I live in a home that generates approx. 1000kwh and was sold a system designed to produce 800kwh...my power company is SCE...how will this affect my bill?

Hmmm...is this a trick question? Seems like you are saying that your new solar panels will only produce 80% of what your home uses. So your new utility bill should only be 20% of your old utility bill.

The answer is it depends.
You are grid-tied right?
What time of day is your electrical consumption?
If you use most of it during the day you will get the expected savings but if you use as much at night as during the day you will use more energy and not get the full savings unless your utility company allows a net meter. I am guessing that is the case?

Use of a net meter will recover some of the energy use lost at night since during the day your meter will spin the opposite way which mean you are feeding the utility company but at night it spins the other way meaning you are using their power.

I don't know what utility policy that SCE has but the installer should have mentioned all this. About the only requirements I have to meet for my solar system will be an IEEE 1547 which is mainly for connecting and disconnecting systems to the utility grid...

Love to know more about your system too. Number of panels, wattage per panel, micro inverter or inverter, etc...