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If you want to raise unhealthy children who are going to perpetuate urban sprawl, then look for the cheapest land for schools, make sure they are segregated from the community, encourage parents to drive their children to school, and lock down the buildings at 3 o'clock. That's how it's done in Canada. Any questions?
I have mentioned schools before.
A study by the German Aerospace Center, commissioned by Greenpeace and Europe's Renewable Energy Council, claims that alternative energy sources could provide nearly 70% of the world's electricity and 65% of global heat demand. The report, Energy Revolution: A Sustainable World Energy Outlook, considers variations in geographic conditions and energy sectors.
And another report prepared by a panel led by MIT, The Future of Geothermal Energy, maps how geothermal energy can be used on a large scale to generate electricity from steam produced at depths of 5,000 feet or more within the US. Ground source heat pumps for space heating are already a reality at the scale of individual homes or institutional buildings (for illustration, have a look at the UOIT thermal energy system in Ontario), but this proposal suggests it's feasible to generate significant quantities of electricity by drilling deep into hot rocks, fracturing them and pumping water in to produce steam.
Update on 26 February 2007: Switzerland is developing an energy source using this method, but it was recently reported that pumping water into the wells of the Deep Heat Mining project caused an earthquake reading 3.3 on the Richter scale.
According to Eskom's 2006 Annual Report, the parastatal collected R1.7 billion in annual sales outside South Africa, and R34.8 billion locally. But South Africa is a net importer of electricity. The biggest supply from outside is 1400 MW from Cahora Bassa in Mozambique. Future projects providing an external source will be the 3500 MW hydropower plant on the Congo River in the DRC, and the 7000 MW hydropower plant on the Capanda River in Angola.
[Source: Cape Times, 24 January 2007]
With vast stores still remaining around the globe, it will be hard to wean ourselves off coal. South Africa's Sasol is rapidly expanding its coal-to-liquids (CTL) project portfolio. Sasol opened a project office in the US in 2001, in China last year, and will soon open an office in Mumbai, India. Currently the only major CTL plant in the world is Sasol's operation at Secunda in Mpumalanga, South Africa, which produces 150,000 barrels of fuels a day.
[Source: Cape Times, 24 January 2007]
Traditional wind towers, first developed in Iran, can dramatically cool buildings in hot, dry climates. The structure captures breezes from any direction, and uses differential pressure to draw warm air up and out. An architect using the technique in California has added mist to make it even more effective with evaporative cooling.
It used to be that a homeowner who wanted to sell electricity to the national grid would set up a solar panel in the back yard, and keep his mouth shut. Guerrilla solar provided the illicit thrill of watching the electricity meter spin backwards as the sun worked its magic, but that's starting to change - for the better. In some US states, you can "net meter" legally, as reported in the Washington Post on 21 Jan 2007:
Federal legislation requires states to consider adopting net metering standards by 2008, though programs are already in place in more than 40 states, according to the Interstate Renewable Energy Council. California is king when it comes to net metering, accounting for 86 percent of the 15,200 customers tallied nationwide in 2004 by the Network for New Energy Choices, a New York City-based renewable energy advocacy group.
This can be a powerful incentive for overcoming the cost of installing photovoltaic solar panels and avoiding the need to buy batteries.
Intensification of development is generally good for maximising use of existing infrastructure and benefitting from economies of scale for everything from water supply and wastewater management to transportation infrastructure and public transport services. But there are risks. Politicians often behave as if any development is good development and the property taxes will cover costs, but Toronto is facing a challenge in funding the infrastructure needed to accommodate growth.
Apart from political intervention, the problem for transport planning is that behaviour doesn't always follow the plan. For example, growth aimed at providing passengers for public transport can backfire: if you plan for high densities around public transport stations, but still find that people use cars instead of public transport, then you have just made the situation worse. This is the conundrum faced by planners who want to support pro-transit policy, but often the problem is half-hearted implementation and lack of a cohesive plan to make sure everything is working towards a common goal.
Fourteen percent of worldwide greenhouse gas emissions are attributable to transport. One of the strategies to reduce CO2 emissions from vehicles is to introduce alternative technologies, but progress is slow. Not only are manufacturers dragging their heels, but even if zero-carbon vehicles were being mass-produced today, it would still take decades to completely replace the current worldwide fleet.
In the UK there is now an action and advisory group, the Low Carbon Vehicle Partnership, whose members share a commitment to accelerate the shift towards low-carbon vehicles and fuels. It is independent of government, but works with various UK government departments.
The South African cabinet has approved a draft biofuels strategy, according to the Cape Times today. The target is to reach 4.5% biofuels in road transport fuel by 2013: 8% ethanol in petrol, and 2% biodiesel in diesel. Reaching this target will require:
The EU has a biofuels target of 5.7% for 2010, and the US has a target of 5% - 7% for 2010, according to Raoul Goosen, consultant to the Department of Minerals and Energy to co-ordinate the biofuels task team.
The Cape Times reported on 3 January 2007 that 10.7 million tons of cement were consumed in South Africa in 2004 – that’s 250 kg per capita – and that annual consumption is expected to increase to 17 million tons by 2010. (According to the NPCA there is a higher per capita rate of consumption in the USA at 300+ and Germany at 400+.)
Cement uses a lot of energy in its manufacture, so just how bad is it for the environment? A 2004 research paper, How Sustainable is Concrete? presents a nice summary of the answer.
Portland cement is usually manufactured by heating limestone and shale in a kiln to around 1500 degrees Celsius, then grinding the resulting clinker with gypsum to form a fine powder. This process gives the cement its high embodied energy, and the reaction also produces CO2. The research found the energy consumed in production of Portland cement to be 4.88 MJ/kg. (That’s about 1.2 GJ per capita in South Africa in 2004.) Producing concrete from Portland cement consumes 2.07 GJ/m3 or 0.89 MJ/kg. Replacing 10% of the Portland cement with fly ash reduces this to 1.94 GJ/m3.
Interestingly, a concrete beam of a specific strength embodies less energy than a steel I-beam of the same strength. For the beam designed in this research, concrete manufacture required 109 MJ and steel manufacture required 237 MJ. A more complex calculation is required to consider the broader sustainability issues related to solid waste, air and water pollution and resource consumption. The ATHENA software package was used to demonstrate that concrete has a lower environmental impact than steel when compared in structures designed for the same engineering function.
