I need to know if there is a power cut in a building. I have to detect this remotely, because I am usually not present at the building. I need to detect the power outage in less than 24 hours to save the foods in the fridge! The process could be either automatic or manual. I am looking for a creative way to do that which is not that expensive. I am specifically looking for solutions based on using phone calls or internet-connected devices to detect power outage.
There are all kinds of complex systems that can be set up to handle this. The key question is connectivity.
Landline + Answering Machine
This is probably the simplest and cheapest way, provided you already have a landline in that building. You do have to make sure that any phone company voice mail is off so that if the answering machine is not able to answer you get ringing instead of voice mail that is (essentially) a virtual answering machine. If the answering machine does not answer then one or more of the following have happened:
- Power is out
- Answering machine is full - not likely if the phone number is not used for regular business, plus many answering machines can be set to answer with a "Machine is full" message
- Phone line is out
Fortunately, generally speaking, phone lines are more reliable than electricity. The odds of "phone line dead" without "power out" is relatively low.
* Note that a newer phone line that uses fiber (e.g., Verizon FIOS) will work just fine here. If the power goes out and kills the phone line as well as the answering machine, the effect (desired) of "ring but no answer" will be the same.
Internet Based - Heartbeat
If you already have an internet connection then this is also relatively easy. You need a computer - which could be anything from a Raspberry Pi to a full PC - and you program it to send a heartbeat message every hour. That can be an email or update a web site or many other things. If you don't see the heartbeat then:
- Power is out
- Computer is dead
- Internet is out
How effective this will be depends on internet connection reliability.
Internet Based - Remote Check-in
Again, an internet connection is required. Instead of programming a computer to notify you, you check in on the computer. This could be:
- Internet Camera - This has the advantage that you can use this for additional security purposes, if needed.
- Web Server - Program a computer to act as a web server and check the web site. Gets a little complicated as you may have to deal with dynamic IP addresses, firewall settings, etc.
- Router Access - If your router lets you do remote administration then this is a zero-cost (beyond the internet connection and router) solution as you don't have to actually connect any camera or computer or other device.
maybe I could have a landline phone plugged in, and then I could call the number everyday to see if that rings.
A landline phone will ring (from the callers perspective) regardless of if it's even connected to the building, and will work if it is connected to the building but power is out (landline phones have their own power.) And unless paying for a landline is a given, they are "not inexpensive" to have. Low-end (particularly data-only, usually) cell service costs less, if cell service is available to the location. You could add a line-powered answering machine or computer attached to a modem (how antique!) and see if that picks up, or not.
There are a number of options, variously "creative" but likely the most straightforward (and "broader than just power out") would be a bog-standard security/fire alarm system, which will raise an alert when power is cut, and has other potential benefits given:
because I am usually not present at the building.
One with cellular notification to a central monitoring service is typically on a par with, or slightly less than paying for a landline phone, last I looked, and may save some (or quite a bit of) money on insurance. You can also configure them to call or otherwise notify you, depending what utilities you normally have at the building (internet, landline, or give it a cell link if you don't have a landline and can get service there.) But you generally don't get much of an insurance savings unless it's centrally monitored.
Landline phones usually are on their own power.
Think what you would need is a wifi power monitor that will phone/notify you when power goes out.
Something like this, first one I found, no recommendation of any.
Many electric companies provide web meter reading.
So, you could check that the meter reading is increasing - some allow 30 minute updating while others can do 2 or 3 minutes.
You may find that the website for your account can send you data (or you scrape...) at specific intervals. Fridges not opened can survive for a couple of hours which gives you a window of time to work with.
A cheap/old android mobile phone can be set up using some tasking software like macrodroid to send a message (email, sms) upon connect/disconnect of a charger.
I fairly confident that when you leave it plugged in, a powerloss will also trigger that event.
Depending on where you are this could be fairly cheap when using a pre-paid sim card.
Here's a cell-phone based suggestion, using an old Android phone, plugged in to a charger, and with a SIM card.
Use the app Tasker with the MyPower plugin which can detect if the phone is charging. Then use a Tasker action to send you an SMS if the power goes out.
In a little more detail, Tasker would run a timing loop to test the power status every minute (for example). The SMS text could be crafted to tell you when the power went off, and another SMS could tell you when it went back on. I'd also set it up to send me a daily "system OK" message.
If you prefer email, that's also possible, but requires a data plan or WiFi; if you've got WiFi avilable, you wouldn't need a SIM card, but the "OK" message would need to be more frequent as the WiFi will go down with the power so the lack of a message becomes the message.
Tasker can talk to apps like FolderSync, which can do FTP, but I've never made that work reliably; if you could get that working it could FTP a simple html file to a webserver under your control either via the phone network or WiFi, then you could query that file at your convenience.
You might have all the necessary kit already to allow you to use a "website monitoring" service, normally intended for businesses to keep an eye on their infrastructure, to check whether your "website" is up. All you need to do is make a "website":
- If your ISP gives you a static IP address, skip the next point. Static IPs are rare because we're short on availability of them, but some people do have them
- If your internet router supports a dynamic DNS service, enable it.
- This will allow you to pick a fixed hostname, something like
BFaleysHouse.DynDns.organd your router will update the hostname's IP address if the IP changes.
- This will allow you to pick a fixed hostname, something like
Then you need to make something the montioring service can reach and check if it's running:
- Configure your router to respond to pings, or
- Enable access to its admin interface from the internet and set a strong password, or
- Find/create another device inside your home network that has some network service on it like an ftp server or web server and create a port forwarding from your router to that device
- This is easier than it sounds; you might even have a smart fridge that has a mini web serve already! Loads of devices have some kind of network accessible control panel website, including printers, scanners, even TVs; all you want is something that will respond in some way (and the website built into the router for admin is ideal)
Finally, use a service like UptimeRobot that will email you whenever it sees your "website" (i.e. your router, or other internal device you;ve forwarded to) stop responding to pings/not give a response to the monitoring company's checks
UptimeRobot and similar services can "ping" the hostname you give; if you've enabled ping responding on your router (and your ISP doesn't block it) then it's a really quick and easy way to check if the router is on. If you havent got the option to enable ping and have instead arranged for a website to run on your router, or inside your network and the router forwards conenctions to the inside, then you tell UptimeRobot the address of the website, and perhaps a keyword to expect when it checks. This means there could be 3 kinds of response to a check:
- The website responds with the usual page (welcome page, whatever) and it does contain the check-word: all is good
- The website responds with an error or some other page that doesn't contain the check-word: you're probably still good
- The website doesn't respond at all: you're either looking at a power cut, or a failure of the ISP network somewhere, so you might need to check on the fridge, call a neighbor etc
As you might detect; it's not foolproof - more can go wrong than just a powercut, that clobbers your monitoring but if your ISP is reliable then it's a reasonable bet that your power is out. If it's vital, I'd certainly recommend to combine it with another method of checking - that could be as simple as a dumb cellphone powered off an ac adaptor rather than a battery. No power, no phone on, can't call it..
..but the main thing about using these uptime monitoring services is that it's all automatic, nothing you need to do other than wait for them to email/SMS you
I have no affiliation with UptimeRobot
That might be related to the intruder alarm you have (my guess is you have one if you are mostly away as you stated). Many of the modern one have the ability to call or text or send an email to pre-defined number. Decent CCTV recorders also have an input other than their camera's signals. But I do not think your CCTV system is powered up with any UPS. What I think and it is a must is an changeover relay married to your distribution board and dropping contacts on power loss. Then 2-wire it to, depending on your intruder/cctv config, one of your security devices. Fail safe config will provide clear status (C and N/C, common and normaly closed). In case of loosing power it drops the contacts making a circuit C-N/C and because alarm systems are in fact battery powered it triggers it to send you an alarm.