If you ask me

We hear from the CEO of Thames Water about the challenges of supplying (and removing) 2,800 million litres of water every day; and in our second article E&T's power editor explains how Britannia still rules when it comes to offshore wind generation.

Replumbing London

Being able to explain the fundamental importance of engineering to society is an essential skill that many of us in the profession enjoy. But it has its frustrations. Whereas every new mobile phone or computer has many times the capacity of its predecessor, much of the basic physical infrastructure that sustains our lives is constrained by the laws of physics and essentially works very much as it did more than a century ago.

For Thames Water, the blend of ancient and modern provides a series of fascinating challenges. More than eight million customers rely on us to treat and supply around 2,800 million litres of water every day. Operating at that scale, while relying on raw material that falls somewhat unpredictably from the sky, requires good planning, sophisticated risk management and the skills of many talented engineers.

In February 2006 the company's models showed that if rainfall in the Thames Valley during the coming summer was less than 70 per cent of the usual average, London would be on water rationing by the autumn. Reservoirs were full, but a second successive dry winter had failed to recharge aquifers.

Fortunately, May saw almost twice the average monthly rainfall. The problem went away and it's now our job to ensure that we never reach that point again.

As always, plans start with reducing leakage. About a third of London's 10,000 miles of cast iron water pipes are more than 150 years old, half more than 100 years old. It was only five years ago that we finally demonstrated to everyone's satisfaction that, in addition to finding and fixing every substantial leak, a wholesale replacement programme was needed. By 2010 we will have replaced 1300 miles of the oldest and leakiest pipes. But that leaves thousands of miles still to be replaced before London has a really sound, modern water network.

At the same time, with population growing and the impacts of increasing climate change, we will need new sources of water. By next year our new desalination plant in east London will be in service and able to treat up to 140 million litres every day when there is a threat of drought or an emergency situation. This option is an important part of our overall plan to meet demand for water sustainably. The plant will be powered by renewable energy, produced from waste oils and fats, and will be used only when essential. This new resource, coupled with further reductions in leakage, will enable us to meet the projected demand for the next 15 years or so. By then we will need to have built a major new reservoir in Oxfordshire to store water taken from the upper Thames in winter when flows are high.

Treating waste water is an equally onerous responsibility. The main sewer network constructed in the 1850s by Sir Joseph Bazalgette was built painstakingly in brick and remains in good condition. The issue is that, although there have been many additions over the years, the major trunk sewers have the same capacity yet now serve around twice as many people, as well as taking the combined flows of sewage and highly variable amounts of rain water.

When Bazalgette built the system he took a pragmatic decision on size, and built strategic overflows to the river for when capacity was insufficient. In the 19th century they operated comparatively rarely, and when they did the discharges went into a river that was virtually dead. The situation today is very different and we are developing a solution, known as the London Tideway Tunnels, which will be 7.2m in diameter, at depths of up to 80m and with a total length of around 39km. Together they will capture and store the vast majority of the flows that would otherwise go into the river, pumping them out at our Beckton works for treatment.

This vast undertaking, finally completing Bazalgette's great design, will be a fundamental piece of infrastructure to support 21st century society. It will form one of the largest construction projects in Europe and provide a challenging task for a whole new generation of engineers. Just don't expect them to get as much attention from the public as the next generation of mobile phone!

David Owens, CEO, Thames Water

A mind for wind

The world is on the cusp of an energy revolution, and offshore wind is the key driving agent in achieving the UK government's ambitious renewable energy targets. Despite continuing interest in the still vast and untapped onshore opportunities in places such as North America and China, world attention is focusing on the emerging offshore market in Europe. We can expect to see at least 40GW of capacity installed by 2020 and even more after then. At least half of that figure will be in UK waters.

I feel it's true to say that the UK is the world leader in offshore wind. We have the most installed capacity - a modest 600MW maybe, but we also have the highest capacity currently in construction at 1.2GW and we have the greatest capacity consented and going forward to construction, another 3.6GW, and a staggering 40GW in planning.

To realise the full potential of this opportunity we must learn the lessons of the past. Too often we have missed out with onshore wind. Our failure to secure planning permission for new wind farms sent manufacturing industry elsewhere. Today we have just 5,000 people working in our industry, while Germany has 80,000 and Spain has 30,000 and even Denmark - with less installed capacity than Britain - has 20,000 employees in the sector.

A report produced by management consultants Bain & Company last autumn showed we could have at least 60,000 people directly employed in UK-based jobs within a decade, while delivering a breathtaking £60bn worth of private investment to create a new and vibrant industry.

This summer should see the publication of the government's renewable energy strategy, which will aim to set out a route map for delivery of the EU-led 2020 renewable energy targets. In just ten years we have to increase the contribution from renewables to the electricity generation mix from 5 per cent to 35 per cent.

Wind energy is key. The renewable energy strategy needs to recognise that and make move moves to clear the decks of obstacles that currently stand in its way. The government must ensure that the planning regime does not undermine the expansion of offshore wind.

Above all we cannot avoid the challenge of grid. We need to build and finance a whole new offshore grid network. 

Ad hoc connections will not provide the confidence and certainty needed for either developers or for manufacturers. We need a zonal approach which allows for a managed market for grid or we simply will not deliver on time. 

In a global context offshore wind is still in its infancy, but Britain is the world leader in offshore wind, and we have the chance to convert that lead into a vibrant and lucrative industry.

Mark Venables power editor

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