Question

Does the Sun generate most of its energy using the CNO fusion cycle?

Answer 1

No.

Explanation:

Since its beginning our sun is comprised of hydrogen and helium. At the end of its life, after its red giant stage, it may produce a few elements including carbon and nitrogen but that will only happen at the end of the sun's life.

Answer 2

No, The Carbon-Nitrogen-Oxygen (CNO cycle) is the dominant method of nuclear fusion in stars more than 1.3 times as massive as the sun.

Explanation:

The Carbon-Nitrogen-Oxygen (CNO cycle) is the dominant method of nuclear fusion in stars that are more than 1.3 times as massive as the sun.
This is because, the temperature required for a self-sustained CNO cycle is mostly found in such massive stars.

In stars like the sun, The CNO cycle contributes to only about 1.7% of the Helium molecules generated.

For further reading:
CNO cycle

Answer 3

Our Sun, unlike larger stars, only produces about 10% of its output from the CNO cycle.

Explanation:

Main sequence stars, like our Sun, are fusing Hydrogen into Helium-4 in their cores. There are two principle Hydrogen to Helium-4 fusion reactions, the proton-proton chain and the Carbon-Nitrogen-Oxygen (CNO) cycle.

The proton-proton chain reaction is dominant in our Sun and stars smaller than about 1.3 solar masses. This reaction is Hydrogen`rarr`Deuterium`rarr`Helium-3`rarr`Helium-4.

The CNO cycle uses Carbon as a catalyst. The Sun isn't hot enough to make this efficient so it only generates about 10% of its output from CNO. The CNO reaction is Carbon-12`rarr`Nitrogen-13`rarr`Carbon-13`rarr`Nitrogen-14`rarr`Oxygen-15`rarr`Nitrogen-15`rarr`Carbon-12+Helium-4.

The output of the CNO cycle increases with increasing temperature. The proton-proton chain reaction isn't so temperature sensitive. It is only in stars over 1.3 solar masses that the temperatures are high enough for the CNO cycle to dominate.