Home-made pv panels

In my last post I introduced some of the differences between low-tech vs. high-tech approachs to green design. The Main Solar Energy Association [MeSEA], based in Lubec, is a great example of the former. Straight out of the pages of the Whole Earth Catalog, MeSEA offers workshops in "do-it-yourself-solar" and publishes a quarterly newsletter, The Maine Sun.

I spoke with the organization's John Burke and Soni Biehl at the NESEA trade show. Soni showed me a functioning home-made pv panel, built from industry seconds, and handed me a copy of The Maine Solar Primer, "a compilation of practical information and diagrams from past issues of The Maine Sun."

Lessons from the Maine Solar Primer

Yes, you can use solar energy in Maine; in fact, if you're industrious, you can build your own solar hybrid green house, solar [air] heater, solar cooker, solar herb and food drier, or "bread box" solar water heater. To help you get started, the Primer contains step-by-step how-to instructions, illustrated with a series of very helpful hand-drawn diagrams.

If you're really ambitious, you can follow the instructions listed in the section on "Passive Solar Architecture" to design your own passive solar house!

The three basic principles of passive solar, as described by Sarah Holland, are as follows:

1. Use windows, Trombe walls*, or solar air heaters to bring heated air into the building.

2. Take advantage of thermal mass* to store this solar heat inside the space.

3. Superinsulate the building to regulate the temperature at night.

*A Trombe wall is a wall system made up of an interior heavy thermal mass layer [often concrete, painted black] and an exterior layer of insulated glazing, separated by a vented airspace. Yes, you read that correctly, it's basically a window in front of a black concrete wall. The way it works is that during the day, sunlight shines through the insulated glazing to warm the surface of the thermal mass wall, which warms the inside space. At night, heat is retained in the thermal mass; the insulated glass and the air space both acting to slow down the process of heat loss to the exterior.

*Thermal mass: is a term referring to the capacity of a material to store heat, it is also known as "heat capacity." Basically, a material with a high heat capacity [referred to as a thermal mass] heats up slowly and then retains this heat. Thermal mass in buildings helps to regulate the interior temperature, especially in climates that are hot and sunny during the day and cooler at night. Building materials with a high heat capacity include: water, soil / rammed earth, stone, and concrete.

Do-it-yourself-solar goes international

MeSEA has been / is currently engaged in a number of international projects. President Dr. Richard Komp has lead pv-making workshops in Rwanda, Haiti, Mexico, Peru, India, and Mali; he is currently working with Suni Solar, the commercial arm of the Nicaraguan Grupo Fenix, to install 50 solar electric systems in various rural schools across Nicaragua.

These projects, as well as MeSEA's domestic endeavors, all exude the same help-people-help-themselves ethos you might expect from a green building organization run by industrious Mainers.