There are numerous 3-D modelling packages out there with prices ranging from free to huge sums of money unless you are prepared to spend the ridiculous amounts of money I would strongly recommend downloading and learning blender.
While it is perhaps a little generic for your use it has the following features that you may well benefit from:
- Free & cross-platform.
- Will run on reasonably priced hardware, (obviously faster is better)!
- Able to produce a 3D model just about anything.
- Add lighting and time of day modelling.
- Can export to and import from most commercial modelling systems.
- Can produce photographic quality renders for clients to see.
- Can produce walk/fly through/round movies.
- Can animate items such as your wind turbines.
- With the game module you can produce interactive models allowing clients to explore the model at will.
- Active user community - i.e. lots of help, books, etc.
- There are even training materials on-line both free and paid for some specialising in architecture.
Downsides include:
- Steep learning curve just about every serious modelling program suffers from this!
- Possibly too generic for the use you are planning
- You will probably need to build up a library of the your commonly used components.
The results can be fantastic:
