The only value I see in tea lights (for emergency or camping purposes) is they are light and easily packed/carried. Otherwise, not enough light and not enough burn time. 'Same with the religious candles in terms of their usefulness. The ones I've seen give off VERY little light, even though the tall glass cylinder does increase the safety factor.

I have 4 oil lamps for stationary light, a couple of battery flashlights for moving around, and a couple of tiny Coleman LED battery-powered lanterns. The LED headlamp is on the list to buy.