במתקן האחסון יש כמה יחידות אחסון.

יש is the Hebrew existential word used for there is / there are.

So:

• יש יחידה = there is a unit
• יש יחידות = there are units

In everyday Hebrew, יש stays the same whether what follows is singular or plural. That is why the sentence uses יש even though יחידות is plural.

Hebrew often puts the location first in sentences like this, especially when the speaker wants to set the scene:

• במתקן האחסון יש כמה יחידות אחסון = In the storage facility, there are several storage units.

This is very natural Hebrew. You could also say:

• יש כמה יחידות אחסון במתקן האחסון

That version is also grammatical, but the original sentence emphasizes the location first.

Because short prepositions in Hebrew usually attach directly to the following word as a prefix.

Here:

• ב = in
• מתקן = facility / installation

So:

• במתקן = in a facility / in the facility

This is completely normal in Hebrew. The same happens with other common prepositions too, such as:

• ל = to
• כ = like / as
• מ = from

This is a construct chain (called smikhut in Hebrew), a very common Hebrew structure for phrases like:

• storage facility
• school building
• car door

In Hebrew, that often looks like noun + noun, where the first noun is in construct form.

So:

• מתקן אחסון = a storage facility
• מתקן האחסון = the storage facility

In a construct chain, if the whole phrase is definite, the ה־ usually appears on the second noun, not the first. That is why Hebrew says:

• מתקן האחסון

rather than:

• המתקן האחסון

Yes. יחידות אחסון is also a construct-style noun phrase.

It is made of:

• יחידות = units
• אחסון = storage

Together:

• יחידות אחסון = storage units

This is similar to English, where one noun can modify another noun. Hebrew uses this kind of noun-to-noun relationship very often.

Because the phrase is indefinite here.

• כמה יחידות אחסון = several storage units

The sentence is not referring to specific, already-known units such as the storage units. It just says that there are some / several such units.

Compare:

• יחידות אחסון = storage units
• יחידות האחסון = the storage units

Here כמה means some, several, or a few.

It does not mean how many in this sentence, because this is not a question. The sentence is declarative, so כמה is giving an approximate quantity.

So כמה יחידות אחסון means:

• some storage units
• several storage units
• a few storage units

The singular is:

• יחידה = unit

It is a feminine noun.

So:

• singular: יחידה
• plural: יחידות

That is why the plural ends with ־ות, which is a common feminine plural ending in Hebrew.

אחסון is a noun, meaning storage.

It is not an adjective. Hebrew often uses nouns where English might think in terms of a modifier:

• מתקן אחסון = storage facility
• יחידת אחסון = storage unit

So in both parts of the sentence, אחסון is a noun that helps define the type of thing being talked about.

Yes, that is close to the literal structure.

Hebrew often expresses these ideas with noun combinations that are a bit more compact than natural English. A more literal breakdown is:

• במתקן האחסון = in the storage facility
• יש = there are
• כמה יחידות אחסון = several storage units / several units of storage

But in natural English, storage units is the better translation.

In a construct chain, the definiteness of the whole phrase is determined by the second noun.

So:

• מתקן אחסון = a storage facility
• מתקן האחסון = the storage facility

Because האחסון is definite, the whole phrase becomes definite. This is a key rule in Hebrew construct phrases and is worth getting used to, because it appears very often.