Nuage Vert (Green Cloud) - HeHe (Helen Evans & Heiko Hansen).
Helsinki, Finland, 2008

Funders / Commissioners: Commissioned for Pixelache Helsinki 08: Pixelache University.

Duration: Presented 22–29 February 2008.

Location Details: Projected onto smoke stack emissions at the Salmisaari power plant, Helsinki, Finland.

Date of Delivery: Presented 22–29 February 2008 as part of Pixelache Helsinki 08: Pixelache University.

Medium: Performance, installation.

Dimensions / Technical Specs: A powerful laser (up to 8.6 watts), associated campaign materials (posters, flyers, etc).

Project Delivery Team: Nuage Vert was developed in collaboration with experts in laser technology, computer science, electrical engineering, energy generation and air quality monitoring. These included: Martti Hyvönen, the environmental director of Helsingin Energia (hereafter ‘Helsinki Energy’) and company engineers; Jussi Palola, researcher at Helsinki Energy’s Electricity Network Company; Esa Räikkönen (a researcher specialising in lasers at the Helsinki University of Technology). The project also involved the collaboration of Dodo, a Finnish environmental activist group.

Funding Sources: Business, Individual, Local Government

Themes: Atmosphere, Energy

Duration: Temporary/Ephemeral

Author: Jodi Newcombe

Nuage Vert (meaning ‘Green Cloud’) was a public art installation presented in Helsinki in 2008 by HeHe (Helen Evans & Heiko Hansen) in collaboration with Helsinki Energy. By projecting green light onto the vapour cloud emitted from that city’s Salmisaari power plant the changing output of the plant is visible. This provided a means for communicating the results of efforts to by local residents and businesses reduce energy use in the Ruoholahti district, during a campaign entitled ‘Unplug!’. The people of Ruoholahti area were asked to unplug their electrical devices between 7–8 pm and to go outside to admire the Nuage Vert laser projection, which grew bigger as residents consumed less electricity. In HeHe’s projects, cloud forms have been used as a visual metaphor for and to aestheticise emissions. As Helen Evans wrote of Nuage Vert:

Of course, there is an element of fiction, in asking people to give up energy to feed Nuage Vert, as if the energy saved is then transferred onto the cloud. And the idea of reading information into a dynamic moving cloud requires a temporary suspension of disbelief. As a transmitting architecture, Nuage Vert conveys multiple ideas: could this green cloud be a toxic cloud or an emblem for the collective effort of the local community?  The meaning is left open for each and all to decide, and will depend upon the level of engagement.



Social Activation/Debate: The work Nuage Vert was intended to confront the inhabitants of Helsinki with the effects of their energy use. Evans has described this aim as follows: 

[I]t doesn’t offer a simple moralistic message, but rather tries to confront the city dweller with an evocative and aesthetic spectacle, which is open to interpretation and challenges ordinary perception. Turning a factory emission cloud green, inevitably, leads to questions being asked. It shifts the discourse about climate change and carbon emissions from abstract immaterial models based on the individual, to the tangible reality of urban life.


Methods of Evaluation

A self-evaluation of the project, written by Helen Evans, was published in Issue 7 of Cluster Magazine in May 2008. This article discussed the project’s concept, the strategic problems encountered and the project’s outcomes.


Aesthetic/Visual and Artistic Merit: The artists have received multiple awards for Nuage Vert. In 2008, they were recipients of the 2008 Golden Nica in the Hybrid Art category, 01SJ Green Prix for Environmental Art, and were co-recipients of the Ympäristötaiteen säätiö (Environmental Art Foundation) award for Environmental Artwork of the Year. According to the Arts Electronica Jury statement, “[The project] impressively demonstrated how art is capable of encompassing an entire city—its public sphere, its industry and its inhabitants—and unfolding sociopolitical relevance.”


Social Activation/Debate: According to Evans’ evaluation of Nuage Vert, engaging the cooperation of the power plant for delivery of the project was crucial to the project’s success in activating the community and stimulating debate, for it meant that the event was more than a symbolic act, making it instead a social process because “the actions and involvement of local residents living close to the active power plant were essential to the social outcomes of the project.”


Energy Efficiency: The artwork Nuage Vert and the associated Unplug! campaign were successful in drawing attention to energy usage and in reducing energy usage. According to the Nuage Vert website, Helsinki Energy reported that, “The load of Salmisaari substation decreased 2 MVA on 29 February 2008 between 7–8 pm. The normal value for decrease during this time is 1,2 MVA, so the effect of the UNPLUG event is approximately 800 kVA.” This was considered a successful result as the Salmisaari substation measured the energy consumed by over 30,000 residents in an adjoining area, in addition to the 4,000 Ruoholahti residents and five large companies participating in the Unplug! Event.

HeHe argue:

This is the first time there has been public monitoring of the collective consumption within a local area. Incredibly, despite the current energy crisis, electricity is only monitored on an individual basis. The results of the unplug event—realised on a tiny budget and with limited resources—shows that making collective information available to a community in a public form can make a difference.  

In 2008, as a result of the success of the project, and in conjunction with Nuage Vert being recognized as an Environmental Artwork of the Year by the Finnish Environmental Art Foundation, Helsinki Energy announced that it would release more real-time data about energy consumption in Helsinki area. According to HeHe:

Since Friday 6 February 2009, the hourly updated information about electricity consumption, heating and cooling has been available online. Inspired by the success of Nuage Vert project, Helsingin Energia is the first energy company in Finland to release this amount of detailed real-time information. This level of information transparency about energy consumption is also rare amongst energy companies in the world today. Helsingin Energia sees this as one method to spread awareness about the need to decrease energy use in near future. This is necessary for reaching the goal of providing a larger share of the total energy use by using renevable energy sources. The energy policies of the City of Helsinki aim to increase the share of renewable energy to 20% by 2020.


Helen Evans has described Nuage Vert as being, “conceived in 2003, whilst living in the suburbs of Paris, Saint-Ouen, looking out of the window onto a wonderfully dystopian view of a waste incinerator.” After being unable to realise the project in France, Evans set out to achieve the work in Helsinki. According to Evans, the production process involved much persuasion and many partners:

The environmental director of Helsinki Energy, rejected the project outright, but was at least open enough to meet. After a long 4-hour debate, he began to warm to the project and personally declared his support. It took another 3 years of discussions and partner building to get the official support of Helsinki Energy, which was achieved just four months before the launch, even though major preparations had already begun. The critical mass of partners, including environmental activists and a governmental think tank, was important enough to persuade the energy company that it had become politically favourable for them to embrace the project, rather than leave it to happen without them.

To realise a project on such a scale, it was necessary to collaborate with a wide range of organisations from sectors that wouldn’t normally work together: from culture, science, industry, communication and ecology. The technical aspects were realised with the help of scientists from the Laser physics department at Helsinki Technical University and the Computer science department at the University of Illinois, as well as a medical laser manufacturer, and the energy producer itself. To mediate the project, a communication strategy was devised that employed a naïve and iconic language designed by Devalence, a Parisian design group. Working with cultural management students, slogans were created for the flyers and posters, such as: “Aurora borealis in Helsinki?”. With Dodo, an Finnish environmental activist group, Nuage Vert was presented to 240 local school children, between the ages of 7 -16.  Local community groups distributed posters and flyers around the area and a sticker for switches & plugs asking people to Unplug! was distributed to 4,000 households.  The project was covered by all the local freesheets, the citywide press, national radio and regional TV news.  Although the communication strategy focused on activating Ruoholahti residents, the greening of the cloud was visible beyond the boundary of the city, over 10 km away.


Evans, Helen. “Nuage Vert.” Cluster: City-Design-Innovation, May 2008.

Evans, Helen and Heiko Hansen. Email correspondence with author, February 1-March 31, 2012. On file with author.

HeHe. Nuage Vert. (accessed February 1, 2012).

HeHe. “Nuage Vert.” Pixelache: Bank of Environmental Research and Power.] (accessed February 1, 2012).

This database is developed by the National Institute for Experimental Arts (NIEA) at COFA, UNSW in association with the City of Sydney and Carbon Arts as part of the Australian Research Council ARC linkage project Curating Cities.