Too Much of a Good Thing: LEDs on Buildings

Here is another demonstration of the rebound effect gone mad.

UNIFUN Chengdu by CLOU architects

Arch-Exist via v2com

CLOU architects show us UNIFUN Tianfu Chengdu, "an online and offline architecture with a multi-media facade system and a large area of outdoor social space." In a press kit, CLOU says that their aim is to "integrate architectural form and digital promotion into a coherent whole." It is basically a building made out of LEDs and is a great example of how the technology is leading to grand new ways to consume electricity and produce CO2 emissions; the Jevons Paradox in lights.

UNIFUN chengdu in evening signage
Arch-Exist via v2com

A decade ago, Ted Nordhaus and Michael Shellenberger of the Breakthrough Institute resurrected the Jevons Paradox to argue that increases in energy efficiency would be eaten up by increased demand. This ruined poor Stanley Jevons's reputation, because as Zack Semke has written, "They like the Jevons Paradox because it plays into the Institute’s pro-nuke, pro-gas, anti-carbon tax, anti-regulation platform and helps them argue that energy conservation is a waste of time and resources." Semke notes that "Jevons research is highly politicized" which is an understatement; to even acknowledge the rebound effect or the Jevons Paradox can make you a bit of a pariah in some circles.

Semke acknowledges that there is a rebound effect, but that it is much smaller than the savings, noting "an Energy Journal survey of the research finds a rebound effect of between 10-30% for efficiency measures in the residential and transportation sectors, and 0-20% for industries, making overall efficiency measures 70-100% effective."

UNIFUN in evening
Arch-Exist via v2com

I have previously tried to make the case that LED lighting is fundamentally different, that it is a technological revolution on the scale of Watt's steam engine, which Jevons was writing about. I noted earlier:

"People invented new uses for steam power as fast as they could build them. It was not just incremental energy efficiency, it was a seriously radical change in the economics of steam engines – which is exactly what has happened with LEDs. A radical improvement in technology has led to an explosion of new opportunities to use them in imaginative and sometimes silly new ways."

When I reported on a study that found light levels were increasing dramatically around the world at a rate of about 2% per year, study author Jamie Fox responded by noting that light efficiency was increasing faster than light levels.

"LEDs use approx. 60% less energy to produce the same light on average due to higher efficiency compared to other technologies on average (80% vs incandescents, 40% vs fluorescent). So to produce x amount of light you need 40 units of electricity instead of 100. So, LEDs can only lead to more energy use if they lead to more than 2.5x the amount of light being used. More light will be used yes, but not that much more. I assumed 15% more in my calculations which is admittedly a guesstimate. "

He didn't believe that the exterior lighting was significant; "within a building, lighting the physical space of the building accounts for most of the light. Additional decorative uses will be a small amount of the total light."

UNIFUN in context and sunshine
Arch-Exist via v2com

Yet here we have a building explicitly designed to be a "digital canvas, as an upgrade of traditional façade advertising, could broadcast exciting and informative content in real-time such as branding images, online advertisement, social media activities, and offline event information." From the press kit:

"Maison de la Publicité Project by Oscar Nitzchke with Hugo Herdeg is considered as a media architecture as early as 1936. The utility of lighting and photomontage transforms the building into a media device that brings a new understanding of façade into the architecture world. One of the important factors that affect the media facade is lighting technology, for instance, the visual of a regular facade can be varied by lighting to present a series of free-flowing patterns. Different lighting effects can be continuously adjusted to change the facade of the building, and will also interact better with the multi-media screen. From light to shade, color, and graphics changes of the façade system, CLOU architects expect to achieve different visual effects for UNIFUN from the outside."

I have never seen Nitzchke's' Maison de la Publicité referenced before; it was a huge influence on me in architecture school, it inspired a whole year's work. it had an entire façade of signage. One could also argue that they have been doing this in Times Square forever, or that one building in Chengdu is just that, one building.

UNIFUN in evening with QR code
Arch-Exist via v2com

But I think we are going to see a lot more of this, with LEDs becoming part of the building fabric, more than just decorative elements but actually, as CLOU architects conclude, "opening up the possibilities and extending the reach of architecture."

Of course, there is a footprint to running all those lights, especially in China where so much of the electricity is coal-fired. According to one manufacturer, the power required per square meter is between 165 and 275 watts. The math is scary, given that Chinese electricity pumps out 721 grams of CO2 per kWh (PDF).

UNIFUN from street in evening
Arch-Exist via v2com

None of this would have been possible without the dramatic efficiency improvements that came with LEDs. Nobody would have imagined even doing this kind of architecture.

In their 1997 study, "Perceptual and structural barriers to investing in natural capital: Economics from an ecological footprint perspective," Mathis Wackernagel and William Rees worried a lot about Jevons, quoting his statement that "the progress of any branch of manufacture excites a new activity in most other branches and leads indirectly, if not directly, to increased inroads upon our seams of coal"

UNIFUN with QR code
Arch-Exist via v2com

Here in Chengdu, the architects have got really excited and their work is leading directly into Chinese seams of coal. Wackernagel and Rees suggested a solution:

"Can we afford cost-saving energy efficiency? The answer is 'yes' only if efficiency gains are taxed away or otherwise removed from further economic circulation. Preferably they should be captured for reinvestment in natural capital rehabilitation."

Perhaps they are on to something.

View Article Sources
  1. "Energy Emergence: Rebound and Backfire as Emergent Phenomena." The Breakthrough, 2011.


  3. A. Greening, Lorna, et al. "Energy Efficiency And Consumption — The Rebound Effect — A Survey." Energy Policy, vol. 28, no. 6-7, 2000, pp. 389-401, doi:10.1016/s0301-4215(00)00021-5

  4. "How to Calculate LED Screen Power Consumption." Finepixel Led.

  5. Wackernagel, Mathis, and William E. Rees. "Perceptual and Structural Barriers to Investing in Natural Capital: Economics from an Ecological Footprint Perspective." Ecological Economics, vol. 20, no. 1, 1997, pp. 3-24, doi:10.1016/s0921-8009(96)00077-8