I am looking to set up a cake delivery business and I am creating a break even for it to educate me about the costs it would entail. However, I have no idea how many kWs it takes to bake a cake. Can anyone help?
As @derober's comment notes, to get a precise number will be darn near impossible. However with some assumptions and generalizations, we can make a guess.
A little Google research yields lots of interesting results. Here's one from BestBuy's appliance buying guide (link to CNet's buying guide, which seems to be a direct cut-n-paste ripoff of BestBuy's. Or vice versa)
According to the Consumer Guide to Home Energy Savings, here is an energy cost comparison of ovens based on cooking an average casserole. It assumes the cost of gas is 60 cents a therm, and electricity is 8 cents a kWh:
Appliance Temp Time Energy Cost Electric Oven 350 1 hour 2.0kWh $0.16 Electric 325 45 min 1.39 kWh $0.11 Convection Oven
You can customize it to your oven and cooking time with some math. Say you do a little research and find out your oven uses 3.5kW/hour and you need to bake your giant sheet cake for 2 hours straight.
3.5kW/h * 2h * 0.08$/kW = $0.56
Running it for a 12 hour day?
3.5kW/h * 12h * 0.08$/kW = $3.36