Not a lot of details. This would be a pretty big satellite. The idea is to use "existing rockets" which does not narrow things down much. From an emissions perspective, the interesting factors are:
1. which launch vehicle
2. what launch rate
3. what period of time
But here is an interesting quote from the CEO: "These space launch vehicles primarily use natural fuels (H2, O2) and have an emissions profile similar to a fuel cell."
So he means Delta IV Heavy I guess. But this notion of "natural fuels" - the word natural is not defined and is usually a marketing ploy - leaves me wondering if this is serious at all.
Also I wonder what PG&E's exposure is. The risk is all Solaren's? I could not even find a website for Solaren. Anyway it looks very cool.