Starters of urban change (4) Air conditioning and façades: the problem of Haussmann’s umbrella


When the Baron Haussman wrote his memories, after having lost his large power over Paris, he told that what Napoleon III really wanted at the Halles was, simply, to create a “large umbrella”. I say “simply” as works began with a classical stone architecture that was criticized, and the image that now everyone remembers, of steel and glass pavilions, resulted from an order to reduce expenditure. With a large umbrella merchants could go without individual ones on rainy days. So were made many things during the last two centuries: doing “large umbrellas”, so you could live without one for yourself if you liked it that way, or it was out of reach for you. Public hospitals against private doctors, public schools against church schools,…

Buckminster Fuller proposed in 1960 the erection of a large dome over midtown Manhattan to control climate, a project that was never built and that could have faced relevant problems. In a given moment, direct satellite mobile phones were introduced to talk between anywhere and any place. The first idea was never implemented due to cost, and the second one was implemented but never gained wide traction. Sometimes simpler systems win.

Air conditioning is an example of the kind of urban catalyzers in the ascending sense. We could imagine a dome over the city, controlling climate, and in fact in some areas district heating exists; in northern Europe there are even interconnected district heating systems, which achieve high energy performances. But for the regions of extreme cold in which energy bills are high, or when large landowners can better manage the energy bill through large systems, in most areas in the world in which heat is intense, the “dowry” (not in the marriage sense…) of the middle class has grown. Once you get into a certain income class, you sure buy a car, but you also buy (before or after is a matter of choice) air conditioning.

In countries such as Anglo-Saxons, with a substantial share of individual homes, this is not that relevant in terms of urban landscape. But in places in which apartments are relevant, as in Spain or China, or in dense cities, architecture is impacted. Sure, some buildings have their mechanical elements over the roof, but this is still a reduced share, as housing buildings tend to last quite long.

Often local rules forbid locating condensation units for air conditioning in façades, but this is the most common solution as the installer can do a simpler work, ducts are more affordable, and the machine works better. As each owner calls an installer when he likes, and he uses his own ideas, brand and model, architecture suffers. Sure, some buildings have scarce previous qualities, but other get an appalling treatment. It is worth reminding that urban landscape quality is not just a matter of sublime elements, but also clutter control.

As dismantling these contraptions from façades is complex, I foresee that many will still be there after years without use. I can even imagine that in a hundred years, even if the system itself is no longer used, some areas will promote their “vintage early XXIst century architecture” bragging about their authentic air conditioning devices….

European choices (4) Zero energy


Directive 2010/31/EU on the energy performance of buildings requires that by 31 December 2020 all new buildings are nearly zero-energy buildings, and also mandates that condition for buildings owned and occupied by public authorities by 31 December 2018.

According to the Directive, a near zero energy building “means a building that has a very high energy performance, as determined in accordance with Annex I. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby”. So the precise, quantified definition (a central matter in such a Directive) is left to each state.

According to the COM/2013/0483final report (covering just some of the states), first in a series of triennial reports on the implementation of the Directive, most of the states have made progress, but only Belgium, Cyprus, Denmark and Lithuania have presented a definition with a quantified goal and a percentage of renewable energies. On the other side, the Netherlands, Denmark, France, Germany and the UK have some rules that go beyond. The numerical definitions oscillate from 0 to 220 kWh/sq m/year, so the report asks whether the goal of the Directive is really that.

The Directive mandates an intermediate goal for new buildings in 2015. So far 15 states have met that mandate, but with diverging measures.

So we have here a policy about climate change (controversial for some) but also about energy independence (will Poles or Baltics be more eager to implement that Directive than, say, Irish, after the Ukraine crisis?). And it is also an urban planning policy, as the buildings add up the energy demand of cities, and renewables are regulated in city planning.

Maps 2014 (9) Renewable energy in the UK

Renewable energy production systems installed in Europe during recent years mean that often areas that for most of the XXth century have just been energy consumers have become producers. This has meant revenues, but also negative externalities of many kinds.

As one more element in an increasingly growing trend all over Europe, the UK, up until now among the forefront states in terms of climate policy and mitigation, shows signs of a shift. And economic reasons are there, which requires at least a thought as in a democracy a government is elected to choose between opposed options. A recent report (November 2013) by Stephen Gibbons, from the London School of Economics, studied the impact of wind turbines on real estate values in neighbouring areas, with reductions averaging 11%. In June 2013 there were news about the study by the UK government of a compensation scheme for neighbouring communities. has published an interactive map showing the extent of the renewable energy systems across the UK, each with a potential impact; and the Highland Council map reveals the degree to which northern Scotland is receiving wind farms. On the other side, the opposition to wind farms in Europe is organizing initiatives as EPAW; its real capacity to push for alternatives  depends on how they will reconcile potentially contradictory demands of their members. Those willing to defend the real estate value of their land, often to build more, can disagree with those opposing wind farms just for the sake of environmental and landscape conservation.

Highland Council map

This can lead, in a context as the European one, with an aging population and a severe depopulation of the countryside, to a division between “franchised areas” in which almost everything is allowed, and “protected areas” in which these impacts are prevented. These protected areas would be rather different from what nowadays we know as such, as these (low or zero human presence, but environmental values) could eventually be “franchised”. After all, the European Landscape Convention says that a landscape exists by virtue of the presence of an observer…

But there may also be here a cultural issue. A 2009 report by the Massachusetts Clean Energy Center, based on US cases, showed just a minimal impact on real estate values. This would not mean Americans love their windmills, but rather that they have a different relative perception of their impact (and a different method in the reports).

Sea, Land (6)

Malta surIn southern Malta you are told to visit the Marsaxlokk harbor, with picturesque traditional boats. On the background you can see the Delimara power station, a strategic energy asset for the islands. It may see an eyesore to many, but Malta is a book case on the issues raised in a place where the land is so scarce you cannot hide needed big infrastructures (an equivalent solar array or a group of wind turbine would be equally visible in such a small island).

Power, weight and energy

An image of project Gamera from its website

Urban energy comes to mind again in Europe. Despite the official statements on the need to develop alternative energy sources and to install large trans-european energy lines to use the Spanish sun or the Scottish wind, it seems clear that oil will still be here for a moment. So, the issue of efficiency becomes central.

Can we learn from other fields? transportation brings some elements. The incremental reduction of airplane weight due to composite materials and, more recently, to additive manufacturing techniques (3d printing) has been joined by aerodynamic improvements. Overall, an addition of succesive 2%- 3% reduction of oil use has made the current airplanes far more efficient than their predecessors. It is also worth noting that the increase in overall traffic has been relevant during the past decades, so this has become a Jevons paradox (increase in efficiency coupled to a strong increase of overall consumption).

in aeronautics the essential element is the weight of a given aerodynamic shape able to withstand forces and deliver performance. You can really go quite far along this way, as Gamera, the research project by the Univeristy of Maryland, shows in the case of a human-powered helicopter. Far from operational or even practical, but intresting. What can be thought of in terms of urban planning, in which weight is not necesarily the central element? to be seen in the next posts…

8.800 kW for 350 km/h

AV-atoch-1You wake up early, to come to the Station. And here are those high speed trains, waiting to take you to your day job. The one you see in the first place is an AVE 103, by Siemens, weights 447 metric tons and it can get 404 passangers at 350 Km/h with an electric power of 8.800 kW.

How much energy is the city using

The London Heat Map, an interesting initiative to adress energy in the city

Accounting the urban energy consumption raises some issues:

–          Electricity is often provided by several private companies that do not disclose detailed information. Gas delivered by pipe is in the same situation. Despite that, you can (theoretically) obtain a figure at the household level.

–          Fuels are rather complex, but for deliveries to big clients. How to count the automotive fuels, at the pump, at the owner’s address, or in the road sections where they are burnt? And the bottled gas sometimes sold in some filling stations? Or wood?

–          Renewable energy can be decentralized generation; if it is later delivered to the general grid its accounting is more complex (but you an always think of a citywide balance)

And there is another problem: efficiency. What matters is not just how much energy you use, but rather how efficient that use is. The district heating systems that are common in northern Europe often begin as isolated power stations, but gain in efficiency as they are integrated in grids, as well as a home can be more efficient if the wall insulation is upgraded. So there is not just an issue of consumption, but also of the benefit that derives.

The energy part of the Green City Index, by Siemens, gave in 2009 the highest mark to Oslo (8,71), while London was 10th (5,64) and Madrid 12th (5,52) among the 30 studied European capitals. These marks resulted from 3 quantitative criteria: energy consumption (Gj per capita), energy intensity (Mj per unit of real GDP), renewable energy consumption (% of total consumption); and a fourth qualitative element addressing energy policies.

Water (1) Desalination

What to do when there is no fresh water nearby? either you make a long aqueduct to bring water from a distant source, or you use a desalination plant if salt or brackish water is at hand. This has been done in some parts of the spanish southeast coast. The Bajo Almanzora desalination plant brings water to an intensive cultivation area without need for long aqueducts.

With a production capacity of 20 cu hm of water per year and a 75,9 million euros investment (23 of which come from European funds), the 150.000 people and the farmers in the area access a more reliable water source than what is normally available in this dry area. Using an inverse osmosis technology, the factory ensures the brine (water with a much higher salt concentration that is discarded as a result of the desalination process) is brought to an environmentally adequate discharge point through a 2,5 km pipe (the sea is close to the plant, as you can see on google maps). The plant takes no more than 5 hectares on the ground.

I don’t know the accurate data on this plant, but if we take an average efficiency of 4 kwh of electricity for each cu meter of desalted water (an usual value for such plants), the yearly demand of 20 cubic hectometers would be 800 Mwh of electricity. With wind farms usually beyond 50 Mw of installed capacity, this can be done on renewable energies (altough it is not always the case, and a connection to the grid is needed for those days in which the wind is not blowing). As an example, a specific publication on the issue. 

Energy (2) Sun

The Charanka solar park, in the Indian state of Gujarat, covers a 20 sq km area; it should attain 1 GW of production capacity when completed. From January to October 2012 the electric output was 686 GWh, so taking into account a per capita yearly electric power consumption of 616 KWh in 2010 according to the World Bank, would serve for a year more than 1,11 million Indian citizens (or slightly more than 111.000 Spaniards, 88.700 French, or 51.000 persons from the US…). It concentrates a set of solar panels from different firms.

The project is associated to an hydraulic system whose canals will be at least partially covered by solar panels, as to reduce the evaporation losses, relevant near the dessert.

Energy (1) Wind

Wind turbines in Gran Canaria. Under their base, agricultural greenhouses

Wind turbines in Gran Canaria. Under their base, agricultural greenhouses

Wind energy is, at least in Spain, one of the most mature renewable generation sources after years of growth through the expansion of the installed power with ever larger turbines. In 2011 its output was similar to that of hydroelectricity. It is also one of the clearest proofs that local energy generation reduces dependence from foreign sources, but also brings back things like space needs and nuisances that we sometimes forget in Europe with oil.

The urban and regional planning limitations to wind power are based on:

  1. The environmental impact of building the wind farms, due to the access roads and the need for electrical lines to connect to the grid, to the noise and to the effects on birds (and on the sea life when wind farms are offshore).
  2. The landscape impact of elements whose efficiency is generally higher when on summits and divides, and therefore on the most visible spots (when offshore the distance usually diminishes impact).

Wind farms can take a long time to obtain permits, and are seen as a long term investment as their position value is not subject to much change. Some wind farms attain a capacity of 1 GW (Chernobyl nuclear plant was 4 GW), as the AltaWind Energy Center in California, a set of 320 turbines on a 36 sq km area. A large turbine is a device that can reach 200 m in height, with a nominal power of nearly 8 MW, and despite the limits to uses around it, in some cases it seems possible to have agriculture and livestock under it.

Wind intermittency and its non-coincidence with demand is a problem; until now the solution has been a balance with hydropower to allow, through secondary reservoirs, to stock the energy by  lifting water to main reservoirs; some companies (as Apple) are researching the use of thermal technologies to stock energy without the need for batteries. Other alternatives are also being researched.

The aforementioned limitations to wind farms in planning are related to permanent venues, but there are other proposals. Uprise Energy integrates a 50 KW turbine in a container that can be moved easily. Regardless of the profitability of using as a fixed element a portable solution, the idea of portable energy generation reminds Archigram’s “walking city”; it would be interesting to see how the environmental law is applied to these elements…

Ona more reduced scale, the integration of wind energy in urban buildings is still uncertain; there are no clear rules for products that have yet to attain a real industrial development, and often you see turbines that seem without reason. Noise could be a problem, but also the long term management of an atomized generation system (and this is not only concerning wind power).