I found some answers online for this -- I will excerpt:
The issues are essentially the same with regards to Havdala [as with Shabbat candles], and many authorities rule that one may use an electric light in place of a Havdalah candle in a time of need (see She’arim Metzuyanim Be-Halachah 96:6; Az Nidberu 8:2; Rivevos Ephraim 3:599).
In fact, it is reported that Rabbi Chaim Ozer Grodzinsky would always use an electric bulb for Havdalah, in order to demonstrate how strongly he felt that electricity is to be treated exactly like fire from the perspective of halachah.
However, some object to the use of electric light bulbs for havdalah purposes, because of the glass casing that covers the fire.
Note also that for purposes of havdalah, only an incandescent light bulb, which has the full status of “fire,” can be used. For Shabbos candles, many authorities write that even fluorescent sources can be used.
Some poskim allow one to use an electric light in place of a Havdala candle in a time of need. In fact, it is reported that Rabbi Chaim Ozer Grodzinsky would always use an electric bulb for Havdala in order to demonstrate how strongly he felt that electricity is to be treated exactly like fire from the perspective of halacha.
Nevertheless, there are those authorities who discourage the use of an electric light for Havdala. Among their opposition to is the fact that the blessing recited upon the Havdala candle includes the word "fire" which seems to imply the need for actual fire, not merely light. As such a light bulb would not be acceptable according to this view. Even among the authorities who permit the use of electric lighting when needed many would disqualify the use of fluorescent bulbs as they work differently than standard light bulbs. 
3. Much the same (but includes reference to a flashlight.
4. Both 1 and 2 are essentially identical to this one.