Carbon free cities

There is no doubt that if the world is going to truly tackle global warming and world energy problems, governments must win over the hearts and minds of average consumers. So far, in the UK at least, sustainable energy has a rather eccentric image (which hasn't been improved by recent television advertisements). But in other countries, a more serious and long-term commitment is being made to informing the population at large about alternatives to fossil fuel.

A major prime time television programme about renewable hydrogen power on the BBC, informing viewers about a carbon-free future for cities would be unusual. Not so with the Dutch channel VPRO. City for the Future describes the advancing technology of hydrogen as another sustainable energy source for the benefit of industry, housing and transport that is actively being developed and instrumented. In the Netherlands, it must be remembered that sustainable energy has already made more inroads than here, with aquifer and ground energy storage tests already taking place.

In the programme in question there were contributions from Shell Hydrogen and Amsterdam's City transport authority. In public information forums university research professors were joined by hard-nosed manufacturing engineers to prove that the means are available to break our dependency on fossil fuels and produce electrical power without walking back down the nuclear road.

The Dutch philosophy is that to reduce our dependency on fossil fuels, renewable energy technologies will, at first, have to be widely integrated into existing energy systems on a local, national and cross-border level.

The Dutch television programme took its viewing public into a simulated hydrogen powered, carbon-free city where urban wind turbines, arrays of photovoltaic solar panels and water were the basic elements for the production of locally generated electricity.

Real examples
It illustrated a simple 'can-do' system. This proposed methodology will depend on cities and urban areas being completely re-plumbed with new service grids. These will allow passage for all the new pipes, tubes and cables of conveyance, along with drainage, water, telecommunications and other supply systems – the essential kit needed for a modern city to operate.

Actual real time demonstration in new urban areas has reached the action planning stage. Automated subterranean supply tube tunnels to transport goods from rail, water and road freight terminals on the outskirts of towns to inner-city shopping areas are already planned. They will soon make their mark in the southern Dutch city of Tilburg with even more extensive plans being prepared for Amsterdam.

City planners and urban engineers are ready to agree that such service grids and road routes would not only be supply lines for hydrogen produced electrical power, but also surface collectors for solar energy, both as a means for creating sustainable road life, building infrastructure thermal heating and cooling, and means of electrical power generation, as described in an earlier article in BSj¹.

Electrical power generation for the UK has become the big issue. The fear is that soon the plug will be pulled and that so far Britain's politicians appear to be sleepwalking into an energy crisis by increasing our dependence on imported gas.

The best forecasts suggest that by 2020 gas will supply 68% to 75% of our electricity requirements. Most of this will be imported from relatively unstable countries where there is a risk that supplies could be cut off. Many engineers believe that Britain needs a more balanced approach with diversity, reliability and security of supply, and this is plainly true.

Many believe that electricity generated by a mixture of coal – with all its advanced technologies of combustion being left on the shelf in the wake of mine closures – oil, gas and advancing renewable energy technologies makes for a much lower-risk scenario to ensure that the lights don't go out.

Nuclear power is of course another option, but one which has its own inherent risks, especially in this new age of world terror and counter-terror. We also still have a long financial road to go down to pay for the decommissioning of existing nuclear plants. And the public view of nuclear power has been tainted by international accidents, stories of fuel leaks and strong anti-nuclear lobbying.

This means that the search is on for another electricity generating power source. Hydrogen could be a key element for a fully integrated European energy economy. It can be obtained from many primary energy resources by treating fossil or biomass fuels, or by the electrolysis of water using electrical power derived from wind turbines, photovoltaics, or installing thermo-couple linear road and pavement systems². Hydrogen can be employed directly in combustion processes in the same way as gasoline or natural gas. However, fuel cells represent the most promising technology for using hydrogen for power generation in a wide range of energy end-use applications. What is important to realise is that electrical production can make a diverse energy portfolio viable while simultaneously meeting local, regional and global energy and environmental demands.

New hydrogen sources
At the time of writing, hydrogen is produced by reforming fossil fuels such as natural gas, which in turn results in CO₂ emissions that could be captured and set apart for later beneficial use. However acres of corn and other biomass plants with a good dose of sunlight can be the cheap and plentiful ingredient to producing hydrogen. American chemical engineers at the University of Minnesota have published details of a new chemical reaction that turns ethanol, an inexpensive and renewable fuel that comes from fermented sugar (corn/sugar cane = starch = sugar = ethanol) is a key to the production of hydrogen in profitable and viable quantities.

According to Lanny Schmidt, the chief scientist of the project: "One of the chief advantages of our new conversion process is that from the fermentation process we are able to squeeze out extra bubbles of hydrogen. This increases the corn-to-fuel conversion and can capture some 50% of the energy stored in corn sugar, whereas burning the sugar in cars as found in Brazil harvests only 20%." He continues: "In the short term the big applications in the USA and Europe is for remote, off-grid emergency applications. However, ethanol from corn is unlikely to provide all the hydrogen we might need for global requirements."

Schmidt underlines the case for diversity and integration of sustainable energy technologies. This points to the need for the UK government to actively support both educational research and development and to finance these new energy industries for the creation of new jobs and new industries that could make British cities carbon free, and to provide new export into an expanding European and world markets³.

It is often forgotten that biomass energy, in the shape of fields of corn, or rape, sustainable woodlands and other fast growing crops, can be part of the city-urban landscape. Interfaced with rivers, lakes and waterways that can themselves augment the quality of city life. Energy crops, even those that can help produce ethanol-hydrogen are cash crops that should be part of both rural and urban landscape. There is nothing that should be left out of this energy debate.

For hydrogen to become a key energy carrier an appropriate infrastructure must be developed. This would include advanced production and storage, as well as distribution and delivery systems which in turn will require extensive pan-European co-operation.

The European Commission's 6th Framework Programme (FP6) has begun to fund industrial initiatives with ways to store hydrogen with improved performance, higher safety standards as well as reduced storage costs. In particular it is looking at metal hydrides for on-board storage in vehicles with a target cost of 10 euros per kWh stored.

Throughout the Netherlands analysis and comparison of production pathways leading to hydrogen production at large-industrial as well as small filling stations, at prices competitive with conventional fossil fuels is currently well underway.

Breaking old patterns
One of the new manufacturers in the field is Hexion BV based in Arnhem. With in-house research and development linked to the Technical University of Delft, a range of specialist test equipment and fuel processors is being manufactured and marketed for the current gas, propane and biofuel triggers for hydrogen production. Hexion has just unveiled its new filling station pump for the use with hydrogen driven vehicles that only emit water vapour as an exhaust.

Whether we are to produce hydrogen; collect, store and transmit solar energy along roads; erect high powered and large wind turbines offshore; or small but high powered urban wind turbines on buildings; or drill into our ground and earthbound waterways to extract energy, we shall need to break existing rules. This will be the case for the generation of electrical power.

Yesterday and today we have central power stations burning soft coals and gas, plus the odd nuclear plant, generating very inefficient electrical power, with high carbon and other greenhouse gas emissions which is then transmitted through a distribution network to homes, schools, hospitals, commercial offices and industry. We need to rethink this way of doing things if we are to tackle global warming quickly.

On-site electricity generation can account for many of our local and cityscape needs. Industry, seaports, airports and other large scale remote locations can be dealt with by designated special plants.

Electrical power generated by hydrogen can be part of a fully integrated network of wind, solar and other forms of energy technologies that can also supply energy independently. They are all interdependent and independent but in unison could create a viable sustainable energy policy for the UK.

Perhaps it is not just a question of breaking the rules, but also of fundamentally rethinking how we build our towns and cities. In the early 1970s I had the task of designing a district heating scheme for 2000 houses in the Midlands industrial town of Corby. One of the proposals was to place all the hot water mains to the houses in a specially constructed SERGRID multiple services tunnel. The drainage sewer would be at the bottom of the egg-shaped tunnel along which a maintenance man could pass and work on the gas, water, electrical, telephone cables together with the district heating mains and space for future tubes and pipes.

Although the engineers of gas, water and electricity thought the idea good, nobody would agree to collaborate. The utilities remain in a time-warp installing their own individual road or pavement systems and causes the madness of increased traffic mayhem because of constant digging for repairs.

In 1999 the Deputy Prime Minister, John Prescott, wrote in the preface of a report put forward by Lord Rogers' Urban Task Force report that: "We (the government) have already started the modernisation of our planning system…and to put into place an integrated transport policy designed to make our urban and rural areas work."

John Prescott has another chance to live up to his promises with the extensive urban developments planned for Thames Gateway as well as other areas of the nation.

The Thames Gateway urban expansion provides an open window to incorporate the technical sinews that make a city work in a more integrated, easy to maintain and less costly form. With the effects of rising sea-levels in our immediate future the whole process of building on waterways will have to be re-thought.

Like the Dutch, buildings will need to either be erected on new floating islands, or set on stilts above the rising seas. Energy transmission and distribution will require new ideas and ways of viability. Waterborne cities will also need to be linked to the natural order of things; such as off-shore winds, solar sunlight and possibly the fields of corn that can be growing amidst the new polder-lands of Essex in the years 2020 and beyond.

The Renewables Innovation Review, conducted by the DTI and the Carbon Trust in late February says that wind-power alone will not be be enough to meet the government's 2050 carbon reduction targets.

  It calls for strategic planning and funding to exploit the full economic and environmental potential of our renewables industry.

Specific key issues being addressed include and examination of any barriers to the development and deployment of expanding new technologies and the report highlights the important role that fuel cells can play in delivering large carbon savings through improved efficiency.

But there appears to be no reference to the proposed demonstration of solar collecting roads as indicated by the UK Highways Agency. "We cannot rest on our laurels", are the words of the energy minister Stephen Timms used when presenting the report⁴. This is important advice, but the government seems unwilling to follow it to any great extent.

More urgency and co-operation
Sadly government reports keep talking in the long term. Such words restrict urgency. Our governmental departments still seem to live in separate rooms and time zones. Surely it is time to radicalise our approach to energy, transport, health and the built environment to benefit the state of the nation. The time has come to go on the fast-track and to overcome what are only perceived barriers towards integration!

Building services and energy engineers are fully aware that there are many viable and sustainable energy sources for which we have the technical knowledge and ability to deploy, as numerous examples from the Netherlands demonstrate.

What needs to be done is to bring together the different technologies along with energy consultants, urban planners, city and government agencies, with people from CIBSE and other institutions to hammer out a real-time working policy to integrate and implement all the renewable technologies we have within our reach.

This would then give the UK a strong and viable energy source bank that with further incentive allows us to be able to export carbon-free electricity from our carbon-free cities and land.