Solar energy Incentive
Solar energy Incentive
It's a good thing I attached a picture of the data plate. I must have you all confused by calling it a 175 watt, sorry! You think it is the same as a 280 that just tested a little lower?
Solar energy Incentive
No worries!
I don't know why I am having problems uploading the .jpg image to UM. The data sheet has the STP275 and STP280 on the same table, side by side. I read that they are the same panel except, as in the case with all silicon wafers, some will be better than others. All semiconductor chips (at least in my day) were sorted at production stage into different "binout"s This is how a company like Intel will sell you a 3GHz cheaper than a 3.2Ghz CPU. They are the same CPU, possibly from the same wafer, but one section of the wafer had different physical characteristics than the other section. It should be the same with these silicon wafers, one slightly different than the other. Put 72 on the panel and no two panel modules will be exactly the same. You see on the data plate it says Output Tolerance 0/+5V. Obviously they are not +5V, otherwise SunTech would have put the 280W label on it and tried to hawk the panels for a few more bucks. I think I posted the 280W label somewhere else on this thread. Anyway, if you look at the side of the panel it will say I1, I2, or I3. I3 will have the STP280W data plate. SunTech is being a bit disingenuous. But hey, it is only a 1W or so, and marketting folks have to make a living somehow
I don't know why I am having problems uploading the .jpg image to UM. The data sheet has the STP275 and STP280 on the same table, side by side. I read that they are the same panel except, as in the case with all silicon wafers, some will be better than others. All semiconductor chips (at least in my day) were sorted at production stage into different "binout"s This is how a company like Intel will sell you a 3GHz cheaper than a 3.2Ghz CPU. They are the same CPU, possibly from the same wafer, but one section of the wafer had different physical characteristics than the other section. It should be the same with these silicon wafers, one slightly different than the other. Put 72 on the panel and no two panel modules will be exactly the same. You see on the data plate it says Output Tolerance 0/+5V. Obviously they are not +5V, otherwise SunTech would have put the 280W label on it and tried to hawk the panels for a few more bucks. I think I posted the 280W label somewhere else on this thread. Anyway, if you look at the side of the panel it will say I1, I2, or I3. I3 will have the STP280W data plate. SunTech is being a bit disingenuous. But hey, it is only a 1W or so, and marketting folks have to make a living somehow
Solar energy Incentive
correction... meant to type 0/+5W not 0/+5V
Solar energy Incentive
I did some research myself. It appears that Suntech uses the i1, i2, and i3 codes to match the panels as perfectly as possible. Pairing the Suntech panels would mean that you should always match the same code numbers. Today I have matched the mono and poly panels together to see what happens tomorrow. I can disconnect either panel any time.
Solar energy Incentive
Thanks for the reminder about trying to match panels up. On a two string inverter, with only one MPPT controller, you definitely should balance out the string voltages, and I guess using the I(1,2,3) label is the fastest way to do that.
I have three panels, two are labelled I1, and have the STP275W data plate, and one is the I3 with the STP280W data plate.
When I first bought the I1 panels, I did not know about the Ix labelling. When you look at an I1 side by side an I3, you can
actually see the difference. The I1 panels show much more patterning whereas the I3 look much more homogeneous. Hard to see in a picture though.
I have three panels, two are labelled I1, and have the STP275W data plate, and one is the I3 with the STP280W data plate.
When I first bought the I1 panels, I did not know about the Ix labelling. When you look at an I1 side by side an I3, you can
actually see the difference. The I1 panels show much more patterning whereas the I3 look much more homogeneous. Hard to see in a picture though.
- I3 code on the STP280W panel (not 275W)
- Different data plate for the I3 binout, suggests SunTech wanted a premium for these
Solar energy Incentive
After all my farting around, I have come to the conclusion that I am getting about 55 percent of the stated wattage from both panels on an average sunny day. A very slight haze is a normal sunny day. On a very clear blue sky sunny day that goes to about 70 percent. The panel orientation seems no where near as important as some believe.
I have decided to leave the 310 watt and 275 watt panels paired together. Apparently there is not that much loss because of the two different panels. Today I was watching the watt meter and it has gone from a total of 275 watt output to 310 watt output and back to 275 watts in just a few minutes. There was no noticeable change in the brightness of the sun that I could see.
In conclusion, you get more bang for the baht with the Poly crystalline panels than the Mono crystalline panels. The main lesson for me was to buy more panels than I thought I needed. Maybe the most important thing is the charge controller. I have a combined voltage of 32.4 volts from the two panels connected in parallel. The MPPT CC holds the voltage to just above the actual battery voltage and raises the amperage.
One interesting thing is that having the two panels side by side, The 310 watt panel must have a better finish because the 275 watt collects a lot more leaves. They just slide off the 310 watt panel.
I have decided to leave the 310 watt and 275 watt panels paired together. Apparently there is not that much loss because of the two different panels. Today I was watching the watt meter and it has gone from a total of 275 watt output to 310 watt output and back to 275 watts in just a few minutes. There was no noticeable change in the brightness of the sun that I could see.
In conclusion, you get more bang for the baht with the Poly crystalline panels than the Mono crystalline panels. The main lesson for me was to buy more panels than I thought I needed. Maybe the most important thing is the charge controller. I have a combined voltage of 32.4 volts from the two panels connected in parallel. The MPPT CC holds the voltage to just above the actual battery voltage and raises the amperage.
One interesting thing is that having the two panels side by side, The 310 watt panel must have a better finish because the 275 watt collects a lot more leaves. They just slide off the 310 watt panel.
Solar energy Incentive
If you are getting 70% of 275W, that is 192W. According to the data sheet, at 20C ambient, and 800W/m2 you should get 201W. The last few days the ambient temperatures here have been in the high 30s C.
As far as the panel angle to the sun, I think that effect is dwarfed by the ambient temp and wind conditions. My panels were performing better during the cold season than now.
The NOCT table is the "realistic" values.
As far as the panel angle to the sun, I think that effect is dwarfed by the ambient temp and wind conditions. My panels were performing better during the cold season than now.
- STP275/280 data sheet
Solar energy Incentive
Yes , the NOCT value is the "real" value . I have looked up some while ago the ideal angle for Udon Thani for solar panels , and the differences at "normal" angles are not bigger then 10/15% of max output . The bigger your system the more this is off course . Cooling your panels will bring more as they are closer to NOCT rating ( or even higher then NOCT ) . Realistic values for Thailand are on a yearly basis between 4 and 4.5kwh/kw/day . On 1 panel this is around 1 kwh/daily . Efficient inverters do bring a lot of extra power without adding extra panels , but their price is also higher . The cheap Powerjacks are not very efficient and are only considerably for a system less then 1 kwp . Anything above and you will find that the price difference will get smaller .
If you have high cable length ( inverter to panels ) and you cannot get around that consider bigger cables , look up in internet how much it can change for your case .
Some things in the system you cannot change , many others you can do and put them all together will get you the best output possible
If you have high cable length ( inverter to panels ) and you cannot get around that consider bigger cables , look up in internet how much it can change for your case .
Some things in the system you cannot change , many others you can do and put them all together will get you the best output possible
Solar energy Incentive
Each panel is connected to the CC with 2.5 sq. mm wiring Both panels have their own wiring (2 sets) at less than 8 meters in length. I get my readings from a watt meter that is installed before the CC and comes directly from the panels. The readings from the MPPT CC is a separate meter that gives voltage and amps going directly to the batteries. There is a DC ammeter between the batteries and the inverter. I also check AC amps with a multimeter coming out of the inverter.
My main interest was what was coming out of the panels and not the overall efficiency of the system. Today the maximum reading was 325 watts with the 310 watt and the 275 watt panels connected together.
My main interest was what was coming out of the panels and not the overall efficiency of the system. Today the maximum reading was 325 watts with the 310 watt and the 275 watt panels connected together.
Solar energy Incentive
Solar energy Incentive
Just had a storm pass through over the last hour or so. Having had three power outages (the worst one was a couple of hours) in the last few weeks, I now just disconnect the valuable/sensitive devices from the grid at the beginning of the storm. I connect my battery array to the little inverter and I can keep a couple of LED lights, a fan, a router, and my notebook computer running whilst we ride out the storm. If the power goes out, it is not much of an event now. I am very happy to have installed this "el cheapo" backup system.
Solar energy Incentive
Myself and my partner have a solar panel company in England so have watched this thread with interest .
Seems to me you need a regular supplier of both panels and inverters , so please PM me. I have udon based contacts and my wife's family are from Udon.
Seems to me you need a regular supplier of both panels and inverters , so please PM me. I have udon based contacts and my wife's family are from Udon.
Solar energy Incentive
wonderful ajsp9..
the wee woman has a house on the build, and I am a solar power user in NZ since 1996, so I will be setting her up with a small probably 12v standby system in Udon maybe next year...couple of panels, inverter or charge controller, and a 109ah battery, afew lights, water pump, float switch..so you might save me lugging it all from NZ..but I do like the Outback Inverter's, but pricey..we will see
the wee woman has a house on the build, and I am a solar power user in NZ since 1996, so I will be setting her up with a small probably 12v standby system in Udon maybe next year...couple of panels, inverter or charge controller, and a 109ah battery, afew lights, water pump, float switch..so you might save me lugging it all from NZ..but I do like the Outback Inverter's, but pricey..we will see
Solar energy Incentive
I'm still learning about solar electric systems. The Internet is both a blessing and a curse. Lots of contradictory information. I have spent countless hours researching every aspect of solar systems. After losing a couple of computers and UPS units to lightning, power spikes and low voltage, I decided that I wanted to have my computer totally isolated from the grid. At this point, my computer room is 100 percent off grid. The home system is small and only powers my computer, printer, lights and a small fan. Three 65 AH sealed deep cycle batteries powered by two solar panels, one a 310 watt mono and the other a 275 watt poly. The panels are connected in parallel. They work just fine together.
Many have said that the inverter is the heart of the system. I disagree. I think the most important component is the charge controller. I had to make the choice of a $15 pulse wave or a $120 MPPT. My 20 amp MPPT controller gets the most out of the solar panels. I have an EP solar MPPT and am impressed with it. The voltage and amps coming out of the solar panels are 35 volts and 7.4 amps. Coming out of the charge controller I have 13.3 volts and 17.5 amps. It is hazy today and I am getting 256 watts. You can't use the 35 volts from the panels to charge your battery bank so I think that using a cheap controller is wasting a lot of energy.
Now for the inverter. I am convinced that buying a pure sine wave inverter costs a little more money but it is money well spent. Many electrical devices don't like modified sine wave dirty electricity. After reading all the hype about the big name brand inverters, I decided to buy a good one. After reading all the specifications, I changed my mind and opted to buy a cheap no name inverter. The name brand inverters cost many times more than the cheapies. Looking at a 500 watt name brand that cost $800 with a 5 year warranty and comparing it to a $135 600 watt cheapy with a one year warranty I bought the cheapy. The cheap inverter has now been running for 8 months with no problems. Since the cheapy may not last long, ?? I have a spare.
After I got my home system running to suit myself, I built a second system for the off grid farm. Two 280 watt cheap poly panels, a 40 amp MPPT EP solar charge controller and a cheap 800 watt inverter. I use two FB deep cycle 125 AH flooded batteries. It was connect and forget so far. My wife's nephew has been staying there nights. He uses a fan, lights and watches TV with a satellite dish. They system will also run an electric drill or a 125 watt water pump with no problems. Whenever I go over there in the mornings maybe about 10:00 am, the green charge controller light is always flashing telling me the batteries are fully charged. That system is working great.
Many have said that the inverter is the heart of the system. I disagree. I think the most important component is the charge controller. I had to make the choice of a $15 pulse wave or a $120 MPPT. My 20 amp MPPT controller gets the most out of the solar panels. I have an EP solar MPPT and am impressed with it. The voltage and amps coming out of the solar panels are 35 volts and 7.4 amps. Coming out of the charge controller I have 13.3 volts and 17.5 amps. It is hazy today and I am getting 256 watts. You can't use the 35 volts from the panels to charge your battery bank so I think that using a cheap controller is wasting a lot of energy.
Now for the inverter. I am convinced that buying a pure sine wave inverter costs a little more money but it is money well spent. Many electrical devices don't like modified sine wave dirty electricity. After reading all the hype about the big name brand inverters, I decided to buy a good one. After reading all the specifications, I changed my mind and opted to buy a cheap no name inverter. The name brand inverters cost many times more than the cheapies. Looking at a 500 watt name brand that cost $800 with a 5 year warranty and comparing it to a $135 600 watt cheapy with a one year warranty I bought the cheapy. The cheap inverter has now been running for 8 months with no problems. Since the cheapy may not last long, ?? I have a spare.
After I got my home system running to suit myself, I built a second system for the off grid farm. Two 280 watt cheap poly panels, a 40 amp MPPT EP solar charge controller and a cheap 800 watt inverter. I use two FB deep cycle 125 AH flooded batteries. It was connect and forget so far. My wife's nephew has been staying there nights. He uses a fan, lights and watches TV with a satellite dish. They system will also run an electric drill or a 125 watt water pump with no problems. Whenever I go over there in the mornings maybe about 10:00 am, the green charge controller light is always flashing telling me the batteries are fully charged. That system is working great.
Solar energy Incentive
I can't see any problem using your "dirty" inverter.
Many will say one must use a good inverter supply with computers but I cannot see the reasoning behind it given the way the computer switch mode power supply operates.
Put simply,firstly the 100 to 240vac input is converted to approx. 300V DC inside the switchmode supply unit. Most will then generate a high frequency wave about 400hz I think, which then is transformed into the various voltage levels needed (AC) and then rectified for the motherboard. Reason overall to go through this process is to mainly miniaturise the transformer and therefore overall size of the power unit.
So if the incoming supply is a bit "noisy or dirty" I fail to see any real problem given it is filtered and rectified in the first stage of the power unit anyhow.
Disadvantage is they run rather hot so components such as electrolytic capacitors tend to have shorter life span. Then again, most things are throw-away these days after 5 years or so.
Many will say one must use a good inverter supply with computers but I cannot see the reasoning behind it given the way the computer switch mode power supply operates.
Put simply,firstly the 100 to 240vac input is converted to approx. 300V DC inside the switchmode supply unit. Most will then generate a high frequency wave about 400hz I think, which then is transformed into the various voltage levels needed (AC) and then rectified for the motherboard. Reason overall to go through this process is to mainly miniaturise the transformer and therefore overall size of the power unit.
So if the incoming supply is a bit "noisy or dirty" I fail to see any real problem given it is filtered and rectified in the first stage of the power unit anyhow.
Disadvantage is they run rather hot so components such as electrolytic capacitors tend to have shorter life span. Then again, most things are throw-away these days after 5 years or so.
Solar energy Incentive
I still have a small UPS modified sine wave inverter. One of the fans I still use is AC. It buzzes like crazy when powered with the UPS and goes very quiet when back on the mains or the pure sine wave inverter. That dirty electricity has to be very hard on electric motors.
As far as my computer, you're right, I can't tell any obvious difference. Inverter manufactures warn about using modified sine wave and say they will shorten the life of many different AC appliances and computers.
As far as my computer, you're right, I can't tell any obvious difference. Inverter manufactures warn about using modified sine wave and say they will shorten the life of many different AC appliances and computers.
Solar energy Incentive
The only reason to buy a MSW is the Watts/$ is much higher. If you look at the devices in your home that use the most Watts (not necessarily Watt hrs), they are resistive appliances. I just bought a 6KW shower heater for my new home. If I wanted to be able to use that when not connected to the grid I'd need an even larger inverter (considering I would not want every other activity in the house to stop because somebody was taking a shower). So, what to do. I have decided to break out the circuit breaker panel to be able to take advantage of that MSW Watt/$ advantage. The ability to feed the resistive appliances with MSW inverter(s), whilst sensitive appliances are fed by a PSW inverter. The circuit breaker panel is going to be a bit complicated for the uninitiated, but it should give me a much cheaper system, that will not require the family (or computer) to watch every watt that they use whilst on backup-power.
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I really wanted to go with solar hot water. Siam Green Power has what looks like a good system but the 70,000 baht price choked me up. Do you know anyone who is using an LPG heater?
http://www.siam.led-gpi.com/solarpower/ ... ating.html
http://www.siam.led-gpi.com/solarpower/ ... ating.html
Solar energy Incentive
I'm looking at a "conversion kit".
Uses solar tubes which have some advantages.
Connects into an existing mains pressure (about 40psi) hot water system.
There are other systems also.............about $1600.00 here in Aus.(48,000 Baht)
Maybe something similar you can get there in Thailand.
http://www.solaroz.com.au/solarhotwater_products.html
Uses solar tubes which have some advantages.
Connects into an existing mains pressure (about 40psi) hot water system.
There are other systems also.............about $1600.00 here in Aus.(48,000 Baht)
Maybe something similar you can get there in Thailand.
http://www.solaroz.com.au/solarhotwater_products.html