ottopaulsen
commented
2 years ago It is an interesting feature idea, but it is pretty demanding to find the best pattern with such additional config, and I am currently not planning to make such a change.
However, I have some other changes in mind that may be used in stead, but it is a little too early to say. I will keep this as an idea anyway, so let's see in some time.
Anyway, I am wondering if not the Best Save strategy actually would give you better savings. As long as it is fully heated in one hour, It might utilize the lowest price points better than lowest price node does in this case. For example, it would turn on at the lowest price point around 14:00, and also at 23:00 the last day. Assuming that the total energy used is the same in any case, and as you want max 8 hours off, maybe Best Save is better.
You could try to make a calculation by for example spreading the consumption evenly over two days, and assuming everything is paid for the first hour after every off-period. What would it cost if you use Lowest Price like this plus a few cheap hours in between making not more than 8 hours off, and compare to what the Best Save would do.
marhoy
First of all, thanks for a great plugin! I think its is brilliant, and it works very well with Node Red/Home Assistant.
I currently use the “Lowest price” node with 8 hours on for my water heater, as consumption history over the past year shows that it typically is on 4-6 hours every day (to have some buffer I use [Hours on =8 ]). This works great, and I see that the schedule selects the 8 hours in every 24 hour period with the lowest price.
However I am aware of the risk of legionella if the temperature drops too much for a longer period of time, so ideally I would like it to stay off for no more than 8 hours. See below image showing the schedule for today&tomorrow. Using [Hours On =8], it turned off this morning at 08:00 AM and will first go on tomorow at 12:00 PM. This is 28 hours, which I believe is a bit too long.
Statistcs show that after the off-period (from Lowest Price node) the water heater is never on for more than 1 hour. This sounds like an ideal case for the “Best save” node; with [Max per sequence = 8] , and [Min recover = 1] . But using such setup, it seems the total hours on during a day is too short – with the above settings I can get as little as 3 hours on during a day.
Would it be possible to include a [Max per sequence] parameter for the Lowest price node as well? It probably should be optional and include some logic or warning if the user tried to configure it in an “impossible” way (e.g. [Hours on = 3] and [Max per sequence=5]), but I think it can be useful for water heaters to avoid too long periods being off.
Edit: This could probably also be achieved implementing a [Max off in a day] for the "best save" node. The idea was to have the ability to control both maximum hours on and longest periods off.