Hi there,
TransAlta Renawable's dividend looks suspect if you are comparing it to earnings as it has a 200%+ payout ratio. However, it is best to look at the safety of the dividend in relation to FCF and OCF. As of writing, it accounts for about 83% and 74% respectively. This isn't bad, but isn't great either.
I would not go out on a limb and say the company's dividend is 100% safe - it stopped growing the dividend in 2018. This is usually a warning sign. On the bright side, the renewable industry has been doing quite well as of late.
The company is generating strong cash flows which are expected to grow YOY. As of last update (in March), cash available for distribution is expected to growth to $300-$330M in 2020, up from $293M in 2019. It would mark the first meaningful improvement in CAFD since 2018 (when they stopped raising the dividend). Given this, the dividend appears sustainable at these levels. If i was to 'heat map' the dividend, it would be a yellow.
Of note, I am long RNW (have been for years).
Mat