Direct Use PV system

[Mahmoud_53]

Hi all,

This is my first post here, and I'm glad to be a part of such a community. Anyway, I am intending to install a PV system that would give me 220V, AC electricity during the day. So it's really neither a grid connected system nor it is an off-grid system, so I hope you guys could help with the components that I might need.

My idea is:
1- The PV panel that I am going to use, speaking of, is a 100W panel sufficient to output 220V AC electricity?
2- Inverter, but what type? and what rating?

These are the basic components, but after some research, I found out I should also have a Solar Charge Controller + a small battery, EVEN if I'm only intending to use the system during the day, so is that correct? If so, what type of Solar Charge Controller do I need that would work with my inverter and the 100W panel? and What should be the Ahour rating on the battery?

Thanks Guys!

[CA_Tom]

Hi all,

This is my first post here, and I'm glad to be a part of such a community. Anyway, I am intending to install a PV system that would give me 220V, AC electricity during the day. So it's really neither a grid connected system nor it is an off-grid system, so I hope you guys could help with the components that I might need.

My idea is:
1- The PV panel that I am going to use, speaking of, is a 100W panel sufficient to output 220V AC electricity?
2- Inverter, but what type? and what rating?

These are the basic components, but after some research, I found out I should also have a Solar Charge Controller + a small battery, EVEN if I'm only intending to use the system during the day, so is that correct? If so, what type of Solar Charge Controller do I need that would work with my inverter and the 100W panel? and What should be the Ahour rating on the battery?

Thanks Guys!

What are you doing with the 220?

Would 110 work? If so there is inverter that is normally grid tie and has an "emergency outlet" that might work... but it's for more power than a 100watt panel I think.

BTW 100watt 220v is very little current... less once you consider inefficiencies. not sure what you'd use it for... most 220v uses use a fair amount of current.

[russ]

What are you doing with the 220?

Egypt - 110 is useless

[Mahmoud_53]

Egypt - 110 is useless

1-Well, I don't really intend to power anything (yet), I am only doing it as a practice. To judge the ease of installing and connecting these components by myself, and once I manage to pull off a good (working) prototype, I am gonna buy more panels. So it's not really important what I use this electricity for

3- 220 VAC yes, but Egypt, not Europe. And yes, the main grid is 220 VAC, so I suppose all the devices that I have work on 220 VAC, so I need a stable 220 VAC power that would allow me to power some devices without any problems. Devices like a 7W-rated LED light bulb, a phone charger, etc... I just need to know if I can get a stable power from direct usage of solar energy or not?


To sum up, this is the first step in building an on-grid system, I am only waiting for the government to finalize the prices of the KW.hrs of electricity that I'll be selling to them, because otherwise I would be just paying taxes AND Kw.hrs of electricity, lol. Anyway, so I want to give it a try with a small system that I will only use during day time, to save battery expenses because I won't need it when they are gonna buy electricity from me.

I hope you understood what I mean, the 100W isn't a requirement, I just want the minimum required panel wattage that will allow me to output a stable electricity during day time (or most of it) to power ANY of my 220 VAC devices

[jony101]

100 watt will give you about 5 amps of charging power during hottest part of the day.
Your 12 volt to 220 watt inverter needs to be connected to a 12 volt battery to get stable electricity, the solar panel will top off the battery as you use power. During the day solar panel power/amp output varies with the clouds, thats why if you connect the inverter to the battery (which is almost always stable) it always gets 12 volts.
You do need a solar charge controller, for 100 watt panel get a PWM 10 amp controller. More expensive MPPT solar controllers will not give you more amps on such low wattage panel.

But you might get better efficiency by just using 12 volt led lights and 12 volt phone chargers. When you use the inverter, it waste energy to convert the current up to 220 volts and then the devices will convert it back to low voltage.

so you need
1. solar panel at least 100 watts
2. 12 volt to 220 inverter at least 200 watts , bigger if you plan to power larger items.
3. PWM 10 amp solar charge controller. Wincong brand is a cheap reliable controller I used on a 120 watt panel.
4. deep cycle battery at least 75 ah (on batteries you dont want to use it below 50 percent to increase their lifetime)

That would be a good way to start out on solar, it wont produce alot but enough to power the items you indicated.
As an example when I started out on solar I used a 120 watt panel and a 75 ah agm battery, I was able to power a 12 volt fridge 24/7, charge my laptop and phones, and run a 12 volt swamp cooler and lights but it was barely keepin up with my demands but it worked, I upgraded as I gained expierence.

[Mahmoud_53]

100 watt will give you about 5 amps of charging power during hottest part of the day.
Your 12 volt to 220 watt inverter needs to be connected to a 12 volt battery to get stable electricity, the solar panel will top off the battery as you use power. During the day solar panel power/amp output varies with the clouds, thats why if you connect the inverter to the battery (which is almost always stable) it always gets 12 volts.
You do need a solar charge controller, for 100 watt panel get a PWM 10 amp controller. More expensive MPPT solar controllers will not give you more amps on such low wattage panel.

But you might get better efficiency by just using 12 volt led lights and 12 volt phone chargers. When you use the inverter, it waste energy to convert the current up to 220 volts and then the devices will convert it back to low voltage.

so you need
1. solar panel at least 100 watts
2. 12 volt to 220 inverter at least 200 watts , bigger if you plan to power larger items.
3. PWM 10 amp solar charge controller. Wincong brand is a cheap reliable controller I used on a 120 watt panel.
4. deep cycle battery at least 75 ah (on batteries you dont want to use it below 50 percent to increase their lifetime)

That would be a good way to start out on solar, it wont produce alot but enough to power the items you indicated.
As an example when I started out on solar I used a 120 watt panel and a 75 ah agm battery, I was able to power a 12 volt fridge 24/7, charge my laptop and phones, and run a 12 volt swamp cooler and lights but it was barely keepin up with my demands but it worked, I upgraded as I gained expierence.

Thanks Jony, This has been a very informative reply.

But I don't understand why would I need such a large battery for? I don't intend to use the devices at night, I only (think) I need it to (as you said) have always have a stable supply during day time. For example (I don't know if that is true or not), I am I am always charging and draining the battery at the same time, like using a laptop with the battery and the AC cable attached. you get what I mean?

But from what you said, I understood that the battery is large enough that it will actually be able to give me some power during the night time.

[CA_Tom]

1-Well, I don't really intend to power anything (yet), I am only doing it as a practice. To judge the ease of installing and connecting these components by myself, and once I manage to pull off a good (working) prototype, I am gonna buy more panels. So it's not really important what I use this electricity for

Are you prepared for tossing the entire system (or *maybe* selling it to someone for them to use camping or at a remote site)?
Because grid tie has very little in common with off-grid.
And you're looking at starting with a very small system, of which I expect nothing will be re-usable for a larger system.

If i were you, I'd probably start with "what do I think I'll want to do eventually?"
And then from there "Which of those components could I use in a small off-grid type system?"
I think the answer to that is going to be you can use the panels.
And maybe there's some other ancillary stuff (wire, crimping pliers)
And knowledge from doing the install.

If you were in a location that used 110V (US, Canada, etc), I'd say you would use the "Secure Power Supply" option from SMA.
Then you could start your install with the minimum input for the inverter. And increase to the maximum later.
And you'd have essentially what I think you're asking about - a way to do a small install that isn't yet grid-tied, but could be upgraded to be grid tied later. And can be increased in size later.
You could contact SMA and see if they have an equivalent configuration for 220V systems.

Good luck.