Odkąd operator systemu dystrybucyjnego wymienił licznik energii, stan licznika jest inny.

In this sentence, odkąd means since in a time sense:

Odkąd operator systemu dystrybucyjnego wymienił licznik energii...
= Since the distribution system operator replaced the electricity meter...

For many learners, odkąd and od kiedy look very similar, and in a lot of contexts they overlap.

A useful practical distinction is:

• odkąd = since, especially when introducing a whole clause
• od kiedy = since when / from what time, often more question-like or more literal

So:

• Odkąd tu mieszkasz? = Since when have you been living here?
• Odkąd tu mieszkam, jestem spokojniejszy. = Since I’ve been living here, I’m calmer.

In your sentence, odkąd is very natural because it introduces the event after which something is now different.

Because the sentence describes:

1. a completed event in the past
2. a present result or present state

So:

• wymienił = replaced → past event
• jest inny = is different → present condition now

The logic is:

Since X happened, Y is now different.

That is very normal in Polish and English alike.

So the sentence structure is:

• Odkąd ... wymienił licznik energii = Since ... replaced the meter
• stan licznika jest inny = the meter reading/state is different

Operator is the main noun, and systemu dystrybucyjnego is a dependent phrase in the genitive.

So:

• operator = operator
• systemu = of the system
• dystrybucyjnego = distribution

Together:

operator systemu dystrybucyjnego
= operator of the distribution system
or more naturally in English, distribution system operator

This is a very common Polish pattern:

• centrum miasta = city center, literally center of the city
• numer telefonu = phone number, literally number of the telephone
• stan licznika = meter reading/state, literally state of the meter

So systemu dystrybucyjnego is genitive singular, because it depends on operator.

Licznik energii means energy meter, usually in practice electricity meter.

Word by word:

• licznik = meter, counter
• energii = of energy

So literally it is meter of energy.

Polish often uses this noun + genitive structure where English prefers a compound noun:

• licznik energii = energy meter
• zużycie energii = energy consumption
• cena energii = price of energy

So energii is in the genitive because it specifies what kind of meter it is.

Because they mean two different noun relationships.

• licznik energii = a meter for energy / of energy
• stan licznika = the state/reading of the meter

In both cases Polish uses the genitive, but the meanings are different:

• energii tells you what kind of meter it is
• licznika tells you whose state/reading we are talking about

So:

• wymienił licznik energii = replaced the electricity meter
• stan licznika jest inny = the meter reading/state is different

This repetition of licznik is perfectly normal in Polish.

In everyday utility/billing language, stan licznika very often means meter reading.

Literally, yes, it is the state of the meter, but in practice it usually refers to the number shown on the meter.

So in this sentence, the most natural interpretation is probably:

Since the distribution system operator replaced the electricity meter, the meter reading is different.

That makes sense because a newly installed meter may start from a different number, often from zero or another initial value.

So:

• literal meaning: state of the meter
• practical meaning here: meter reading

Because inny means different / another, which fits this sentence.

• jest inny = is different
• różny usually means various / diverse / differing, not simply different from before

Examples:

• Teraz wynik jest inny. = Now the result is different.
• Mamy różne wyniki. = We have different/various results.

In your sentence, the meaning is that the meter reading is not the same as before, so inny is the correct natural choice.

Polish does not have articles like a and the.

So:

• operator can mean an operator or the operator
• licznik can mean a meter or the meter
• stan licznika can mean the meter reading or a meter reading, depending on context

The context tells you what is meant. Here it is naturally understood as something specific:

• the distribution system operator
• the electricity meter
• the meter reading

That is one of the big differences between Polish and English.

Yes, Polish word order is more flexible than English word order.

The original sentence is completely natural:

Odkąd operator systemu dystrybucyjnego wymienił licznik energii, stan licznika jest inny.

But you could also say:

Stan licznika jest inny, odkąd operator systemu dystrybucyjnego wymienił licznik energii.

This has the same basic meaning. The difference is mostly in emphasis:

• starting with Odkąd... foregrounds the time/background condition
• starting with Stan licznika jest inny... foregrounds the result

The original version sounds very natural in formal or neutral written Polish.

Wymienił is the past tense masculine singular form because the subject operator is masculine singular.

Polish past tense agrees with the gender and number of the subject.

Here are the forms:

• wymienił = he / masculine singular replaced
• wymieniła = she / feminine singular replaced
• wymieniło = it / neuter singular replaced
• wymienili / wymieniły = they replaced

So:

• operator wymienił licznik = the operator replaced the meter
• firma wymieniła licznik = the company replaced the meter

Even though firma refers to an organization, grammatically it is feminine, so the verb becomes wymieniła.

Wymienić is perfective.

That matters because perfective verbs in Polish usually present an action as completed.

So wymienił licznik means:

• he replaced the meter
• the replacement was completed

That fits perfectly with odkąd, because the sentence refers to a finished event after which a new situation exists.

The imperfective partner is wymieniać.

Compare:

• wymienił licznik = replaced the meter, completed
• wymieniał licznik = was replacing / used to replace the meter / replaced in an ongoing sense

In your sentence, the perfective is the natural choice because the completed replacement caused the current difference.

Yes, very much so.

The vocabulary is fairly formal and technical:

• operator systemu dystrybucyjnego
• licznik energii
• stan licznika

That sounds like something from:

• customer service communication
• an energy bill dispute
• a complaint letter
• administrative or utility-company correspondence

A native speaker would probably feel that this is not casual everyday conversation, but rather official or semi-official language.

Yes. It is a formal industry term.

In everyday speech, many people might simply say something like:

• firma energetyczna
• dostawca prądu
• pracownik zakładu energetycznego

But operator systemu dystrybucyjnego is precise and bureaucratic/legal. It refers specifically to the entity responsible for the distribution system.

So a learner should understand that this phrase is correct and natural, but stylistically more official than everyday speech.

A more everyday version could be something like:

Odkąd wymienili licznik prądu, jego stan jest inny.

or

Odkąd firma wymieniła licznik prądu, stan licznika jest inny.

These versions are less formal because:

• licznik prądu is more everyday than licznik energii
• firma or just wymienili is less technical than operator systemu dystrybucyjnego

But the original sentence is still perfectly correct; it is just more official in tone.