Le fournisseur d’énergie facture au kilowattheure.

Because de contracts before a vowel sound.

• de + énergie becomes d’énergie
• This is very common in French:
  • de eau → d’eau
  • de accord → d’accord

So le fournisseur d’énergie means the energy supplier.

Fournisseur means supplier or provider.

It comes from the verb fournir, which means to supply or to provide.

So:

• un fournisseur d’énergie = an energy supplier
• un fournisseur d’accès internet = an internet provider

It can refer to a person, but in real-life use it often refers to a company.

Here, facture is a verb.

It is the third-person singular present tense of facturer, which means:

• to bill
• to charge

So:

• il facture = he/it charges
• le fournisseur facture = the supplier charges

Be careful, because une facture as a noun means a bill or an invoice.

So French has both:

• facturer = to bill
• une facture = a bill/invoice

Au here means something like per or by the in this pricing context.

Grammatically, au is the contraction of:

• à + le = au

So au kilowattheure literally looks like at the kilowatt-hour, but in English we usually translate it more naturally as:

• per kilowatt-hour
• by the kilowatt-hour

This use of à / au / à la is common when talking about rates, prices, or measurement.

Yes, par kilowattheure is possible and very understandable, but au kilowattheure is very natural in pricing language.

A useful distinction is:

• par often means per in a general, mathematical, or neutral way
• à / au / à la is very common for charging/selling by a unit

For example:

• vendre au kilo = to sell by the kilo
• payer à l’heure = to pay by the hour
• facturer au kilowattheure = to charge per kilowatt-hour

So au kilowattheure is idiomatic and fits this sentence well.

Because French often uses the singular after expressions of rate or pricing.

So:

• au kilowattheure
• au kilo
• à l’heure

This works like saying by the kilo or per hour in English. You are talking about the unit of measurement, not a count of many separate items.

So even if many kilowatt-hours are being billed, the expression stays singular because it names the pricing unit.

Yes, Le fournisseur d’énergie means the energy supplier.

French often uses the definite article where English might or might not use one, depending on context.

This sentence could refer to:

• a specific supplier already known from context
• a generic supplier in a general statement

For example, French often says:

• Le chien est fidèle. = Dogs are loyal / The dog is loyal
• Le fournisseur d’énergie facture au kilowattheure. = The energy supplier charges per kilowatt-hour or Energy suppliers charge per kilowatt-hour, depending on context

So le does not always mean one very specific individual in the narrowest sense; it can also express a general truth.

Yes, it is commonly written as kilowattheure in one word.

You may also see the unit written in its abbreviated form:

• kWh

In ordinary language, French often uses the full word, while technical or commercial contexts frequently use the abbreviation.

So these are both normal:

• au kilowattheure
• au kWh

The word order is very straightforward:

• Le fournisseur d’énergie = subject
• facture = verb
• au kilowattheure = expression showing the billing unit/rate

So the structure is:

Subject + Verb + Rate expression

French often keeps this basic order, especially in simple statements.

A rough pronunciation guide for an English speaker is:

luh foor-nee-sur day-nayr-zhee fak-tyur oh kee-lo-vat-uhr

A few notes:

• fournisseur has the French r, not an English r
• énergie sounds roughly like ay-nair-zhee
• au sounds like oh
• heure is tricky; the final part of kilowattheure is not pronounced like English hour

A more careful breakdown:

• Le → luh
• fournisseur → foor-nee-sur
• d’énergie → day-nayr-zhee
• facture → fak-tyur
• au → oh
• kilowattheure → kee-lo-vat-uhr

If you want to sound more natural, try to link the rhythm smoothly instead of stressing every word equally.

Usually, yes. Facturer means to invoice, to bill, or to charge for something.

Examples:

• L’entreprise facture ses clients tous les mois.
  The company bills its customers every month.

• Le plombier facture 80 euros de l’heure.
  The plumber charges 80 euros an hour.

So in your sentence, it clearly refers to how the supplier calculates the customer’s bill.

Yes. That is exactly how it is usually understood.

Facture au kilowattheure does not just mean that one bill exists; it means the supplier’s pricing is based on the number of kilowatt-hours used.

So the sentence describes a billing model or pricing method:

• usage is measured
• the customer pays according to the number of kilowatt-hours consumed

That is why au kilowattheure is so important: it tells you the unit used to calculate the charge.