The debate about the environmental benefits of solar power is not dead. This short story is intended to raise serious issues about how we can evaluate the environmental degradation attributable to any choice of technological alternatives.
There are two identical islands, untouched my humans. As part of a real life experiment a group of participants is sent to each island and given the following instructions:
You are to produce 1,000kWh of 240v AC power and send it along a copper wire provided at each island. This wire leads to a remote sensing facility where your electricity output will be measured.
You must generate this electricity with the minimum environmental disturbance.
Your island does not produce any other goods, so all resource use will be attributed to the electricity you generate.
The first group, the ‘Nasties’, agreed that using coal to fire turbines, which would in turn drive a shaft through some coiled copper wiring, would be the simplest and quickest way to go.
The other group, the ‘Greenies’, decided that love child of the green movement, solar electricity from photovoltaic panels, was the obvious way to go.
Neither group faced any knowledge barriers. Each group was full of technical experts who understood all the aspects of metallurgy, pottery, mining, engineering, even agriculture and plant breeding.
They both began their plans in earnest while their impact on the environment was observed via satellite from a remote location.
Both groups need to first establish a reliable water supply, build some shelter, search for edible plants that could be farmed, and manufacture some tools. By the end of the first week, both islands saw a striking transformation in a protected cove as the groups built shelter, cleared land, gather food, planted seeds, and diverted springs. Both groups were confident they would use the least resources on the electricity challenge.
Once water, food and shelter were reliably established, the next major step was to manufacture tools. The island was not short of rich metal ores, and each group began building clay furnaces to extract the metals, which would be used for both tools and later for their own choice of electricity generation.
A few months on, and both islands are occupied by a happy, productive workforce. Each individual member is spending every waking moment contributing to the electricity project. There is no such thing as recreation!
Kilns have been running for some time, and tools have been cast from the metals, such as axe, shovel and pick heads, which are now being used to by the ‘Nasties’ to mine coal. The Nasties feel close to the end of their project. Once they have extracted some more copper for wires, some steel for building pressure vessels and shafts, they will see victory!
The Greenies across the ocean are facing some tough decisions. While they can make fairly impure metals with their furnace, they must be further refined if they are to become part of a photovoltaic panel. Also, the group realises they need a low impact way of growing pure crystal silicon blocks that can be later sawed into wafer thin pieces if they are going to finish their project soon.
The Nasties have cast their pressure vessel, with intake and outlet holes. They have filled the vessel with water, and have joined the inlet and outtake with a long cooling tube. The strands of copper that were roughly beaten and rolled into wire have been built to a crude alternator on the shaft that leads out of the turbine, which itself is a rudimentary contraption on the side of the pressure vessel.
As the winter approaches, the pattern of habitation on the two islands is clearly diverging. The Nasties have a simple network of tracks between their protected domestic dwellings on the lee side of the island, and the coal and ore reserves to the east. A small area of land that was cleared during their first week was yielding native crops that were feeding the group. They have a built their makeshift powerstation just metres from the exposed copper wire that disappears through thick plastic tubing into the ocean. A steady stream of workers brings more coal and ore and they realise that quality of their metals needs to be improved, before the turbine will generate power.
But the Nasties are confident. They had generated some power. A boat had arrived that brought a multimeter so that they could refine their generator to produce the required electricity. After current was detected on the wire, and the device was sent to both islands to assist in the final refinement.
The Greenies thought the delivery of such a device was a little premature. They had been trying to use as little coal as possible, but soon realised that to generate the 2000 degrees Celsius necessary to extract silicon from sand, which is much higher than they need to extract the metals, they would need lots more coal, and a better insulated furnace.
The pattern of habitation on the Greenies island grew rapidly around their original settlement. They were in a period of growth, expanding their abilities to extract metal, and silicon, and expanding their mining to include sand. They worked hard both physically, and intellectually, with their greatest minds devoted to establishing more efficient methods of silicon extraction and growing.
It was exactly 10 months after their first footsteps on the island that the Nasties had met their electricity generating goal. Another boat arrived this time to collect them and observe the environmental conditions on the island. While there was obvious disturbance around the settlement, and cleared tracks leading to ore deposits, as well as smaller tracks that were used when foraging for wild food, most of the island remained untouched. The observers estimated the total consumption of timber, coal, and mineral ores by the Nasties.
We will stop the story there. The point here is that we would need such an experiment if we were ever to really know the environmental impact attributable to single consumption decision. My gut feeling is that the Nasties would have an easy time of outdoing the Greenies at their own game.
Of course, there are plenty of issues with the design of this type of experiment in the first place - what's the major one?