Spotřeba energie je vysoká.

Because it agrees with spotřeba, which is a feminine singular noun.

• spotřeba = feminine singular
• vysoká = feminine singular form of vysoký (high)

In Czech, adjectives must match the noun they describe in gender, number, and case.

Spotřeba is in the nominative singular because it is the subject of the sentence.

You can think of the structure as:

• Spotřeba energie = energy consumption
• je vysoká = is high

So spotřeba is the thing being talked about.

Because spotřeba often takes another noun to show what is being consumed, and that noun is typically in the genitive.

So:

• spotřeba energie = consumption of energy
• literally: consumption energy-GEN

This is very common in Czech. Compare:

• cena domu = the price of the house
• spotřeba vody = water consumption
• výroba elektřiny = production of electricity

Here it is genitive singular, even though it looks identical to the nominative singular.

That is normal for some Czech nouns: the form does not always visibly change in every case.

So in this sentence:

• energie = genitive singular
• function: it depends on spotřeba

Learners often find this confusing because the ending does not help much here, so you mostly recognize it from the structure: spotřeba + genitive.

In a normal present-tense sentence like this, je is usually needed.

• Spotřeba energie je vysoká. = correct standard sentence

Czech does sometimes omit forms of to be in headlines, notes, or very informal styles, but in ordinary full sentences you normally keep je.

So this is different from some other Slavic languages where present-tense to be is often omitted.

Yes. Vysoký / vysoká / vysoké can mean both tall and high, depending on context.

Here it means high, because we are talking about a level or amount:

• vysoká spotřeba = high consumption
• vysoká cena = high price
• vysoká teplota = high temperature

For a person, it could mean tall:

• vysoký muž = a tall man

Yes, Czech word order is fairly flexible, but the neutral order here is:

• Spotřeba energie je vysoká.

Other orders are possible, but they change the emphasis:

• Vysoká je spotřeba energie. → emphasizes high
• Energie je spotřeba vysoká → not natural in normal usage here
• Spotřeba je vysoká. → possible if energie is understood from context

So the original sentence is the most natural, neutral version.

Because Czech has no articles.

English says:

• the energy consumption is high
• or energy consumption is high

Czech simply says:

• Spotřeba energie je vysoká.

Whether it means the, a, or no article at all depends on context.

A rough English-friendly guide:

• Spotřeba ≈ SPOT-rzheh-ba
• energie ≈ EN-er-ghi-ye
• je ≈ yeh
• vysoká ≈ VI-so-kaa

A few useful points:

• Czech stress is usually on the first syllable of each word:
  • SPOTřeba
  • ENergie
  • JE
  • VYsoká
• ř is a special Czech sound. English does not have it. It is often described as something between r and zh.
• j in Czech is like English y in yes.
• á is a long vowel, so the final syllable of vysoká is longer.

It is mainly consumption.

So:

• spotřeba energie = energy consumption

In some contexts, English might naturally translate it as energy use or energy usage, especially in technical or practical writing. But the core meaning of spotřeba is consumption.

Related examples:

• spotřeba vody = water consumption
• spotřeba paliva = fuel consumption

Yes, absolutely.

That means The consumption of electrical energy is high, or more naturally, Electricity consumption is high.

Here elektrické energie is also in the genitive, because it still depends on spotřeba:

• spotřeba
  • čeho? = of what?
• elektrické energie

This version is more specific than just energie.

Yes, but it is not always exactly the same in nuance.

• spotřeba energie = literally consumption of energy
• energetická spotřeba = energy consumption / energetic consumption

In many contexts they can overlap, especially in technical language. But spotřeba energie is the clearer and more basic expression for learners.

So if you want the safest, most transparent phrasing, use:

• Spotřeba energie je vysoká.

The dictionary form is vysoký.

Czech dictionaries usually list adjectives in the masculine singular nominative form. Then the forms change depending on the noun:

• vysoký = masculine
• vysoká = feminine
• vysoké = neuter

Examples:

• vysoký dům = a tall/high house
• vysoká spotřeba = high consumption
• vysoké číslo = a high number

So vysoká is just the correct agreeing form for spotřeba.