How politicians could end droughts FOREVER: But they don't want to
They'd rather ration your water than do some simple sums
If you ever actually drive your car, washing it with desalinated seawater isn't worth worrying about
Because, we are told, desalination is "carbon intensive". That is, the energy used in a reverse-osmosis plant involves serious CO2 emissions.
Is that right? On the face of it we're talking about a lot of energy here, no less than 2,920 gigawatt-hours per year in the every-drop-from-seawater case for the whole of London's supplies. That equates to a hefty-sounding 1.25 million tonnes of CO2 emissions each year.
Maybe we should, in fact, stop watering our gardens, stop washing our cars - even stop washing our clothes and ourselves, as some scientists advocate.
But in fact this is a foolish argument to make. That one kilowatt-hour per day for each of us to make 167 litres of water from sea brine is actually trivial. Each Londoner already uses 52 kWh every day on all his or her other, hugely more significant, energy expenditures - transport, heating, cooling, lighting and the rest. Normal non-London Brits, who live in different kinds of buildings, who drive more and use public transport less, get through an even heftier 70 kWh or more daily.
The fact is - and this applies everywhere, not just the capital - if you ever drive your car, washing it using a hosepipe fed from a desalination plant adds almost nothing to the energy you use. If you heat water up at all (that is if you use it for cooking or washing, which accounts for the vast majority of domestic water use) the fact that it is desalinated seawater means almost nothing in energy terms. And if you use a hosepipe to water green growing plants in urban terrain, the fact that you are helping take carbon from the air and reduce the urban "heat island" effect in hot summers certainly outweighs the small amount of energy required to make that hose water from pure brine.
In the reality right now, where most London water would still necessarily come from rivers and boreholes in order to prevent floods and we'd be desalinating not sea brine but merely-brackish Thames estuary water, the effect on energy use and carbon emissions would be completely imperceptible: an increase of a very small fraction of a single percentage point.
Even the most hardline extremist greens, who take it as a solid fact that carbon emissions are a deadly threat and must be reduced at any cost, would - if they were thinking sensibly - surely hesitate to expend any serious amount of their sharply limited supply of political capital, of hard-won public goodwill, on achieving such a tiny carbon reduction. This is all the more so as hosepipe bans during rainless summers actually make cities less green. A green campaigner wanting to reduce energy use and carbon emissions would achieve more by doing almost anything else: persuading people to use public transport, insulating buildings better, battling against patio heaters, encouraging less washing etc etc.
But the Greens don't have to expend any political capital on this, as mainstream politicians have decided that desalination is bad already. There can't be anything much crazier than presenting desalination as a significant environmental problem and using political power to suppress it - and then using political power again to ration people's water to deal with the artificial "drought" that political idiocy has caused. But that's what London - and national - politicians are doing.
But come on - surely it can't be the Greens and the mainstream politicians' fault, not when there's a multibillion-pound monopoly supplier like Thames Water in the picture. Certainly the company's customers, watching their bills surge upward as their gardens, parks and cars turn brown and dusty this summer, will not be pleased to hear that Beckton is shut down right now and that it ran at a measly 10 to 40 per cent of full output in March2; though a company spokesman assures The Register that it will be "running throughout the summer" and that there "may be days" where it is run at full power, depending on demand and rainfall in the months ahead.
That's not very impressive, though, when Thames Water has had the cheek to impose a ban on hosepipes using delegated governmental powers which it can employ at its own discretion. Running Beckton at full power wouldn't cost Thames Water much, as we've seen - but simply ordering a hosepipe ban costs the company nothing at all.
But to be honest, given the imbecilic political climate it was operating in, Thames Water probably deserves quite a lot of credit for getting Beckton built at all. Left to itself there can't be much doubt that the company would have built more Becktons as this would have achieved a lot more at less cost than digging up pipes and replacing them - though of course Thames Water is reluctant to say so for fear of drawing more flak from numerically illiterate Greens and journalists.
Instead the company has felt compelled to spend billions on reducing leakage in its pipe network by a relatively paltry amount3 - money which could have built more desalination plants and made London's water supplies drought-proof by now. There's no doubt that a lot of the city's aged Victorian pipes needed (and that many still need) replacing, but this was plainly not the most cost-effective way to spend the money with a serious supply shortage going on.
Sponsored: Benefits from the lessons learned in HPC