost of material for my
6061 aluminum ground mounts has increased so much (way more
than the panels mounted), it makes economic sense to mount twice
as many panels, facing opposite directions. The original objectives
were to maximize energy collected with a 15KW peak limit, and double
output under clouds.
Bruce Roe

[J.P.M.]

Each array has strings that equally feed both inverters. If marked it would look like checkerboard.
Originally the east and west sides were not mixed, but there were shade situations where one was
clipping but the other was under peak. Checkerboard conversion cured that. Bruce

Thank you.

I'll rate each array by assigning inverter capacity as [(15/35) * array size] and use a DC/AC ratio of 2.333 for each array unless advised otherwise.

J.P.M.

[bcroe]

Bruce:

Can you tell me a bit about your inverter setup ?

I'd like to know which arrays feed which inverter.

Thank you.

J.P.M.

Each array has strings that equally feed both inverters. If marked it would look like checkerboard.
Originally the east and west sides were not mixed, but there were shade situations where one was
clipping but the other was under peak. Checkerboard conversion cured that. Bruce

[J.P.M.]

Bruce:

Can you tell me a bit about your inverter setup ?

I'd like to know which arrays feed which inverter.

Thank you.

J.P.M.

[bcroe]

I did not pick it, but could not change it. Bruce

[J.P.M.]

Those sound like pretty good dates. The original big S array I asked to have a tilt option, but could not
get a drawing in advance. When it went up it was set at the low extreme for convenient construction
(another long story of issues). It turned out it would take a multi person crew with equipment to elevate
over 400 lb 10 feet in the air at 12 positions, twice a year. This was not a practical thing and likely
would have involved damage, so it has stayed put. Given that the total has been able to keep in
clipping any sunny day, better angle would not gain much energy. But winter energy and snow do
rather poorly, so possibly the 2018 design and fewer panels would be advantageous. Bruce Roe

Understood. I'll fart around some with those dates.
Sure not my call, but if I was doing a redesign, I might consider a tilt closer to latitude (or maybe a bit more for snow considerations). Just sayin'.

[bcroe]

Bruce: Thank you.
Life is in the way just now, but the modeling is on my do list.
I'm considering using 11/15 and 03/15 for 1st/last snow dates on the var. tilt array unless you advise otherwise.

Q: Why the 23.5 deg. tilt on the big array ?

J.P.M.

Those sound like pretty good dates. The original big S array I asked to have a tilt option, but could not
get a drawing in advance. When it went up it was set at the low extreme for convenient construction
(another long story of issues). It turned out it would take a multi person crew with equipment to elevate
over 400 lb 10 feet in the air at 12 positions, twice a year. This was not a practical thing and likely
would have involved damage, so it has stayed put. Given that the total has been able to keep in
clipping any sunny day, better angle would not gain much energy. But winter energy and snow do
rather poorly, so possibly the 2018 design and fewer panels would be advantageous. Bruce Roe

[J.P.M.]

Update, from flat on the ground, the elevation angle of E-W facing array are both 74 deg, the
original S facing is 23.5 deg, and the newest facing E is 75 deg (variable). The ultimate hope
is with better angles set twice a year, and other tweaks (3% less wiring loss, etc), perhaps a
few less panels will still generate enough for my needs. Bruce Roe

Bruce: Thank you.
Life is in the way just now, but the modeling is on my do list.
I'm considering using 11/15 and 03/15 for 1st/last snow dates on the var. tilt array unless you advise otherwise.

Q: Why the 23.5 deg. tilt on the big array ?

J.P.M.

[bcroe]

Bruce: If/When you get the time, on average , +/-, about when do you adjust the tilts on the arrays ? Also, what are the tilt angles ?

Thank You.

Update, from flat on the ground, the elevation angle of E-W facing array are both 74 deg, the
original S facing is 23.5 deg, and the newest facing E is 75 deg (variable). The ultimate hope
is with better angles set twice a year, and other tweaks (3% less wiring loss, etc), perhaps a
few less panels will still generate enough for my needs. Bruce Roe

[bcroe]

Bruce: If/When you get the time, on average , +/-, about when do you adjust the tilts on the arrays ? Also, what are the tilt angles ?

Thank You.

J. P. M., The only panels I can adjust tilt are the 2018 construct, seen about page 21 of this thread
late March 2018. Take out 6 ground level bolts (on a not windy day), crank the tilt (90 degree range),
put the 6 bolts back in. The plan is to convert all the earlier attempts to this design. Except if I had
known how well it would work, even this first construct would have been 2 sided (design in progress).
Also there follows cable trenching operations.

Tilt change time would be in anticipation of the first snow, and at conclusion of significant snow. This
would be more important for the S array (if it gets built), which have much more potential for improved
energy collection and snow rejection. Current angle (to be measured) is about right for summer,
terrible for winter. If this all follows through, it should be more efficient and need far less snow removal,
might even reduce in size a bit. Bruce Roe

[J.P.M.]

Bruce: If/When you get the time, on average , +/-, about when do you adjust the tilts on the arrays ? Also, what are the tilt angles ?

Thank You.

[J.P.M.]

Hey design reviews are good and educational. I had a career of them with reviewers a lot tougher
than you guys. He whose design is being reviewed needs to see it as an oportunity to improve, it
certainly helped me.

Here is a Goog.. Ear.. today of the array, on the left 6KW pretty much facing E elevation about 82
degrees, operational Mar 2018. At the top 18KW sort of south maybe you can get the orientation,
May 2013, need to check elevation. In the middle 5.5KW facing sort of E, also 5.5KW facing sort
of W, elevation of 74 deg from flat Nov 2013.

There is a plan to revise everything to the newest design, hopefully before the treated wood 2
faced rots. Bruce Roe.


GearthJun20.jpg

Bruce: Thank you for the response and consideration. I'll be chewing on that for awhile.
As the used to say on the idiot box, "Updates as they become available. Film with the 10 o'clock news."

Regards,

[bcroe]

Thanks for demonstrating that outside the box solutions can work and accomplish the owners goals.

Sure, you now have enough info to identify a lot of my earlier mistakes. Bruce Roe