Depending on how much Steem power you have in your account, you could be earning anything from fractions of a penny to hundreds of SP per second.
Steem power accumulates interest at a rate of 0.0066% per day
So if you have 1000 Steem power today, and don't earn any rewards, tomorrow you'll have (1000 balance * 1.0066 interest rate = ) 1006.6 Steem Power
That gives us a daily rate, but what about hourly, or by the minute, or even by the second?
Well, there are 24 hours in a day, so if we if we take our interest rate of 0.066 and divide it by 24 we get 0.000275
For minutes, we divide that again by 60 (because there are 60 minutes in an hour), to get what my calculator shows as 4.583333333333333e-6
and for seconds we're going to get a really tiny number - divide by 60 again (for 60 seconds in each minute) and you'll get something like 7.638888888888889e-8
Whichever value you want to get the interest rate for - I'm using seconds here - add 1 to it, so now I get 1.000000076388889 as my interest per second. The 1 is to preserve our original value as we multiply the interest onto it.
Now copy the resulting value to your calculator memory, and type in your balance. Hit multiply, then put in your interest rate, then hit enter.. that shows you your new total after 1 second.. and hit enter again, and again, and watch it grow. That's the power of compound interest! :D
Incidentally, the value needed to earn about 0.001 SP/second seems to be somewhere around 9000 SP
I think my maths(*) make sense here, but I'm not really great at this stuff, so I've I've screwed up somewhere let me know.
(*) That's maths, as in "I did my maths wrong and got too much aluminium. And it's the wrong colour, too. Shit weather, innit? Fancy a cuppa? Toodle pip, tally ho, chocks away old chap!"
Edited: Fixed several places where I referred to Steem Dollars instead of Steem Power. Thanks for pointing that out,