5 minutes ago, BritManToo said:

My 5 panels produced 136 units, leaving me a bill for 846bht.

 

I wish, our bill was still 3,334 Baht ???? 

 

Madam's koi (although I've reduced their power demand somewhat) plus our A/C loving grandkids who are here for the covid duration and myself having to work from home made sure of that.

 

No PEA discount this time ???? 

 

Just now, Crossy said:

 

I wish, our bill was still 3,334 Baht ???? 

 

Madam's koi (although I've reduced their power demand somewhat) plus our A/C loving grandkids who are here for the covid duration and myself having to work from home made sure of that.

 

No PEA discount this time ???? 

 

April last year with my old bedroom air-con I used 500 units

April this year with my new inverter bedroom air-con I used 350 units.

 

Replacing the old air-con saved me 150 units in one month.

May netted us a very satisfactory 840kWh despite a few yukky days.

 

 

 

We are just coming up to the 1st birthday of the system as currently configured. Payback is still on target for just under 3 years.

Very nice project, i believe diy is the way to get economy in a solar project. I like your diy rails for the mounting.. I have the steel roofing who is common here and did read solar panels could be placed direct on the roofing, the shapes on the roofing works as rails. If i go that route i need some way to fasten the panels, any ideas?

 

 

Pink

1 hour ago, Pink7 said:

solar panels could be placed direct on the roofing, the shapes on the roofing works as rails. If i go that route i need some way to fasten the panels, any ideas?

 

Many ways to fasten. I would rather build up of the roof to keep the PV's cooler and more efficient. TOA sells aluminum braces 15Bht per meter. Right angle brackets to fix PV'S 5 Bht each.. Not sure of price of tech screws but needed... Less holes need drilling through the roof to fix this way....

 

Thanks for that, I have lots of something similar i used in my ceiling but this maybe thicker? 

 

Quote

Many ways to fasten. I would rather build up of the roof to keep the PV's cooler and more efficient. TOA sells aluminum braces 15Bht per meter. Right angle brackets to fix PV'S 5 Bht each.. Not sure of price of tech screws but needed... Less holes need drilling through the roof to fix this way....

 

 

I'd certainly like to see a reasonable gap under the panels, as Thaifish said it gives ventilation it also makes it a less desirable residence for the local wildlife.

 

I have no idea why the "proper" channel and fittings are so expensive but it's little trouble to make them. If you do go DIY remember the full-size panels are HEAVY so make sure your fixings are robust enough.

 

I would be very careful with penetrations in your house roof, in our car port a leak or two wouldn't matter in your bedroom it's a different animal.

I had a idea to do a DIY solution with steel bars maybe 1x1 and i will make some some spacers to get it up from the roof panels (like crossy did), i see now thats better Then give them some coat of some protective paint. Then ground them.. 

 

Pink

On 5/1/2021 at 6:10 PM, BritManToo said:

April last year with my old bedroom air-con I used 500 units

April this year with my new inverter bedroom air-con I used 350 units.

 

Replacing the old air-con saved me 150 units in one month.

We got a smaller inverter unit and hardly any change at all...  on top of that, the samsung unit amuminium core needed changing, within waranty (also got an older one changed core AC guys dont like them) and doule for parts / maint  due to being an inverter type...

Happy Birthday to the car-port solar ????????????????

 

It's one year since the system began operating in its current form (two extra panels were added in January 2021).

 

In that time it's generated 7,866kWh of electricity saving us around 32,500THB, that's about 34% of the installation cost. So we are on target for the original estimate of 3 years to pay back.

 

I'm definitely not complaining ???? 

3 hours ago, Crossy said:

Happy Birthday to the car-port solar ????????????????

 

It's one year since the system began operating in its current form (two extra panels were added in January 2021).

 

In that time it's generated 7,866kWh of electricity saving us around 32,500THB, that's about 34% of the installation cost. So we are on target for the original estimate of 3 years to pay back.

 

I'm definitely not complaining ???? 

Congrats, 3 years are great. 

 

Pink

On 6/16/2021 at 12:26 AM, Crossy said:

In that time it's generated 7,866kWh

@Crossy, how many kW (DC) is that again?  Trying to get at your annual equivalent daily hours… and my recollection of 1kW would mean 21 hours of full sunshine per day. 

On 6/10/2021 at 3:42 PM, Seeall said:

We got a smaller inverter unit and hardly any change at all...  on top of that, the samsung unit amuminium core needed changing, within waranty (also got an older one changed core AC guys dont like them) and doule for parts / maint  due to being an inverter type...

Samsung are rubbish!

1 hour ago, tjo o tjim said:

@Crossy, how many kW (DC) is that again?  Trying to get at your annual equivalent daily hours… and my recollection of 1kW would mean 21 hours of full sunshine per day. 

 

6.5kWP installed on our car-port.

 

It's not quite ideally angled but isn't shaded and does face due south.

 

Daily production varies from a measly 5kWh (a particularly miserable day) to a very satisfactory 34kWh per day. Average is around 21kWh per day.

 

 

7 hours ago, Crossy said:

but isn't shaded

Except for a post just like mine.

A very satisfactory output. Well done you.

Crossy, have you (or anyone else) looked into better thermal coefficient panels?  At home (Hawaii, average temperature closer to 27 during the day), my 8kWP system gets 54-55kWh on a great day, and 12-13MWh per year

17 hours ago, tjo o tjim said:

Crossy, have you (or anyone else) looked into better thermal coefficient panels?  At home (Hawaii, average temperature closer to 27 during the day), my 8kWP system gets 54-55kWh on a great day, and 12-13MWh per year

 

Yeah, at fully 10C cooler (is Hawaii really that cool?) I can see getting better output. Our panels get warm enough that the pigeons hot-foot off if they happen to land on them around mid-day.

 

We're not aiming to squeeze every last watt out of the array, we have plenty of space. Whether panels with better thermal properties (read more $$$) would be worth it, I don't know.

 

2 hours ago, Crossy said:

 

Yeah, at fully 10C cooler (is Hawaii really that cool?) I can see getting better output. Our panels get warm enough that the pigeons hot-foot off if they happen to land on them around mid-day.

 

We're not aiming to squeeze every last watt out of the array, we have plenty of space. Whether panels with better thermal properties (read more $$$) would be worth it, I don't know.

 

You don't just get more power from the panels, you also get a longer life. Don't forget, it's not just the sun that heats them. The more current they deliver, the warmer they get. There are some panels (not readily available) that have a liquid coolant radiator arrangement on the rear surface and there are many You Tube vid's of people who have arranged water sprays to lower their panel temperatures. Another idea is the application of phase change cooling blocks. I haven't tried any of these yet but maybe one day.........

I've heard , poly solars are better at hottest temp , while the monos are better in lower light conditions . Yes i've seen many dealing with this behavior , cooling them with water . It does work , no question about it . However , you also need to put waterlines up there , and i guess tap water contains calciumcarbonate , which over time will put a film on them reducing their power . All can be solved , but is it worth it ? Solar panels aren't too expensive anymore , and 1 extra panel is the least of the cost of the installation ( well not completely but you get the picture ) . I think easiest is taking care when putting them somewhere is putting a angle on them , and leave plenty of space underneath , so the biggest heat of the panels can go away . A bit of wind does do a lot , and maybe that is the case for Hawai and near coastal areas , but inside Thailand , many times there is no wind .

16 minutes ago, sezze said:

I've heard , poly solars are better at hottest temp , while the monos are better in lower light conditions . Yes i've seen many dealing with this behavior , cooling them with water . It does work , no question about it . However , you also need to put waterlines up there , and i guess tap water contains calciumcarbonate , which over time will put a film on them reducing their power . All can be solved , but is it worth it ? Solar panels aren't too expensive anymore , and 1 extra panel is the least of the cost of the installation ( well not completely but you get the picture ) . I think easiest is taking care when putting them somewhere is putting a angle on them , and leave plenty of space underneath , so the biggest heat of the panels can go away . A bit of wind does do a lot , and maybe that is the case for Hawai and near coastal areas , but inside Thailand , many times there is no wind .

All silicone solar panels, be they mono or poly, are rated at 25 deg. C. As the temperature rises above that the panels loose power. It can get to the point of loosing as much as 20% of the output at 40 deg. + self heating. Typical silicon solar panels have a temperature coefficient of about -0.4 to -0.5 percent/deg. C.

3 hours ago, Muhendis said:

Typical silicon solar panels have a temperature coefficient of about -0.4 to -0.5 percent/deg. C.

Is it that low nowadays?  I remember just a few years ago it being a fill 1.0%/deg C, and the premium Panasonics were the best at around 0.26%.

31 minutes ago, tjo o tjim said:

Is it that low nowadays?  I remember just a few years ago it being a fill 1.0%/deg C, and the premium Panasonics were the best at around 0.26%.

Silicone panels are subject to improvements as time goes by and new processes are tried. Also strides have been made to improve the purity of the chemicals used in the manufacturing process. Every little helps but the fundamental physics of semiconductor bandgap will always be there. 

Data for June generation a total of 795.73 kWh.

 

Slight format change now, the site I was using has gotten its knickers in a twist so I'm using data from my own metering, probably more reliable too.

 

 

There are also changes afoot with the addition of a new hybrid inverter, more panels and a battery pack in anticipation of PEA coming along with smart / no-reverse meters.

 

Watch this space.

10 hours ago, Crossy said:

Data for June generation a total of 795.73 kWh.

 

Slight format change now, the site I was using has gotten its knickers in a twist so I'm using data from my own metering, probably more reliable too.

 

 

There are also changes afoot with the addition of a new hybrid inverter, more panels and a battery pack in anticipation of PEA coming along with smart / no-reverse meters.

 

Watch this space.

Hi Crossy. Did you make your own 48 V battery bank?

On 7/2/2021 at 4:27 AM, carlyai said:

Hi Crossy. Did you make your own 48 V battery bank?

 

Yup, details coming soon.

 

My initial "test" pack came from a mate who bought the cells as 100Ah but they turned out to be 50Ah when tested. Of course he only noticed when his system failed to perform as expected, by which time it was too late to return them, that Lazada seller is now in my "naughty list".

 

So I've got 16 x 200Ah used golf-cart cells sitting on my bench (at 5kg a piece it's creaking somewhat) awaiting my attention. One cell on the capacity tester at present but since my LiFePO4 charger only manages 4A the capacity test may take a while. There's a 1 month warranty on the cells so if they turn out to be not as advertised they can go back. These are from a seller I've used before so I suspect they will be fine. We shall see.

1 hour ago, Crossy said:

 

Yup, details coming soon.

 

My initial "test" pack came from a mate who bought the cells as 100Ah but they turned out to be 50Ah when tested. Of course he only noticed when his system failed to perform as expected, by which time it was too late to return them, that Lazada seller is now in my "naughty list".

 

So I've got 16 x 200Ah used golf-cart cells sitting on my bench (at 5kg a piece it's creaking somewhat) awaiting my attention. One cell on the capacity tester at present but since my LiFePO4 charger only manages 4A the capacitiy test may take a while. There's a 1 month warranty on the cells so if they turn out to be not as advertised they can go back. These are from a seller I've used before so I suspect they will be fine. We shall see.

Sounds good. I'm in Aus at the moment out of quarinteen into Sydney lockdown but planning (thinking of planning), a smallish system to run all my shed (greenhouse, aquaponics, irrigation and pool), then go from 3 phase back to single phase and run the house as well. So thinking at the moment.

Looking forward to your posts.

Your power data logging system is still pretty well as per your posts in that thread, no major mods not in the thread?

Things are afoot! The steel and welding monsters are at large!

 

 

With just two of us and a young assistant working only Sundays this could take a while, 3 weekends to get this far ???? 

 

Something I can do on my own is sort out the new inverter, the beast on the right is a Sofar HYD-5000ES 5kW grid-tie hybrid, it dwarfs the existing 6kW pure grid-tie unit on the left (it also weighs >20kg, nearly did myself a mischief getting it on the mount). DC breakers and surge suppression in place. Contrary to my earlier information these hybrids DO run as (very expensive) pure grid-tie with no batteries connected, it's currently under test hooked to one of my existing 3kW strings whilst the roof gets sorted.

 

The cage on top of the left hand unit is a literal bird cage, to stop the local wildlife making its home up there (it gets pretty warm so I expect any eggs would cook), the new unit will get one too.

 

I like the trussed beams. They look super strong. Would you care to share the calcs? 

18 minutes ago, Muhendis said:

I like the trussed beams. They look super strong. Would you care to share the calcs? 

They are copied from the existing car port which was built by my step-son and his gang of khmer labour, if the new bit didn't match Madam would kill me.

 

My original design (from "the net") didn't have the trusses and it was decided that if we were putting half a ton of solar up there it wouldn't be strong enough on a nearly 6m span, hence the trusses.

 

I doubt they were ever actually "designed" probably copied from the factory roof they were building the week before (which is likely where the steel came from too). To be honest they are well over-engineered (100kg of farang can hang on there with no perceptible movement), they'll be a convenient place to hang my engine-crane if I ever need one.

 

EDIT And they make a very convenient place to mount stuff like inverters up out of the way ???? 

Trusses are up (Sunday) they are 'kin heavy.

 

 

New sections have a bit of 1¹/₂" square tube bolted inside to align then 10mm threaded rod to pull the sections together before welding, it's going nowhere.

 

Before final alignment / leveling and welding.

 

 

 

Roof next week with luck if it doesn't rain too much. It's all 6m lengths so no cutting needed.