Please look more closely at net metering and the energy exchanges that
happen under it. It seems to be similar to the kind of mechanism you are
looking for, as follows: It measures the individual contribution of a
solar owner's surplus (the reversal in the electric meter) to the grid
supply, and which entitles the solar owner to credit equivalent to his
contribution. You can look at this contribution as a contribution to
the common supply of electricity, although it just so happens that this
contribution is privately appropriated by the utility at this time. But
one can imagine the surplus contributions of many solar owners as
something similar to code, information, etc. contributed to a common
pool. From this perspective, the grid is a network that is now
poised to turn into a commons where the accounting mechanism (my term,
equivalent to your 'economic calculation', I believe) has already been
found--net metering. I'm not sure yet that this is so, but it think it
deserves a second look.