Energy management systems and control of washing machine, dryer, and property

Evening :) I believe this is my first post in the forum :)

I have been automating my entire house myself for years – lots of tinkering, nothing off the shelf. Photovoltaic system, heat pump – none of that (yet) installed – however: we will demolish the current house and build a new one. That's why I'm searching for information and also thinking things through myself.

On the topic:
I currently have a power contract with Tibber and a main meter from Discovergy. With a bit of programming, you can get data from both (current hourly electricity price and the electricity price for the next day from 2 pm onwards). Since Tibber charges by the hour and the electricity price can vary quite a bit during off-peak times(!), I wrote a small tool that basically shows me the best times for our lifestyle to use the washing machine/dryer. This means that sometimes you don't start the washing machine immediately when it's full but 2-3 hours later. These are certainly just cents, but it's quite easy to incorporate into the daily routine. There are days when you have 18 cents per kWh for hours, basically just grid fees etc., and then, for example, from noon onward it goes up to 40 or 50 cents.


As an example: Price for tomorrow (30.1.21) – around 18 cents including charges until 3 pm. After that approx. 37 cents.
Would I turn on the dishwasher earlier because of that? No
But would I like to have my laundry done before 3 pm? Hell yeah!

For the new build, I am considering something else: the photovoltaic system should also get a storage battery. In winter, it's basically dead capital. High consumption due to the heat pump – low yield.

My idea: to charge the battery at night (usually cheaper, but also sometimes a few hours during the day) with "cheap electricity" and basically take advantage of the low prices during the day. Since I can 1. somewhat predict the electricity price in advance (maximum one day) and 2. at least approximately find out the weather forecast automatically, it should actually make sense. This way, I can save myself “smart” end devices.

Whereby you have to add about 20% charge/discharge losses when using batteries (it's really that much). As long as electricity prices fluctuate by more than this amount, there might be something to gain. Is it really the case that spot prices are that much cheaper at night?

What do you want to build? We have a total electricity consumption of about 4,200 kWh/year and even without automation 70% self-sufficiency, i.e. only about 1,200 kWh/year grid consumption. What else do you want to optimize there? Sure, hobby is hobby.

When using batteries, you have to add about 20% charging/discharging losses (it's actually that much). If electricity prices fluctuate by more than this amount, there might be something to gain. Is it really true that spot prices are so much cheaper at night?

I understand the losses. That’s why I wrote: At least in winter, the battery is dead capital.

In my screenshot, you can see what can happen from 18 to 37 cents, that’s 100% more. So I would charge the battery fully by 3 p.m. as long as no solar yield is forecast. And yes, these fluctuations exist! Not every day, but quite often.

What do you want to build? We have a total electricity consumption of about 4,200 kWh/a and even without automation 70% self-sufficiency, i.e. only about 1,200 kWh/a grid feed-in. What else do you want to optimize? Of course, hobby is hobby.

I only have appointments for more detailed considerations/calculations with a specialist in two weeks.

So what you’re writing here sounds all great, but I still miss the connection to reality. We usually turn on the dishwasher in the evening because it’s full then. Sometimes there are things in there that need to be clean by the next morning. By the way, that’s how many families I know do it. The alternative would be to run it at noon and all the things I want to use in the morning have to be washed by hand. Great progress and certainly exactly what I want :rolleyes:

With the washing machine, is there only one load a day or what? That doesn’t make much sense with 4-5 people and isn’t really realistic either.

Automation is fine and all, but there are things you prefer to keep under your own control because otherwise it’s just way more complicated. In my opinion, automation will never prevail in such cases. At least not with the currently available household appliances.

For your world, you’re doing everything right...finest worrywart...

The train has long since left the station and is constantly gaining more and more speed.

Do you have concrete examples from everyday life? Not futuristic ideas, but something that already works now with reasonable effort? We are still talking about household appliances here and not, for example, control of lighting, heating, or ventilation systems.

No, the alternative is: You use it normally as usual AND if you want to save something, you can also fill it in the morning and leave. The dishwasher then does the rest itself. explained that exactly right.

What exactly do I save if I have to invest a lot of money and time upfront into automation?

At work (an IT company) I am constantly forced to find processes that can be automated. But of course only those processes are selected where a benefit can be seen in the foreseeable future. And I don’t see that benefit in the examples in this thread either. You haven’t been able to name it so far either but have always remained very general. Automation is your hobby, not mine. I am an ordinary user. And therefore I also have to have a benefit. Automation must either save time or money or things must be simplified or improved. But in any case, the ratio has to be right.

For your world, you are doing everything right... worrywarts of the finest kind...

Sorry, but that is nonsense. Every kind of automation costs money and must have a benefit, and that also for those who have not discovered it as a hobby for themselves. Otherwise, it simply doesn't make sense for the majority of households and won't be used.

To stay with household appliances: With the dishwasher, you can adapt and save money as a result. But how is that supposed to work with laundry? We in our four-person household cannot manage to have a load of somewhat similar laundry almost every day. However, to use such a function sensibly, this would have to be the case. Otherwise, I (and certainly many others as well) would not be willing to spend money on it.