Years ago, there was a website, Brainbench, that offered free certification exams. They still do today, in addition to other services. Really, though, no one considers Brainbench (or any other free, web-based) certifications to be worth much. The effort that goes into developing exams that really test a person's knowledge requires charging a fee for the exam. Also, it's too easy to cheat on a web-based exam, so they usually do not help.

I completed the LPI level 1 back in 2000. It was a good experience, mostly for what I learned. I don't know that it actually helped me in a search for a job, but the knowledge certainly helped me do my job better.

It looks like you can take courses right there in Madrid for the Red Hat exam. The Red Hat RHCE certification is generally considered better for demonstrating knowledge with Linux.

A certification is two things, a demonstration of ability, and an investment. Generally, the Red Hat is a better demonstration because you test in a lab with results-based tasks; LPI is simply picking the right answer to a question. LPI is still better than others, like Linux+ or Brainbench, though. Also, a certification is an investment. We expect to get the money we spend back by getting a better job. So, if you spend a few hundred euros on the study and exam, you should have opportunities for a higher paying job that you would not have if you don't get a certification.

Good luck.