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District Energy – A Smart Option for Cities

Robert Reipas's picture

Let’s talk recycling: Not plastic and paper, but power…

Combined Heat and Power SystemThese days, by far, the majority of electricity used in high-income countries comes from thermal power plants; these operate by heating water into steam that then spins a turbine. Thermal power plants, however, typically only use 33% to 48% of the total heat they produce. The rest just gets released into water or air. It’s a shame; if only there was a way to recycle all that ‘low-grade’ heat.

Today, 37% of the energy demand in OECD countries is for heating of buildings; only about 21% of energy demand is for electricity. We use much more energy for heating and cooling than we do for electricity.  The low-grade heat that gets wasted by most power plants is still hot enough to be used for heating (and cooling) and water heating in buildings.

Why do we use so little of the heat we produce? That’s like buying a tub of fried chicken just to eat the skins!

A Fourth ‘R’ ?

Kevin Wagner's picture

Reduce, Reuse, Recycle…  Recover.  As the population in large cities worldwide grows, waste management becomes an even bigger challenge.  Recycling programs can divert large amounts of materials from landfills but some garbage still needs to be disposed of in landfills or Energy From Waste (EFW) sites.  EFW facilities are capable of recovering energy from garbage that would otherwise be unused in landfills.

EFW and landfill gas capture systems operate on similar principles:  produce steam to turn a turbine which generates electricity.  The difference is the fuel used to produce the steam.  Landfill gas based electricity generation relies on methane from the decomposition of organic material, while EFW facilities combust the solid waste.  Both are good options as they prevent methane gas from escaping into the atmosphere.  Methane has a global warming potential 72 times that of carbon dioxide.  Both options sound good, so which is better?  The better question is:  ‘How much land and money do you have’?

Urban Careers and the Twenty-Ninth Day

Dan Hoornweg's picture

Lily pads on lakeA helpful way for young math students to grasp the concept of exponential growth is to look at water lilies growing on a pond. They grow exponentially and double in area each day. If they will fully cover the pond by the 30th day, on what day is the lake half covered? The twenty-ninth day[1].
 
This year I had the honor of teaching 4th year energy systems students who will graduate later this month (their blogs on energy issues will be presented on this site over the summer). These graduates are particularly essential. During their careers they will be part of the world’s largest ever city-building spree. Their task will be to again double the world’s cities.

The Buzz of Cities

Dan Hoornweg's picture

BeeFor bees, bigger hives are better. 

Last week researchers at the University of Arizona published their findings: bees of bigger hives have more information and forage better. With improved communications, bees from the bigger hives sent new foragers to known resources up to four hours earlier than bees from smaller hives.1

This better communications also seems to work in bigger cities. Geoffrey West and the Santé Fe Institute provide impressive modeling on the scaling of cities. Double the size of a city and you get 1.15 times the growth of economy, patents and innovation. And as long as you can keep congestion and pollution in check, you can get this economic growth at only 0.85 times the cost of additional infrastructure. In other words, larger cities have a disproportionate impact on a country’s communications, and therefore a bigger impact on economy and culture.

Living Together Tomorrow: Urbanization and Global Public Goods

Warren Evans's picture

This post was originally written for the Collective Solutions 2025 blog, a forward-looking study and collaboration platform to explore how the World Bank and similar multilateral institutions can best support developing countries to meet long-term sustainable development challenges in a post-2025 world. Read more about the study and join the collaboration site here.



I don’t particularly like cities. I’m a country boy. But I have lived in cities for the last 35 years; 10 in Bangkok, 15 in Manila, and 10 in Washington, DC (though DC might be called a town if it were in India or China). In the 1990s, I led work on environmental investments in east and south Asian cities. Most of the cities I worked in were severely “under-infrastructured and under-serviced,” and because many of them are built on coastal zones, this was particularly pronounced when it came to low-lying slums, drainage and sanitation. The heaviest price tag was often for drainage and flood control. During those years, I often wondered if and how the city and country leaders would ever catch up on infrastructure needs with the growing urban populations. Many have done well—while others are in worse shape now because they haven’t been able to meet the human tide.

The Earth Hour City Challenge: How cities are leading the way towards a more sustainable future

Jim Leape's picture

Vancouver crowned Earth Hour Capital 2013On the eve of Earth Hour, taking place this Saturday 23 March, WWF this week announced the City of Vancouver in Canada as its Global Earth Hour City Challenge Capital 2013 at an award ceremony in Malmö, Sweden. The Earth Hour City Challenge is an initiative that takes Earth Hour beyond the symbolic gesture of switching off lights for one hour, encouraging concrete action on the ground to combat climate change.

The City Challenge is designed to identify and reward cities that are prepared to become leaders in the global transformation towards a climate-friendly, one planet economy. Working in collaboration with the leading association of cities and local governments dedicated to sustainable development, ICLEI – Local Governments for Sustainability, WWF worked across six countries (Canada, India, Italy, Norway, Sweden and USA), from which a total of 76 cities registered for the City Challenge.

Mayors Behaving Badly

Debra Lam's picture

Prison cell inside Alcatraz, San Francisco, CAEarly this year, former Mayor of New Orleans (2002-2010), Ray Nagin was charged with using his office for personal gain, accepting more than $160,000 in bribes and gifts in exchange for city contract work after Hurricane Katrina, as well as other city benefits.1 In total, a federal grand jury charged Nagin with 21 counts of corruption, including bribery, conspiracy, money laundering, wire fraud, and false tax returns. Nagin’s deputy mayor, Greg Meffert already pleaded guilty to accepting bribes and kickbacks for influencing city contracts in 2010. Nagin was Mayor of New Orleans when Hurricane Katrina hit, which makes the charges all the more damming. One of the worst natural disasters to hit the US, Katrina killed almost 2000 people across five states. FEMA’s estimated damage totaled $108 billion.2 New Orleans was especially hard hit, with the infamous levees and other infrastructure failing, and widespread socio-economic despair. Of course there were many factors, including the federal and state responses or lack thereof that made preparing for and rebuilding New Orleans challenging. But a strong mayor would have benefited New Orleans tremendously, and Nagin was not up to the task.

One Fish, Two Fish, Red Fish, Blue Fish*

Dan Hoornweg's picture

Blasty Fish, Dr. Seuss‘From there to here, from here to there, funny things are everywhere!’
That one blue fish cost a million plus,1 that one blue fish and all the fuss.

In cities here and cities there, you’d think by now we’d be aware.
That we’d take some care for what is rare. But here’s another to make you stare:

Soup can come with a shark’s fin; yes, so strange a fin that’s mixed right in.2
So much money is being spent, just how far can we go, and to what extent?

‘Say! What a lot of fish there are.’ Yet there they go near and far.
Tuna, sharks and even rhinos too; all sold in a city near you.

Save a fish, save a tiger, save an elephant or two. Here’s what a kid could do
Shout ‘Oh Mr. Mayor in that great big chair, is your city doing its fair share?’

Hey Cities, Slow Down

Dan Hoornweg's picture

‘Lord give me patience, but please hurry.’1 Everyone working with cities has probably felt this sentiment. We see the new buildings, read the reports, and know that the hurly burley rush to urbanize across the world is picking up speed – we are about to repeat the amount of city-building we did in the last 200 years, but this time we will do it in just 40 years. Surely we have no time to slow down.

Chaucer said it well in Canterbury Tales, ‘In wicked haste is not profit.’ Or as in the sage Chinese proverb, ‘A hasty man drinks his tea with a fork.’ Haste makes waste. In the rush to urbanize, we are in danger of wasting many opportunities within our cities, as we lock in little foibles and big mistakes.

Controversy Continues to Hound Groundhog Day Celebrations

Dan Hoornweg's picture

Punxsutawney Phil, Groundhog's DayPunxsutawney, Pennsylvania: Saturday around 7:00 am, Punxsutawney Phil (PA, USA) emerged from his burrow, did not see his shadow and predicted an early end to winter. A few minutes later and a few hundred miles north, Wiarton Willie (ON, Canada) surfaced, didn’t see his (or is it her) shadow and also predicted an early spring.

Once again, like last year, immediately after the groundhogs issued their prognostications, the Houston and Calgary based ‘Committee for Climate Certainty’ rebutted the groundhogs’ findings, claiming the science was uncertain. The Committee released several years of hacked emails between Wiarton Willie and Punxsutawney Phil – “What are we going to do about those climate doubter’s concerns? We are likely to have a repeat of last year.” Willie is purported to have written Phil in an email. “Let’s stick to the date, fudge the timing, and hope no one notices,” Phil is reported to have responded.

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