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Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 4:51 am
by gedogen
By necessity I have my panels almost flat. Like the 60 degree east west, it seems to have a flatter power output throughout the day. My off grid battery storage is only about 30AH and choose to use the energy real time with almost 3K of panels. Unconventional, but it works really well. Batteries are just money down the toilet. I'd rather buy panels.

Those grid ties will find in a few years that the utilities will economically force panels to face west.

Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 5:57 am
by australsolarier
the weather has turned cloudy now. but i still watched and compared the two south facing arrays. the 32 and the 20 degree arrays together put out more than 1 north facing array. but keep in mind this ratio will probably change for the worse in midwinter.
on the sideline here, i am adding new roof area for more solar panels. i was playing around different orientations and tilts trying to calculate yearly average maximum. (partly shaded because of a 30 degree tilted array on the north end.) i tried all kinds of combinations. the most bang i got with 4 arrays flat and 1 array facing south. keep in mind that is a theoretical calculation. but optimised for winter cloudy weather.
so a couple of month down the line i might have a 40 to 50 degree south facing array to compare. now now, the addition to the roof has to be built first.
another sideline, through being lucky i picked up a bunch of 260wp poly panels. 115$ each. when i put in the grid feed solar in 2002 those panels would have put me back 3000$ each. so gedogen yes, have as many panels as there is room or you can afford. but a 30ah battery looks a bit tiny to me.if you want to run a whole house. however it is probably just a beginning. i started with a 200ah battery and this grow to my present system(s).
i will keep you interested guys posted in midsummer.

Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 6:40 am
by Warpspeed
A 30ah battery looks a bit tiny to me.if you want to run a whole house.

It really depends on how many cells there are.
I run thirty 50Ah Winstons (100v 5Kwh)
At this time of year my night time load is around 1.2 Kwh and just over double that in mid winter.

Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 8:15 am
by australsolarier
warpspeed,
just out of curiosity , what is your consumption over night in winter?

Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 8:28 am
by Warpspeed
March 1.4Kwh
April 2.1Kwh
May 2.6Kwh
June 2.6Kwh
July 2.5Kwh
Aug 2.3Kwh
Sept 2.5 Kwh
Oct 1.2 Kwh

Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 9:20 am
by australsolarier
warpspeed, thanks for your data.

as for me with a 400ah/48V lifepo4 battery:

now, and october so 87% soc, so overnight use is 2kwh, this includes the selectronic inverter, but not the outdoor lights. (basically fridge, freezer chest, lights, tv) at the moment at 7am the solar produces equal to house consumption.

in the winter so 66% soc, which comes to 7kwh . but this is because i turned on the aircon to heat the house at 4am.
basically i hardly used the solar hydronic heating system this year, just to see how things work out electrically only. the aircon probably would have used so 4kwh or thereabouts. mind you this winter was extraordinarily sunny. now the water tanks are practically empty.

Re: orienting solar panels south??

PostPosted: Sat Oct 28, 2017 9:56 am
by Warpspeed
At night my only loads are refrigeration and some LED lighting, plus the blower fans in gas space heaters during winter.
The big jumps in March and October seem to be due to daylight saving. End of daylight saving makes a very big difference because the sun rises an hour earlier, one hour less need for heating and lighting on cold mornings.

All required heat here comes from natural gas, cooking, hot water, space heating, and even a home made gas tumble dryer.

Re: orienting solar panels south??

PostPosted: Sun Jan 07, 2018 3:54 pm
by australsolarier
we have had a few days sunny weather here.
so i tested my south facing arrays. by now i have 3 arrays each with 3 panels, 250wp. 2 arrays about 20 degrees and one array about 30 degrees tilt. the last two days they generated 12kwh each. amazingly this is the same like my north facing 30 degrees tilted arrays. it is summer now and in the winter it will be different i am sure. i will find out.
i filled in the spaces between the tilted arrays. so that empty space is being put to use. the gap there is because in winter it is being shaded. another advantage might be the north and south facing arrays catch each others reflection. but again i am not sure about that.
the power curve is flatter though, more like a tracked system.

Re: orienting solar panels south??

PostPosted: Fri Mar 23, 2018 6:41 am
by australsolarier
ok, update here:

we are at the equinox and i did another measurement. the three south facing arrays generated 5.4kwh. this compares to about 10kwh to an equivalent kwp north facing 30 degree tilt array.
it will be interesting what it does in the winter.
i mention here again, the south facing arrays are more for cloudy weather than sunny weather.

Re: orienting solar panels south??

PostPosted: Thu Jun 14, 2018 3:52 pm
by australsolarier
more update:

we are close to the winter solstice. today the south facing strings generated a meekly 0.9kwh . as compared with 8kwh north facing. that is in cloudless weather. i suspect they would generate more in cloudy weather this time of the year. i will test that next cloudy day.

ok i hope it helps some of you that are in the designing phase.