White is the new green

White roofs and surfaces could be worth a staggering $1,100 billion according to recent research.

Nobel prize winner Steven Chu, Obama's Energy Secretary, is promoting this change. Chu says just changing the colour of roofs and blacktopped freeways and streets is equivalent to taking all of the automobiles in the world of the road for eleven years.

White reflects heat and a worldwide change would help cool the world. As a bonus, light surfaces can help reduce the cost of cooling buildings which reduces emissions. However, Hashem Akbari, the lead scientist behind some of this research is careful to point out that converting to cool urban surfaces does not address the underlying problem of global warming.

These impressive numbers from white roads and roofs are not the only option. Living green roofs and walls can drop temperatures (and associated air conditioning costs) by as much as eleven degrees.

Winds of Change

In just eleven years, since 1997, the proportion of the world's electricity generated from wind has almost quadrupled. There are some impressive absolute numbers behind this global proportion.

In 2008 Australia's total capacity increasing by over 50%, China doubled its total installed wind power and growth was 50% in the USA.

With this impressive growth comes an equally impressive challenge. Coal still provides over 40% of the world's power. While wind is growing at 29% a year, versus coal's 4.5%, in absolute terms coal still dominates over wind. The International Energy Agency wedges illustrate the challenge.

Big Solar for Oz

The 2009 Australian budget delivers 1.4 billion dollars - over 6 years - for solar power. So how much solar electricity will Australia get?

The government subsidy is for new solar plants that together produce a coal plant's worth of power - up to 1000MW. Abengoa Solar, a leading solar power company currently constructing solar plants worldwide, put the cost of a 300MW plant at 1.2 billion euros in 2007. In 2009, the Arizona state government announced a 200MW plant for 1 billion US dollars.

The actual cost and reliability of the power generated is as important as the government subsidy for construction costs. The U.S. National Renewable Energy Laboratory estimates, for solar plants generating power 24 hours a day by storing the sun's heat, electricity will soon cost about US 13 cents a unit.

On this scale, sun power is starting to become competitive with expected future power prices.

Three into One

Can you fit three houses into one without compromising amenity? If you can then the environmental impact of a home would be cut – significantly!

Recent work by Lend Lease (through Delfin Lend Lease) with the Queensland EPA and GreenMode shows how it can be done. The results, appearing in the Queensland Government's Smart and Sustainable Homes newsletter, are for 35 different homes of the types typically constructed in South East Queensland.

By implementing simple measures - such as insulation, orientation, high efficiency cooling and heating, and window shading - the Ecological Footprint of a home with people living in it is cut by a factor of five.

When construction and the physical maintenance of the house are also included, three of these sustainable homes could fit in the footprint of one 'standard' house (of the type commonly constructed in Queensland).