[MOTOTRBO] Cost projection on DMR based on breadth of the TG site coverage.
I got bored, took the local 'pyramid' of talk group repeater count spread, applied the electrical costs for a repeater at 45W transmit, and multiplied that out over increasing talkgroup repeater counts.
Kind of interesting, basically 20min of tx time on North America roughs out at $4 in electricity consumption alone.
I did this as a tool to show people the significance of minimizing the reach of the talk group used to make a contact.
Intro - Why?
Electricity Cost Per Minute While Transmitting on the DMR-MARC/NEDECN Network - de KC2RGW 11/15/2015 rev.2.1
So out of boredom I was wondering what it actually costs in electricity when you multiply the effect of a user transmitting on the DMR-MARC network (NEDECN biased). I’m doing this as an illustrative tool for people to think about how they use the network from a localization and least number of repeaters impact to make their contacts.
This isn’t meant as any sort of environmental impact statement or even one that is very specific to DMR technology. It is however specific to DMR in the way a single user has power and leverage over a vast network of resources. Site per site, if anything, DMR should be more efficient than analog due to efficiency of throughput with TDMA and the lower duty cycle of the mode.
Metrics
Single repeater power consumption:
- A Motorola 8400 repeater runs at roughly 120V AC @ 4A on transmit
- Taken from Motorola’s data sheet
- This works out to 480W consumption.
- So a revision here...at 45W output we had a site owner measure actual consumption at 144W with a Kill-A-Watt meter on the source. Figures have been dropped to reflect this.
- I used $0.12 kW/hr as a rough cost for power
- This is lower than it is locally, but national avg is $0.10 kW/hr
- I adjusted to $0.10 kW/hr in the revision as well but remember, some areas are over $0.15 kW/hr
- The cost per hour in transmit mode is about $0.0144 <- revised as well
- This works out to $0.00024/minute for a single repeater while it is in transmit
