In developed countries, the relatively high energy costs of pumping and treating water for household, industrial or mining purposes are broadly accepted. In developing countries, great care must be taken to ensure that water treatment and distribution systems remain affordable. The relatively modest financial returns from food production in both developed and developing countries means it rarely pays to pump water over long distances for agricultural purposes. In recognition of this, Saudi Arabia has recently shifted its food security policy from one that subsidises water use at home to one that invests in the development of agriculture in other countries where water supplies are more abundant. This is enabling Saudi Arabia to access food at more affordable prices and use the revenue saved for other, more sustainable, purposes (Lippman 2010).
Appreciation of the nexus between water and energy highlights a set of green investment opportunities that are starting to emerge. In Durham, Canada, for example, a water efficiency field trial3
was able to reduce water use by 22 per cent, electricity by 13 per cent and gas
by 9 per cent, with a resultant annual reduction in CO2 emissions of 1.2 tonnes per household – an 11 per cent reduction (Veritec Consulting 2008).
3. The field trial took a sample of 175 households in the region of Durham, east of Toronto. The sample homes were given upgrades in efficient clothes washers, dishwashers, toilets, showerheads, fridges and landscape packages to quantify the potential water, energy, gas, and CO2
savings
from efficient fixtures, appliances and landscape design. To control and measure demand for each of the resources, sub-meters and data loggers were installed on fixtures and appliances within the home. The savings in resources could be attributed to both efficient fixtures and appliances and efficient water and energy use habits of the homeowners. The annual utility cost savings are expected to be more than US$ 200 a year, which allows recovery of the additional installation cost in 3.4 years.