Yes, some gas geysers need electricity in the form of batteries or from normal 220v. Currently, there are no gas geysers on the market that do not require some sort of electricity. Most natural draft gas geysers only require 2 D cell batteries. Fan force gas geysers use 220v ac power to power a fan and other electronics to achieve perfect combustion and maximum efficiency.
If you are in the market for a gas geyser we highly recommend getting a fan force driven gas geyser because of their superior efficiency and convenience. They can still be operated when there is no power by using a generator or a UPS as they only consume a very small amount of power (max 80 watts).
If you have no alternative source of ac electricity then the battery operated gas geysers are your go-to option. They are not as efficient as fan force gas geysers but will still get the job done. We recommend getting a constant temperature gas geyser as they allow you to set the temperature of the gas geyser meaning you only heat up the water to the temperature you need not anything more.