The Water Food Energy Climate Nexus (Pt. 1)
by Eamon Keane
“Before the world’s fossil fuels are finally exhausted, it is likely that their extraction will require an unimaginable amount of water”
“When measured in calories, the energy market is twenty times the food market. So if governments would replace only 10% of global energy consumption with first-generation biofuels, they in the same stroke would double agricultural water withdrawals”
“The share of biofuels in total use of coarse grains is projected to increase until 2015, reaching 13%”
“The area currently under cultivation is 1.5 billion hectares, so if all that extra land could be used it would represent an increase of one-third. In fact a lot of it either should be left alone for environmental reasons or would be too expensive to farm.”
above quotes, it is a
wonder that most energy outlooks pay only cursory attention to the
interrelationship between water, food, energy and climate.
Signs of stress in the water-food-energy
complex are visible in the record high food prices, dropping water
tables and the
need for cooling in power plants is on vivid display in northern Japan.
Do you know
how/if it will affect your investments? Maplecroft's water
security index shows nearly the entire Middle East and North
the origin of much of the world's oil, as under extreme risk of water
a nice graphic in the World
Economic Forum’s Global Risks 2011 which highlights some of the
water-food-energy interactions in
Figure 1. I’ll try to concisely address them in this series.
Figure 2 shows the water required to extract and refine energy, while Figure 3 shows the energy required to make different forms of electricity. The water needed in primary extraction of oil, gas and coal is not that significant, however it depends on local availability. For instance in China’s Shaanxi Province, the coal reserves cannot be tapped due to lack of water. The plan is to desalinate sea water and pump it uphill for 600 km: “We need water, and the sea can provide it”.
The oil industry uses some 220 mb/d of water for enhanced oil recovery, for an average of about 3 mb/d water per mb/d oil. This is about 0.3% of global water use (4,500 bn m3/year or 77,500 mb/d). In some cases this will be the reinjection of the water cut, however where steam injection is used, the quality is required to be higher. For fossil fuel extraction, the issue is not the absolute volume of water but the environmental pollution that inadequate environmental care can cause. An estimated 12,000 miles of waterways are adversely affected by abandoned coal mines in the US. Shale gas uses relatively low volumes of water, but a few cowboy fraccers could lead to the contamination of rivers or groundwater and so close regulation is required.
elephant in the energy-water
nexus is biofuels, with irrigated corn requiring up to 100,000 litres
Converted to oil, this is an impressive waste of 3687 mb/d water
per mb/d of oil equivalent, or 4.8% of the
water consumption. This is the number one reason why first generation
biofuels are doa
once governments recognise
uses significant quantities of water. Due to the massive
water used in open loop cooling in old designs of nuclear and some
power plants, in 2005 41%
of American water abstraction (withdrawal
from a water source) was used to cool power
plants. The operation
of open loop nuclear plants requires
this steady flow of water, or else they must shut down. Only 3%
of US water is actually consumed by power plants, the rest returned to
slightly warmer. Hydro plants evaporate large quantities of water/MWh.
New power plant designs can significantly reduce power generation water
consumption through a range of technologies,
hybrid cooling systems. This has significantly reduced the water
requirement of the 100
MW Tonopah solar tower
Nevada that recently got the go-ahead, with water consumption a key
2 will look at the food-water
|Tweet||Add to Flipboard Magazine.|