tube

Green transit in London

August 7, 2025 By EarthWise Leave a Comment

TfL – Transport for London – the operator of the transportation system in Britain’s capital city, has signed a deal with EDF Renewables to purchase electricity from a huge solar array to be erected next year in Essex. TfL has the goal of powering 100% of its entire transit system – including its sprawling underground railway network – with renewable electricity by 2030.

The forthcoming 1,000-acre solar facility will also transform low-quality farmland by incorporating the planting of trees and hedgerows as well as setting aside some areas for natural regeneration, attracting a greater number of species of plants and animals, expanding biodiversity in the area. Looking after nature and protecting the environment are key elements in TfL’s contracts, in keeping with its wider goals to be greener, more sustainable, and well-adapted to climate change.

The solar facility will generate 80 gigawatt-hours annually for the transit authority, roughly enough electricity to power 29,000 homes, comprising about 20% of its total output. Powering the entire sprawling London underground railroad network is equivalent to powering 420,000 homes. Over the course of the 15-year contract with EDF, TfL expects to save over 30,000 tons of carbon from its operations.

TfL plans to secure 70% of its electricity use from power purchase agreements for renewable electricity from various sources with the remainder from green tariffs. The Mayor of London has set the goal for London to be a net zero carbon city by 2030.

**********

Web Links

London Inches Closer to Running Transit System Entirely on Renewable Power

Photo, posted March 5, 2017, courtesy of Albert Koch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A New Fishway Technology | Earth Wise

February 5, 2021 By EarthWise Leave a Comment

Freshwater fish populations have declined by more than 80% over the past forty years across the globe. This is in part due to hundreds of thousands of dams, weirs, and barriers stopping their movements. These river barriers have disrupted fish reproduction cycles the world over by preventing river fish from migrating to spawn.

Fishways or fish ladders are waterways constructed on or around obstructions in order to provide passageways for fish and other aquatic species. Often, they consist of a series of small overflow weirs and pools constructed in the form of steps. Fish need to jump from one pool to another to migrate to the upstream. Such fish ladders require a large space to construct. These and several other types of fishways tend to be expensive to install and maintain and are not always successful in allowing fish to get to where they need to go.

Researchers at the University of New South Wales in Australia have come up with an ingenious new type of fishway. Called a “tube fishway”, it is a low-cost and low-energy installation that works by pumping fish at high velocity – protected by a cushion of bubbly water – through a tube running over the obstructing barrier to deliver them safely into the water on the other side.

They successfully demonstrated a prototype system on a rugged slope behind a campus building that transported fish from one tank to another about 25 feet up the slope.

Fish are attracted into the chamber by suitable geometry and the system uses the energy available from the upper reservoir to lift the fish. Modeling shows that the system will work for pipes as large as three feet in diameter and could lift fish more than 300 feet vertically.

**********

Web Links

New fishway technology to get fish up and over those dam walls

Photo, posted October 19, 2019, courtesy of Andrew Harvey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electronic Waste On The Decline | Earth Wise

January 6, 2021 By EarthWise Leave a Comment

A new study published in the Journal of Industrial Ecology has found that the total mass of electronic waste generated by Americans has been declining since 2015. Given that electronic devices are playing an ever-growing role in our lives, this finding seems rather surprising. It also seems like pretty good news, but the underlying facts should dampen our level of enthusiasm.

The main reason for the decline is the disappearance of large, bulky cathode-ray tube televisions and computer monitors. Since about 10 years ago, CRT displays have been on the decline in the waste stream, thereby leading to an overall decline in total e-waste mass.

Many state regulations with respect to e-waste recycling have targets based on product mass. The regulations were typically designed to keep electronics with high levels of lead and mercury out of landfills.

At present, the more pertinent concern is how to recover valuable elements like cobalt (from lithium-ion batteries) and indium (from flat-panel displays). These elements are not so environmentally toxic, but rather are relatively scarce in the earth’s crust.

The main conclusion to be drawn from the declining mass of electronic waste is not that we are necessarily winning the battle against generating it but rather that e-waste is changing and regulations concerning it need to be rethought. Focusing regulations on capturing critical elements not only would have significant economic benefits but also would be important in addressing geopolitical uncertainties that potentially could threaten what could be termed the mineral security of the U.S.

E-waste recycling is regulated at the state level and only half the states have e-waste recycling laws. It may be time for more uniform policies across the country.

*********

Web Links

Electronic Waste on the Decline, New Study Finds

Photo, posted January 22, 2013, courtesy of Thorsten Hartmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.