So I was cruising through EUB Decision 2002-014, the simply fascinating regulatory approval for the Keephills expansion, and I noticed an interesting thing. As a condition of operation, Transalta is required to purchase carbon offsets equivalent to the difference from a combined-cycle natural gas facility of the same capacity, or whatever new standards require, for the life of facility, 30+ years. That's a big effin' deal. First of all, if you believe in the whole offset business (and the EUB won't take either Transalta's or Alberta Environment's word for it, they have to get a third party audit), it cuts about 63% off the GHG emissions. So now the electric bike wins easily, as long as I don't pedal too hard. (I still want a motorcycle. Vroom vroom.) But it's also a big change from the financial side too. Building a fossil plant is a risk. It's a bit cheaper today than a renewable plant, but you have to accept the risks of what the fuel is going to cost in the future. You pay your money, you make your choices, and you try to build a diversified portfolio, but still, prices may go up or down. (If you own the coal mine, the risk is hedged, but it's still there.) What committing to offsets does is add a whole new class of risk: carbon offset price fluctuations. Sure, they are cheap today, but you just promised to buy millions of tons a year, for decades into the future. What's more, at least with coal, there's hundreds of years of experience in how the prices fluctuate. With offsets, the market is totally new, and the scientists haven't even totally decided what offsets count yet, much less figured out how to pass the issue on to the accountants. Can you say price uncertainty? European carbon went from 5 EUR/ton to over 30, in less than six months. What will carbon cost in 2035? I don't know, but Transalta shareholders are going to find out.