Great question, yes I agree with your assessment that the PV Associate credential will be valuable for you. It is a well recognized credential in the industry.
The course can be taken over 4 weeks. Typically we recommend spending 5-10 hours per module, so 30-60 hours total depending on your background and how much energy you want to put in to test prep and practice exams etc. We have a very high passing rate in the 97% range for people who sit for the exam, so as long as you study and put in the time you should have a good chance of passing and getting the credential.
The exams can be taken at any Scantron testing center: https://www.scantron.com/test-site-cities/. After the course you'll submit an application as well as a $150 exam fee, which we will then forward to NABCEP on your behalf to verify you have completed the required course. Once that is done, you'll be able to schedule your exam at a testing center near you.
The PV Boot Camp course is very successful at getting students to pass the NABCEP Associate Exam, but as any course goes, you get out what you put into it. The course goes along with my book Solar Photovoltaic Basics and the NABCEP Associate JTA. The JTA was put together to teach students design among other things.
I go over different types of design software and tools. We will determine system sizing for interactive (grid-tied) and stand-alone (off-grid) systems. We will learn about the different types of shading analysis tools, how to calculate voltage based on temperature, how to design systems on buildings based on the 2017 NEC (I will be adding 2020 NEC over the coming weeks),
The course is go at your own pace. Many people will finish the course in a few weeks. Even after you finish the course, you will still have access to all of the material and discussion forum for a year after you finish the course. Many students favorite part is how active I am on the discussion forum. I answer questions every day, with few exceptions.
Since you are interested in designing systems in different countries, I do have a lot of experience with that. I am working in Argentina this week and a few weeks ago Angola. I sometimes make analogies in the course about different standards around the world. The US NEC is the most comprehensive set of rules for installing PV systems and energy storage in the world by a long shot.
I also recommend taking the 40-Hour Advanced PV Training course and preparing to take the NABCEP PVIP Certification Exam in the future.