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Imagine a city in which the network of gas mains delivers renewable fuels. And buildings where water runs on two circuits 鈥� one to supply drinking water, the other combining grey water and run-off harvested from roofs to produce non-potable water. It might sound like a design feature of one of the new 鈥渟ustainable鈥� cities that China is building. In fact, this could be how Londoners get their energy and water in the years to come 鈥� if Allan Jones, chief executive of the London Climate Change Agency, has his way.

Jones, whose role is to advise London mayor Ken Livingstone on radical ways to tackle global warming, is convinced that renewable fuels will eventually take the place of natural gas 鈥� particularly in densely populated urban areas. He says the Greater London Authority is working on projects to produce alternative and hydrogen-rich fuels, and that new plant and equipment should be 鈥渄esigned to cope with changes in fuels and technologies鈥�.

His plans for water supplies are equally radical. They are one of his suggestions for the revised London Plan 鈥� a strategic document setting out the social, economic and environmental framework for London over the next 20 years. Public consultation on the proposed alterations ended in December, and Jones appears confident the changes will be accepted. 鈥淐onsulting engineers need to get themselves up to speed with the London Plan,鈥� he warns, 鈥渂ecause compliance will not be optional.鈥�

The stipulations of the original plan on energy production were already challenging for designers and engineers. Three years ago, mayor Livingstone introduced a groundbreaking ruling calling for 10% of the energy requirements of all major new developments in the capital to be met from renewable energy generated on site. This has resulted in a growing number of schemes incorporating renewables. Jones is about to make that task even tougher with proposals to double the renewables requirement and to change the criteria by which it is measured.

Jones is no stranger to radical initiatives. Before joining the agency in October 2004, he was a humble council official who almost single-handedly transformed the energy strategy of the borough of Woking. By the time he left, the Surrey town of 100,000 people had almost 10% of the UK鈥檚 photovoltaics; it was home to the country鈥檚 first 鈥減rivate wire鈥� network of combined heat and power (CHP) plants; and the council鈥檚 swimming pool had the first fuel cell CHP system in the UK. As a result of his efforts, CO2 emissions from public buildings were cut by 77%.

Now he wants to 鈥渁chieve something on a far bigger scale鈥� 鈥� and not just for London. 鈥淭he world鈥檚 cities are responsible for about 75% of the world鈥檚 CO2 emissions,鈥� he explains, 鈥渟o if you are going to tackle climate change it is not state governments but the big cities that will actually make a difference. That is why we鈥檝e been working internationally with some of the biggest cities around the globe through the Clinton climate initiative.鈥�

According to Jones, what makes London鈥檚 initiatives of interest to other cities is the holistic approach, with policies to tackle climate change that cover energy, water, waste and transport. 鈥淪ome cities have done more than we have in particular areas, for example New York has about 30 fuel cells,鈥� Jones says. 鈥淏ut it has not linked this to water, waste and transport.鈥�

Consulting engineers need to get up to speed with the new london plan, as compliance will not be optional

The establishment of the London Energy Service Company, or ESCo, is fundamental to this holistic approach. An ESCo is, effectively, a mini energy company set up to deliver power, heating and cooling for a development, as well as taking responsibility for the ongoing operation and maintenance of the plant. It will usually contribute towards the design and construction of an onsite energy centre in return for a contract to supply energy to the scheme.

The London ESCo is a joint venture between the GLA and French energy company EDF. The fact that Jones regards the company鈥檚 formation in September 2006 as his biggest single achievement since joining the GLA gives a sense of its fundamental importance in his plans. The business model for the ESCo is based on the same 鈥渄esign, build, finance and operate鈥� model that Jones used at Woking; but in London the ESCo鈥檚 remit has been broadened to include the use of alternative fuels, such as gas from waste.

He believes that providing developers with the possibility of establishing an ESCo makes it more difficult for them to challenge any requirement to incorporate renewable energy. Some of the big London regeneration projects, such as the Olympics and the Elephant and Castle, are already in discussions about the use of renewable energy and CHP solutions with the London ESCo.

CHP systems are another keystone of his vision for London. 鈥淒ecentralised energy production offers the best path for the rapid expansion of renewable energy,鈥� he says. London鈥檚 mayor has already declared his intent for 50% of London鈥檚 power needs, and 30% of its heat requirement, to be provided from decentralised technologies by 2025. He says that CHP has one of the 鈥渂iggest hits鈥� in terms of a reduction in CO2 emissions simply because it recovers the heat from electricity generation that large, centralised power

stations waste. The other big advantage, he argues, is that decentralised energy generation enables rapid expansion of renewable technology installations.

One of the more onerous alterations Jones is proposing to the London Plan is to increase the percentage of onsite-generated renewable energy on a scheme from 10% to 20%. In addition, in an attempt to displace electricity in favour of gas, he has also changed the wording in the Plan from 10% of 鈥渆nergy鈥� to 20% of 鈥渃arbon dioxide emissions鈥�, making the target even more difficult for consultants to achieve.

Jones accepts that the 20% requirement for renewables is not without controversy. He acknowledges the criticism that technologies such as wind turbines are less effective in the swirling wind of an inner city development than they would be out of town. 鈥淚 understand that, but the planners can only ask for something over which they have control,鈥� he says; hence the requirement for onsite renewables.

The easiest way to hit the target is to cut a scheme鈥檚 energy needs at the outset

He says the 20% figure will be difficult to achieve by relying on photovoltaic and wind technologies; and the change of emphasis from 20% of energy consumed to 20% of CO₂ emissions means that designers will have to take into account the carbon content of grid electricity when incorporating technologies such heat pumps. He is keen to point out that the easiest way to achieve the target is to reduce a scheme鈥檚 energy requirement at the outset, then use CHP fuelled from waste and biomass or connect to an existing CHP

system on an adjacent site. 鈥淚f you can use an alternative to natural gas or electricity then you are on the way to 100% renewable 鈥� it makes a seismic difference,鈥� he explains.

Jones expects the fuels of the future to be generated from waste or biomass, which he claims will be suitable as energy for both transport and buildings. He says there are plenty of non-recyclable wastes that can be converted into fuel, such as industrial and commercial waste, municipal waste, sewerage waste, biomass and energy crops, which could be converted into a common energy carrier such as a gas or a liquid fuel.

Of course, one way of getting around the requirement for renewable power sources would be to install them and then forget to run them; putting in a biomass boiler adjacent to a gas boiler, for example. Jones hints that the government is on to this particular ruse. 鈥淵ou are going to see some changes in the coming year 鈥� some of which will be driven by the government鈥檚 Energy White Paper.鈥� He says the paper, due to be published in the next month or so, will cover areas 鈥渘ot normally covered in energy papers, such as the retrospective testing of systems鈥�.

Much of the agency鈥檚 work thus far has involved energy, but Jones鈥� revisions to the London Plan also set tough new targets for water supply. 鈥淚n London, we produce water to drinking water standards and only consume 2% of it,鈥� he says. He is also keen to point out that London has had 20 months of continuous drought. 鈥淟ondon is now dryer than Istanbul or Dallas,鈥� he says. He adds that his proposal for the two circuits of potable and non-potable water on a scheme will also result in savings of CO2 emissions through reduced pump loads, something he says the planners will take into account when assessing a scheme.

The London Climate Change Agency has just moved into the Alsop-designed geometric Palestra building in London鈥檚 Southwark, a few buildings down the road from BSj鈥檚 HQ. So how green is its office? Jones says he was involved in the selection process, which included questions on the building鈥檚 BREEAM rating (it achieved a Very Good). It must have been quite a shock for the letting agents because he says one of the key questions the agency asked was if it would be possible for it to install a combined cooling heat and power system (CCHP) as well as use renewable energy.

The CCHP system is being designed at the moment. Originally it was planned just to supply the agency鈥檚 offices, but the building鈥檚 other tenant, Transport for London, has now agreed to be part of the initiative. 鈥淲e are looking to supply the whole building and possibly some of the surrounding buildings, as well as a hotel proposed for construction next door,鈥� he says.

One of the more visible additions to the building was a bank of 14 wind turbines on the roof, along with an expanse of photovoltaic panels. The peak output of the PVs is 63 kW, with the turbines expected to provide another 21 kW. However, the turbines have disappeared after a safety recall by the manufacturer. Prior to their removal Jones says the combined output of the turbines and that of the roof-mounted PVs was about 2 MWh in the first month. The manufacturer will replace the turbines soon, but it proves that, even for Jones, the issue of renewables is not without its challenges.