outside is going to be much better. You can't tell but glass is actully opaque to many ranges of 'light'.
If you look at advertising for windows you may see claims to reduce sun fading of your carpet/ furniture. That is because the glass blocks UV. Solar panels get some of their energy from UV light.
Also some windows are engineered to block IR to help insulate better when the house is cooler than the outside. Again, solar panels get some of their energy from light in the infrared range.
And finally if you're charging batteries the 'off angle time' is still important. The amount of light absorbed is pretty closely related to the cosine of the angle that the sun is 'off' of the direct. so when the sun is 45 degrees off of perpendicular the panels still get cos45 =.707 or about 70% of the available energy. (In practice it's a little less than that because not as much energy gets to the panel to be absorbed as at midday). But anyway, you can figure two hours of morning or late afternoon sun will give you as much energy as 1 hour of midday sun. So if the panel is inside, you miss out on that available energy.
Solar Panel Emergency Portable Battery Charger for HTC EVO3D/Sensation/7Mozart, Portable 5000mAh Charger Solar Panel Battery For Phone MP3/4 PDA Camera 6000D SV, Solar Panel Emergency Portable Battery Charger for Samsung S5830 Galaxy Ace, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 P, 2600mAh Portable Solar Powered Panel Charger for Mobile Phone iPhone 4 4S iPad 2, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 U, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 S, Portable 5000mAh Charger Solar Panel Battery For Phone MP3/4 PDA Camera 6000D BK, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 U, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 G, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 G, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 S, Portable Travel Solar Panel Phone Battery Charger For Apple IPhone 3GS 4 4S Gen, Portable Solar Powered Battery Charger With Detachable Panel For Sony Ericsson, Portable Solar Power Panel Battery Charger For Blackberry CURVE 8530 8520 9860, Portable Solar Panel Backup Battery Charger White For Apple iPhone 3GS 4 4S Gen, Portable Solar Panel Phone Battery Charger White For Blackberry 9800 9810 9900, Portable Emergency Solar Panel Phone External Backup Cell Phones Battery Charger, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 P, Mini Portable Solar Power Charger With Detachable Panel For Cell Phone Battery, Brand New 16000mAh Portable Solar Panel Battery Charger for Laptop Phone MP3 PSP, 10W 12V mono solar panel for battery charger solar module portable free shipping, Gold Mining Highbanker Dredge Electric Portable 2-inch with 60W solar panel, Portable Multi-function USB Solar Battery Panel Charger for Cell Phone MP3 MP4 P, 12v mobile Portable Solar power panel Charger battery for phone laptop 11200mah, Portable Solar Battery Panel Charger for GPS MP3 MP4 Motorola Nokia Samsung, Solar Panel Camping LED Light Lamp Brightest Lantern Portable For Camping, New 12V Briefcase Portable Solar Panel 13 Watts Charger, Portable Solar Panel Power Supply Charger For AA/5 rechargeable Battery 1.5V New, New 12V Briefcase Portable Solar Panel 13 Watts Charge, ETON NRKS100 Rukus Portable Bluetooth Sound System with Solar Panel Black, UK Portable 2600MAh USB Solar Battery Panel Charger for Mobile Phone MP3 MP4 PDA, Portable Travel Solar Panel Phone Battery Charger For Apple IPhone 3GS 4 4S Gen, 4 x 100W Semi-Flexible solar panels for car boat caravan factory outlet portable, Portable Solar Powered Battery Charger With Detachable Panel For Sony Ericsson, Portable Solar Panel Backup Battery Charger White For Apple iPhone 3GS 4 4S Gen, Portable Solar Panel Phone Battery Charger White For Blackberry 9800 9810 9900, Solar Panel Emergency Portable Battery Charger for Samsung C5212/C5220/E215/F210, Portable Emergency Solar Panel Phone External Backup Cell Phones Battery Charger, Portable Solar Power Panel Battery Charger For Blackberry CURVE 8530 8520 9860, Mini Portable Solar Power Charger With Detachable Panel For Cell Phone Battery, Solar Panel Emergency Portable Battery Charger for Blackberry 8120/8130 Pearl, Solar Panel Emergency Portable Battery Charger for Blackberry 8220 Pear Flip, 80w portable solar panel, 80watt folding pv module for 12v battery system, Solar Panel Emergency Portable Battery Charger for Blackberry 9850/9860 Torch, Solar Panel Emergency Portable Battery Charger for Blackberry 9670 STYLE, Solar Panel Emergency Portable Battery Charger for Blackberry 7130g/7130c/7130v, Solar Panel Emergency Portable Battery Charger for Blackberry 9100/9105 Pearl 3G, Mono portable solar panel, mono crystalline folding solar module, pv power 12v, Mono portable solar panel, mono crystalline folding solar module, pv power 12v,
