Wednesday, December 8, 2010

Wind Farms:

The Real "Footprint"

This is one more in a series of pieces I am writing to try to examine non-nuclear technologies under the same microscope usually reserved for nuclear technologies.

I have been puzzled in the past about conflicting claims regarding the "footprint" of wind farms. A recent report and some very astute analyses by some colleagues of mine has opened my eyes. For wind farms, it seems, things are not as they first appear.

The argument made by wind advocates is that wind farms take hardly any land at all. They can be sited in the middle of farmland, and their only footprint is the small base of each tower. Crops or livestock can surround them. That certainly seemed plausible, so I have not fully understood the criticisms that the footprint of a wind farm was really much larger than the area occupied by the towers.

Let me hasten to point out that this post will address only wind farms sited on farmland. It will not address the special environmental and scenic implications of wind turbines on mountain ridges, and it will not address implications of offshore windmills. These have their own issues. I cover here only the "real" land use implications of windmills on farmland.

The report provides some numerical data on the real land use of wind farms. However, it errs in its comparisons to nuclear power, because, as a colleague has pointed out, they fail to factor in the megawatts per unit acre generated by a nuclear power plant compared to that from a windmill. Adjusting for the generation per acre makes nuclear much more land efficient--up to about a factor of 10 or more, depending on which end of the stated range you use for each. (The observation is from Margaret Harding in a communication and to my knowledge is not available on a website.)

She and others have noted other farm-related implications of windmills on farmland:

• The land requirements for rights of way to access the wind turbines.
• The added difficulty of operating large tractors and combines around the bases of turbines (probably resulting in an effective loss of the land immediately surrounding the towers).
• The sensitivity of livestock to the noise and light from wind turbines.
(There are anecdotal reports of reductions in milk production by cows.)
• The difficulty and danger of crop dusting, which is causing crop dusters in some areas to refuse to work around windmills. The net result is either application of pesticides by less efficient (and more petroleum-intensive) methods, or reduced crop production per acre.

Some of these reports are anecdotal, so clearly, this is another case where we need more facts. I doubt that these factors would rule out the use of wind farms on agricultural land. However, the ultimate findings could affect how much we can really expect such wind farms to penetrate the nation's farmland, where they can be sited with least impact, and what side effects we would have to tolerate, and perhaps, how to minimize them.



  1. While it is a slightly different topic, wind's carbon footprint is typically calculated for electricity at the grid connection. The unattributed additional carbon burden that the system takes on to balance the variability of wind will be heavily system dependent - whether the existing system has spare fast-responsive capability, like say hydro-rich Norway, or not, like most. For a system that has been built with load-matching handled by gas, the variability of wind incurs significant additional gas burning, as well as the requirements of lower-efficiency fast turbine use and spinning-reserve needs.

  2. Similar environmental concerns regarding the acquisition of land for uranium tenements have been raised in Australia.

    The lease of the “largest” uranium mine in the world, the Olympic Dam project in South Australia covers some 18,000 hectares, though the OD also mines copper, gold and silver. However, the U tailings retention structures have a total area of 360 hectares and a design height of 30 metres and currently holds over 50 million tonnes of tailings.

    The Ranger uranium mine in the surrounds of the world heritage listed Kakadu Park in the Northern Territory is on a 7860 hectare lease and the tailings dam is leaking an unstoppable 100,000 litres of uranium solution every day.

    The EPA environmental scoping document advises that the footprint for BHP Billiton's Yeelirrie uranium project activity in Western Australia “will cover a maximum area of approximately 10,000 hectares which will be disturbed over the life of the mine. The tailings storage facility will cover 80 hectares, in pit storage: 1,600 hectares and the evaporation pond, 20 hectares."

    Canadian uranium miner, Cameco has exploration tenements of more than 795,000 hectares of land in Western Australia.

    Western Australia has been in virtual drought for some thirty years and there remains a critical water shortage. The use of groundwater proposed for new uranium mines will be significant considering the Uranium Conference’s 2009 press release advising that “currently 450 uranium projects in Western Australia are reporting to the global financial markets.”

  3. Ms. Fox's point on creating forest 'edges' is also an interesting one. A wind farm requires a network of access roads which will almost certainly create 'islands' of forest. The significant barrier these roads present to some species means their effective habitat is reduced enormously in size. On the contrast, a nuclear plant could make do with a single access road which would be circumnavigable in many cases.

  4. Gail, farmers in Texas are receiving a yearly income of $10,000 per wind turbine placed on their land. At that rate, if a farmer has enough land for say 10-15 turbines, I have to ask myself does the farmer lose incentive to continue farming? Is there a requirement that he/she must continue farming? I don't know the answers to these questions yet, but I know that farming is hard work even with modern machinery thus if easy money comes around, they might not find farming so appealing anymore.

  5. BHP Billiton’s proposed expansion of the Olympic Dam uranium project in South Australia includes spending at least five years digging the world’s largest open pit set to be 3 kilometres by 3 kilometres at the surface, and 350 metres deep.

    This project will not only leave a huge hole in the ground because there are no plans to rehabilitate, or to fill in that pit, but also the storage proposed would cover an area of up to 44 square kilometres to a height of up to 65 metres.

    The OD expansion has the potential to destroy native animals and their habitats, the clearance of much native vegetation and a drastic increase in CO2 emissions.

    South Australia's uncapped drillholes at Coober Pedy are already killing an estimated 10-28 million reptiles every year. There are no plans to cap the drillholes.

    Australia already bears the ignominious title of having the highest mammal extinctions on the planet, one of the highest CO2 emissions per capita and one of the worst records for climate change action.