People have been talking for quite a while about grid parity for solar power, the point at which solar becomes as affordable as power purchased from the grid, where it may come from sources such as coal. While we waited for grid parity, solar was still becoming attractive: rebates, tax incentives, and leasing options made it possible to start saving money in fewer years, in some cases right away.

Now, a study conducted at Queen’s University in Kingston, Ontario, claims we need not wait any longer: Grid parity is here! In some parts of North America, the study says, this hoped-for result has already been achieved.

The change that has made this possible? Technological advances played a role, but the biggest factor has been the plummeting costs of solar, which have decreased an astonishing 70% since 2009. That’s the kind of decrease rarely seen in any industry and is likely the main cause for Solyndra’s failure — which was in fact an indication of the robust success of the solar industry as a whole.

In addition, the study points out that contrary to the widespread belief that solar panel productivity can decrease 1% per year, the real figure for top-of-the-line panels is more like 0.1 – 0.2%.

While the study’s conclusions are likely to be debated, it’s clear that solar has become more viable more quickly than anyone would have predicted. That’s one bright ray of sunshine to take us into the new year.