What are the secrets of sustainable living? E&T looks at towns and cities from around the world as look at renewable energy, recycling and green living as they try to curb their carbon emissions to combat global warming.
On 4 May 2007, one of the strongest tornadoes ever recorded ploughed through Greensburg, Kansas, levelling the rural town and killing eleven of the 1,500 residents. Storm chasers reported the twister to be nearly 3km in diameter, wind speeds hit 330km/h and insured losses alone totalled $153m. Within hours of the disaster, the entire town was evacuated with the mayor of Greensburg stating 95 per cent of his community had been destroyed.
What has happened since is remarkable. Only days after the storm, the community gathered and decided to rebuild Greensburg as a model 'green' town for the future. The city council passed a resolution stating that all municipal buildings should be built to 'LEED platinum standards'. This, the highest rating in the US Green Council's 'Leadership in Energy and Environmental Design' green building rating system, marked a US first.
Today, around half of the town has been rebuilt. The town's first platinum building, the 5.4.7 Arts Centre named after the date of the tornado strike is one example.
Designed and constructed by 22 University of Kansas architecture students, electricity is provided by three 600W turbines to the rear of the building while solar PV panels are sited on the ground and roof. Solar lighting is installed, recycled building materials have been used and a geothermal heat pump heats and cools the building. Rainwater, harvested through gutters and down-spouts into a cistern, waters the outside yard through a pump system, while a white roof reflects heat.
Other buildings that have earned platinum certification include a development of 16 apartments making use of high-efficiency air-source heat-pumps and a John Deere Dealership and Service shop drawing electricity from two wind turbines. Greensburg's very own wind farm comprising ten 1.25MW turbines is about to be switched on.
The grid-connected system will meet the community's pre-tornado electricity demand with additional supplies coming from a hydroelectric power plant in Lawrence, Kansas, when the turbines cannot generate sufficient electricity to fulfil demand. A biodiesel generator will also provide back-up power in an emergency.
Clearly, the rate of progress has been breathtaking. As Daniel Wallach, executive director and founder of Greensburg Greentown, a non-profit organisation created to help businesses and residents learn about sustainable living, says: 'We're a month away from being 100 per cent renewable; people in small-town America are very practical. Greensburg citizens were already building their homes with solar orientation, and while some were resistant initially, it wasn't hard for them to embrace sustainability.'
This is at least part of the secret of Greensburg's success. From day one, the local council realised it was key to get the community behind sustainability and laid out a clear vision on how to be a model 'eco-community'. Meanwhile a local Kansas planning and architectural firm, BNIM architects, led a community master plan for rebuilding Greensburg, while the National Renewable Energy Laboratory provided education and on-site assistance to residents. Testament to Greensburg's community spirit is that many of the new homes use about 40 per cent less energy than the typical home before the tornado.
Another major contributor to Greensburg's success has been cash. For example, its $3.4m business incubator building received $1m in funds from PepsiCo subsidiary Frito-Lay while actor Leonardo DiCaprio donated $400,000. State and federal funding covered the balance.
Today, however, the US recession means cash flows are drying up. Plans for a biodiesel plant to provide fuel for the general market have stalled. A chain of 12 'eco-homes', each to serve as a 'living laboratory' of building techniques and energy efficiency features, has been scaled down.
'The contraction in the housing market has impeded our plans here, as we were counting on a lot of donations the construction industry is definitely not in that position now,' explains Wallach. 'However, we have two built and will now tweak our plans to do very small-scale homes. The concept is still there and we are very excited about it.'
Cash and community support are crucial to implementing a programme of renewable and energy efficiency development in any town or city. Växjö is a small city in the south of Sweden with a population of 78,000, as well as a long history of renewable energy development. Its achievements are largely due to local government backing and an enthusiastic community.
In 1996, the city council, with a municipal annual budget of 400m, unanimously decided that its city should become fossil fuel-free by 2050. It set targets for local greenhouse gas emissions per capita to be reduced by 50 per cent by 2010 and by at least 70 per cent by 2025, relative to 1993 levels. Today, emissions are down by some 32 per cent and at 3.5t CO2/capita, are one of the lowest levels in the world.
The city's renewable energy supply is mostly from biomass, sourced locally and used in CHP district heating plants. As P.R Wallin, climate protection engineer at Växjö's Executive Office says: 'This hasn't changed the daily life of the citizen here at all. We also have a lot of forests in our region, so it's been good for business and we've created around 300 jobs.'
Other projects have included solar panels on the school roof, wood pellet burners at the airport and solar water heating at the swimming pool. For those living outside the city, district heating wasn't an option so the government subsidised the installation of wood pellet boilers and solar panels to these homes.
However, while emissions from heating and power have plummeted, those from transport have risen with this sector providing 80 per cent of Växjö's CO2 emissions. According to Wallin, emissions haven't increased dramatically since 1993, it has just been easier to reduce emissions from heating and power. Plans are currently underway to improve cycling paths and public transport.
Energy efficiency has also featured prominently in Växjö's race to be fossil fuel-free. Wallin points to the city's various information campaigns to use, say, energy-efficient light bulbs, and highlights the drive to build energy-efficient buildings. Indeed, four eight-storey wooden buildings are currently the tallest in Europe to be made from wood.
A smart metering programme has also proven successful with customers living in municipal-owned apartments; in the past two years users cut their electricity consumption by 24 per cent and hot water use by 43 per cent. Importantly, the system includes a Web portal that allows users to see their hourly rates of consumption and make comparisons with their neighbours.
'I think this has been more of a behaviour issue. The technology is already there and we have many products around us,' says Wallin. 'However, it's very important that people can see their changes and track their progress.'
Masdar is a green city with a difference. Located in the heart of the OPEC countries, 30km east of the United Arab Emirates capital, the $22bn development has a mandate to champion renewable energy technologies. When complete, the government-backed initiative will be carbon neutral, have zero waste and use 100 per cent renewable energy.
Recently the city built a 10MW photovoltaic solar power plant, which is the largest grid-connected facility in the Middle East and North Africa. A project is also underway to construct the world's largest hydrogen-fired power station; once grid-connected, the 500MW plant will provide energy to Abu Dhabi's growing electricity demand.
Like Greensburg and Växjö, energy efficiency will be a key feature of the city. As part of this, US-based energy business GE has set up its first 'ecomagination' centre at Masdar, which demonstrates the latest energy-efficient technologies.
Keith Redfearn is general manger at GE for transmission and distribution in Europe, the Middle East, Africa and India. As he explains, generating plant at Masdar has already been connected to the transmission and distribution network supplying electricity directly to homes.
'A range of smart appliances such as washing machines, fridges and heaters can now receive signals from the generation station. If a generator indicates that the price of electricity has gone up, a fridge freezer, for example, could than defer its defrost cycle to the middle of the night when there is more capacity on the grid,' he says. 'There is a whole host of things you can do with smart white goods to balance out energy usage in the home without necessarily impacting the end-user.'
Indeed, taking into account the impact of a new technology on a customer has been crucial to success of many of the technologies implemented in each of the cities.
As Redfearn points out: 'Masdar is very much about educating and enlightening customers. Not only from a technology point of view, but from a social acceptance point of view as well.'
Social understanding aside, the common-ground between Greensburg, Växjö and Masdar is clear. Each has cash, government and community support. Växjö, however, provides the most enduring and realistic model for building a 'green' city. Greensburg has relied heavily on personal donations while Masdar is unique in having the financial backing of one of the world's wealthiest nations. What's more, Växjö has very firm political support; it's politicians want a fossil fuel-free city.
And as Wallin points out: 'Our local authority also has money, responsibility and possibility. We own the schools, the energy plants and the sewage works. Compared to other cities in, say, England, we have more power to change, and this is the big difference between us and other municipalities around the world.'