9.0 Notes (page 8)

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Design Baseline

Figure 9.0-1 - Temperate location expansion phases.

The Personal Factory system is designed to expand in a series of phases (Figure 9.0-1). Each phase takes inputs of energy, parts, and raw materials, and uses them for production of expansion elements to add to the location, as well as desired outputs. As the new elements are completed, they are immediately put to use, and become part of the next phase for further development. The development of the location is actually a continuous process, but breaking it into discrete phases simplifies the design task, since each phase has fewer new items. A particular phase is described in the following sections by (1) a set of initial performance goals which that phase will meet, (2) a list of system elements which make up the location at the start of the phase, and (3) the set of changes within the phase by adding, modifying, or removing elements to reach the next phase. In general, each phase has a larger quantitative output capacity, a more diverse set of production equipment that can make a wider range of outputs, and higher levels of automation and integration.

Output Goals

The general output goal is to provide some of the physical needs for a steadily increasing number of people until the maximum design capacity of the location is reached. For example, food is one of the outputs, and we start Phase 1A with supplying food for 0.25 people the first year, increasing by 0.25 people/year. The steady growth will require preparing more land and producing more farm equipment by the factory.

We start to make the easier outputs in the early phases, with the more difficult ones added later, when the Factory has more capacity and types of equipment available. Therefore performance improvements, in terms of percentage of physical needs met, will get smaller with each phase as the harder products are added. At the same time the quantity of outputs grows in size with each phase. This is for two reasons. First, the equipment is designed to make copies or larger versions for itself, so the rate of growth compounds with each phase. Second, as it becomes more integrated and automated, the cost of production goes down, and therefore more people will want the outputs it produces.

The fraction of physical needs being met is measured in economic terms calculated from the current (Jan 2013) Consumer Price Index (CPI). The index is compiled from surveys of what people spend their money on in the US. Since our goal is to satisfy the factory owner's and customer's needs, the CPI serves as proxy for what people want. The actual owners may want a different mix of products, but this serves as a starting point for design. The index can be divided into goods and services, with the former being physical material and energy needs. The second number for each of the goods items is the percentage of the goods category:

Goods: 77.1% of total consumer items (100% of Goods)

Services (22.9%)

We do not try to design our factory to supply the services category (at least not in Phase 1). We assume that services are provided by residents at the location, or by outside suppliers. The factory can, however, supply the physical needs to make the services possible. For example, it will not supply medical care directly, but it can provide the buildings and utilities for that service, thus lowering its cost.

System Elements

Element Organization

We use a common organization structure across the entire project, which groups items by their function. Using a consistent system makes it easier to track changes across the various phases.

Element Naming

We want a consistent method to name the various system elements and their designs. Our method includes

Example: Solar Furnace, Model 10, Type A, Version 0.1 - 22 Mar 2013

Phase 0: Conventional Workshop

The first phase of the Personal Factory project (1A or Seed Factory) has a set of starter equipment that must be built somewhere. We will assume that is done in a conventional workshop at the location, and uses purchased tools, equipment, parts, and materials. The purchased tools and equipment are types which did not need to be custom designed for this project. Prior to final production of the starter set, we assume we need to build some prototypes to test the processes and validate their performance. Therefore the workshop equipment list will includes items needed to build the prototypes as well as the final version of the Phase IA "Seed Factory" elements.

As the prototypes and 1A starter set elements are completed, they can assist in further production. To whatever extent they remain useful, the conventional workshop equipment will remain part of the later phases. Some items may be custom-built at outside locations if it is not practical to make them locally.

Workshop Planning

To help cover the cost of a conventional workshop, it should be attractive to outside users or make useful products. Features that can be included to make it attractive include operating it as a maker-space or business incubator. Users would pay a membership fee for access to the equipment, or lease working space. For security, a combination of roll-up doors (as in self-storage places) and roll-away lockable work carts can be provided. The work carts can be taken out and put away with work in progress, and brought to different tool areas. Larger users might have shipping containers for storage. For business incubators, separate offices or outside doors can be provided, or a shared merchant area. All of this would use a modular design, so that layouts can change as needed. The combined workshop + other areas would expand over time.

Phase 1A (Seed Factory)

Figure 7.0-2 - Phase 1A Production Block Diagram.

The Phase 1A Seed Factory adds a starter set of automated equipment to the conventional workshop, starts to produce useful outputs, and begin the expansion process that leads to later phases (Figure 7.0-2). The block diagram shows the 8 major parts of the factory and the flows that move between them, and to and from the outside. The diagram is a version 0.3 draft, and does not yet show all the flows. The flow arrows would make the diagram too cluttered if they were continuous from box to box. Instead, only the ends are shown, and labels are provided for where the other end connects. Where flows divide or merge, the single merged flow is equal to the sum of the pieces.

Performance Goals

- Cereal and bakery - 2.4%
- Meats, fish, and eggs - 3.7%
- Dairy - 1.6%
- Fruits & Vegetables - 2.4%
- Drink & Beverage - 1.7%
- Ingredients & Other Foods - 4.2%

Therefore to meet the goal of 10% of physical needs (7.7% of total consumer budget) we need to supply a bit less than half of these categories. The mix of foods to grow will depend somewhat on what is easy to do at an early stage, and end user preferences.

- Excavation, Foundation, Backfill - 9.3%
- Framing, Trusses, and Sheathing - 14.7%
- Roofing - 2.9%
- Siding - 4.7%
- Drywall - 4.4%
- Cabinets and Countertops - 5.6%
- TOTAL - 41.6%


Outputs

Having set our performance goals, we now turn those into more specific output capacities by type:

Energy Supply Outputs

We want to supply 8%/12.45% = 64% of energy needs as part of the overall goal of supplying 27% of physical needs in this phase. The question is then what type of energy will be supplied? For local and sustainable sources we see three early options: solar, biofuel, and wind, with the possibility of using a mixture of them.

The annual value of one unit of capacity is 2.5 kW average x 8,760 hours x $0.13/kWh = $2,847/year. On-site storage is not likely to cover all needs, and peak demands for high-energy processes are likely to exceed the peak power generation. Therefore we assume a "net metering" connection to the utility grid. This sells surplus power when generated, and draws power from the grid when needed, and the utility bill represents the net used/sold. Any surplus power sales are used to pay for other forms of energy such as transport fuels. Peak process needs can be met by auxiliary electric heating drawing from the grid, above whatever the solar concentrators can produce.
To meet our specified goal, 15 kW of peak electric output is built each year at the start of Phase 1A. With no previous experience, and a desire to use concentrated solar for different purposes (electric power, industrial furnaces), we adopt a starter size of 3750 W electric/15 kW thermal. Therefore 4 units this size need to be built the first year. With experience, we can nominally build 2 x 7500 W electric the second year, and 1 x 15 kW electric the 3rd and 4th years. The actual mix of unit sizes will be determined by what we need them for, but later growth phases serve more people and have higher outputs, so we plan a general increase in unit size over time. The nominal unit sizes total 60 kW peak electric to serve 1 person's desired level of energy needs in 4 years. The set of 8 units in various sizes should cover the diversity of industrial/power needs with different targets at the focus.
Energy Payback - The solar concentrator is estimated to use 10 kg glass and 20 kg steel/m2. The embodied energy, as tabulated in the Inventory of Carbon and Energy, for recycled glass is 11.5 MJ/kg, and for recycled steel sections is 10 MJ/kg. Thus the energy required/m2 is 315 MJ/m2. Given 800 W/m2 collected, including mirror efficiency x 4 hours average operation/day, we supply 11.5 MJ/day thermal energy. Thus the thermal energy payback is 27.5 days, and electrical energy payback is 110 days. The actual payback time will then depend on the mix of electric and thermal power required.

Food Supply Outputs

Our goal in this phase is to provide a bit under half the diet of 0.25 people per year, so the growing area addition required is 62.5 m2/year, of which 22 is greenhouse, and 40.5 is open field/garden. These are fairly small areas, so we will assume the acquired land is larger, and additional greenhouse and fields are prepared each year. Our Phase 1A Seed Factory then needs to output the materials and equipment to build this area, and then operate it afterwards.

Shelter and Furnishings Outputs

We want to supply 9% of physical needs from these categories to meet the overall goal. Shelter and furnishings account for a total of 48.1% of physical needs, therefore we want to supply 18.7% of typical construction cost. Candidates include Roofing, siding, and drywall (12%), Excavation, foundation, and backfill (9.3%), Framing and cabinetry (20.3%), and Furnishings (3.3%). These total 44.9% of construction costs, so we only need to supply some of them.

Average US Southern forest contained 14.8 m3 (524 cf) softwood and 19.5 m3 (690 cf) hardwood timber/acre, with net growth of 0.85 and 0.68 m3 (30 and 24 cf)/year respectively. Initial construction then requires clearing 1.3 ha(3.2 acres). We use 0.2 ha/person for production and habitation, and need 2.15 ha/person for sustained wood for maintenance. Thus our maximum land needs are 2.15 + 0.2 = 2.35 ha/person, of which we clear a small portion and thin about 50% of the rest for initial construction, and leave the remaining trees and regrowth to supply continuing needs. Land with a high level of timber stock and fertility can reduce this substantially, as well as good timber management practices.

Expansion Outputs

We do not know the rate of expansion to the next phase because we don't know the level of contributions from project members in advance. We will assume this rate is US$1500/month, to which we add our surplus outputs either in the form of direct production, or sales to pay for new items. The nature of the expansion outputs is to enable annual production of user needs for 6 2/3 times as much energy, and 7 times as much food and shelter/furnishings, with a wider range of outputs.

Maintenance Outputs

Maintenance can be divided into items the factory can replace internally, and items which need to be supplied from outside. For those which must be supplied from outside, the project sells items it can make to pay for those it cannot. Even the Phase 0 conventional workshop equipment will need maintenance. These can be examined for replacement by internal production rather than purchase.

Surplus Outputs

Surplus outputs during Phase 1A will rise from 100% at the start of the phase, to 250% of needs + maintenance by the time Phase 1B elements are completed.

Phase 1A Elements List

The following are the elements identified to support the outputs of this Phase. They are listed by function numbers, where 1A represents the Phase at this first project location, and the next digits are 1 for production, 2 for transport, and 3 for habitation.

1A.1.1 Control Location

1A.1.2 Supply Power

1A.1.3 Extract Materials

1A.1.4 Process Materials

1A.1.6 Store Inventory

1A.1.8 Grow Organics

1A.2.1 Protect from External Environment

1A.3.4 Supply Internal Transport

Control is optionally by a seated operator, a remote manual control unit, or a local automated control system. The control systems can be swapped out like other attachments, converting the tractor from manual to automated. In this early phase, we aim for simplicity of manufacture, so we adopt a piston or turbine steam engine which drives a hydraulic pump. An electric drive may have lower maintenance, but fabricating copper wires and batteries in the factory is more complicated as a starting point, so we consider that as an alternative for later study. The fluid pressure drives the wheels and attachments via hydraulic motors and cylinders. We plan to use a bio-origin hydraulic fluid for safety. Any of a number of heat sources can be used to generate steam, including liquid fuels, wood, or stored thermal energy. A radiator is used to condense the water for re-use. The size of the chassis is determined by the excavation task, which we assume is the most heavy-duty operation. Other tasks (logging, tilling, and general transport) will use attachments scaled to the chassis size and power output.

- Fixed solar array charging station - Replaceable battery packs - can be left at the charging station and swapped as needed, or charge the robot by parking it. - Direct rail contact or plugs for fixed location operations

Phase 1B

Performance Goals

Phase 1C

Capacity to meet 61% of physical needs for 4 people per year, by economic value.

Phase 1D

Capacity to meet 72% of physical needs for 12 people per year, by economic value.

Phase 1E

Capacity to meet 80% of physical needs for 32 people per year, by economic value.

Phase 1F

Capacity to meet 85% of physical needs for 75 people per year, by economic value.


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