few questions about solar power....

[robbob2112]

oh.. so my battery isnt receiving 200 watts right now ???
btw. i felt the 12v battery was sufficiently charged 20 min ago.. so i plugged in the tower to the inverter.. and so far so good...

Your battery is likely receiving around 150 watts when your 3 panels are in full sun with no shading. As soon as a cloud passes over or an airplane or anything that casts a shadow on any part of a panel the 50 watts that panel is producing dips momentarily or drops to nothing. Your days are sunny enough that you should be able to charge the battery during the day and use it a few hours at night.


I am going to over simplify here - all numbers below are just spitball guesses

So, assume you have 5 hours of full sun on the panels during the day with NO shadows on them at all. That will give you 150watts x 5hrs = 750watt hours.

Assume your computer and monitor draw 100 watts and you use it while the sun is shining. That reduces the power going into the battery to 50watts x 5 hours = 250watt hours.

So if your computer and monitor is off during the day you can use it for 7.5 hours at night. If they are on during the day you can use them for 2.5 hours in the night.


What I left out was the conversion losses - the PWM is not very efficient and the inverter you have is not very efficient.

PWM as a class are just not as efficient as the MPPT I am recommending as your next buy since you are currently working. The MPPT will get more of the 150w from your panels into the batteries. Say the PWM is shoving 110watts of the 150 into the battery. The MPPT will shove around 140w into the battery.

I can tell your inverter is not efficient because it generates a lot of heat - all that heat is wasted power.

 

[corporal_Canada]

Your battery is likely receiving around 150 watts when your 3 panels are in full sun with no shading. As soon as a cloud passes over or an airplane or anything that casts a shadow on any part of a panel the 50 watts that panel is producing dips momentarily or drops to nothing. Your days are sunny enough that you should be able to charge the battery during the day and use it a few hours at night.


I am going to over simplify here - all numbers below are just spitball guesses

So, assume you have 5 hours of full sun on the panels during the day with NO shadows on them at all. That will give you 150watts x 5hrs = 750watt hours.

Assume your computer and monitor draw 100 watts and you use it while the sun is shining. That reduces the power going into the battery to 50watts x 5 hours = 250watt hours.

So if your computer and monitor is off during the day you can use it for 7.5 hours at night. If they are on during the day you can use them for 2.5 hours in the night.


What I left out was the conversion losses - the PWM is not very efficient and the inverter you have is not very efficient.

PWM as a class are just not as efficient as the MPPT I am recommending as your next buy since you are currently working. The MPPT will get more of the 150w from your panels into the batteries. Say the PWM is shoving 110watts of the 150 into the battery. The MPPT will shove around 140w into the battery.

I can tell your inverter is not efficient because it generates a lot of heat - all that heat is wasted power.

i already used a wattometer on pc.. it read 105 watts. you can add 25-35 more for the additional hdd ive added.. monitor.. only 27 watts...

so i will round it off to 150 watts for a rough guesstimate

 

[corporal_Canada]

Your battery is likely receiving around 150 watts when your 3 panels are in full sun with no shading. As soon as a cloud passes over or an airplane or anything that casts a shadow on any part of a panel the 50 watts that panel is producing dips momentarily or drops to nothing. Your days are sunny enough that you should be able to charge the battery during the day and use it a few hours at night.


I am going to over simplify here - all numbers below are just spitball guesses

So, assume you have 5 hours of full sun on the panels during the day with NO shadows on them at all. That will give you 150watts x 5hrs = 750watt hours.

Assume your computer and monitor draw 100 watts and you use it while the sun is shining. That reduces the power going into the battery to 50watts x 5 hours = 250watt hours.

So if your computer and monitor is off during the day you can use it for 7.5 hours at night. If they are on during the day you can use them for 2.5 hours in the night.


What I left out was the conversion losses - the PWM is not very efficient and the inverter you have is not very efficient.

PWM as a class are just not as efficient as the MPPT I am recommending as your next buy since you are currently working. The MPPT will get more of the 150w from your panels into the batteries. Say the PWM is shoving 110watts of the 150 into the battery. The MPPT will shove around 140w into the battery.

I can tell your inverter is not efficient because it generates a lot of heat - all that heat is wasted power.

any specific amperage mppt i should order ??? or will 30 amps do ????

 

[robbob2112]

any specific amperage mppt i should order ??? or will 30 amps do ????

Well, were it me I would order the 40 amp version if you can swing it. The 30 amp version will work but you might eventually add another one.

When you eventually get the LFP battery I've been suggesting it will take all the current your panels can collect from the 3 panels you currently have and the 320w panel you were looking at.

In the meantime it will collect more watts and push more power to the battery you have. It does work with your current battery.

PowMr MPPT 20A/30A/40A Solar Charger Controller 12V/24V Solar Panel Voltage Regulator | Lazada PH

PowMr. snadi inverter 1kw 12v on sale. solar panel set home full set. mppt controller with inverter. snadi solar charge controller. epever mppt charge controller. Model POW-Keeper1220(20A POW-Keeper1230(30A POW-Keeper1240(40A). Type MPPT. Rated voltage: 12/24V Auto. System voltage: 12/24V...

www.lazada.com.ph

 

[Brucey]

(Not that I smoke.)

OK, what's the electric rate in Montreal?

In Oakland, I pay $0.60/kWh

I would be time shifting like crazy at those rates. What's the off peak rate?

 

[corporal_Canada]

Here, ordered this, I hope it merts your approval, the fuse should arrive before this, I stuck with 30A... Because I don't know any better... I mean, if all solar panels are going to the scc or mppt at 18v but going to battery at 12 or 14v... How do I. Calculate what wattage the battery is receiving...

 

[corporal_Canada]

I would be time shifting like crazy at those rates. What's the off peak rate?

I'm sorry what is "peak rate" ??? In MTL I paid 30$cad for UNLIMITED electric usage this does not apply for houses that consume more power for heating during winter months

 

[corporal_Canada]

i have spare funds.. im considering purchasing 2 similiar 12v 50ah batteries... so either i link it with the battery i have now in parallel.. i believe ive mentioned that i do not want to exceed 12v although some of you are egging me on in that direction of 24v but the wayt i figure it.. i already have 2 inverters for a 12v battery why overcomplicate my life.. and another identical battery to replace the ups battery.. and yes i am making sure i wont fry the rest of the ups before i connect anything.. any input before i place any orders ??? and yes i value your opinions.. even if some of your acronyms give me aneurysms....

 

[42OhmsPA]

Here, ordered this, I hope it merts your approval, the fuse should arrive before this, I stuck with 30A... Because I don't know any better... I mean, if all solar panels are going to the scc or mppt at 18v but going to battery at 12 or 14v... How do I. Calculate what wattage the battery is receiving...

Can you cancel the order?
Normally if they have USB ports they are a cheap PWM knockoff.

 

[Supervstech]

Here, ordered this, I hope it merts your approval, the fuse should arrive before this, I stuck with 30A... Because I don't know any better... I mean, if all solar panels are going to the scc or mppt at 18v but going to battery at 12 or 14v... How do I. Calculate what wattage the battery is receiving...

Battery charge voltage times amps into battery.
That is the watts you are getting.

 

[Hedges]

I would be time shifting like crazy at those rates. What's the off peak rate?

I think Peak is $0.577, off-peak $0.472, only $0.10 difference? Not a net metering rate in Oakland.

Peak $0.557, off-peak $0.372, $0.185 difference? off-peak net metering in San Jose

Electric company has it figured out

Only a matter of time Also known as the death spiral. A similar thing happened in Hawaii, when the utilities delayed approving solar. People just installed solar and batteries and self consumer their power. My brother did that in Maui.

diysolarforum.com

The SBS + LG RESU-10H I picked up can time shift for about $0.09/kWh. Not a huge return on investment.
It's more about setting back thermostat when price goes up.

An installing GT PV NEM 2.0, so I roll my own kWh for $0.025

 

[robbob2112]

Here, ordered this, I hope it merts your approval, the fuse should arrive before this, I stuck with 30A... Because I don't know any better... I mean, if all solar panels are going to the scc or mppt at 18v but going to battery at 12 or 14v... How do I. Calculate what wattage the battery is receiving...

That is another PWM controller. It will work, but it will not support anything but the 18v panels. Certainly not what I would have done. And, since it is deliberatly mis-marked as a MPPT I certainly would not trust any amperage rating on it.

If you can cancel the order or have not yet placed the order, please do yourself a favor and order what I linked in the 40amp version.

It does NOT exceed 12v.


You should be running out of toes by now. Shooting yourself in the foot to save a buck and buying junk.


Save up and buy something that works right the first time and is expandable for the future.


Another option would be this - it would replace the inverter and PWM you currently run. You can parallel your current battery with another identical.

1.2kW 12V/24V Built in MPPT 40A 30A Toroidal Hybrid/Off-Grid Inverter/ LiFePo4 Support | Lazada PH

LVTOPSUN. solar inverter hybrid offgrid. snat inverter 3kw 12v 24v 36v. byd lifepo4 battery 24v 250ah. inverter 24v to 220v original. mppt solar charge controller

www.lazada.com.ph

 

[corporal_Canada]

Can you cancel the order?
Normally if they have USB ports they are a cheap PWM knockoff.

And by knockoff you mean just a nicely painted scc ?? No the item is marked as shipped already, F it, I will just do what I can with it and pray to Keanu Reeves that nothing explodes..

 

[corporal_Canada]

That is another PWM controller. It will work, but it will not support anything but the 18v panels. Certainly not what I would have done. And, since it is deliberatly mis-marked as a MPPT I certainly would not trust any amperage rating on it.

If you can cancel the order or have not yet placed the order, please do yourself a favor and order what I linked in the 40amp version.

It does NOT exceed 12v.


You should be running out of toes by now. Shooting yourself in the foot to save a buck and buying junk.


Save up and buy something that works right the first time and is expandable for the future.


Another option would be this - it would replace the inverter and PWM you currently run. You can parallel your current battery with another identical.

1.2kW 12V/24V Built in MPPT 40A 30A Toroidal Hybrid/Off-Grid Inverter/ LiFePo4 Support | Lazada PH

LVTOPSUN. solar inverter hybrid offgrid. snat inverter 3kw 12v 24v 36v. byd lifepo4 battery 24v 250ah. inverter 24v to 220v original. mppt solar charge controller

www.lazada.com.ph

Looked at it and I can tell you aren't familiar with Chinese scamms like an external HDD that claims to be 2tb but just has weights in it, that link is just like that.. an scc in a bigger box....

 

[42OhmsPA]

And by knockoff you mean just a nicely painted scc ?? No the item is marked as shipped already, F it, I will just do what I can with it and pray to Keanu Reeves that nothing explodes..

A nicely painted PWM scc, not the MPPT you paid for.
I laughed out loud at the praying to Reeves, thanks.

Did you see Robs post above this one?

 

[corporal_Canada]

Battery charge voltage times amps into battery.
That is the watts you are getting.

I'm aware but which voltage ? The one that comes out of solar panel or from scc to battery... that is where my confusion is

 

[corporal_Canada]

A nicely painted PWM scc, not the MPPT you paid for.
I laughed out loud at the praying to Reeves, thanks.

Did you see Robs post above this one?

Well Keanu reeves is our physical God don't you know.. that is until Ryan Reynolds releases his badass Canadian movie in July.. hell I'm not using Celine Dion as an example.. no

 

[corporal_Canada]

A nicely painted PWM scc, not the MPPT you paid for.
I laughed out loud at the praying to Reeves, thanks.

Did you see Robs post above this one?

I see all posts, but I'm not a good money saver, if I don't waste the money on this now, it will go for cigarettes, liquor or the fairer sex...

 

[42OhmsPA]

I see all posts, but I'm not a good money saver, if I don't waste the money on this now, it will go for cigarettes, liquor or the fairer sex...

But wouldn't this actually save you money in the long run to spend more on the things you enjoy? Just don't use to much of one before the other...

 

[Supervstech]

I'm aware but which voltage ? The one that comes out of solar panel or from scc to battery... that is where my confusion is

What matters is the voltage at the battery.
And the amps into the battery.

Especially with a pwm controller... panel volts are meaningless.