[9588]

5000 classified patents per year in the US alone. No one else publishes a number.

Modest estimate would be 200 000 over the last 30-40 years.

Some of it must relate to energy.

[ThomPete]

Those patents aren't about fundamentals in physics. This is a physics problem not a product/market problem.

There are plenty of patents on energy just not many fundamental breakthroughs.