Måleraflæsningen viser kilowatttimer.

It is a compound noun:

• måler = meter or gauge
• aflæsning = reading (the act or result of reading a meter or instrument)
• måleraflæsning = meter reading
• måleraflæsningen = the meter reading

Danish very often builds long nouns by combining smaller words into one single word.

The ending -en is the definite article attached to the noun, so it means the.

In Danish, instead of usually saying a separate word for the, you often add it to the end of the noun:

• en aflæsning = a reading
• aflæsningen = the reading

Because måleraflæsning is a compound, the whole word takes the definite ending:

• måleraflæsning = meter reading
• måleraflæsningen = the meter reading

Viser is the present tense of at vise = to show.

Danish verbs do not change according to person the way English does. So the same present-tense form is used with different subjects:

• jeg viser = I show
• du viser = you show
• den viser = it shows
• de viser = they show

So viser can mean show, shows, or are showing, depending on context.

Because Danish normally writes compound nouns as one word.

So:

• kilowatt
• timer = hours

combine into:

• kilowatttimer = kilowatt-hours

This is very normal in Danish. English often uses separate words or hyphens where Danish prefers one compound word.

Because the word is formed from:

• kilowatt
• timer

When they join, the final t of kilowatt and the initial t of timer both stay, giving ttt:

• kilowatt
  • timer = kilowatttimer

This may look strange to an English speaker, but it is correct Danish spelling. You do not need to pronounce three clearly separate t sounds; the spelling mainly reflects how the compound is built.

Here kilowatttimer is an indefinite plural noun used in a general measurement sense.

So the sentence is simply saying that the meter reading shows kilowatt-hours. Danish often leaves out an article in this kind of context, especially with units, quantities, and categories.

Compare:

• viser kilowatttimer = shows kilowatt-hours
• viser antallet af kilowatttimer = shows the number of kilowatt-hours

The first version is shorter and very natural.

Kilowatttimer is plural.

The forms are:

• en kilowatttime = a kilowatt-hour
• kilowatttimen = the kilowatt-hour
• kilowatttimer = kilowatt-hours
• kilowatttimerne = the kilowatt-hours

So in your sentence, the object is plural.

It follows normal Danish main-clause word order:

• Måleraflæsningen = subject
• viser = verb
• kilowatttimer = object

So the structure is:

Subject + Verb + Object

That is very similar to standard English word order in a simple statement.

They are related, but they do not mean the same thing:

• måleren = the meter
• måleraflæsningen = the meter reading

So:

• Måleren viser kilowatttimer = The meter shows kilowatt-hours
• Måleraflæsningen viser kilowatttimer = The meter reading shows kilowatt-hours

The first refers to the device itself.
The second refers to the reading/result taken from it.

The letter æ is a separate Danish vowel. For an English speaker, it is often roughly similar to the vowel in cat, but not exactly the same.

In aflæsningen, the æ is the vowel in the stressed part -læs-.

A rough learner-friendly breakdown is:

• må-ler-a-flæs-ning-en

You do not need perfect pronunciation at first; the important thing is to recognize that æ is its own vowel sound and not just a spelling variation of a or e.