What Your Home Appliances Really Cost: Watts to kWh, Cost per Cycle, Standby, Replacement Payback, Time-of-Use Timing & a Home Energy Plan

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn the power and daily use of seven fictional appliances into kWh and money per day and per year, and find out how long the TV runs for one currency unit.
• Price every fictional washing, dishwasher and dryer programme per cycle with electricity and water, scale it to a year and find which share of the laundry bill comes from the dryer.
• Turn the small standby power of eight fictional devices into kWh and money per year, add up the whole flat's standby cost and price the three biggest users with LARGE.
• Compare an old fictional fridge-freezer with three new models, work out the saving per year, the payback time and the net saving over a new model's life, and find which model pays off best.
• Price a meal with five fictional cooking methods, add up the monthly cost per method, see what moving the oven meals to a smaller appliance would change and total the cooking bill for a year.
• Calculate the kWh and money saved per year by replacing old fictional bulbs with low-watt ones in five rooms, the payback in months per room and the saving for the whole home.
• Price four fictional shiftable loads at peak and off-peak rates, find the maximum monthly saving from shifting them and check whether a time-of-use tariff beats a flat tariff when only part of the runs move.
• Bring all fictional appliances of the flat into one table, price them per year, total the cost by category with SUMIFS, value the planned saving actions and show the categories in a chart.