Bad days for Solar Production.

[Partimewages]

I wish we would just go to KW everything from everywhere else is so I am always converting!

 

[shadowmaker]

Winter Solstice is Thursday December 21st @ 10:27pm EST in. North America this year. This corresponds to Friday, December 22, 2023 at 03:27 UTC.

So yes, depending on your location Winter may start on the 21st or 22nd this year.

What the hell. We are having close to -30C and winter hasn't even started yet?
?

Typical daily yield 7-8kWh out of 44kWp system, though 50kWh today as it was almost sunny. Typical consumption 180kWh per day.

I have a pallet of panels (20kWp) sitting in my barn, but it's too cold and icy to do anything with those right now. And 6kWp aren't even mine as I'm just storing those for my father-in-law. Also it seems there's very little difference having 44 or 58kWp system when there's just no sun. One really sad month behind, two still to go.

 

[Nobodybusiness]

I've been reading in the forums over on Hearth.com. Interesting reading when it comes to buffer tanks. The move has been towards gasification boilers combined with buffer tanks. Some are building buffer tanks out of 500 gallon or larger LP tanks, using spray foam insulation on the tanks after modifying and cleaning the tanks.

The idea is an efficient burn with only firing the boiler once a day or 1.5 days. UpNorthandpersonal uses a gasification boiler with about 800 gallons of storage. https://medium.com/@upnorthandoffgrid/6-heating-systems-5c5727c1607e

OzSolar uses an even bigger buffer tank and fires once a week. https://diysolarforum.com/threads/feast-or-famine-the-off-grid-solar-dilemma.63293/post-809392

Using an air to water heat pump with a large buffer tank is probably the way of the future. 1500 gallons of water heated on days of good sun to be able to go thru the days of no sun.

Look at those big old GARN batch heaters.

They have something like 2000 gallons of water around the fire jacket.
It’s like an old steam locomotive but for heating houses.

Products | GARN

 

[SparkyJJO]

Are you guys still using British Thermal Units over there? We stopped using them at the end of the last century

BTUs all the way. I have kind of a clue how much heat it is. How it translates to watts I have no clue at all.

Frankly, we should have dumped BTUs a long time ago. And come up with a vastly superior ATU (American Thermal Unit). Just because.

 

[Zwy]

Look at those big old GARN batch heaters.

They have something like 2000 gallons of water around the fire jacket.
It’s like an old steam locomotive but for heating houses.

Products | GARN

Pretty hard to get that down in my basement plus the solar takes up one whole corner.

I purchased a boiler already, it goes into building we will build next summer. Pipe the hot water over to the house where the buffer tanks will be located. The boiler I purchased only holds 59 gallons. That should work well with 200 to 400 gallons of buffer tank.

 

[Nobodybusiness]

Pretty hard to get that down in my basement plus the solar takes up one whole corner.

I purchased a boiler already, it goes into building we will build next summer. Pipe the hot water over to the house where the buffer tanks will be located. The boiler I purchased only holds 59 gallons. That should work well with 200 to 400 gallons of buffer tank.

Yea they usually build a separate building for them.

 

[millsan1]

This is my first year with solar, and yeah, December showed a marked decrease from November.

That being said, my winter KWH use is small. I have a wood boiler that heats the house and hot water.

We do have a ton of small electric crap, however. Wifi, Ring, Litter Robot, all sorts of techy stuff. Overnight, my draw is about 700w/h, and during the day it goes up to 1-1.2 kw/h.

We jsut added a second bank of Lifepower4 batteries, bringing total up to 12. Charged them up full, and ran down to 20% over the course of 2 days or so, with zero sun, and wife doing laundry, washing machine, etc.

I am interested to see how summer works out, with electric HW and a geothermal for AC. The geo is very efficient, but I am running a pump and dump system, so there is a big old well pump, very deep, that feeds the geo and chews up a lot of power. We also have 2 EVs.

 

[RV10flyer]

Well, today (Mon 12/4, we harvested 37 kWh with our 32 kWpv (Up from 20.6kWpv last winter). Just barely enough to recharge to 100% today. Very little sun from 2-4 PM. Low last night 32F. Still able to heat 2000 sqft with 16 & 20 SEER HP’s. 15 cords of firewood ready to go. How was your kWh today?

 

[Zwy]

Battery charged 0.5 Kwh. Load for day was 7.9 Kwh, battery discharged 6.6 Kwh. Yesterday was 1.0Kwh, load 10.9 Kwh, 11.9 Kwh battery discharge.

Currently at 50.93V and switch to grid is set for 49.0V.

Might get some sun tomorrow. Thursday looks better. Your days are coming as this crap moves east.

 

[42OhmsPA]

Might get some sun tomorrow. Thursday looks better. Your days are coming as this crap moves east.

You mean there is more coming ? ? ?.
Since the beginning of the month I've tripled my array size and quadrupled my battery bank plans when I build completely off the grid....

 

[OffGridForGood]

crap up here today too, less than 5kW collected from a 9.6kW array today.
looking like more of the same for tomorrow before we get back to some sun.

 

[Zwy]

You mean there is more coming ? ? ?.
Since the beginning of the month I've tripled my array size and quadrupled my battery bank plans when I build completely off the grid....
View attachment 181204View attachment 181205

You will be getting it.

Fog this morning, sky was clear. As soon as the sun just about cleared the fog layer, it clouded over, completely gray sky all day. It was dark here by 4 pm. Damp as heck too, the cold just seeps thru clothes.

 

[42OhmsPA]

You will be getting it.

Fog this morning, sky was clear. As soon as the sun just about cleared the fog layer, it cloudy over, completely gray sky all day. It was dark here by 4 pm. Damp as heck too, the cold just seeps thru clothes.

Sweet, I just love that weather.
Even better news, I just watched the forecast... Snow on Thursday, the day my panels are supposed to deliver.
Bah! Humbug!

 

[n2aws]

Yup
December sucks. Not looking forward to January, either.
I'm going to throw a bunch of panels on the ground, in the back yard.
What the hell, it can't get worse.

I hear you have a BUNCH of panels available for that

 

[andrew-d]

Blergh, too much snow and freezing rain up here in Ottawa ??


12.35kWp of panels w/Tigo TS4-A-O means nothing when there's 6" of snow on top of everything...

 

[timselectric]

Today sucked.
Made 11kwh.

 

[OffGridForGood]

Blergh, too much snow and freezing rain up here in Ottawa ??
View attachment 181214

12.35kWp of panels w/Tigo TS4-A-O means nothing when there's 6" of snow on top of everything...

I find the ice is not as much of an issue as snow, if you can brush off the snow, the next sunny day will melt the ice as the panels start to generate even through pretty thick ice, takes a while, but it warms up enough for the ice to slide off.

 

[andrew-d]

I find the ice is not as much of an issue as snow, if you can brush off the snow, the next sunny day will melt the ice as the panels start to generate even through pretty thick ice, takes a while, but it warms up enough for the ice to slide off.

Yeah, I grabbed one of these roof rakes that has a super soft head, and it works pretty well at getting the snow off the bottom row of panels. Need a longer pole and probably a ladder to reach the upper row though ?

 

[OffGridForGood]

you can use an extension pole - like the commercial painters have - available at Home Depot IIRC.
or get a length of metal conduit that will just fit your pole handle - to make an extension to the handle.

 

[Balrog006]

Yeah, I grabbed one of these roof rakes that has a super soft head, and it works pretty well at getting the snow off the bottom row of panels. Need a longer pole and probably a ladder to reach the upper row though ?

I got the 18’ version of this, they go to 24’

Snow brush

They’re OOS currently but should be back in stock soon

 

[RV10flyer]

Today sucked.
Made 11kwh.

Yes it did a few miles east too.

 

[RV10flyer]

Yeah, I grabbed one of these roof rakes that has a super soft head, and it works pretty well at getting the snow off the bottom row of panels. Need a longer pole and probably a ladder to reach the upper row though ?

I have one of extendable window washer aluminum poles with the 20” wide soft squeegee. Works good for cleaning them and brushing snow off. Didn’t have enough last winter to worry with.

 

[Balrog006]

Today sucked.
Made 11kwh.

Made 9.9kw here in a 13.6 system.

 

[OzSolar]

Using an air to water heat pump with a large buffer tank is probably the way of the future. 1500 gallons of water heated on days of good sun to be able to go thru the days of no sun.

I agree and there are even some situations where straight resistance will make sense. EG: I'm nearly done adding a 11kW straight resistance my 1200g storage tank. I've modified a 50g water heater so it can run both 5,500 watt elements at the same time. I've nicknamed it the "kWh eater".

So if you have a place to a put a lot of BTU's (kWh's for our metric friends) and can chose what time of day or even better what day of the week you do it you've bought yourself a ton of flexibility.

The formula for BTU's and water is not that hard to get. 1 BTU will change the temp of 1lb of water 1 degree F. 1 gallon of water weighs ~8.3lbs at room temp but loses weight as it gets warmer but for now we're going to ignore the finer points of water changing density with temperature.

You can store 8.3 BTU's in each gallon of water that you raise or lower by 1 degree F.

100 gallons of water raised 50f would look like this.
8.3 x 100 gallons x 50 = 41,500 BTU's

Here's an idea for a buffer tank. Even has a built in heat exchanger.

Richmond 120 gal. Tall 6-Year Solar Electric Water Heater with Universal Connect S120U-1 - The Home Depot

The Richmond 120 Gal. universal connect solar storage tank with multi-port connections are available as electric backup water heaters and as storage tanks for solar water heating systems. The connection

www.homedepot.com

 

[andrew-d]

If anyone is thinking of getting a resistive hot water buffer tank, can I recommend the Rheem Marathon? It's got about 3" of insulation around it, so it doesn't lose heat to the environment nearly as quickly as a "standard" tank. We have one here on a timer that only heats overnight when power is super cheap (2.4¢/kWh), and can be turned on when overproducing solar... though that's not happening this month.