Wireless Water Metering Update
Since my last blog post, we have installed wireless water meters in three more houses in our community. A lot of water is getting wasted everyday. We have faulty flush tanks which keep leaking, float valves which fail to stop inflow into tanks, workers who forget to turn off taps and monkeys who have learnt to open taps and on occasions even broken the plumbing to cool off in this really hot summer. As I mentioned earlier, our community relies a lot on tanker water (around 50 tankers per day). Prices are only going to go up. Given all this, we decided to provide high resolution information on water consumption. Our four meters are sending water consumption data to the cloud once every 5 minutes.
You can see the consumption data from one of the meters in the figure below. You can see data for around 16 days from April 27 to May 11. The data is pretty consistent. The graph starts from zero liters at 12 am (midnight) and shows the pattern of consumption for the next 24 hours after which it again starts from zero. This allows quick comparison of day to day consumption.
The figure below shows the consumption on May/7/2016.
The graph below shows water wastage due to a fault float valve in the overhead tank in another house.
This kind of detailed information can really help in reducing wastage and even usage considerably. Manual water meters are read once a month and therefore cannot help in locating leakages or changing consumer behavior. Even battery operated smart meters do not provide this level of detail.
Given the alarming water situation in most Indian cities, we believe that this level of resolution is necessary. The downside is that such meters cannot run on non-rechargeable batteries alone. Either solar or mains power is necessary. In India we have frequent power cuts so battery backup is also required.
All the four meters installed by us run on mains power and have a Lithium-Ion battery as backup. When mains power is available, it powers the WiSense node and the water flow meter while charging the Lithium-Ion battery at the same time. When mains goes, the Lithium-Ion battery immediately takes over immediately. The WiSense radio node and associated electronics do not experience any power loss during the switch over.