Power is outside of the realm of time. P = E/t, so that's why I assumed power. For example, say the sun produces 384 yottawatts, that would be 384 yottajoules per second. Say the flare goes on for 6000 seconds and uses an average of 38 yottawatts, or 228,000 yottajoules over that time period (fun fact, yotta is where SI stops. Strange.)
There's been a movement for a while to add hella as the next SI prefix, for 10^27. It's already been adopted by Google and Wolfram Alpha, among others.
