Are DIY Solar Panels Worth it?

[SunEagle]

So it is the logic behind introducing Micro Inverter to connect little load with each panel and combine those inverters output in parallel will increase their efficiency, less loss and increase wattage.

No. If your system includes batteries then a Micro Inverter can't be used since it converts the DC panel voltage to AC voltage. You would not be able to charge your batteries that way unless you use an AC to DC charger which then introduces more losses.

Micro Inverters work well for grid tie pv systems to get the most out of each panel if shading is involved. But I have not heard of anyone using them for a solar/battery system.

[SNF]

So it is the logic behind introducing Micro Inverter to connect little load with each panel and combine those inverters output in parallel will increase their efficiency, less loss and increase wattage.

[SunEagle]

I agree with you, It is hard to understand the logic they are trying to give. By the way, Mr. SunEagle I am getting 8 Ampere in total from the both panels, connected in parallel. one thing make me clear please, let say I use a 1000 watt inverter to run 100 watt load in total, yet it will drain the battery or this problem is connected with only heavy load.

Using an inverter that is much bigger than your load ends up wasting more power due to the higher inefficiency of that inverter. If you check the spec the "losses" are usually some % of the total wattage rating. The bigger the wattage the more watts lost. Probably not enough to quickly drain your battery but enough to increase your "true" daily watt hour usage.

[SNF]

I agree with you, It is hard to understand the logic they are trying to give. By the way, Mr. SunEagle I am getting 8 Ampere in total from the both panels, connected in parallel. one thing make me clear please, let say I use a 1000 watt inverter to run 100 watt load in total, yet it will drain the battery or this problem is connected with only heavy load.

[SunEagle]

Then What about the solar generator, with 150 watt only panel giving us 5 kva power by some company. I saw a product while searching youtube.

Most of those products will take the battery voltage and Ah rating to calculate the amount of power you can generate even though you will never get 100% out of the battery more than once.

The other false advertising is they claim the system can provide X number of watts based on the Inverter rating. Even though that inverter would drain the battery within minutes if that high a load was connected to it.

Last thing you really should understand is the youtube is for purely an entertainment process. Over 98% of what is posted is not accurate or truthful.

[jflorey2]

Then What about the solar generator, with 150 watt only panel giving us 5 kva power by some company. I saw a product while searching youtube.

They clearly want your money. Remember - just because something is advertised doesn't mean it's real.

[SNF]

Bad idea. They are expensive and not readily available in the power levels you will need. In addition your efficiency will decline, and you will likely have stability problems with your inverter.

Then What about the solar generator, with 150 watt only panel giving us 5 kva power by some company. I saw a product while searching youtube.

[SNF]

Well, I have an idea about 24 volt system but I am unable to adopt this option. It is out of my capacity, even I cannot afford to replace PWM Charge Controller with the MPPT Charge Controller within my existing system due to its high cost.

[jflorey2]

I am thinking to run a 24 volt inverter from 12 volt battery using DC to DC Boost converter, is it good or bad?

Bad idea. They are expensive and not readily available in the power levels you will need. In addition your efficiency will decline, and you will likely have stability problems with your inverter.

[SunEagle]

Thanks SunEagle.

I totally failed My investment gone waste. What I am getting from the panel just 8 amps maximum.

Well 8 amps from a 150watt panel is about correct. So not really a waste. Wiring 2 of those 150w panels in parallel will get you about 16 amps while on the low side of the charging scale for that battery system is workable.

Whenever you use a device to change the voltage (24v to 12v) you lose some efficiency and get less out of the battery system. The same happens when you "boost" the voltage.

You could wire the batteries in series to make a 24volt system but you would need to wire the panels in series to increase the voltage enough to charge a 24v battery. Unfortunately you then lose half the charging amps because you are using a PWM CC. You might want to look into finding a quality MPPT type charger to get the most out of your 300 watts.

[SNF]

I am thinking to run a 24 volt inverter from 12 volt battery using DC to DC Boost converter, is it good or bad?

[SNF]

Thanks SunEagle.

I totally failed My investment gone waste. What I am getting from the panel just 8 amps maximum.

[SunEagle]

Hello SNF and welcome to Solar Panel Talk

Based on the wattage of those fans and lights your load is estimated at (2 x 80w x 3 hr = 480wh) plus (3 x 3.5w x3 hr = 31.5wh) ~ 512wh daily. That 12v 200Ah battery (2 x 100Ah wired in parallel) system gets you (12v x 200Ah x 25% = 600wh per day) which should be enough to run your loads each day without hurting the batteries.

Now with a PWM CC your charging amps would be the Imp of each of those 150w panels x 2 or I estimate that to be about 16 amps total times the number of sun insolation hours each day.

That comes to 200Ah/16A = 12.5hr which is the minimum needed to charge a 200Ah system. So some days you may not get enough amps to charge the batteries back up to 100% SOC.

A 150w panel might be able to charge a single 12v 100Ah battery but one battery will not provide you enough power to run both fans and all 3 lights for 3 hours.

One last item. A PWM charge controller is robbing you of wattage. It basically turns that 300 watts into about 200 watts because it can only generate the total amps at the battery voltage or (16a x 12v = 192watts). Once you go above 200 watts you should consider using an MPPT type charger which will use all 300 watts for charging.

[SNF]

I have 300 watts Monocrystalline Panels, each one is 150 watt, with 30 Amp PWM Charge Controller.
I want to run:
- two 80 watts of ceiling fans
- and three 3.5 watts of LED Bulbs

Just for 3 hours during night.

1.How much above mentioned load I can run during daylight with battery charging?
2.How long it will take to fully charge a 12 volt 100 Ampere battery?
3.Is it enough to charge a 12 volt 100 Ampere by a 150 watt panel?

[SNF]

I have installed 300 Watts of Monocrystalline Panels, each panel is 150 Watt, with 30 Amp PWM Charge Controller. I want to run:
80 watt of Ceiling A/C - 2 Fans.
3.5 watt LED Light A/C - 3 Lights
Just for 3 hours in night.

1.During daylight how much load above mentioned I can run?
2.How much current required to fully charge the battery?
3.Is 150 watt panel enough to fully charged a 12 volt 100 Amp battery?
4.How it will take long to be fully charged on 150 watt panel or 300 watt panel?

Secondly, How it would be if I replace 12 volt 1000 watt inverter with 24 volt 500 watt inverter. Now I try to run 24 volt inverter with 12 volt battery through 12 volt to 24 DC converter, will it be efficient?