No, if you are having the usual
video-hybrid-intel-nvidia-440xx-prime setup it means you are at the moment in HYBRID mode, so your desktop runs on Intel but Nvidia is powered on and available on demand with:
Only this environmental variable will trigger Nvidia to be used for a given app.
Hybrid mode is not able to output picture to secondary device (another monitor) and will have lesser battery usage then on fill Nvidia mode but still will use more battery than Intel. This depends on various settings and the hardware. The newest hardware allows for Nvidia to be powered down, some older can still have it on but use only small amount of energy. With few year old hardware, the energy usage will be pretty high thou.
For better GPU management and better battery saving study the link you got above, where you are shown how to install optimus-manager. This is what I use. In the guide you also have links to documentation about power management and what you could try to improve situation. Again, it all depends on hardware so results may vary.