When the Ontario Power Authority (OPA) released data projections made in supporting the development of Ontario's latest Long Term Energy Plan (LTEP) they showed the cost of purchasing generation from solar would grow about $280 million in 2014 (in 2012 dollars), and $443 million in 2015. The OPA anticipated that 45% of the growth in in generation costs from 2013 through 2015 would be due to the costs of purchasing production from solar panels.
45% of the cost increase over a 2 year period puts solar, in 2015, as about 1% of supply but 10% of total supply cost (according to the OPA work for the LTEP).
I've spent some time trying to incorporate hourly estimates of solar input into my tracking of Ontario electricity data. It's not easy, and it's dynamic, so I'm writing this post to explain how I'm estimating solar production, why my estimates change, why they are better than anything else most, if not all, will see - and what the estimates show.