Moody's gives Atlantic Power a B2. B1 is better, B3 is worse.
Aaa highest quality, minimal credit risk.
Aa high quality, very low credit risk.
A upper-medium grade, low credit risk.
Baa moderate credit risk, medium grade may have speculative characteristics.
Ba speculative elements, substantial credit risk
B speculative, high credit risk.
Caa poor standing, very high credit risk.
Ca highly speculative, likely in, or very near, default, some prospect of recovery of principal and interest.
C typically in default, little prospect for recovery of principal or interest.