Le prix du kilowattheure est élevé.

Because du is the contraction of de + le.

• de + le = du
• So le prix du kilowattheure literally has the structure the price of the kilowatt-hour

French normally uses this contraction automatically:

• de le livre → du livre
• de le café → du café

But:

• de la stays de la
• de l' stays de l'
• de les becomes des

French often uses the definite article where English may use a more general expression.

So Le prix du kilowattheure est élevé is a normal way to talk about the price of the kilowatt-hour in general, not necessarily one specific price in one specific bill.

This is very common in French:

• Le café est cher.
• La vie est belle.
• Le temps passe vite.

English sometimes drops the article in broader statements, but French usually keeps it.

Here, prix is singular.

That is confusing at first because prix looks plural, but the singular and plural forms are spelled the same:

• singular: le prix
• plural: les prix

You tell the difference from the article or other words around it.

In this sentence:

• Le prix = singular
• The verb est also confirms that it is singular

Because élevé agrees with prix, and prix is masculine singular.

Agreement rules for adjectives used with être:

• masculine singular: élevé
• feminine singular: élevée
• masculine plural: élevés
• feminine plural: élevées

Since prix is masculine singular, the correct form is élevé.

Here élevé means high in the sense of a level, amount, or figure.

That makes it a very natural choice with things like:

• un prix élevé
• un taux élevé
• un niveau élevé

Why not the others?

• haut usually refers more to physical height or position, though it can sometimes be used more broadly
• cher means expensive

So:

• Le prix du kilowattheure est élevé = the price level is high
• Le kilowattheure est cher = the kilowatt-hour is expensive

Both can work, but élevé sounds a bit more formal or analytical.

Yes. That is a perfectly possible sentence.

The difference is mainly in focus:

• Le prix du kilowattheure est élevé focuses on the price
• Le kilowattheure est cher focuses on the kilowatt-hour as something expensive

The first sounds a bit more formal, technical, or written. The second sounds a bit more direct and conversational.

In French, compound nouns are often written as a single word, especially technical units and measurement terms.

So kilowattheure is the standard spelling for the unit kilowatt-hour.

You may also see the abbreviation:

• kWh

For example:

• Le prix du kWh est élevé.

That is very common in energy bills, articles, and technical writing.

Kilowattheure is masculine:

• le kilowattheure
• un kilowattheure

That is why the contraction is du kilowattheure:

• de + le kilowattheure → du kilowattheure

Its plural is:

• les kilowattheures

Because élevé here is not directly placed before or after the noun as part of the noun phrase. It is used with the verb être.

Structure:

• Le prix du kilowattheure = subject
• est = verb
• élevé = adjective describing the subject

This is just like:

• Le livre est intéressant.
• La maison est grande.

You can also use élevé directly before or after a noun in other contexts:

• un prix élevé

But in this sentence, it comes after est because it is part of the predicate.

No, the x in prix is normally silent.

prix is pronounced roughly like pree.

A few pronunciation notes:

• le ≈ luh
• prix ≈ pree
• du ≈ dew with a French u sound
• kilowattheure is roughly kee-lo-va-teur
• élevé ≈ ay-luh-vay

In normal speech, the final consonant of est may link to the next vowel sound:

• est élevé can be pronounced with a liaison, roughly eh-tay-luh-vay

The accents help show pronunciation.

In élevé, the é indicates a clear ay-like sound.

So:

• é is pronounced differently from a plain e
• élevé has the sound pattern ay-luh-vay

The accents are part of the correct spelling and should not be omitted in standard writing.

Yes, but the meaning changes slightly.

For example:

• Le prix de l'électricité est élevé.

That means the price of electricity is high in a broader sense.

By contrast:

• Le prix du kilowattheure est élevé specifically refers to the price per unit of electricity

So the original sentence is more precise, especially in billing, economics, or energy discussions.

It sounds mostly neutral to slightly formal.

Why?

• le prix du kilowattheure is fairly technical
• élevé is a slightly more formal way to say high

In everyday conversation, people might more often say:

• L'électricité est chère.
• Le kWh est cher.

But the original sentence is completely natural, especially in:

• news articles
• reports
• bills
• discussions about energy costs