Home Energy Analysis

By 2011, we Melbourne residents should have a proportion of desalinated water in our water supply. This is in response to low rainfall over the last 10 years leading to very low levels in our reservoirs. The HEAS site has a page describing our household’s attempts to adapt to this new reality.

The proposed plant has a capacity of 450 billion litres of water per year, and will require 90 megawatts of energy annually. The Victorian government has promised to add an equal amount of renewable energy, probably in the form of wind turbines. If the water does end up having a greenhouse cost, HEAS will be able to handle it.

There has been very little objection to the need for action of some kind, although many find desalination expensive in dollar and energy terms. There has been support for better use of stormwater which currently eventually finds its way to the sea. Many households are installing rainwater tanks which can be plumbed into toilets and washing machines. However, adding tanks to an existing house can be expensive - a neighbour has spent $13,000 on adding some storage in his back yard. In comparison, our total water usage bill is approximately $300 per year making tanks hard to justify in economic terms.

Most of us are familiar with the term “Peak Oil”: the idea that oil production will at some stage decline if it hasn’t already happened. Similarly, Uranium is estimated to last for 80 years at current usage rates. Consumption will accelerate as nuclear power is inceasingly used for power generation, but exploration is likely to increase reserves.

A recent article in New Scientist (David Cohen, “Earth Audit”, May 26) listed some lesser known minerals which will be depleted in the near future. Hafnium, which has some use in photo-voltaic technology, has approximately 20 years of known reserves at current usage rates. Indium is also used in PV technology and LCD screens and could be exhausted earlier. The list goes on, but the message is that even emerging technologies will potentially have difficulties with raw materials.

It would be a tough form of justice if we humans still had some oil when the materials enabling now emerging technologies have gone. 

This list is by no means exhaustive, and mentions some books that we’ve recently read that have had an impact on us.

The Weather Makers by Tim Flannery (2005). Describes climate changes over millions of years, and explains the science behind the current forecasts. The book discusses the science in a comparatively simple way. Short chapters and anecdotes enliven what could be a very dry subject. He also explores some of the mechanisms that might lead to events such as the Gulf Stream stopping flowing. Flannery is a passionate advocate of the need for action. He is also “Australian of the Year” for 2007. This certainly does not mean that his views are those of our leaders.

Heat by George Monbiot (2006). The author gives an action plan for reducing carbon dioxide emissions by 90% by 2030. Written using British and European examples, but globally applicable. Perhaps even more passionate than Flannery, Monbiot is deeply opposed to corporations which act to preserve the status quo and have acted to falsely discredit climate science. He is also properly cynical about some of the energy solutions which are not feasible, for example home based wind generators. See his website to sample his opinions.

Two books by Jared Diamond don’t have climate change as their subjects but do explore the interactions between humans and nature. The first describes some examples of “unintended consequences” Collapse: How Societies Choose to Fail or Succeed. The earlier Guns, Germs, and Steel won the Pulitzer Prize for its explanation of the effects of geography on the development of civilizations. Diamond is one of the luminaries who has praised Flannery’s book.