Solar Fire Concentrator

Note: this name is a legacy name from the time when we were pursing the lower-efficiency Tesla turbine as the heat engine of choice.

Solar Fire

The current solar concentration design under development for the GVCS is Solar Fire. Solar Fire started as a simple technique to roast coffee and cocoa at the village scale. These designs are available on www.solarfire.org.

Recently the technique has made significant developments to reach the local crafts (semi-industrial) scale.

Best way to understand the current model is through the film below.

Film

1. Download the video directly in MP4.

Notes about the film

1. The steam pipe arrangement was temporary since we hadn't worked out yet the best way to pass the steam pipe directly down through the main post and out the bottom.
2. A compressor has small cylinders to pump a small amount of water at high pressure, the compressor is for pumping water back into the steam generator (micro-boiler) but in the video just pumps back into the tank for a visual aid. The same amount of power into a water pump would have significantly more volume.
3. We had to make the video before rather than after, since the Energy Vagabonds (who were crucial in developing this model) were leaving the next day and they had a HD camera.
4. Shortly after I fell extremely sick and only got better the morning of my flight back home.

Structure

1. See Solar Fire Concentration Structure for notes on the structure.

Tube setting and mirror bending

1. Note: In reality the mirrors would be turned 90 degrees to be perpendicular to the rows. The mirror is shown here placed parallel to the row simply because it was easier to draw.
2. See Solar Angle Calculator for notes on the angle setting.

Cost Analysis

The design reduces costs by:

1. Using only standard construction material.
2. Requiring no mechanical bending.
3. Requiring no special skills not widely available.
4. Requiring no machining of pieces (just cutting, holes, welding).
5. Requiring no electronic tracking to be used effectively (though we will also develop automatic tracking for situations that call for it)

[Tinytech Plants http://www.tinytechindia.com/solar6kwtp.htm], can supply the machine for 5000 - 7000 USD, which works out to 156 to 218 USD per square meter, 250 to 350 USD per peak kilowatt thermal. They are currently working on a larger machine that they estimate will be about 33% less per watt, and run the steam engine seen in the video continuously. These costs are lower than all other concentrators I know of.

So, the economic viability of the technology is sound, and it can be built locally for less.

The final intended fabrication model is that local companies build most of the structure, and only special parts/applications are shipped from outside, similar to how the construction industry operates already.