Solar powered tube trains for the future?
The tube trains of the future could get some of their juice from solar power, as Transport for London (TfL) is looking for a supplier who could plug solar cells directly into the TfL electricity grid.
The project is primarily focused on private wire connections to new-build solar photovoltaic generation, and the contracts are for four years, with options to extend afterwards.
TfL has previously committed to delivering 1.1 megawatts of generating capacity by retrofitting solar panels across its larger existing rooftops, but that is a drop in the ocean compared to the amount of electricity the tube trains consume.
In comparison, the new contract could bring up to 64 megawatts (MW) of electricity to the network, which is approximately five percent of the electricity needed to run the Tube network.
It’s not likely that the solar cells would be plugged directly into the railway track, as that causes problems with power spikes and troughs, although a trial is attempting to deal with that. The power would likely be plugged into wider network and feed all TfL services.
Mete Coban, Deputy Mayor for Environment and Energy, said: “The Mayor has ambitious goals to cut London’s carbon footprint, so powering London’s world-leading transport system with green energy is a clear win-win. Installing solar panels as a source of renewable energy is one of many ways organisations in London can lower their carbon footprint.
“Not only will the solar panels help TfL to cut running costs and save passengers money, they will also create green jobs while helping TfL to reduce its carbon emissions.
“This is a great opportunity for organisations to work with us as we build a greener, fairer London for everyone.”
TfL is the largest single electricity consumer in London with a demand equivalent to the electricity consumed by around 420,000 homes or 12 percent of homes across London.
The tender documents are here.
TfL currently sources its electricity directly from the National Grid, and was awarded grants earlier this year to upgrade some of its buildings to reduce its power consumption.
“In comparison, the new contract could bring up to 64 megawatts (MW) of electricity to the network”
Per what? Per second, minute, hour, year? It’s a pretty useless number without expressing the period over which it is used too.
Bob – A watt is one joule per second, so 64 megawatts is 64 million joules of energy per second.
Oh so this the permanent draw in the grid! That is insane! I thought it was going to be over a period of time.
As the article says, TfL currently have solar capacity (i.e the highest possible power output on a sunny day) of 1.1 MW, this increases it to 64 MW. This is a ‘private wire connection’, in other words connected on the TfL side of the metering so reduces their demand on the grid. This can reduce grid costs for connection capacity (MW) and use-of-system (MW-hour), as well as the supplier energy costs. TfL have an extensive power network, a legacy of the days it was an isolated grid which generated all of its power, but these days it’s grid-conected hence the solar is synchronised to grid frequency and its power is shared with the grid.
And greenfield sites at / near tube terminals are proposed !