A planet moving around the sun is a good illustration of the law of conservation of energy ? Explain

We know that every planet revolves around the sun in elliptical orbit. The sun is situated at the foci of elliptical orbit. When  planet comes closer to the Sun,  its speed increases and thus it has more kinetic energy and less potential energy. But, when it is away from the sun it speed decreases and it has more potential energy and less kinetic energy. Thus, sum of potential and kinetic energy of the planet remains constant at every instant during its motion. Thus, a planet moving around the sun is a good illustration of the law of conservation of energy.