Looking for a beam robot to use indoor...

Just about any beam robot will run inside your house. What you want it
for is a different matter. 99% of beam robots are there to look nice, as
aesthetics is a key component of beam robots. The rest couldn't exactly
do your ironing yet but advances are being made. If you're interested in
starting out have a look at solarbotics.net - it has a ton of info to
get you going =D.

You have a supply and demand problem.

Most solar cells will not produce much power under 20W Fluorescents.
Take a typical cell and place it under your lighting. Measure the
output voltage and current. Use Ohm's law to determine how many solar
cells you will need. A typical Beam photovore requires a 3-4V and
20-50mA.

To run around your living room, assuming carpeting and the like,
you'll likely want more than a photovore. These require smooth
surfaces. Perhaps a turbot or a walker would be more appropriate. Of
course, these types of robots use motors with higher power demands.

You may want to consider using batteries.

Hope that helps,

J Wolfgang Goerlich