It's no secret that light rail trains are some of the cleanest vehicles around. They efficiently move tens of thousands of people every day between Mesa, Tempe and Phoenix, all without the air pollution associated with gas engines. That's due to the fact that light rail vehicles run on electricity... but, just how much electricity does it take to operate a light rail train?

Many of us had model trains as a kid, and most likely, they ran on electricity too. You might have had to plug an adapter to the wall outlet or install batteries to get it going. The principle is the same for light rail trains, although it should come as no surprise that with cars that weigh more than 100,000 pounds, it takes a lot more juice to get them moving than what you'd get out of your typical Duracells.

Valley Metro light rail vehicles require 850 volts to operate. That's more electricity than it takes to power three typical houses! The electricity is delivered throughout the system by wires mounted on catenary poles and suspended over the trains.

Catenary pole

There are many fail safes built into the system to make sure the trains keep moving, even during occasional blackouts due to weather.  Twenty-four substations positioned up and down the line manage the power supplied to the system. The entire line doesn't need to be powered for the trains to run. It's common for sections of the system to be powered down to allow for maintenance crews to do electrical work at platforms.

The electricity used to power light rail trains might sound like a lot, but it's a drop in the bucket compared to the amount of power that's available. Valley Metro project planners have determined that the light rail system doesn't do much to increase the overall energy consumption in the Valley. It uses about 0.001% of the electricity used by all Maricopa County households.

It's difficult to definitively say how much the light rail system cuts down on air pollution. However, we know a few things that might give us an idea. According to the latest Valley Metro ridership report from December, more than 43,000 people boarded light rail trains on a typical weekday and rode for an average of four miles. EPA figures show that an average passenger vehicle emits a little more than 400 grams of carbon dioxide per mile.  If we assume all those people would have otherwise used another vehicle for their trip, that means their light rail trips eliminated more than 150,000 pounds of CO2 from the air for the month of December!

Valley Metro's light rail system aims to enhance lives and connect communities. As you can see, it does it in a way that's good for the environment, as well as the economy.

Alex Tsotsos
Rail Operations Communications Specialist
Writer, editor, musician, gamer, and former news professional. Frequently seen at Phoenix Rising matches and jogging around Gainey Ranch. May throw things in the presence of typos.