ati - How to use only intel graphics and power off radeon with proprietary Catalyst drivers?

I've been using Linux for quite a while in everyday computing and programming.
But now i got this new laptop with amazing battery life on windows which runs pretty cool even while gaming. But for some reason on Ubuntu I get like 1/3 battery life and it gets hot even while browsing the web.

I have the proprietary drivers for radeon, but I'm thinking about upgrading from Ubuntu 12.04 to 14.04, and I would like to know how can I use only the Intel graphics and have radeon always turned off? Since I do not need the discrete graphics on Ubuntu and I'm pretty sure my problem is related to the radeon sucking up my battery and generating heat.

My laptop technical specifications are:

• Dell latitude 3540


• Intel core i7 4500U (with Intel hd4400 graphics
  )


• Ati Radeon HD 8850m with 2GB GDDR5 VRAM


• 8 GB DDR3L @1600mhz


• Toshiba 256gb SSD


• Ubuntu 12.4.3

If you need any additional info, please tell me :)

Install Catalyst Control Center:

Open your Terminal and execute:

sudo apt-get install fglrx

Then reboot.