Grammar fix

strong demand

a lot of need

When there are many people who want or need something, often more than what is available.

collocationB1common

Hear it in context

Notice where the phrase sounds natural.

There is strong demand for affordable housing in big cities.daily life
In my country, there is strong demand for English teachers, especially in large cities.IELTS speaking

Pattern: strong demand for [noun]

WrongThere is a big demand of electric cars.

RightThere is strong demand for electric cars.

Demand FOR something (not 'of'), and it's 'strong', not 'big'.

Patternstrong demand for [noun]

Choose the version that sounds natural in speech.

Stiff There is a considerable level of consumer demand for the product.

Natural There's strong demand for the product.

'Strong demand' is the standard business collocation; the paraphrase is padded.

Words that usually travel with it.

‘Strong demand’ is more common and natural than ‘big demand’ or ‘high demand’ in many situations.