Lighten up: the power of water and bleach

liter of light

This concept has been introduced a couple of years ago, the result however is very impressive so I’d like to put it in the ‘spotlight’ again. In 2002 Alfredo Moser in Brazil came up with the idea to use bottles filled with water and bleach as a light source. Nine years later in the Philippines Illac Diaz from the MyShelter Foundation and students from MIT further developed the concept. They made the ´solar bulbs´ available to the public by means of a “local entrepeneur” business model. This approach combined two great initiatives: providing light in dwellings without electricity and creating jobs for locals. Within a year over 200.000 bottle bulbs were installed. The goal of the MyShelter Foundation is to light up 1 million homes by the end of 2015. At the moment the solar bottles are being installed in over 15 countries.

The concept of the solar bottle bulb is fairly simple: a used plastic bottle is filled with a mixture of water and a little chlorine – to keep the water clean and transparent. The bottle is sealed and pushed through a galvanized steel sheet that serves as a metal lock to prevent the bottle from slipping. It is then embedded into a corrugated iron roof. Only a small part of the bottle is left outside while the rest protrudes into the dwelling. The sunlight that enters the inside of the bottle becomes omni-directional through the refractive qualities of the water. The effect: an amount of light equal to that produced by a 40-60 Watt electric light bulb.

More info at: Liter of Light.

Home for life: an intelligent new species

home for life edited

One of the most interesting requests I received while working in building physics has been to evaluate the energy efficiency of the project ‘Home for Life’ according to Dutch energy standards. This dwelling is an example of the active house strategy: the dwelling is energy efficient (even produces more than it needs), creates a comfortable living environment and relates to the local context. A combination of sensors that register heat, CO2 and humidity in all rooms, an outdoor weather station and an intelligent control system ensure a comfortable indoor climate. To optimize energy efficiency a hybrid ventilation system has been applied: the house is naturally ventilated during summer and mechanically, with incorporated heat recovery, during winter. During summer this means saving energy that otherwise would be needed to operate fans. Some more extraordinary measures: when the indoor temperature exceeds the programmed values, windows in both facade and roof automatically open to create a ‘chimney effect‘ which helps reduce the temperature. And automatically controlled solar shades not only exclude excessive heat during hot (summer) days, but are also used to insulate the facade during cold nights to keep heat inside. When focussing on energy efficiency in buildings, designers generally aim to maximize the insulation of  the skin by minimizing the total amount of window area (the weakest link). The quality and amount of daylight within the ‘Home for Life’ however is impressive: over twice as much window area is implemented compared to a standard dwelling. The intelligent building concept manages to enable an exceptionally bright indoor atmosphere  while maintaining a high level of comfort within the dwelling. More info at Active House.