Solar panels for a hobbyist

[5olaris]

I have thought about building a grid tied solar panel system of a small scale.
Currently I may not have a big space in my roof, maybe for a simple 100W-200W solar panel, but in the future I would like to expand the system for more panels.
How easy will it be to purchase 1-2 solar panels to feed my house's electricity via a grid tie inverter and then adding additional panels in the future?
Will I need to replace my old panels each time I expand the system?
When expanding the solar panel system, do the new panels have to match a certain criteria?
My purpose is more ideology than economic, but I would still like to maximize electricity from my roof.

Thanks for the helpers

[bcroe]

Getting panels is easy. But you need a PoCo permit & approval to grid tie, and they don't go for extremely small systems or
frequent upgrades. Perhaps you could find a small load to be driven directly by your system, without a grid tie. Bruce Roe

[5olaris]

Getting panels is easy. But you need a PoCo permit & approval to grid tie, and they don't go for extremely small systems or
frequent upgrades.

That would be no problem to me as I live in a country with no restrictive rules regarding a grid tie inverter

[DanS26]

Every POCO in the United States has rules......don't ignore them.....they will find your bootleg grid tie inverter.

[5olaris]

I'm not from the US.

[Mike90250]

I'm not from the US.

Alright, you are ok, because only the US has rules about connecting to the Grid infrastructure. or maybe not.

[bcroe]

Panels in the 250-300 watt range are a lot more economical per watt than small panels. A grid tie system could be built with one or
several big panels and one grid tie inverter. Then more such independent systems could be added later. The inverter must have an
input range of V and I which entirely covers the range the panels might produce. Bruce Roe

[Guest]

Just a simplistic approach from me . I found solar panels of around 250 watts were getting about pretty cheaply having come from China. I bought 12 and an inverter and all the installation gear from an installer going out of business for $1500 AUD or about USD $1000.

Cheap deal but the point is those deals are around if you look . Second hand panels are the go too. People move ,take their" you beaut" system with them and can't be bothered re-installing them.

So say you get 4 panels and they each put out 30 Volts . Connected in series thats 4 x 30 = 120 Volts out . So the inverter you get must turn on with a voltage lower than that ie 80 Volts maybe. Each panel puts out 7 amps max maybe so the whole system puts out 7 amps at 120 volts . I'd imagine anything smaller might be restrictive to add on to later.

Those figures are in full sun.
So you get it all up and find it does not reach 80 volts until 10.30 am and drops below at 3.00pm so you only get useable stuff for 4 1/2 hours on sunny days and none on rainy days. If you go ahead that way at first , its quite an eye opener and it should still give you stuff you can add to and definitely use later without huge capital outlay.

[Sunking]

That would be no problem to me as I live in a country with no restrictive rules regarding a grid tie inverter

Wrong. Every POCO cares deeply what is connected to their lines. Your neighbors do not give a crap if you kill yourself and burn your house down, they will bring marshmallows to watch you burn. POCO does not care if you burn your house down either. Have at it. Rest of us will bring marshmallows and popcorn to watch.

However the POCO does care about who and what is connected to their lines. Unless you have a contract and meet the POCO rules, you will not have a grid tied system.

[brewbeer]

5olaris, what country are you in, and who is your power company?

[5olaris]

5olaris, what country are you in, and who is your power company?

I'm from Israel, the israeli power company is my power company

[brewbeer]

I'm from Israel, the israeli power company is my power company

5olaris There is a link on the wikipedia's "Grid-tied electrical system" page to Israel's "Public Utility Authority" Photo-Voltaic Guidelines. (I'd post the link here but posting links on this website is problematic.) I'd post what the link says but it's in hebrew, which I don't read very well at all. You should check the utility company website: pua.gov.il

[5olaris]

It says any customer is allowed to install up to 15 kW for home use and up 50 kW for business use.
That is much more than I am talking about right now.

[SunEagle]

5olaris

Is that 15kw a grid tie system that can back feed into the POCO?

[5olaris]

Yes .

[Amy@altE]

You should look into micro inverters. You'll want at least around 250W, and each panel connects to it's own microinverter on the roof. When you add more panels, you just add more microinverters and use their cabling to connect them together.

[5olaris]

Aha, so with one microinverter I simply plug it into my home power socket.
What happens if I have 2 or more? are they all connected together to something that is connected to the power socket or each of the connects to his own socket?

[Amy@altE]

Never plug an inverter into a socket. The microinverter connects to a new breaker in your main breaker box. When more are added, they will also connect to that one breaker. The breaker must be sized correctly for the size wire and current. What you would probably do is wire everything for multiple microinverters, and just add them when possible. That way you don't have to redo the wiring each time. Look at Enphase microinverter install giudes as an example.