Today is quite nippy and a reminder that winter is just around the corner. However it isn't quite nippy enough to turn the gas central heating on. It makes you wonder how does the cost of gas central heating compare with the cost of using an electric heater to heat just one room.
This actually isn't a trivial question because there's so many variables. The main problem is how to measure and compare gas versus electricity. For that we'd need to do some testing and frankly, that takes a lot of time. We need to simplify.
OK. We're going to heat just the family room area which is where we spend the most time. Really this is two rooms. The kitchen a family room, so it's a fair size area. Next we're going to assume that whatever appliance we use it will run at the setting we use for the entire time. That is, even though we can use the thermostat to control the temperature of the room. Without doing testing we can't know when the devices will turn off and on and for how long. In addition conditions may change so running one test and then another may be quite hard. It can be done, but it will as I said take some time.
The gas central heating has a disadvantage in that it has to heat more rooms. The thermostat is outside the family room are. We can close off vents, but still we have the family room area, kicthen and hallways. Electricity tends to be known as more expensive.
Checking the gas heater it uses a nominal 120MJ/h. We'll assume that figure for the comparison. The electric heater we've chosen is a column heater. It has three heat settings, low, medium, high and a fan mode, which appears to set the heater to medium plus the fan. The following is my rounded nominal measurements.
Low - 1,000 watts
Medium - 1,400 watts
High - 2400 watts
Fan mode - 2000 watts
Our cost for electricity is easy as we use an Anytime rate of 26.169 cents per kWh. We get a pay-on-time discount of 30%.
Gas is a bit trickier as the more gas you use, the lower the rate. The rates for use are 2.167 c/MJ first 98 MJ/day, 1.639 c/MJ for next 49 MJ/day and the balance at 1.309 c/MJ. We get a 20% pay-on-time discount. Our base usage per day is around 35MJ/day when not using heating. We only have hot water on demand and heating. If you have gas cooking then that needs to be considered. As I said, there's lot of variables. Since this is a nippy day, during our lower usage period, we'll usage the highest rate.
Let's now compare running the appliances for one hour.
Gas 120MJ at 2.167 cents less 20% discount giving us $2.08
Electricity @ 26.169 c/kWh less 30% giving us 18.31 c/kWh
Low - 18.31 cents
Medium - 25.63 cents
High - 43.94 cents
Fan mode - 36.62 cents
I must admit seeing these figures in writing for the first time I'm very surprised. This is not the result I expected. Electricity always gets a bad wrap for heating as being expensive, but if you only need to warm a smaller area, it looks like electricity may be a more efficient and cost effective way to go.
I decided to check the MJ usage for gas heaters. The first unit I found uses 5.5 to 11MJ/h which would cost us around 9.5/19 cents per hour to run. This is where gas is cheaper than electricity. However for us, the gas heater wouldn't be in the area we use most.
At first glance it now appears for those nippy mornings where we need to warm up a smaller area for a short period of time, the electric heater may be more cost effective. To be sure however I'd now need to do some testing to determine the actual usage of each appliance over the desired time and take into account the on/off cycle time.
I hope others find this information useful. It certainly helps me to put my thoughts in writing and to compare different heating strategies. If you'd like to use an electricity cost calculator to help determine the cost of using an electrical appliance, I written one which is available at www.justlocal.com.au/clients/energy-cost/.
Kelvin Eldridge
This actually isn't a trivial question because there's so many variables. The main problem is how to measure and compare gas versus electricity. For that we'd need to do some testing and frankly, that takes a lot of time. We need to simplify.
OK. We're going to heat just the family room area which is where we spend the most time. Really this is two rooms. The kitchen a family room, so it's a fair size area. Next we're going to assume that whatever appliance we use it will run at the setting we use for the entire time. That is, even though we can use the thermostat to control the temperature of the room. Without doing testing we can't know when the devices will turn off and on and for how long. In addition conditions may change so running one test and then another may be quite hard. It can be done, but it will as I said take some time.
The gas central heating has a disadvantage in that it has to heat more rooms. The thermostat is outside the family room are. We can close off vents, but still we have the family room area, kicthen and hallways. Electricity tends to be known as more expensive.
Checking the gas heater it uses a nominal 120MJ/h. We'll assume that figure for the comparison. The electric heater we've chosen is a column heater. It has three heat settings, low, medium, high and a fan mode, which appears to set the heater to medium plus the fan. The following is my rounded nominal measurements.
Low - 1,000 watts
Medium - 1,400 watts
High - 2400 watts
Fan mode - 2000 watts
Our cost for electricity is easy as we use an Anytime rate of 26.169 cents per kWh. We get a pay-on-time discount of 30%.
Gas is a bit trickier as the more gas you use, the lower the rate. The rates for use are 2.167 c/MJ first 98 MJ/day, 1.639 c/MJ for next 49 MJ/day and the balance at 1.309 c/MJ. We get a 20% pay-on-time discount. Our base usage per day is around 35MJ/day when not using heating. We only have hot water on demand and heating. If you have gas cooking then that needs to be considered. As I said, there's lot of variables. Since this is a nippy day, during our lower usage period, we'll usage the highest rate.
Let's now compare running the appliances for one hour.
Gas 120MJ at 2.167 cents less 20% discount giving us $2.08
Electricity @ 26.169 c/kWh less 30% giving us 18.31 c/kWh
Low - 18.31 cents
Medium - 25.63 cents
High - 43.94 cents
Fan mode - 36.62 cents
I must admit seeing these figures in writing for the first time I'm very surprised. This is not the result I expected. Electricity always gets a bad wrap for heating as being expensive, but if you only need to warm a smaller area, it looks like electricity may be a more efficient and cost effective way to go.
I decided to check the MJ usage for gas heaters. The first unit I found uses 5.5 to 11MJ/h which would cost us around 9.5/19 cents per hour to run. This is where gas is cheaper than electricity. However for us, the gas heater wouldn't be in the area we use most.
At first glance it now appears for those nippy mornings where we need to warm up a smaller area for a short period of time, the electric heater may be more cost effective. To be sure however I'd now need to do some testing to determine the actual usage of each appliance over the desired time and take into account the on/off cycle time.
I hope others find this information useful. It certainly helps me to put my thoughts in writing and to compare different heating strategies. If you'd like to use an electricity cost calculator to help determine the cost of using an electrical appliance, I written one which is available at www.justlocal.com.au/clients/energy-cost/.
Kelvin Eldridge
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