Introduction to Engineering Model

The Walden Three Project proves sustainable cities with a luxurious life for all are possible today!

Overview of Phase II: Energy-Mass Flow Model (Word document)

Phase II: Flow Chart 1 (Word Document)

Interactive Flowcharts (Fig. 1-5)

Phase II: Energy-Mass Flow Model (Excel document)

We continue to research the most cost effective technologies widely available now to produce the highest quality necessities for citizens in a sustainable city. Available for download here is an energy-mass analysis with an arbitrary initial population of 100,000 people. This is an ideal model with gaps and assumptions. It is open to everyone, free (open source), so it can be modified and corrected to suit specific realities, needs, preferences, and new technologies. Nothing on this site is copyrighted, though we do appreciate being given credit for producing it. If you make changes and publish it, please inform others of your changes. We actively seek corrections, expansions, refinements, and suggestions.

Existing housing units, municipalities, counties, states, and countries can adapt this model to their realities and play "what if?" Population, square footage of living and work areas, efficiency of solar cells or other processes, and a myriad number of other factors can be individually adjusted to evaluate how production, consumption, requirements, and outputs are affected. For example, you can increase solar panel efficiency to match the cells or location you desire. You can increase or decrease the number of inhabitants. You can change the relationship between recycled materials versus newly produced goods.

In our idealized model, particular attention was paid to choosing the most efficient labor, energy, and material production methods. With the emphasis of maximizing materials recycling potentials, glass bottles were chosen over plastic because of their lower recycling costs and highly reduced energy requirement due to multi-use.

The cities' waste that cannot be recycled is converted into usable fuel: High organic waste (e.g., manure/sewage) is converted into methane. Fuel waste (e.g., bio-waste) is turned into synthesis fuel gas (syngas), and non-fuel waste is processed in a plasma melter system resulting in a slag by-product.

The city produces its own cement, aluminum, silicon, and other materials needed for necessities as well as the components of many luxuries. The city uses primarily syngas and methane for electric power production and only a minimum of fossil fuel in its industrial plants. In addition. solar energy (PV and heat) provides a significant portion to the energy balance; with the surplus energy fed back into the country's electric grid.

This model shows how planning and creating luxurious, sustainable cities for everyone is possible today, rather than decades or centuries from now.


Hassan Fathy's book, Architecture For The Poor, contains a workbook which we have put into an Excel worksheet. Click here to see just what it would take to start a city with nothing but mud and an adz.


Oceana is a libertarian design similar to what we propose in some ways. It is designed for only 5,000 people and they do not have the factories to produce all that they consume.

http://reality.sculptors.com/~salsbury/Oceana/