Liter of Light at COP21

The 2015 United Nations Climate Change Conference (COP21) is being held in Paris (France) on 30 November – 11 December 2015. COP21 aims to to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2°C. The conference is expected to attract close to 50,000 participants including 25,000 official delegates from government, intergovernmental organisations, UN agencies, NGOs and civil society. The Liter of Light movement will be present at COP21 organizing several workshops and activities.


The main objective of the annual Conference of Parties (COP) is to review the Convention’s implementation. The first COP took place in Berlin in 1995 and significant meetings since then have included COP3 where the Kyoto Protocol was adopted, COP11 where the Montreal Action Plan was produced, COP15 in Copenhagen where an agreement to success Kyoto Protocol was unfortunately not realised and COP17 in Durban where the Green Climate Fund was created.

In 2015 COP21, also known as the 2015 Paris Climate Conference, will, for the first time in over 20 years of UN negotiations, aim to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2°C.

Liter of Light is a global open source movement aiming to provide ecologically sustainable and cost-free lighting for simple dwellings with thin roofs. The device is simple: a transparent 1.5–2 L plastic bottle, as typically used for carbonated drinks, is filled with water plus a little bleach to inhibit algal growth and fitted into a hole in a roof. The device functions like a deck prism: during daytime the water inside the bottle refracts sunlight, delivering about as much light as a 40–60 watt incandescent bulb to the interior.

The Liter of Light began in the Philippines with one bottle light. Eventually, the movement grew to brighten up 28,000 homes and the lives of 70,000 people in Metro Manila alone. Now Liter of Light is present in India, Indonesia, and even as far away as Switzerland. Their goal is to install one million bottle lights around the world in 2015.

Liter of Light Key Events at COP21

  • Liter of Light Workshop and Information Space at Shamengo - Espaces Generation Climat

Where: Villa Shamengo and atelier

December 1 - 11 | 10:30am - 7:00pm

December 2 | 3:00pm - 5:00pm, workshop to build solar bottle lights

  • Innovation Night in partnership with the Economic Social and Environmental Council (CESE - Conseil Economic, Social, et Environnemental)

Where: Place d'Iena, 75016

December 3 | 7:30pm - 11:30pm, an evening to introduce entrepreneurs and innovations

  • COP21 Solutions and Innovation Week

Where: Grand Palais

December 6 | 2pm - 2:50pm, conference speech to introduce Liter of Light and explain our community-build solar technology

December 7 - 9 | information booth where participants can learn more about Liter of Light

About IYL 2015

The International Year of Light and Light-Based Technologies (IYL 2015) is a global initiative adopted by the United Nations (A/RES/68/221) to raise awareness of how optical technologies promote sustainable development and provide solutions to worldwide challenges in energy, education, agriculture, communications and health.  With UNESCO as lead agency, IYL 2015 programs will promote improved public and political understanding of the central role of light in the modern world while also celebrating noteworthy anniversaries in 2015—from the first studies of optics 1,000 years ago to discoveries in optical communications that power the Internet today.  The IYL Global Secretariat is located at the Abdus Salam International Centre of Theoretical Physics (ICTP).

The Founding Partners of IYL 2015 are the American Institute of Physics (AIP), the American Physical Society (APS), the Deutsche Physikalische Gesellschaft (DPG), the European Physical Society (EPS), the Abdus Salam International Centre of Theoretical Physics (ICTP), the IEEE Photonics Society (IPS), the Institute of Physics (IOP), Light: Science and Applications, the International Network, 1001 Inventions, The Optical Society (OSA) and the International Society for Optics and Photonics (SPIE). 

Patron Sponsors include Bosca, the International Association of Lighting Designers (IALD), Royal Philips Lighting, Thorlabs and UL.


Ami Valdemoro
Director Liter of Light

John Dudley
Steering Committee Chair
International Year of Light and Light-based Technologies 2015

Joe Niemela
Global Coordinator (IYL Secretariat)
International Year of Light and Light-based Technologies 2015