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Comment by mrweasel | Hacker News Reader

My dishwasher has a "wifi-button", so I decided to figure out what it does, as it turns out, it's completely useless. The only features you get is "you're out of rinse aid" and "Turn on remotely".

The thing is that turn on remotely is useless, it requires that you've added soap, closed the dishwasher and that it's turned on. At that point you might as well just set a timer.

There are two features I could see being useful: Auto-start during the night, when the electricity cost is lowest and a detailed error report, like heating element is 100% function, or water is leaking. None of those features will ever be available, because that's not why they are adding "smart" features.

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We got a new dishwasher a while back and it came with a mobile app - this was a bit of a faff to get working but was mildly useful in that it would send a notification once the cycle was done.

Then after a few weeks the company decided they had to change their authentication scheme to something really complex and I couldn't be bothered - deleted the app and don't really miss it.

> There are two features I could see being useful: Auto-start during the night, when the electricity cost is lowest

Your dishwasher might not implement it, but the existence of wifi-connected start function probably means that home assistant could enable this.

My 20-something year old dishwasher has a delayed start option that I use to run it in the middle of the day. It's great. No app required.

I measured the energy consumption of my connected iQ-500 Siemens dishwasher. It used 750 Wh per load total, regardless if I used eco (3h55min) or 40/50 degree standard program (2h15min). I am guessing the "eco" mode only saves water.

There's no money to save on spot price optimization there.

I intentionally bought the dumbest dishwasher I could find. It has two cycles: "Normal" and "Heavy Duty", a "Heat Dry"/"Air Dry" selector, and a start/stop button. I could not find one that was simpler.

"Less to go wrong" is my mantra for appliances. I want to switch them on and forget about them.

Remote start could be very useful if you want to maximize self-consumption for your solar panels. Do they support that?

Dishwashers aren't very solar-friendly if you don't have net-metering.

They typically have a very powerful 2.5 kilowatt heater they run in bursts - for like 5 mins when prewashing, for like 10 mins when starting the main wash, and like 10 mins again when drying.

In between those times, the machine uses only ~60 watts for pumps.

I have often pondered what a world of machines designed to meet solar output looked like - and for a dishwasher it would involve the heater being modulated to match the solar output (and knowing that sometimes the wash cycle would take longer if a cloud was overhead so heating was delayed by a half hour).

I guess you could also use a small battery to help smooth things out.

The money efficiency isn't great - if you had control of the design of the dishwasher, simply having a hot block of concrete inside that you heated when there was spare energy would work out far cheaper.

Concrete costs far fewer $$$'s than batteries do, per kwh of heat stored, it also doesn't require inverters, balancing or safety systems, ad lasts millions of cycles rather than thousands.

How expensive would it be, transportation included, compared to an insulated water container of comparable heat capacity?

Or maybe store hot water and heat it up at the best time...?

The water is too hot to store safely.

You can still slowly heat it up to 70 or 80°C and just add some extra heat on use, but that will still leave a lot of immediate power to deal with.

I can't imagine a scenario where you've got a large enough solar system that you'd want to be running a dishwasher off it, and you don't already have some battery storage elsewhere in that system.

Waves from Australia

However, since my array is currently 4.4kw at 3 in the afternoon, a 2.5kw burst isn't a problem.

Just have more dishwashers, and use them as storage cabinets: pick from a clean cabinet if you need tableware, deposit in a dirty cabinet when you are done and if you have at least three of them the transition is free to take a lot of time.

That sort of thing seems solvable with batteries used as a a capacitor, rather than trying to reprogram the dishwasher logic

I tried to do things like this in my home. It turns out for washers, dryers and dishwashers you should just set a timer to start at noon.

Once you've started an appliance on a cycle it's going to keep running, even if the sun goes behind a cloud. So you don't need to start it when the instantaneous solar power is at its highest, you need to start it when the predicted next two hours of solar power are at their highest.

And it turns out you don't need complex monitoring to figure that out.

That's exactly what I'm using this for. I have a home assistant automation that starts the washing machine when the daily solar peak power (as estimated by a web service for my location) is reached. Of course, I have to prepare everything in the morning. On sunny or even just bright days, no grid power is used.

No, not out of the box. They don't really support any automation, you can build something using Home Assistant or If This Then That, but now we're already past what I care to manage. There isn't even HomeKit integration (which I noticed is a trend, Google Home will be supported, but not HomeKit).

At some point I discovered that the dishwasher I own has wifi.

I will absolutely never enable it.

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