I have interests in playing around with solar panels and generators, but also I have had lots of time with arduino and building many different gadgets and systems, this is why I have a profound interest in Electrical/electronic engineering
You have to invest a pretty big sum of money in loans to do any of these courses, so it worth thinking about what you want to do and look around.
If you think you may want to get into research, it may be a good idea if possible to go with the location that is strongest in your areas of interest. For example, University of NSW has had Dr Green since the 1970's and he is a world leader in solar cell theory and design. This is a semiconductor design field and not solar cell application field. As an undergraduate, you will hardly touch any high level theory, but it does give you a chance to make yourself known.
I would only do the double degree if it was part of a plan I had. It is hard enough to be great in one field, and it is better to be great on one field then average in two fields unless you goal is management.
If you need to go to Curtin because it is local and you cannot afford to live away from home, it is not a bad choice, but for post graduate work, you will definitely want to go wherever you need to go to find the best expertise in your field of choice.
If you want a degree so you can go out and get a job, the key thing is landing a good job, and from that point the degree hardly matters. It is more a question of how to survive the course with the least amount of damage and to really work on finding and landing the job you want. After the first job, most good employers will be more impressed by your previous jobs and they way you present yourself then your degrees.
If you last education was school, one of the things you have to remember is that you are now the customer and your money is paying the lecturers and tutors. If a course is bad, complain - they are wasting your time and money. If you are having trouble understanding something, go see the lecturer in his room. 20 year old students are usually better at this then 17 year old students.