Tools

You want to reduce your energy consumption, but what's the most effective way of doing it ? Here's some tools for working out what to do:

Also, do you know how much space you are taking up on the planet ? Use the Ministry for the Environment's ecological footprint calculator to find out.

Solar Water Heating as an Investment

Urban Sustainability

Reurbanise has analysed some costs and benefits of investing in a solar water heating system. The results seem to indicate that , compared to simply putting your money in a term investment, a solar water heater will start to come out on top after about 13 years.

The spreadsheet used for the analysis can be downloaded either as an OpenOffice spreadsheet (you can get OpenOffice from http://www.openoffice.org) or as a pdf.

The major assumptions with this model are:

  • A typical unit costs around $4000
  • The money invested in a term deposit would earn around 4.5% (after tax)
  • The price of power is increasing at around 7% per year (based on data from the last couple of years). If anything, this rate will probably increase in the coming years as cheaper sources of power generation (particularly natural gas) are exhausted.
  • A solar water heating system will probably last you 20 years and still be working well after that time.