Info required for solar power setup

[yousuft]

Hello
I am planning to install solar panel for residential use. The purpose is electricity bill saving. My Plan is to power up air conditioner with solar power without battereis during sun light only. I live in Asian country with typical hot weather with 8 - 9 hours of sunlight.Kindly advise no of panels required for setting up solar power below is load values

Airconditioner load (AC power)= 1980 Watt approx 2 KWatt

Also kindly advise for designing solar power what is formula to convert AC power into DC power and how much DC power will be required to power up 2KW AC power.

Thanks

[SunEagle]

Hello yousuft and welcome to Solar Panel Talk

Running an Air Conditioner unit directly from your solar panels is not easy or cheap. Due to the start up load of an air conditioner compressor, your panel wattage may need to be 4 times the running wattage of 2k. Also while the sun may shine for 9 hours it will not be enough to generate power for almost half of that time frame. Depending on where you live you may get as much as 7 good hours during the Summer but most places get less.

Probably the best way for most solar pv installations would be to connect it to the grid power. But if that is not allowed then you will need to build an off grid system which unfortunately will require batteries.

[yousuft]

Thanks for reply. I will be using inverter air conditioner whose starting load is very less as compared to traditional air conditioners so start up load is not an issue. Inverter air condioner consume 2KW power. I live in Pakistan where solar radiation value is 5KWh/m2 and here we get 7-9 hours of sun light. Solar system will be connected to grid power and it will be running on grid power when solar power is not available in night. Kindly help me to design solar system for 2 KW load.

[Logan005]

Even if you invested in the Hotspot 48 volt AC, you still need a 48 volt battery bank at least 100AH avail for daytime only run. up to 8 to 9 hrs. I am not aware of any AC unit that runs w/o a battery. Maybe engineers are working on something not yet on the market. If you have grid power avail, consider a grid tie system to off set your usage.

[yousuft]

Basically inverter air conditioner operates on AC voltages it have AC input which is converted into DC by built in inverter. I have check starting load it doesn't have torque load it starts on 1 A which gradually increases to 6.5 A. So kindly advise how to design solar panel design for this air conditioner.

[silversaver]

Thanks for reply. I will be using inverter air conditioner whose starting load is very less as compared to traditional air conditioners so start up load is not an issue. Inverter air condioner consume 2KW power. I live in Pakistan where solar radiation value is 5KWh/m2 and here we get 7-9 hours of sun light. Solar system will be connected to grid power and it will be running on grid power when solar power is not available in night. Kindly help me to design solar system for 2 KW load.

With the size this small, I'm not sure were the saving will really go....

[sdold]

it have AC input which is converted into DC by built in inverter.

Are you sure it doesn't have a DC input that converts to AC within the unit? An inverter converts DC to AC, not AC to DC. That's a rectifier.

[Logan005]

If you can off set 2K watts through grid tie, your AC will generally cycle 40 to 60%, so you may off set enough for shoulder hours and maybe even some night time run.

[yousuft]

Are you sure it doesn't have a DC input that converts to AC within the unit? An inverter converts DC to AC, not AC to DC. That's a rectifier.

Sorry it have a builtin rectifier which convert AC into DC and airconditioner input is AC voltages.

Please advise how 2 Kwatt solar system will be designed using 250 watt solar panel and which rating panel (200/250/300) is best to use. Also i have one query what is output voltages of 250 watt panel. On data sheet it s written Max power Voltage 29.67, Open circuit voltage 37.25. As per my understanding solar output is 24 Volt and 2 panel will connected in series to generate 48 V.

Kindly clarify. Thanks

[SunEagle]

Sorry it have a builtin rectifier which convert AC into DC and airconditioner input is AC voltages.

Please advise how 2 Kwatt solar system will be designed using 250 watt solar panel and which rating panel (200/250/300) is best to use. Also i have one query what is output voltages of 250 watt panel. On data sheet it s written Max power Voltage 29.67, Open circuit voltage 37.25. As per my understanding solar output is 24 Volt and 2 panel will connected in series to generate 48 V.

Kindly clarify. Thanks

To simplify panel categories they are labeled as 12 volt "battery" panels or 24 volt "grid tie" panels. But that is misleading since a "battery" panel usually has a Max power voltage ~ 18volts and a "grid tie" panels has a Max power voltage ~ 30v or greater.

To charge a 12 volt battery you really needs something > 15volts. To charge a 24volt battery system requires voltages above 30volts and to charge a 48volt battery system requires voltages above 54volts.

So two of those 250w panels (Vmp = 29.67v) wired in series could be used to charge either a 24v or 48v battery system with an MPPT type charge controler but only one of those Vmp = 29.67v may not be enough to charge a 24volt battery.

So 8 of those 250watt panels will add up to 2000watts but in my opinion that will not be enough to run your air conditioner since when converting from DC wattage to AC wattage you can lose about 15% of the output so a 2000watt DC system could be as low as 1700watts AC.

[Logan005]

get grid tie panels with micro inverters and install 2K watts of panels with proper inclination for your latitude, "If legal in your country" back feed the grid to off set day and some evening use. You really need to do a energy use assessment. Use a "Kill a watt" device and figure out how much power you really use. Will make sizing your system easier.

[yousuft]

To simplify panel categories they are labeled as 12 volt "battery" panels or 24 volt "grid tie" panels. But that is misleading since a "battery" panel usually has a Max power voltage ~ 18volts and a "grid tie" panels has a Max power voltage ~ 30v or greater.

To charge a 12 volt battery you really needs something > 15volts. To charge a 24volt battery system requires voltages above 30volts and to charge a 48volt battery system requires voltages above 54volts.

So two of those 250w panels (Vmp = 29.67v) wired in series could be used to charge either a 24v or 48v battery system with an MPPT type charge controler but only one of those Vmp = 29.67v may not be enough to charge a 24volt battery.

So 8 of those 250watt panels will add up to 2000watts but in my opinion that will not be enough to run your air conditioner since when converting from DC wattage to AC wattage you can lose about 15% of the output so a 2000watt DC system could be as low as 1700watts AC.

Thanks for clarification.

get grid tie panels with micro inverters and install 2K watts of panels with proper inclination for your latitude, "If legal in your country" back feed the grid to off set day and some evening use. You really need to do a energy use assessment. Use a "Kill a watt" device and figure out how much power you really use. Will make sizing your system easier.

Please share some more detail on grid tie panels, micro inverter and how to back feed grid to off set day / evening. Appreciate if you can share a link.

Thanks.

[SunEagle]

Any hardware that you install that can back feed the grid will require your Electric Power Company (POCO) to approve it. I would check with someone in your area to find out what can be installed and what can't be.

If you choose not to follow their rules they could turn off your power or remove all of your solar panels & equipment.

[DanKegel]

Please share some more detail on grid tie panels, micro inverter and how to back feed grid to off set day / evening. Appreciate if you can share a link.

Have you looked at local vendors like http://www.solarsystem.pk/grid-tie-solar-system.php or http://www.cti.com.pk/on_grid/ ?

[yousuft]

Dear friends kindly advice which solar panel are good mono or poly and which panel is best for residential load