cheap/simple device to measure actual power used by HVAC- building solar just to run AC
- Thread starter hertfordnc
- Start date
Im using 6 255 watt panels and a
Both basically serve the same purpose from what I can tell. The iotawatt is better if offline is a must and or having the data local only.
But just from a measuring standpoint the emporia is about 1/2 the price and can measure 16 circuits besides the mains where the iotawatt just does 10 circuits besides the mains though the unit shows 14 plugs on the box but claims 10 sensors come with it looking at the website.
Im not a brand fan but I would think for the average user the emporia would be the better choice at $165 vs $314 for the iotawatt.
Both basically serve the same purpose from what I can tell. The iotawatt is better if offline is a must and or having the data local only.
But just from a measuring standpoint the emporia is about 1/2 the price and can measure 16 circuits besides the mains where the iotawatt just does 10 circuits besides the mains though the unit shows 14 plugs on the box but claims 10 sensors come with it looking at the website.
labeeman
Solar Enthusiast
One word of caution about Vue or any product with cloud service for that matter, it is only a matter of time before the company (emporia) decides to move more and more features behind a firewall (other chinese manufacturers would just disconnect their cloud service making your investment a paperweight) - Remember philips vue and many other products
It was very easy for me to 'upgrade' the vue to esphome and have local monitoring with home assistant (sadly no native web interface for esphome/vue but it is coming)
Once it is integrated with home assistant, i can have full energy dashboard as well as forecast and ability to program loads (once I have smart circuit breakers or wifi controllable thermostats). Possibilities are endless
Iotawatt can do 12 circuits besides mains or 14 total , but he doesn't need to buy 14 sensors. He only needs one for each heat pump so he would save money.
I monitor a system where there isn't internet yet so the iotawatt made more sense and is also simpler to install. I believe the built in graphing also shows more data than the emporia.
For example, does emporia have a way to add math channels? Eg if you want to show total use minus monitored circuits?
chrisski
Solar Boondocker
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I want to build something similar to Level 2 charge a Tesla. I really doubt that what I’m asking for is cheap. For me the requirement would be a 6 kw load for two hours a day. The battery pack would be 15 kWh.
It would be hard to build that for less than $10k by myself, once all the real costs are figured in. This will get me around 40 miles a day of charging. One of the things keeping the cost high is the need to have UL rated equipment and permitting.
It would be hard to build that for less than $10k by myself, once all the real costs are figured in. This will get me around 40 miles a day of charging. One of the things keeping the cost high is the need to have UL rated equipment and permitting.
Installation is actually the same hardware wise. The two units look identical to me (I actually figured they were clones of each other at first glance) and the software is simpler on the emporia. As for seeing total use minus the monitored ones thats what the balance field shows if Im understanding what you mean.
Ampster
Renewable Energy Hobbyist
Are you trying to charge a Tesla with a 15kWh battery pack or are you trying to put 15kWhs into your Tesla? The cost difference would be significant.
chrisski
Solar Boondocker
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The 15 kWh battery pack would be needed since most of my charging will be done after panels would stop producing. Work requires me to be away from the house during the day.
I think what the OP wants is something similar Especially if the goal is to run HVAC both day and night in cloudy weather and at night. A battery pack can get pretty expensive for this.
If installed grid tied with no battery, for planning prior to a quote I would use $12k to $15k for the install prior to rebates.
Most ways I see this to reach the end goal are pretty expensive.
How are the analytics? Can you see min max average for a time frame? For example the last 30 mins?
Zapper77
Renaissance Man
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Iota Watt does, but you already know that.
I know the iotawatt does. I have one. I'm asking if you can do that with emporia vue- I don't think so
Ampster
Renewable Energy Hobbyist
I have an Emporia and the analystics are good. I can see data in graph form that allows me to see min and max. I don't recall if average is actually calculated over a thirty minute period but it can be inferred from the graph. Raw data can be exported and you can run any averages if you put it in a spreadsheet.
Iotawatt shows it with actual numbers for any time period you want, which I like. It can also export to csv.
It was a little more expensive but I liked the features out of the box a bit better than Vue.
How much data does Vue store? Does it store data even if not connected to internet?
Ampster
Renewable Energy Hobbyist
I don't think the Emporia stores any data for any length of time. It is all based on the cloud.
I thought so but wasn't sure. That was a another factor for me. The iotawatt will store up to 15 years worth of data that I can recall at any time, without the Internet
MrM1
I'm Here, But I'm Not All There
@hertfordnc I would consider a separate, smaller portion of your home be retrofitted with an AC/DC Mini Split (or splits) to cool critical rooms. These AC/DC mini splits can be operated in day light hours with NO AC line input at all. Just 3-6 solar panels direct. But can also be wired AC for night time use.
This is easier than trying to build a complete system that will run your existing AC unit off grid. and then any off-grid system you build does not have to be so large only powering lights fans and even refrigerators.
Benefits of an AC/DC direct solar Heat Pump solution
- smaller off grid set up
- can run on solar only
- can be used in tandem with existing AC, but on solar for lower power bills
- A combo small off grid system + AC/DC solar input mini spilt could be less than a large off grid system that powers existing AC
Just a thought.
This is easier than trying to build a complete system that will run your existing AC unit off grid. and then any off-grid system you build does not have to be so large only powering lights fans and even refrigerators.
Benefits of an AC/DC direct solar Heat Pump solution
- smaller off grid set up
- can run on solar only
- can be used in tandem with existing AC, but on solar for lower power bills
- A combo small off grid system + AC/DC solar input mini spilt could be less than a large off grid system that powers existing AC
Just a thought.
JWLV
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You mentioned that you wanted to do this because of Hurricane Isabel in 2003. Going solar to power a heat pump HVAC means you'll likely need many solar panels. If a strong enough hurricane knocked out power for 8 days in 2003, will your solar panels survive a hurricane like that? Solar panels are almost like sails on a boat.
Its cloud based which is why in the earlier post I did on this I said
"Im not a brand fan but I would think for the average user the emporia would be the better choice at $165 vs $314 for the iotawatt.
Both basically serve the same purpose from what I can tell. The iotawatt is better if offline is a must and or having the data local only."
The emporia will show you how much a circuit is using, has used, etc over a given period of time you select.
So again if you have internet and just want to know how much something is using power wise including load spikes (which the op asked for) and have internet for it to work with $165 beats $314.
If you want to go all offline and not have it sending data then the iotawatt is a good buy.
I have multiple homes and shops and being able to find what my stuff is doing with my phone or a pc from anywhere in the world is pretty handy to me which is why I like the cloud based method.
I originally wanted nothing to do with the cloud method but after having it vs the local method which is what the first unit I had did I prefer the cloud method now and Im pretty anti-cloud/net server for most stuff.
But as I said either will do what the op wants I just think the iotawatts price is overkill for what he said he wanted to do.
One thing the iotawatt shows which I appreciate is the power factor of a load. Does the Vue perchance show this?
From the data tables? No.
As for data thats stored in the cloud it hangs around like this :
1-second data available for 3 hours
1-minute data available for 7 days
15-minute data available for one year
1-hour, day and above available for lifetime of device
I downloaded the export from it just now to see what was in it just to see and its very detailed.
Personally for my usage it worthless to me since I get all the info I need from the web interface but its nice if I wanted it for some reason.
The 1 second data is only useful to me for seeing whats pulling what at that exact moment. Great for hunting down pesky phantom loads in the house. Either someone left something on or a grand kid forgot their charger somewhere
I never use the minute or hourly stuff personally.
The daily info is my "goal" for the day. Its also how I figure out what the months power bill is going to run.
The monthly one serves the same power bill usage too.
The live display set to by the second on the website is what I leave it one if Im monitoring whats actually going on.
I think this is what the original poster wanted.
This is a by the minute graph of one of my heat pumps. You can see where it surged to 1.53 when coming on.
Since the data is captured per circuit you can call up reports of what each one is doing or has done.
This is a by the minute graph of one of my heat pumps. You can see where it surged to 1.53 when coming on.
Since the data is captured per circuit you can call up reports of what each one is doing or has done.
JLBinTN
New Member
Panels and inverters are relatively inexpensive. Batteries per kWh are not. You'll spend a a large sum of money attempting to store enough power to operate an HVAC unit all night.
Personally, I'd start with enough panels and a sufficient inverter to operate during a mostly cloudy day, along with a a single 5kWh hour battery (enough to maintain power if PV drops below necessary level for a short period of time), and then just flip a transfer switch on the unit to run on grid at night. Additional batteries can always be added to the system later, and I suspect future batteries will get less expensive over time.
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