MONDAY 16 MARCH, 2009 |
Geoengineering and solar power
One of the more drastic approaches to addressing climate change has been the
concept of geoengineering, in particular ejecting particles into the upper
atmosphere to cool the planet.
The idea has been based on natural incidents in the past where massive volcanic
eruptions have been observed to have a cooling effect. When Mt. Pinatubo erupted
in 1991, airborne sulfur reduced temperatures around the Earth for about two
years following the event.
While the controversial idea has gained some support with scientists as an
absolutely last ditch effort to dampen the impact of climate change, the long
term effects remain unknown. However, according to the USA's National Oceanic
and Atmospheric Administration (NOAA
such a move would see reduction in electricity generation by solar farms
concentrate the sun's energy using mirrors and lenses.
In such a scenario, for every watt of sunlight the particles would reflect away from the Earth, another three watts of direct sunlight are converted to diffuse sunlight.
and evacuated tube
solar hot water systems
and solar arrays based on
photovoltaic panels, such as those used on home solar power
systems and some solar
, can utilise
diffuse sunlight. However, large solar farms that concentrate sunlight for maximum efficiency depend solely on direct sunlight and cannot use diffuse light.
According to the NOAA, after the eruption of Mt. Pinatubo, peak power output of
solar farms in California fell by up to 20 percent, even though the
stratospheric particles from the eruption reduced total sunlight that year by
less than 3 percent.
As solar power is one of the best hopes for moving away from fossil fuel based
power generation, based on the NOAA's findings such a drastic move to curb the
effects of global warming could not only have wide ranging unknown negative consequences
on the environment generally, but actually see the need for burning fossil fuel
in high quantities extended.
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