De warmtepomp verbruikt minder energie.

Word for word:

• De = the
• warmtepomp = heat pump
• verbruikt = uses / consumes
• minder = less
• energie = energy

So the sentence literally matches English quite closely: The heat pump uses less energy.

In Dutch, every singular noun takes either de or het as its definite article.

• de words are common gender
• het words are neuter

Warmtepomp is a de-word, so you say de warmtepomp.

Unfortunately, this usually has to be learned with the noun. There are some patterns, but for many nouns you simply memorize the article together with the word.

Yes. Dutch very often forms compound nouns by writing them as one word.

• warmte = heat
• pomp = pump
• warmtepomp = heat pump

This is very normal in Dutch. Where English may use two words, Dutch often combines them into one.

The infinitive is verbruiken, meaning to consume / to use up.

In this sentence, the subject is de warmtepomp, which is third-person singular, so the present tense form is:

• ik verbruik
• jij verbruikt / verbruik
• hij/zij/het verbruikt
• de warmtepomp verbruikt

So verbruikt is the correct present tense form for the heat pump.

This is normal Dutch main-clause word order.

In a basic statement, Dutch usually puts:

1. the subject first
2. the finite verb second

So here:

• De warmtepomp = subject
• verbruikt = finite verb
• minder energie = rest of the sentence

This is often called the verb-second pattern in Dutch.

Minder means less.

In this sentence, it modifies energie, so minder energie means less energy.

Dutch uses minder much like English uses less with uncountable nouns:

• minder water = less water
• minder tijd = less time
• minder energie = less energy

Dan means than, and it is used only when the comparison is stated explicitly.

For example:

• De warmtepomp verbruikt minder energie dan de oude ketel. = The heat pump uses less energy than the old boiler.

In your sentence, the comparison is implied but not spelled out, so dan is not needed.

Here energie is being used as an uncountable noun, like energy in English.

With uncountable nouns in this kind of sentence, Dutch usually does not use een:

• minder energie
• veel energie
• genoeg energie

Using een would usually change the meaning and sound unnatural here.

Yes, there is a difference.

• gebruiken = to use
• verbruiken = to consume, use up

With electricity, gas, fuel, or energy, Dutch often prefers verbruiken, because the idea is consumption.

So:

• De warmtepomp gebruikt energie is possible in some contexts
• De warmtepomp verbruikt energie is more precise and more natural when talking about energy consumption

A rough pronunciation guide:

• warmtepomp ≈ VARM-tuh-pomp
• verbruikt ≈ fur-BRAYKT or vur-BRAYKT
• minder ≈ MIN-dur
• energie ≈ en-er-ZHEE

A few helpful notes:

• Dutch w sounds more like an English v
• Dutch g in energie is soft here because it comes from French-style pronunciation
• ui in verbruikt is a difficult Dutch vowel, so an exact English match does not really exist

Yes, minder implies a comparison, but the thing being compared may be left unstated.

So the sentence suggests:

• less energy than another system
• less energy than before
• less energy than expected

If you want to make the comparison explicit, you add it:

• De warmtepomp verbruikt minder energie dan een gasketel.

Without that, the listener usually understands the comparison from the context.