World-famous for their picturesque windmills, the Netherlands has always had a love affair with wind energy. While it was originally used to pump water or grind grain, wind is now helping Dutch commuters get to work. Earlier this week, announced that, since 1 January, every single one of its electric trains have been running on energy harvested from wind.
They have been working with , a ‘sustainable energy supplier’ operating in the Netherlands, for several years. Their goal was to operate all NS trains on electricity produced by wind turbines by January 2018. spokesman Ton Boon . 2015 was a record year for the country’s wind industry – according to the , turbines capable of generating 586 MW of electricity were installed between January and December. In 2016, Dutch wind hit the headlines again, when a became the most ‘cost-effective’ in the world. The construction of these wind farms – along with others in the Netherlands, Belgium, and Finland – helped NS and Eneco to hit their target so far ahead of schedule.
And given that the company carries 600,000 people per day, the amount of electricity they need isn’t trivial – around 1.2 billion kWh of electricity a year. That would power a large proportion of all of the households in Amsterdam**. So, the fact that they can now reliably produce it from wind is big news.
But if you’re reading this and thinking “How can trains run on electricity?”, fear not. I’ve included a (slightly-edited) mini-excerpt from my recent book, , to explain:
“Electric locomotives don’t have conventional ‘engines’. Rather they act like a component in an electric circuit. Rail networks source this electricity from the grid, and just like for our homes, it’s transmitted to them via high-voltage lines. Once it’s in the network, there are three main options for getting the electricity to the trains themselves:
- On-board energy storage systems, such as batteries;
- An overhead wire that the train connects to; or
- An extra ‘live’ rail that has direct current flowing through it at all times.
You’ve probably noticed at least one of these options on your rail journeys. Overhead wires are best suited to tram and intercity services, whereas the more compact ‘third rail’ option is preferred for underground trains. The role of the third (or conductor) rail is to ensure that the electricity is always directly available, so it’s installed alongside, or in between, the pair of running rails (Keep an eye out for it when you’re next on an underground train).
Conductor rails carry lower voltages than overhead wires, although ‘low’ is a relative concept. London Underground’s system provides 600V of direct current to their conductor rails, still enough to be potentially lethal. In addition, the use of conductor rails sets a speed limit on trains of about 160kph (100mph) – above this, the metal contact blocks (called pickup shoes) can lose contact with the rail and result in a drop in power. The pickup shoes do occasionally lose contact anyway, albeit very briefly, at track junctions. This is the cause of the very bright, blue-white spark you sometimes see near the third rail, as well as flickering carriage lights. For high-speed trains, overhead wires are the better choice.
However the electricity is delivered to the train, once it’s there, it is used to power lights, and air-conditioning, as well as the traction motors, which are what turn the train’s wheels. Electric trains also use regenerative braking, similar to what’s found in hybrid and electric cars. These systems are found on underground trains in Los Angeles, Auckland and Buenos Aires, among others. By using the ‘brake’ to change the connections on a train’s motors, they stop turning the wheels, slowing the train, and instead produce electricity that can be used elsewhere.
This article was sourced from http://newsyellowstone.com