This Maker hacked his washing machine with an Arduino to reduce costs and add convenience.
Depending on where you live, you may or not be familiar with time-based pricing for power consumption. Basically, this refers to a system where power is priced not only by how much of it you use, but at what time the consumption takes place. Simon Jowett lives in an area of Australia where “peak” power, from 2 PM to 8 PM on weekdays, is charged at 51 cents (Australian) per kilowatt hour (kWh). The “off peak” rate, from 10 PM to 7 AM, is only 11 cents per kilowatt hour. In other words, where he lives if you’re willing to use power when most people are asleep, it costs less than a quarter of what it would during the most expensive times.
In order to take advantage of this pricing scheme without disturbing his sleep, Jowett squeezed an Arduino into his washing machine’s control panel, along with several relays to act as a delay timer. As he notes in step 2, “Mains electricity is dangerous” so you shouldn’t attempt this if you’re not “confident and or competent.” Additionally, as he puts it later when trying to find DC power to run his Arduino from the machine, “There is a risk here of really mucking things up.”
Warnings aside, his delay-enabled machine seems to work quite well, and, as seen in the video below, has a very usable display and interface. Now he can set up the machine to wash, go to bed, and his laundry will be washed when he wakes up in the morning! Intrigued? Head over to the project’s page here.
External control of washing machines having mechanically advancing machine control could be useful for increasing own consumption of PV linked to the grid.