Reply To: Richard Branson – Virgin Pledge

[DaveMart]

I would have thought the economics of using mines would be horrendous. As others have said you would firstly need to sel the surfaces to prevent contamination by heavy metals and so on, and that then brings you to the main problem – the weight of all that earth and rock overhead.
It costs a lot of money to maintain mines in that high pressure environment – the greatest difficulty would probably be for the aquaculture idea, as it would then be very difficult to detect leaks bringing in contaminents.
In an environment where you were growing trees etc then you would need to maintain the pumping operations to limit water ingress.
All of it could be done, but why?
There is no shortage of waste land – all that you normally have to do is add water. Cheap power would make it easy to do that, without any of the costs and difficulties of the approach you suggest.
If for some reason you wanted to minimise land use, the productivity attained by hydroponic or systems where the roots are suspended in air is massive – you basically would have a series of containers, easily accesible at ground level.
Given reasonably cheap power, there would be little difficulty in getting enormous productivity form such a system.
If for some reason you wanted to economise even more on land use, rather heavier construction of the containers would allow the roofing over and planting to grass of the entire production area – still one heck of a lot cheaper and easier than keeping open a deep mine.
Sorry, it doesn’t sound like a flyer to me.
Regards,
DaveMart