How to Grow Indoors (Nearly) Free

greenfriend

ganja farmer
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I believe the the cannabis industry needs an energy overhaul. Besides your sky high electric bill, power use by cannabis growers (estimated at 2-3% of total US consumption) is highly damaging to the environment due to coal-fired power plants. Why not kill two birds with one stone by producing your own electricity with no significant emissions? I would like to present an adjustment to a well-known method of energy production able to produce 20 kW at much lower cost than any other source. This particular solution is only applicable for larger scale grows with access to lots of any organic material.

The basic premise is using anaerobic digestion of organic material to produce methane (CH4), the combustion of which drives an engine linked to a permanent magnet generator that will produce the current. However, current methods require an enormous amount of organic material and lots of digesters to produce the flow rate required. By increasing the speed and efficiency of digestion (m3 CH4/ kg raw material), this process can produce a higher flower rate using less physical space. Studies have shown that phased thermophilic digestion used in conjunction with a thermal pretreatment is most efficient at CH4 production. Finally, the raw biogas produced consists of mostly CH4, about 30% CO2 and 1% other gases. Using a fractionating water wash stack, you can separate and tank the CH4 and CO2 while releasing the 1% unwanted portion.

The energy required for hydrolysis and digestion would greatly reduce the efficiency of this process, but not if it is waste energy captured from subsequent processes.

The use of off the shelf natural gas generators is not viable because they require periodic major maintenance outside the skill set of most growers which adds unnecessary costs. Instead, you can use a combination of boiler and steam engine(s) (ex. Green Steam Engine tm), with each steam engine coupled to an off the shelf permanent magnet alternator.

The key is capturing both the hot CO2 from the boiler and the hot steam from the engine. The heat from both will be used for the thermal hydrolysis, the CO2 will be cooled and tanked, and the water is recycled to the boiler. (In order for the boiler exhaust to be pure CO2 you must use an air separator to get pure O2 since combustion of air will produce other unwanted compounds in varying amounts)

Permanent magnet alternators have advantages and disadvantages. They require no current (from grid or battery) to power the excitation field. The downside is that the voltage produced is proportional to angular velocity (rpm). The steam engines, unlike typical gas generators, operate most efficiently at lower rpm, so some electrical engineering is needed to step up the voltage from 20V-30V to 240V. By using a grid-tied system you can also be earning $$$ by putting power into the grid when the load is less than less than the current generated.

I'm currently working on producing a prototype from mostly off the shelf parts. Its slow going - I have a backround in organic chemistry and some physics, but process engineering comes with a steep learning curve.

Any mechanical/electrical engineering inclined folk have any thoughts/criticisms/advice?
 

NorCalHal

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What's happening greenfriend. Been a while bro, glad to see you still around.

I read your post twice. Still lost. No kinda input at all, except if you get it working...I'll take 3 of them.

Hope all is well.
 

greenfriend

ganja farmer
Joined
May 29, 2008
Messages
529
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What's happening greenfriend. Been a while bro, glad to see you still around.

I read your post twice. Still lost. No kinda input at all, except if you get it working...I'll take 3 of them.

Hope all is well.
Hey NCH hows it going? Yea I'm still here - no growing been going on for a long time while at school but now that I'm finished I'm hoping to build this thing and stick it to PG&E once and for all.
 

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