I have been using Adwords for many years, and I have a very good knowledge about how to make good campaigns etc. So I thought about it, and it would be fun and a great thing to do to help companies with there adwords campaigns. So my question is, is there a market for someone who wants to be a google adword consultant?
There is a market for you... if you go to the adwords site you can see what you need to get certified. I know a guy that does this and he makes a pretty good buck.
There is, but it's needs more than a bit of 'good knowledge'. Usually you would be expected to be qualified under the Google Adwords Professional program - https://adwords.google.com/support/select/professionals/bin/answer.py?hl=en&answer=12241 If you think you can meet the requirements to qualify, then go for it, but generally it needs agency experience.