The true costs of keeping cool this summer
Finding the heat unbearable, but concerned about your energy costs?
With this week’s heat wave continuing unabated and temperatures set to rise to a sweltering high of 35°C on Thursday, keeping cool has become a national concern over the last few days.
Naturally, the need to keep cool comes with a price tag, but do we know how much it really costs to run appliances like fans and air conditioners all day?
Understanding kilowatt hours and energy output
In simple terms, a kilowatt hour (kWh) is a unit of measurement for energy usage. It measures the amount of energy used if a 1,000 watt (W) appliance were to run for an hour.
For example, a 25 watt light bulb running for 40 hours would use 1kWh (1000W).
If you want to calculate the costs of running a 50W appliance, divide its wattage by 1000 and then multiple the result by the number of hours you wish to run the appliance. This figure will give you the cost in kWh.
50W ÷ 1000 = 0.05kWh
0.05kWh x 12hrs =0.6kWh
Using the kWh figure, multiply it by your energy supplier’s unit rate (the cost per kWh) and this will give you a final total of an appliance’s running costs.
0.06kWh x £0.14 = £0.084
If you are still unsure about your energy supplier’s unit rates, then you can use the national average of £0.14 per kWh to calculate your extra energy costs.
Estimated running costs for cooling appliances
Unit rates vary between regions and suppliers, but personal finance website Nimblefins presented an average figure of £0.14 per kWh.
A generic 45W tower fan running for 12 hours a day generates 0.54kWh, which costs just under 8p. Over the course of a week, that would set your energy bill back by around £0.56 a week.
By comparison, a more high-tec model like the Dyson Hot+Cool AM09 Jet Focus fan boasts 1500W, so in comparison, running this device for 12 hours a day would cost £2.59 or £18.13 a week.
While air conditioning units are an attractive option for staying cool, they are also notoriously costly to run. An average home air conditioning unit runs at about 3000W (3kWh) and adds up to around 43p per hour. Multiplied by a running time of 12 hours a day, that equals approximately £5.18 per day or £36.26 a week.
Although tomorrow has been poised to be the hottest day of the year, with some urban areas like London predicted to rise to a sweltering 38°C, temperatures look set to cool down to 24°C from Friday onwards.