Due to the very fluid nature of policy-making right now around energy and climate change in particular, I would recommend that it start at a frequency of annual, and then after things have perhaps settled down in the policy world, it could stretch out to every couple of years or so, or line up eventually with the Statistics Canada deep census.
Right now, I'm quite involved in Ontario and we know that things are changing radically from one year to the other, so I would say annual to start.