Moser Lamps: The Brazilian Sun Tunnel

At the beginning of this century, Alfredo Moser was living in his home city of Uberaba in Brazil. The city was badly afflicted by power cuts. Like most people in his neighbourhood, Moser lived in a house with a corrugated iron roof, so he relied on electricity to light his home even during the day. In response to the problem of frequent power outages, Moser developed his eponymous lamp – a sun tunnel for the developing world that is now used in over a million homes.

How it Came About

The genesis of the idea occurred during one of those conversations that men the world over seem to enjoy. Moser and his friends were debating how they would light a signal fire if they were in a plane crash in the Andes and had no access to matches. One person stated that they would use a clear plastic bottle to focus the sun’s rays to start a fire. Moser was interested in whether this was even possible. His experiments did not produce a focussed beam capable of starting a fire, but what he observed turned out to be even more useful.

The First Moser Sun Lamp

Moser noticed that refracting the sun’s light through a water-filled plastic bottle produced a light of between 40 and 60 watts – about the same as an average indoor lightbulb. By making a hole in his roof and installing the bottle into the hole, Moser was able to provide free lighting inside his home.

A Million Users

First, the idea caught on in his neighbourhood. Then, as word spread, other neighbourhoods and other cities and even other countries began to make and install the lamps. It is estimated that around a million Moser Lamps are providing free light in developing nations all over the world.

Making a Moser Lamp

A Moser lamp couldn’t be easier to make. Fill a plastic bottle with water and a few millilitres of bleach to inhibit algae growth. Screw on the cap (a black cap works best or you can glue a black plastic film canister to the top). Install the bottle in your corrugated iron roof so the top half is above the roof and the bottom half below. Seal with silicone glue to prevent your roof from leaking.

Installing a Sun Tunnel 

If your roof is not made from corrugated iron, you may want to consider installing a sun tunnel instead. The principle is the same: a sun tunnel lets natural daylight illuminate dark corners of your home. 

For more information on skylights and sun tunnels, call our office on 01603 418818.

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