Steibel Eltron conducted a test that compared the cost of heating water using a conventional electric geyser to a gas geyser.
They have kindly allowed us to publish their test.
A 100 litre electric geyser was mounted right next to a gas geyser on an outside wall above a 100 litre drum. The electric geyser was emptied into the drum twice a day, once in the morning, once in the evening. The drum was filled with hot water from the gas geyser also twice a day, at about the same times.
In this way the same amount of water was heated using each different method, using the same inlet water, at about the same times every day for a month.
This was done every day for a month and the costs compared.
Both systems were set to heat water to 55C, and both used the same inlet water.
The geyser operated normally, without a timer.
The gas bottle was only opened for each test run to eliminate any potential excess gas consumption caused by leaks.
Electricity tariff during the test – R1.22/kWh
The gas used was from a 45 kg cylinder which cost R 1,070.00 (incl. VAT). This equates to a rate of R23.78/kg.
Using those prices, the cost of heating the water for each method during duration of the test was:
Electric geyser – R 469.70
Gas geyser – R 502.21