Thursday, November 29, 2012

Wind Turbine

 I had been wanting to make my own electricity for a while so I decided to commit to it.  

I learned most everything I needed to know on the Internet, but there are books available at your local library on homebrew electric generation.  
Hugh Piggott is a good starting place for learning about wind and hydro  power.  Websites are always coming and going but Otherpower has been a reliable source for pdf. documents and all sorts of homemade electricity ideas (rabbit hole)

I made the choice to build my own generator instead of trying to scavenge or buy a industrially manufactured motor/generator.  Homemade axial flux alternators are a very good option for homebrew power generation because they can be custom built to suit a specific power demand and have a high output voltage per rpm. This means that gear boxes are not required to produce enough voltage, which cuts down on material demand and maintenance.

Side View Drawing of Axial Flux Alternator

Material List
11lbs of 14awg magnet wire                          $120    What I used.... $11
16 Neodymium Magnets, 1.5" x .75" x .25"             $90              
Steel sheet, .25" x 12" x 48"                        $16     What I used.... $7
Hardware, bolts and nuts                             $45
Fiberglass resin 1.5 qts                             $30
Bike crank arm, Bottom bracket, Frame               Free
Sheet metal 16"x16" 1/16" thick (scavenged)            Free

So the cost of the alternator thus far has been $183 and 8 hours of working/learning.

The Complete Alternator

Alternator with Stator and 
Outer rotor removed

The Stator

The trickiest part of making the generator was finding a suitable bearing and hub assembly.  I wound up taking a bicycle and cutting its bottom bracket assembly off with the angle grinder.  I cut the arm of the drive side crank leaving only the chainring mounting tabs, which would be bolted to the rotor.

 Next I will start on the electrical system, then make the blades and the tower.

Saturday, November 24, 2012

Hoophouse (9/23/12)

Welcome to the Aquaponic Hoop House. 

Currently growing radishes, carrots, turnips, basil, lettuce, spinach, scallions, chives, cabbage and broccoli in pots with a compost/coco/worm poo soil mix. Watercress, duckweed, horsetail and wandering jew are growing directly in water.  There are red wiggler worms in the compost bins and snails in the water tanks

                       South side grow tray, 24"W x 14'L               Center growing tray, 24"W x 14'L

Triple decker.  
The real advantage of an aquaponic farm setup is the ability to raise the growing beds off the ground and use vertical space.  In traditional farming where plants are grown in the ground, very little investment money is needed but nutrients and viable growing space are very important to having a successful garden.

In a vertical aquaponic growing setup the farmer has to invest more money into the farm but has less need for nutrients because they can be grown in the green house.  
Its all about utilizing symbiotic relationships to reduce the Resource Input to Output ratio.  Multiple different species can be grown in a small area and the ability to produce enough biomass to keep the systems  sustainable becomes a reality.

The South side tray has 
Potted plants and duckweed growing on top
10x20 trays with sprouted micro greens and sprouts in the middle
10x20 trays seeded with micro greens and sprouts on the bottom.
This setup turns a 2'W x 14'L foot print or 28' sqft in to 78' sqft.

The Center tray has 
Potted plants and duckweed growing on top
10x20 trays with mature micro greens and sprouts in the middle
A row of three gallon pots below that and
10x20 trays seeded with micro greens and sprouts on the bottom.
This setup turns a 2'W x 14'L foot print or 28' sqft in to 98' sqft.

Water is Pumped up from the sump tank and then is carried by gravity through the trays which have gravel in them.  The water height in the trays is 1.5 inches and the rocks are mostly below the water line. 
The water flows from the trays to a above ground 24"W x 18"H x 30"L (44gal) main tank and then to the  below ground sump tank thats 30"W x 36"L x 14"D (55gal). The tanks have a foot print of 9' sqft.

Bacteria that live on the wet areas of the aquaponic trays (plastic, rocks, pots and soil) convert fish waste form the fish tank into useful nutrients for the plants.  Duckweed is grown on every open water surface available. 

 Worm bin made from pallets, 360 gallons total, (32' sqft area)
Compost bins made from pallets, 360 gallons each, 720 gallons total, (32' sqft area) 
Compost piles produce heat from decomposition and can warm to 100-140 Deg F which heat the greenhouse.

Currently the area being used for production is 249' sqft 
   Total Area enclosed by hoop house 260' sqft 

Its all about the 
Area being used for production
Area enclosed (footprint)

Sunday, November 18, 2012

The Hoop House

My second greenhouse that the neighbors down the street let me build in their yard. 

Its dimensions are; 13'W x 20'L x 8' H
 I spent about $420 on the foundation, metal framing and four year cover plastic.

I managed to scavenge a door and some internal materials.
All the other materials I had around the house.
I used $250 worth of wood,
$50 worth of HDPE 30 mil pond liner (5'x20'),
A small water pump (400 gpm, 20w) and 10' of PET tubing, probably $50
Seventy five 3 gallon nursery pots and 200 gallons of compost, Free.

A total build cost of $770 approximately.
Uses 330 watts per hour, running 24/7
80 cents a day, $24 a month for electricity.

The water tank has a 300w aquarium heater in it currently that cost $40.  I want to see if a small heater can bring the water temp up, currently the water temps are 50F in the morning and 64F at dusk. I want to see what it takes to get the water to stay above 70F.

Simple tube bending jig made from a large pallet, some scrap pieces of wood and screws.
The tube is held stationary on one end and manually bent around the form six feet at a time.

I built a pretty basic foundation with untreated 2x6's and tie straps. 
Beneath the wooden frame, soil was removed and replaced with 6 inches of fine gravel to help with water drainage around the frame. The frame was then secured to the ground with 24" long hooked rebar at six points.

Rebar was driven in to the ground at four foot intervals along the inside of the frame.  
The rebar stakes were 24"long with 12" above ground level.  

The tubes that were bent earlier are connected together and then erected.  The open tube is placed over the rebar stakes and secured to the greenhouse foundation with metal straps and screws.

Once all the vertical ribs are in place horizontal supports are attached, in this case I used bolts but would probably use straps in the future.  All joints are covered with tape to protect the plastic from abrasion.

I covered the ends first and secured the plastic on the interior of the frame with staples.  On the exterior the plastic is stapled to the frame and taped over to seal the puncture.  

Where the plastic meets the ground it is rolled around a long strip of wood and then screwed to the frame of the hoop house.

The Hoop House 
13'W x 20'L x 8'H
260 sqft

Wednesday, November 14, 2012

Aquaponic Growing Trays

Two story aquaponic tray
Built for $190 w/o pond liner
$275 with tray liners and main tank liner

 Two 4'W x 8'L x 4"D grow trays on top and the water tank on the bottom.

This design requires some digging for the in ground tank.

 The 24" deep water tank will be bellow ground level with 12" protruding above ground level.

Single story aquaponic tray and Worm bins
Built for $130 w/o pond liner
$155 with tank liner
One 4'W x 8'L x 4"D grow tray on top with two 4' x 4' x 18" worm bins underneath

Friday, November 2, 2012

Urban Farming and Sustainable Living Solutions

Drawings of sustainable living solutions and a design and price estimation for a aquaponic greenhouse. I figured they would be more useful if they were posted on the web them rather than letting them sit in a folder.

 Aquaponic and Compost system

The greenhouse works as a living symbiotic system, kinda like a plant or animal cell.

Water : Blood
Pump : Heart
Pipes and Trays : Artery and Viens
Grow beds : Lungs + Stomach
Greenhouse Covering : Skin
Growing Trays and Greenhouse Frame : Skeleton
Compost Bins : Mouth
Worm Bins : Teeth and saliva
Worms and Bacteria :  Beneficial Bacteria
 (there are at least ten times as many bacteria as human cells in our body)
The Heart of the system is the aquaponic setup, water is pumped from the 2500 gal fish tank to ebb and flow growing trays where water is filtered by plants and bacteria on gravel then oxygenated when falling back to the main tank. 

The large volume of water is what keeps the greenhouse cooler in the summer and warmer in the winter, because water takes more energy to heat up than air it acts as a coolant within the greenhouse when air temperatures are high and when then air temperature is lower than the water temp the water acts as a heater.  The aquaponic trays have a large surface area and function as a radiator that are either absorbing or releasing energy to the surrounding air in the greenhouse.  

If the aquaponic system is the heart then the composting bins and the worm bins are the stomach and digestive tract of the greenhouse.  The compost bins are on the north side (shady) of the hoop house and are used as a thermal mass to regulate the greenhouse temperature.  The bins are filled with pretty much any type of organic waste with exception to human or unverified animal waste and meat . The compost is them moved to worm bins on the south side of the hoop house where the compost is further broken-down by thousands of hungry worms.

After three months in the worm bins the compost is removed, most of the worms are removed and the compost rich in worm castings in put in 3 gallon pots mixed with shredded coconut husk.  The pots are put in the aquaponic grow trays where they are planted with the desired crop.  A single pot in my dome can sustain healthy plant growth for 10-14 months before the pot is removed from the grow tray and the material is recycled to outdoor compost bins.

By combining soil growing and the aquaponic system pants can grow heather with an abundance of trace minerals and nutrients.  Even more importantly though, more species of nitrifying bacteria can be supported in the soil/coco/gravel medium than just gravel or expanded clay mediums.  The few worms left in the compost can also crawl out of the pots when the trays drain and feed on decomposing organic matter in the gravel then retreat back to the pots when the beds refill with water.

Aquaponic greenhouse design
The prototype trays from the previous post Aquaponic-Growing-Trays are the ones for this design.