# Convert pulses into KWh

Hi all, I have a sensor on my smart meter counting the pulses and it reports the current usage in watts via MQTT to OpenHAB. At the moment I also have it sending a 1 every time there is a pulse. The meter does 1000 pulses per KWh.

Am I naive to think that if I wanted to track cumulative power usage then if I counted 1000 pulses that would be 1 KWh used. And for more frequent updates I could say that 10 pulses counted would mean 0.01KWh used?

Power, watts, Kwh… This is something that confuses my no end so any advice would be appreciated.

You got it right, every pulse is equivalent to 1Wh consumption. If you get 1 pulse every 3.6 seconds, this would be equivalent to 1kWh per hour (or a power consumption of 1kW)

Imagine a light bulb with 60W power consumption. If you would switch it on, the smart meter would send one pulse per minute -> 60 pulses per hour -> 60Wh. If you would use two bulbs, it would send two pulses per minute -> 120 pulses per hour -> 120 Wh.

In fact, the meter does an integral calculus for power consumption over time (I don’t know if this is the right term, didn’t have maths in english lessons ).

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