No, at this point, there doesn’t appear to be any specific taxation legislation dealing with income derived from feed-in-tariffs.
Whether it’s assessable income depends on the income producing nature of the activity. If it can be demonstrated that the system was installed with a view to making a profit, then receipts under the feed-in-tariff would be considered assessable income, while all expenses associated with the income generating activity would be deductible (eg depreciation). In most cases, systems installed at domestic sites would not be taxable as they would be considered as personal use (i.e. not in the nature of a business or profit making scheme). If the system is installed at a commercial site, it will most likely be considered taxable. However, system owners should consult their accountant for advice or contact the Australian Taxation Office.