Chill factor: the N200 solar bulb basks in the winter sun.

The mercury reads 12 degrees outside, but it feels like minus 2 with the windchill. That's Fahrenheit--the numbers are depressingly lower in Celsius here in Canada. Still, when I hang Nokero's new N200 bulb on a tree, its solar cell recharges without a hitch.

Denver-based Nokero debuted last year with the N100 solar light bulb. It recently released an improved version, the N200, and I had a chance to try it out.

First off, the Nokero bulbs are designed to replace homemade kerosene lamps, not standard bulbs. They're aimed at hundreds of millions of people in developing countries who have little or no electricity. Many burn kerosene for light, which, aside from costing money, is a fire and air pollution hazard.

The N200's light is only 13.5 lumens on the high setting (a 60-watt incandescent bulb is 850 lumens). That's very dim, but it's comparable to a kerosene lamp. It's also better than the 8.5 lumens of the N100 bulb.

Meanwhile, the N200 can last more than six hours on its low-intensity setting after a single-day charge in sunlight. The N100 was rated at four hours if charged in equatorial regions, where the sun is strongest. Nokero says typical kerosene lamp users burn their lamps for 1.5 hours every night.

Obviously, several of these solar bulbs are needed to effectively light a small room or tent. The N200 is priced at $20, which is $5 more than the N100. Nokero says it has lower bulk wholesale prices for both bulbs.

The N200 is slightly larger than a conventional bulb. Its main design difference over the N100 is that it can swivel on a chrome-plated steel loop to best catch the sun with its single solar cell, which can capture more light.

New Life Orphanage Co-Director Sherry Moseley with a tent city family in Haiti.

Power is stored in a replaceable AA-sized, 1,000 mAh Ni-MH battery, which is rated to last two years. The company says it can be replaced for about $1.

The bulb has four LEDs, a switch for high or low settings, and a safety hook for hanging. It's rainproof and impact-resistant, and rated from minus 4 to 131 degrees.

So I've been recharging it outside in the cold, including days when the windchill factor was about minus 5, and it worked fine, illuminating a dim corner of my kitchen. It also recharged to some extent on cloudy days.

One interesting feature is the bulb's auto-shutoff function. It will only shine when ambient light falls below about 200 lux. This power-saving feature is probably valued by those with the least electricity.

A year after Haiti's devastating earthquake killed tens of thousands of people, the N200 bulb is being distributed there through American Green, a media group that brought the lights to the New Life Orphanage and a tent city outside Port au Prince.

According to Nokero, Haitian families often spend $10 to $30 on batteries, kerosene, or other lighting methods a month. For that amount, they can buy one or two solar bulbs that can last years. The company and American Green are trying to get Haitians interested in starting up businesses buying and selling them.

The bulbs have been tested in countries like Pakistan and Kenya and are also being shipped to needy families by Project C.U.R.E., the world's largest distributor of donated medical supplies.