SSP Energy Return On Investment.

Geoffrey Styles at energyoutlook.blogspot.com in his most recent post, briefly discusses Energy Return On Investment (EROI). He mentions that Space Solar Power may only return a positive EROI after the first 5000MW of power are installed. For some time I've been thinking of crunching the numbers on this to see what the EROI for SSP actually would be. Anyone willing to have a go at this task? One of my main questions is what is how much does SSP EROI actually vary against the number of MW produced and to what extent could a larger system improve EROI apart from requiring fewer actual workers per MW.