Thread for discussing money saved with OpenHAB

6

They do offer a weather station but it’s a little pricey. I think it lacks a rain bucket too so it can tell you that it’s raining but not how much fell, and it’s the later that matters when it comes to deciding whether watering is needed or not.

There are challenges with using soil moisture meters in the lawn though. Mowing, tripping, dogs digging things up all become a hazard to the sensor. Power and communications is a bit of a challenge to. I think that’s probably why they don’t do it. Just using the weather and rain sensors is probably close enough for most purposes. Anything more is diminishing returns, at least i most parts of the world where when it rains it rains everwhere. Where I am an area less than half a mile in diameter could see a half inch of rain and just a hundred feet outside that area receive none at all.

Gardening is challenging to say the least.

7

I achieved even higher savings in March, as the local electricity company was then selling energy at 16c/kWh:

1-31.3.2023

Consumption: 1201,96 kWh
Average spot price paid: 7,26 c/kWh
Energy bill total: 90,81€ including tax and 0,22c/kWh margin

At the same time our local energy company was providing one of the cheapest fixed energy prices in the country at 16 c/kWh. 1201,96 kWh x 0,16€/kWh = 192,31€

Total savings in March 101,5 €.

Total savings since I got the spot price control of the heat pump working at end of feb is around 150€. I paid around 60-70 € for the Orangepi 3LTS board and wifi relay that I connected to the heat pump aux.

What do I do with all this saved money? :wink:

8

I’m a Tibber Pulse customer in Germany. Without Pulse, I would be billed according to the dynamized Standard Load Profile (SLP) H0 published by Standardlastprofile Strom | BDEW.

Saving money by shifting usage of white goods into cheap hours:

grafik

Starting the dishwasher tomorrow(+) at 13:01 will save 0.22 cents (compared to highest price) - for details see Optimizing energy costs (washing machines, tumblers, dishwashers, ...).

A difficult question to answer is whether it makes sense to use the Pulse when there are no electric vehicles and/or photovoltaic systems involved.

I use KNIME Analytics Platform to compare the cost based on the SLP to the actual cost based on consumption measured (and billed) by my Pulse. Example for May 2023:

SLP calculated (one bar corresponds to one hour):

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grafik1829×927 25 KB

Consumption (arbitrary units):

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Comparison billed vs. billed without Pulse:

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grafik1816×927 24.6 KB

If there is any interest in such “what if” analyses, I could write a tutorial on how to integrate the KNIME output into openHAB.

BTW, here are my final results for April 2023:

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So the preliminary answer for May 2023 and the definite answer for April 2023 is: yes, using Pulse makes sense and did save 4,01 EUR (compared to SLP) in April 2023 …

1 Like
9

Buy more stuff to plug into openHAB? :wink:

3 Likes
10

Here is the heating plan for today calculated by the OpenHAB scripts based upon outdoor temperature and wind forecast, incoming solar radiation forecast and day ahead electricity spot prices. Yellow bar is the planned heating time by OpenHAB, blue area is electricity price during the day. Money saved.

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1 Like
11

Here’s the output of my openHAB based Energy Management System for my own home month-to-date.
I run a heat pump on Tibber using the algorithm we discussed in the other thread.

‘Kosten ohne EMS’: cost without openHAB
‘Kosten ohne PV’: cost with EMS but without solar plant (i.e. EMS operating heat pump using Tibber)
‘Deine Rechnung’: total bill of my EMS operating household appliances on solar power and dynamic tariff combined with heat pump, factoring in grid feed compensation

savings2
savings21920×1027 96.8 KB

1 Like
12

TBH my big money savers derive from the fact that my house is “thermal friendly” (good walls and windows) and I have 11 months of non-cloudy weather per year, which allows me to make good use of solar panels (to produce electricity and hot water). But OH helps a lot in optimizing:

  1. Automatic temperature control of my heating: I have sensors to measure outside temperature and set temperature targets for heating (air conditioner and pellet stove). Reduces both electricity and pellets bill
  2. heating is controlled by zone using PIR sensors and calendar
  3. My solar panel to heat water comes with an electric resistence. Originally it switched on every night during winter. Now, with OH and a temperature sensor, it only switches on when needed, and only during the time required to achieve target temperature (dinamically calculated by number of people at home)
  4. garden watering: using moisture and rain sensors I keep my water consumption to the minimum

I estimate OH monthly savings ~20€ (5x cold months), and ~5€ in warm months.

3 Likes
13

Tonight the electricity price is negative here in Finland in the night and near zero during the day.

It’s crazy. It’s party!

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14

Is that including transmission cost ?
Net negative cost is not all that uncommon, in Germany I’m seeing it at least once a month.
But with ~16ct for anything beyond pure kWh i.e. transmission, taxes etc that’s still no reason to party :unamused:

15

Now that’s interesting, I think/hope. So far I’m optimizing by demand air ventilation (on humidity, CO2, VOC and presence) because that causes my biggest losses. But I’ve noticed the incoming solar radiation has a influence on heating. Of course the heatpump will respond to that but I’ve been thinking about anticipating. If I know a sunny day is coming, I could heat a bit less the night before.

So I’m curious how your script takes this factor into it’s calculations!

16

If I understood your question correct, yes my script corrects the heating plan for tomorrow based upon the solar energy forecast for tomorrow. It does that by reducing the number of hours my heating stays on.

17

The price is excluding transmission, which is 9€/month plus 3c/kWh.
Negative electricity price is not very common in our market.

18

My biggest saving came from being able to control a pool pump.

Originally it ran 24x7 (0.9kwh)
As it is a 15amp, the easiest solution was Aeotec 40amp inline + Z-wave dongle

which is what got me into Automation and thus openHAB

So for an outlay of;

  • Raspberry Pi 3b (now 4)
  • Aeotec inline plug
  • Z-Wave dongle

say NZD$500 I pretty much saved that in the first 2x months of operation.

Now 6 years in …

5 Likes
19

You did. I was interested in the how, but I found code (using a webservice) in the other (huge :innocent:) topic And some more, using the AUX on the NIBE heatpump to control on/of of heating and the remark that there’s profit in spring/autumn when heating and cooling may occur on the same day. I’ve also noticed that and my simple solution for now is manually disable heating at a certain day. So new ideas for the future, thanx!

1 Like
20 
Börsenstrompreise am 21.05.2023


 0:00 | + |   6,21 Ct/kWh | ########
 1:00 | + |   4,76 Ct/kWh | #######
 2:00 | o |   4,03 Ct/kWh | ######
 3:00 | o |   3,42 Ct/kWh | ######
 4:00 | o |   3,56 Ct/kWh | ######
 5:00 | o |   3,36 Ct/kWh | ######
 6:00 | o |   3,66 Ct/kWh | ######
 7:00 | o |   3,28 Ct/kWh | ######
 8:00 | o |   2,38 Ct/kWh | #####
 9:00 | - |   0,25 Ct/kWh | ####
10:00 | - |   0,00 Ct/kWh | ####
11:00 | - |  -0,06 Ct/kWh | ####
12:00 | - |  -0,94 Ct/kWh | ###
13:00 | - |  -2,98 Ct/kWh | ##
14:00 | - |  -4,92 Ct/kWh | 
15:00 | - |  -2,33 Ct/kWh | ##
16:00 | - |  -0,05 Ct/kWh | ####
17:00 | o |   0,26 Ct/kWh | ####
18:00 | + |   4,92 Ct/kWh | #######
19:00 | + |  10,17 Ct/kWh | ##########
20:00 | + |  10,81 Ct/kWh | ##########
21:00 | + |  10,83 Ct/kWh | ##########+
22:00 | + |  10,70 Ct/kWh | ##########
23:00 | + |   9,94 Ct/kWh | ##########


Bruttopreise. Inklusive Mehrwertsteuer (MwSt.).

Börsenstrompreise am 28.05.2023


 0:00 | + |  10,36 Ct/kWh | ##########+
 1:00 | + |  10,00 Ct/kWh | ##########
 2:00 | + |   9,75 Ct/kWh | ##########
 3:00 | + |   9,27 Ct/kWh | ##########
 4:00 | + |   9,27 Ct/kWh | ##########
 5:00 | + |   9,10 Ct/kWh | ##########
 6:00 | o |   8,57 Ct/kWh | ##########
 7:00 | o |   7,72 Ct/kWh | #########
 8:00 | o |   4,49 Ct/kWh | ########
 9:00 | o |   0,00 Ct/kWh | ######
10:00 | - |  -0,37 Ct/kWh | ######
11:00 | - |  -2,15 Ct/kWh | ######
12:00 | - |  -5,80 Ct/kWh | ####
13:00 | - | -15,46 Ct/kWh | 
14:00 | - | -15,47 Ct/kWh | 
15:00 | - | -11,67 Ct/kWh | ##
16:00 | - |  -2,22 Ct/kWh | ######
17:00 | - |  -0,01 Ct/kWh | ######
18:00 | o |   5,95 Ct/kWh | #########
19:00 | o |   8,68 Ct/kWh | ##########
20:00 | + |   9,52 Ct/kWh | ##########
21:00 | + |   9,26 Ct/kWh | ##########
22:00 | o |   8,78 Ct/kWh | ##########
23:00 | o |   8,27 Ct/kWh | ##########
```
1 Like
21

NL: 2023-05-21 12-13 CEST: -7.6 ct/kWh (plus - AFAIK - 21% VAT; source: epexspot)

1 Like
22

(!)

23

NL: 2023-05-28 14-15 CEST: -40 ct/kWh (plus VAT, source: epexspot)

24

You already know the prices of tomorrow? :crazy_face:

I hope dynamic energy tariffs for pivate costumers will become more common in the future. So that someone without own pv system can profit from this.

I mean in germany we are talking about lots of founded pv systems, BEV and “intelligent” wallboxes, smart grid ready heat pumps and in many cases the potential fizzles out.
So I also hope load management in private households finds more popularity.

25

I’m not sure whether negative prices for energy are a good sign, but let’s not get into politics - BTT:

Tibber doesn’t seem to be able to handle negative prices for energy: neither the App nor the API have the prices for tomorrow. Prices for tomorrow were published by epexspot at 14:30 CEST …