Thank you very much, @Mutt for your Details explanation
Maybe ¯_(ヅ)_/¯
But I’m not realy interested in what’s recommend. I’m just using what feels best for me and my wife.
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Smart homes can save money. In most cases any savings would be negligible. To see a significant cost savings you would have to replace literally everything dumb with something smart and then think about renewable energy on top of that. Then there’s the question of return on investment. If you save 100 per month which is an extremely aggressive amount you are looking at 5 to 10 years or more just to reach the break even point on the premium between smart and dumb products.
Imo a smarthome is about convenience and nothing more. Anyone who puts cost savings as top priority probably needs to realign their expectations.
I would agree that 23% of my gas bill would not even buy the temperature sensor. (see below)
But as you say it’s about convenience, interest, problem solving and achievement.
Any savings will be year on year and I’ll try anything to reduce my carbon footprint
Edit Actually, I calculated that saving 23% of my gas bill would pay for at least three z-wave temperature sensors.
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I guess somehow one has to balance the time invested vs. the money saved. Since, in western cultures time=money … one must balance the two.
I’ll talk about my own experience.
- The kids (and the wife) know how to turn lights on, but not off … so, I installed some smart dimmers and motion sensors throughout, to turn lights off when there is no-one around. I also switched to all LED lighting to reduce consumption even more.
- I installed a Sense energy monitor, to better understand the biggest energy hogs at home. My always on consumption hovers around 500W … whereas some other people in the Sense forum are at 80 W … They put many of us to shame.
- Installed a Flume water meter, to monitor how long and how often the kids take showers. Though, with this Covid confinement it’s a bit of a mixed bag. The kids take fewer showers, but they do use more water at home … go figure.
- Smart thermostats - They were very useful in the past, as heating/cooling would turn off when no one was at home. Now that the home is occupied 24/7 (thanks to Covid again), we spend more $$$ on heating/cooling the house.
There are many other examples, but I think to save energy, one must start by monitoring usage first.
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The energy saving argument is good for commercial and to sell devices, not for real saving energy.
In my mind it depends on a lot of factors if you can save energy or not. This needs research by monitor the usage and consumption, but also on physical aspects.
I have done a lot of research to the power consumption of our elictric devices. It turns out the 30 year old washer Is way more energy saving when it uses the warm water from the central heater. Offcorse this costs more energy for the heater, but this could be more efficent depending on the heater and usage.
And the biggest consumer, no one ever talk about in this discoussion about it, is the stove where you cook every day. I can not rember the exact number, but it was around 400-600 kWh/year. Where our whole consumption was ~2500kWh.
Note: One easy way to save energy while you cooking is to use a pressure cooker.
The lights are in most cases are not the big consumer if they are LEDs. But there is potential to save energy by reducing brightness and on time
One other big consumer is the heating system, with an oil powerd heater. In action it needs 400 W and is running 20-40 minutes per hour. Most of this consumption came from the pumps.
It seems to be possible reducing the heater on time by using a buffer, while oil heaters only know full power. So this means it provides often more heat energy as needed, which means this energy get lost.
And more energy can be saved by replacing the pumps with new one.
Hold Temperature or reducing it?
Not that easy question. But keep in mind heating up water from 19 to 20° costs 4 time the energy as to hold it for 1 hour.
So the best energy saving strategy is to avoid fast changes in temperature and big temperature difference from inside to outside or in heating circulation system.
As lower the difference as lower the loss.
And at this point smart home can save a lot of energy, while you can use forceast to power down your heater/radiator earlier. Reduce the room temperature while be away for a longer time period or to avoid a large difference between inside and outside.
In case of electricity, the answer is not really. As the main consumption comes from devices like fridge, washer, dishwasher, heating system and stove. They are mostly already optimized.
If you have a lot of media devices they are always in standby there is a bit potential to lower energy usage, by cutting them off if not in use. But since there is a law that says standby devices do not have more than 1W in standby, this makes less sense. All actuators i have seen takes around 0.5-1W standby.
Save energy? Probably not. For me over the past 7 months using HA it’s all been about distracting myself. Learning a little soldering and coding. Removing your devices from the cloud. Waiting on the postman bringing little packages. Constant updating. Breaking changes and how great it feels when you get it working again. Not forgetting checking the forum multiple times a day. 
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Recently I have changed my windows and I opted for those who let the sun heat get inside. We have cold winter and hot summer. In winters, the sun heat our house several degrees, and in summers, we have automated ouside blinds that open/close depending on sun incidence to perform a shadow and prevent sun heat to go through windows.
For me, that’s the perfect example of a smart home that saves energy.
Also, if we talk about the money that cost energy, we need to take in mind that, at least in my country, we have different range of prices, one for daylight (more expensive) and one for night (cheaper). So if you run the electrical hot water heater on night hours you will save a lot.
Besides, we also pay more in the bill depending on the power capacity provided (have 3kw/h max power contracted is not the same as 6kw/h, you will pay way more). So we have a low power contracted and with automated switches you can intercalate appliances.
Other minor thing is that we have warnings to inform us when outside temperature is better than inside or close, so we can decide which time is better to open windows or so.
I think the biggest advantage of smart homes is awareness and data. This both combined provides you the option of the future usage, the savior can be in terms of comfort, time, money, etc. The problem I see is the standards, instead of collbrating, each manf comes up with their own implementation. I am not just talking about implementation as an HA or Philips Hue,etc, it is about storage of the data as well. We need to define a proper way to define the data so that future technologies can use them appropriately. The technologies will continue to chnage and hence expecting that 1 standard will apply throughout is a big ask, but data can be simple, secure and should be reused.
Hopefully the recently formed Amazon/Apple/Google/Zigbee alliance can come up with ‘communication standards’ that make integration and cross-communication much easier than it is today … It’ll take a while, but would love to see ‘Plug-n-Play’ devices and an ‘easy-to-use’ programming language to have them talk to one-another. A very long shot yes, but very desirable for sure.
[Probably should start a new thread on this if we want others to chime in…]
I hope this works out. My biggest issues right now are:
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The full name is Project Connected Home over IP (emphasis mine.) What does this mean for Zigbee? Why would the Zigbee alliance want in on this?
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The project aims to make it easier for device manufacturers to build devices that are compatible with smart home and voice services such as Amazon’s Alexa, Apple’s Siri, Google’s Assistant, and others.
Historically, the way manufacturers accomplish this has been to require the device to connect to their own proprietary cloud servers, and offer an API for integration to things like Alexa, Siri, Google Assistant, etc. This is by far the “easiest” way for device manufacturers.
That would be a non-starter for me. This is why I’m moving away from all the different IP-based devices with all their non-standard integrations. I do hope Zigbee doesn’t go that way.
I think home automation has potential to save energy but it comes at upfront costs in money or time. The potential for savings will depend upon the variables in each users home. We priced out an on demand water heater with smart controls that would let you schedule a preheat cycle. If you take morning showers you can set a schedule so the internal heating element is prepped and ready to go. Thus wasting a few less gallons of water. The upfront cost was around $7500 USD though.
Creative savings that take a time investment for me would be something like an outdoor weather station and taking the time to code something that calculates my indoor “real feel” temp. With an attic fan I could have the automation tell me when I could potentially open windows and kick the fan on over using the AC.
Summers where I live are HOT and humid. Using the stove or the dishwasher can make the kitchen very uncomfortable. Maybe I can rig something up to the exhaust hood to auto kick on to help combat these conditions and save a cycle on the more expensive to run AC. It drives me crazy to see the dishwasher pumping humidity into the house when that is the ONE thing I spend money on to remove in the summer.
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There is already a topic about CHIP on the forum.
One of the things I have found is that the ability to instrument my house and understand how it works, how air flows around it, where it gets hot, where it gets cold and when (cold climate and south windows create crazy temp gradients). I’m not sure it’s saved me energy per se, but it helps me make it more comfortable and has given me ideas for things to automate that will increase efficiency.
Isn’t Project CHIP just a glorified ‘Thread’? Lets the specs come out and we shall. OpenThread is already a great solution and all the existing chip manf have the chip that already support thread, have been supporting from couple of year atleast!
The one ‘concern’ about these mega projects is ultimately, the ‘big’ players find a way to collaborate, so they all can turn mega profits at the expense of the End-User … Why should there be inner-fights, when we can all agree on sharing such enormous pie ?
Well, especially since we now often do “Home-Office”, the fact that I have “smart-home” helps on my energy cost.
In 2019 when my wife sometimes had to do “Home-office” for a day or 2 she would just turn the heater on in the guest bedroom where we have a spare desk, work there, and later go back to the normal office. But then I later find the office has been at 23 degrees constantly.
Now with my smart home, I have it scheduled. Heater goes on in the morning and off in the after noon.
“But that is not really a smarthome, that is just thermostat with a timer.”
Yes, it is, but since it is now connected to HA, I seem to adjust/disable the “timer” whenever her “home-office” days change.
When we are visiting familly and don’t know when we will be home, we usually left the house reasonably warm. Now, we don’t!
When we left the house, and I forgot to turn the heaters off, I do it in my phone.
And later when we are on our way home I turn the heater back on.
But I also make my home smarter by beeing sneaky.
Whenever my wife gets home it will turn the thermostat to 23 degrees, nice warm and comfy for her. BUT, I also made sure the thermostat goes back to 21,5 half an hour later.
She experienced the house was nice and warm before, and she could check that thermostat was at 23. And then when it later slowely cools down, she seems to not be cold anyway. So my smart/sneaky home made it possible to have a lower heating cost, while my wife feels like it is warmer. 
Energy saving on lights is virtually none. It does not consume much. And I noticed that replacing normal lights with smart lights will just cost more on the lights, and the energy used all day long in “OFF” mode is still plenty.
The biggest cost saver (no energy saver), is probably if you can make it really smart in combination with hourly electricity prices.
Like heating you house in the morning BEFORE the price shoots up, charging you car not when you come home, but later during the night when the prices have dropped enough. Heating your water-boiler to max when the prices are low.
Or something like opening the blinds in the winter during daytime on a suny day. Or closing the blinds in the summer if the forecast is a hot day, to reduce the need of the Airco when you come home.
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This has been touched on before, and I know there are folks with powered blinds out there. But I really think a big-picture approach to indoor environment could be a huge cost saver.
I live in a temperate zone, so we have days in the spring, summer and fall when I can open or close windows and blinds at just the right times to keep the house comfortable all day or all night, without heat or air conditioning. But I’m not always home, or I may not wake up early, or stay up late, enough to catch when the temperature outside passes the temperature inside, so I can’t always take advantage of it. Some automation there would be helpful.
It would be a huge project to retro-fit an existing home. But if outside air intakes in the HVAC system, and powered windows and blinds, were designed in, I bet I could cut my heating and cooling bills dramatically. And there would be the benefit of more fresh outside air.
It seems to me like close to 70% of my electricity wintertime here in Norway is heating only. When it’s cold we often have periods of substantially higher electricity cost. There are also sometimes extreme changes during the day following a regular pattern. Thermostats are based on defined conditions lowered on a scale from normal to saving-minimum-temp defined per area/oven. Examples: cost % change from daytime average cost, boost temp up if substantially more expensive coming hours, time since last heating period etc. I manage to move the heating to times of day when the cost is lower, and that is the by far the biggest money saver. No, I don’t use a lot less energy. But I pay a noticeably amount less due to timing. (We have cost per hour for the next 48hours available through HA integration.) It’s definitely possible to save money if hourly rates are at play.
Hey!
The smart valve actuators are actually all pretty bad, if you don’t combine them with an external temperature sensor.
I have also included a heatsource detection for the kitchen where it detects instantly that the stove is running by measuring the current from the exhaust hood etc. same goes for windows.
The programming did take a while, since the actuators tend to underestimate how much energy the radiator stores, so the temperature swings 2-3 degrees up and down over 24 hours.
So I’ve added some raising temperature shutoffs and closes the valve when it’s too wide open for a longer period (and the temperature doesn’t demand it).
Works perfectly for me.
Regarding the batteries, just solder a 2 bucks 3V1A power supply to the contacts on the PCB.
Here’s my automation:
It’s always difficult to say.
If I see how much stuff I installed in my house, I think this cost a lot of grey energy to produce.
But besides that, I definitelly can say that I save energy.
Since I have a power meter for monitoring the energy consumption of our house I’ve optimized various things (dehumidifies settings, room temperature during winter and so on).
And since I’ve built my DIY water meter I’ve noticed that my water spray cat repellent was triggered by the cover of our lunge an sometimes was spraying all night long (50-100l per night). And if you see that you’re using 200 liters of water for showering, next time you’ll shower a bit more consciously
Also if you’re using 500 liters for watering your garden. I’m now collecting rainwater and since last July I never used fresh water for watering anymore (of course this depends also on the weather, if it doesnt rain for 3-4 weeks, then I wouldn’t have big enough water tanks for such a period).
So I’d say creating awarness has in my case maybe the bigger effect than the savings because of automatisations. I never calculcated it properly, but it’s roundabout 10-20% energy and even a bit more water that I’m saving since I’m monitoring it.