While the political debate has centred on carbon emissions, Antony Oliver (NCE 25 May) points out that 'desalination is very power hungry' and that means costly.
With world fuel prices set on an inevitably rising trend, water from this technology can only become ever more expensive as the years go by. Desalination may be economic compared with a panic programme of mains replacement, but the proper test is whether the marginal cost of augmenting supplies in this way is in balance with the value of this additional water to consumers.
Justication for introducing desalination can only be based on metering all supplies and increasing the price progressively so as to constrain demand to the level that can be met reliably from existing sources.
As a nation we have become accustomed to extravagant use of water. It takes only a short stay in a country lacking abundant supplies to realise how much less water would meet our needs if the incentive to economise was there.
Peter O'Neill (M), The Old Village Hall, Cocking, West Sussex, GU29 0HN