No, not for what you plan to grow. There might be enough light just from the sun to germinate and grow tomatoes and peppers but you will not get fruit. You should have without the sun, 20,000 lumens or about 250 watts or 2 1/2 amps to get fruit and get plenty of light, minimum.
The other factor is the light you get from the sun is attenuated as it is low in the sky AND the daylight HOURS are too short. Plants are very sensitive to the type of light (spectrum) and length of daylight hours. They will KNOW it is winter and (want to go back to bed)?
To grow tomatoes and peppers you want to completely dictate to their needs longer daylight hours such as 16 hours and stronger grow lights. For your starts, you should use blue colored bulbs for about 2 months to get enough vegetative growth and then go to red colored bulbs to do the reproductive phase (make sure your fertilizer is lower in Nitrogen than Phosphorous and Potassium, we've lots of information if you get this far).
Always have a fan going, water deep and allow to dry. Match the plants to their pots; tiny plant, tiny pot; larger plant larger pot and ALWAYS use potting soil when growing in pot. I'd make a room out of black contractor trash bags and duct tape. Hang your grow lights (fluorescent is better than LED, my opinion, high pressure sodium and metal halide are even better, with ballast) and turn on the fans. I would not use tap water!
To make this short, NO you won't be able to have enough light to get fruits in the manner you are considering. You just might get one or two small, green fruits and if that is all you care about, then try it. Your plants won't be vigorous, most likely spindly, anemic looking. A window sill is just not large enough to do determinate or even indeterminate tomatoes. As they get larger, the little light they do get will be even less, blocked by its own foliage. The peppers will do far better. I've gotten great harvests with peppers in 4 and 6" pots (starts are in 2 and 3" pots transplanted up to 4 and 6" pots) with artificial lighting. Also I keep the temperature dipping no lower than 60 degrees F. Pots have to have a drainage hole and JUST potting soil in the pot.