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The Carbon Footprint of Indoor Cannabis Production

  • Lawrence Berkeley National Laboratory (Retiree Affiliate)

Abstract and Figures

The emergent industry of indoor Cannabis production -- legal in some jurisdictions and illicit in others -- utilizes highly energy intensive processes to control environmental conditions during cultivation. This article estimates the energy consumption for this practice in the United States at 1% of national electricity use, or $6 billion each year. One average kilogram of final product is associated with 4600kg of carbon dioxide emissions to the atmosphere, or that of 3 million average U.S. cars when aggregated across all national production. The practice of indoor cultivation is driven by criminalization, pursuit of security, pest and disease management, and the desire for greater process control and yields. Energy analysts and policymakers have not previously addressed this use of energy. The unchecked growth of electricity demand in this sector confounds energy forecasts and obscures savings from energy efficiency programs and policies. While criminalization has contributed to the substantial energy intensity, legalization would not change the situation materially without ancillary efforts to manage energy use, provide consumer information via labeling, and other measures. Were product prices to fall as a result of legalization, indoor production using current practices could rapidly become non-viable.
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The carbon footprint of indoor Cannabis production
Evan Mills
Energy Associates, Box 1688, Mendocino, CA 95460, United States
article info
Article history:
Received 7 September 2011
Accepted 10 March 2012
Available online 17 April 2012
The emergent industry of indoor Cannabis production – legal in some jurisdictions and illicit in others
utilizes highly energy intensive processes to control environmental conditions during cultivation. This
article estimates the energy consumption for this practice in the United States at 1% of national
electricity use, or $6 billion each year. One average kilogram of final product is associated with 4600 kg
of carbon dioxide emissions to the atmosphere, or that of 3 million average U.S. cars when aggregated
across all national production. The practice of indoor cultivation is driven by criminalization, pursuit of
security, pest and disease management, and the desire for greater process control and yields. Energy
analysts and policymakers have not previously addressed this use of energy. The unchecked growth of
electricity demand in this sector confounds energy forecasts and obscures savings from energy
efficiency programs and policies. While criminalization has contributed to the substantial energy
intensity, legalization would not change the situation materially without ancillary efforts to manage
energy use, provide consumer information via labeling, and other measures. Were product prices to fall
as a result of legalization, indoor production using current practices could rapidly become non-viable.
&2012 Elsevier Ltd. All rights reserved.
1. Introduction
On occasion, previously unrecognized spheres of energy use
come to light. Important historical examples include the perva-
sive air leakage from ductwork in homes, the bourgeoning energy
intensity of computer datacenters, and the electricity ‘‘leaking’’
from billions of small power supplies and other equipment.
Intensive periods of investigation, technology R&D, and policy
development gradually ensue in the wake of these discoveries.
The emergent industry of indoor Cannabis production appears to
have joined this list.
This article presents a model of the modern-day production
process – based on public-domain sources – and provides first-
order national scoping estimates of the energy use, costs, and
greenhouse-gas emissions associated with this activity in the
United States. The practice is common in other countries but a
global assessment is beyond the scope of this report.
2. Scale of activity
The large-scale industrialized and highly energy-intensive
indoor cultivation of Cannabis is a relatively new phenomenon,
driven by criminalization, pursuit of security, pest and disease
management, and the desire for greater process control and yields
(U.S. Department of Justice, 2011a; World Drug Report, 2009). The
practice occurs across the United States (Hudson, 2003;Gettman,
2006). The 415,000 indoor plants eradicated by authorities in
2009 (and 10.3 million including outdoor plantations) (U.S.
Department of Justice, 2011a, b) presumably represent only a
small fraction of total production.
Cannabis cultivation is today legal in 15 states plus the District
of Columbia, although it is not federally sanctioned (Peplow,
2005). It is estimated that 24.8 million Americans are eligible to
receive a doctor’s recommendation to purchase or cultivate
Cannabis under existing state laws, and approximately 730,000
currently do so (See Change Strategy, 2011). In California alone,
400,000 individuals are currently authorized to cultivate Cannabis
for personal medical use, or sale for the same purpose to 2100
dispensaries (Harvey, 2009). Approximately 28.5 million people
in the United States are repeat consumers, representing 11%
of the population over the age of 12 (U.S. Office of National
Drug Control Policy, 2011).
Cultivation is also substantial in Canada. An estimated 17,500
‘‘grow’’ operations in British Columbia (typically located in residen-
tial buildings) are equivalent to 1% of all dwelling units Province-
wide, with an annual market value of $7 billion (Easton, 2004).
Official estimates of total U.S. Cannabis production varied from
10,000 to 24,000 metric ton per year as of 2001, making it the
nation’s largest crop by value at that time (Hudson, 2003;
Gettman, 2006). A recent study estimated national production
at far higher levels (69,000 metric ton) (HIDTA, 2010). Even at the
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This article substantively updates and extends the analysis described in
Mills (2011).
Energy Policy 46 (2012) 58–67
lower end of this range (chosen as the basis of this analysis), the
level of activity is formidable and increasing with the demand for
No systematic efforts have previously been made to estimate
the aggregate energy use of these activities.
3. Methods and uncertainties
This analysis is based on a model of typical Cannabis produc-
tion, and the associated energy use for cultivation and transporta-
tion based on market data and first-principals buildings energy
end-use modeling techniques. Data sources include equipment
manufacturer data, trade media, the open literature, and inter-
views with horticultural equipment vendors. All assumptions
used in the analysis are presented in Appendix A. The resulting
normalized (per-kilogram) energy intensity is driven by the
effects of indoor-environmental conditions, production processes,
and equipment efficiencies.
Considerable energy use is also associated with transportation,
both for workers and for large numbers of small-quantities trans-
ported and then redistributed over long distances before final sale.
This analysis reflects typical practices, and is thus intended as
a ‘‘central estimate’’. While processes that use less energy on a
per-unit-yield basis are possible, much more energy-intensive
scenarios also occur. Certain strategies for lowering energy inputs
(e.g., reduced illumination levels) can result in lower yields, and
thus not necessarily reduce the ultimate energy-intensity per unit
weight. Only those strategies that improve equipment and pro-
cess energy efficiency, while not correspondingly attenuating
yields would reduce energy intensity.
Due to the proprietary and often illicit nature of Cannabis
cultivation, data are intrinsically uncertain. Key uncertainties are
total production and the indoor fraction thereof, and the corre-
sponding scaling up of relatively well-understood intensities of
energy use per unit of production to state or national levels could
result in 50% higher or lower aggregate results. Greenhouse-gas
emissions estimates are in turn sensitive to the assumed mix of
on- and off-grid power production technologies and fuels, as off-
grid production (almost universally done with diesel generators)
can – depending on the prevailing fuel mix in the grid – have
substantially higher emissions per kilowatt-hour than grid power.
Final energy costs are a direct function of the aforementioned
factors, combined with electricity tariffs, which vary widely
geographically and among customer classes. The assumptions
about vehicle energy use are likely conservative, given the longer-
range transportation associated with interstate distribution.
Some localities (very cold and very hot climates) will see much
larger shares of production indoors, and have higher space-
conditioning energy demands than the typical conditions
assumed here. More in-depth analyses could explore the varia-
tions introduced by geography and climate, alternate technology
configurations, and production techniques.
4. Energy implications
Accelerated electricity demand growth has been observed in
areas reputed to have extensive indoor Cannabis cultivation. For
example, following the legalization of cultivation for medical
purposes (Phillips, 1998;Roth, 2005;Clapper et al., 2010)in
California in 1996, Humboldt County experienced a 50% rise in
per-capita residential electricity use compared to other parts of
the state (Lehman and Johnstone, 2010).
Aside from sporadic news reports (Anderson, 2010;Quinones,
2010), policymakers and consumers possess little information on
the energy implications of this practice. A few prior studies
tangentially mentioning energy use associated with Cannabis
production used cursory methods and under-estimate energy
use significantly (Plecas et al., 2010 and Caulkins, 2010).
Driving the large energy requirements of indoor production
facilities are lighting levels matching those found in hospital
operating rooms (500-times greater than recommended for read-
ing) and 30 hourly air changes (6-times the rate in high-tech
laboratories, and 60-times the rate in a modern home). Resulting
power densities are on the order of 2000 W/m
, which is on a par
with that of modern datacenters. Indoor carbon dioxide (CO
levels are often raised to 4-times natural levels in order to boost
plant growth. However, by shortening the growth cycle, this
practice may reduce final energy intensity.
Specific energy uses include high-intensity lighting, dehumi-
dification to remove water vapor and avoid mold formation, space
heating or cooling during non-illuminated periods and drying,
pre-heating of irrigation water, generation of carbon dioxide by
burning fossil fuel, and ventilation and air-conditioning to remove
waste heat. Substantial energy inefficiencies arise from air clean-
ing, noise and odor suppression, and inefficient electric generators
used to avoid conspicuous utility bills. So-called ‘‘grow houses’’ –
residential buildings converted for Cannabis production – can
contain 50,000 to 100,000 W of installed lighting power (Brady,
2004). Much larger facilities are also used.
Based on the model developed in this article, approximately
13,000 kW/h/year of electricity is required to operate a standard
production module (a 1.2 1.2 2.4 m (4 48 ft) chamber). Each
module yields approximately 0.5 kg (1 pound) of final product
per cycle, with four or five production cycles conducted per year.
A single grow house can contain 10 to 100 such modules.
To estimate national electricity use, these normalized values
are applied to the lower end of the range of the aforementioned
estimated production (10,000 t per year), with one-third of the
activity takes place under indoor conditions. This indicates
electricity use of about 20 TW/h/year nationally (including off-
grid production). This is equivalent to that of 2 million average
U.S. homes, corresponding to approximately 1% of national
electricity consumption or the output of 7 large electric power
plants (Koomey et al., 2010). This energy, plus associated fuel uses
(discussed below), is valued at $6 billion annually, with asso-
ciated emissions of 15 million metric ton of CO
equivalent to
that of 3 million average American cars (Fig. 1 and Tables 1–3.)
Fuel is used for several purposes, in addition to electricity. The
carbon dioxide injected into grow rooms to increase yields is
produced industrially (Overcash et al., 2007) or by burning propane
or natural gas within the grow room contributes about 1–2% to the
carbon footprint and represents a yearly U.S. expenditure of $0.1
billion. Vehicle use associated with production and distribution
contributes about 15% of total emissions, and represents a yearly
expenditure of $1 billion. Off-grid diesel- and gasoline-fueled
electric generators have per-kilowatt-hour emissions burdens that
are 3- and 4-times those of average grid electricity in California. It
requires 70 gallon of diesel fuel to produce one indoor Cannabis
plant (or the equivalent yield per unit area), or 140 gallon with
smaller, less-efficient gasoline generators.
In California, the top-producing state, indoor cultivation is
responsible for about 3% of all electricity use, or 9% of household
This corresponds to the electricity use of 1 million average
California homes, greenhouse-gas emissions equal to those from
1 million average cars, and energy expenditures of $3 billion per
This is somewhat higher than estimates previously made for British
Columbia, specifically, 2% of total Provincial electricity use or 6% of residential
use (Garis, 2008;Bellett, 2010).
E. Mills / Energy Policy 46 (2012) 58–67 59
year. Due to higher electricity prices and cleaner fuels used to
make electricity, California incurs 50% of national energy costs but
contributes only 25% of national CO
emissions from indoor
Cannabis cultivation.
From the perspective of individual consumers, a single Cannabis
cigarette represents 1.5 kg (3 pounds) of CO
emissions, an amount
equal to driving a 44 mpg hybrid car 22 mile or running a 100-watt
light bulb for 25 h, assuming average U.S. electricity emissions. The
electricity requirement for one single production module equals that
of an average U.S. home and twice that of an average California
home. The added electricity use is equivalent to running about 30
From the perspective of a producer, the national-average
annual energy costs are approximately $5500 per module or
$2500 per kilogram of finished product. This can represent half
the wholesale value of the finished product (and a substantially
lower portion at retail), depending on local conditions. For
average U.S. conditions, producing one kilogram of processed
Cannabis results in 4600 kg of CO
emissions to the atmosphere
(and 50% more when off-grid diesel power generation is used), a
very significant carbon footprint. The emissions associated with
one kilogram of processed Cannabis are equivalent to those of
driving across country 11 times in a 44-mpg car.
These results reflect typical production methods. Much more
energy-intensive methods occur, e.g., rooms using 100% recircu-
lated air with simultaneous heating and cooling, hydroponics,
or energy end uses not counted here such as well-water pumps
and water purification systems. Minimal information and con-
sideration of energy use, coupled with adaptations for security
and privacy (off-grid generation, no daylighting, odor and noise
control) lead to particularly inefficient configurations and corre-
spondingly elevated energy use and greenhouse-gas emissions.
The embodied energy of inputs such as soil, fertilizer, water,
equipment, building materials, refinement, and retailing is not
estimated here and should be considered in future assessments.
The energy use for producing outdoor-grown Cannabis (approxi-
mately two-thirds of all production) is also not estimated here.
ventilated light fixture
High-intensity lamps
Motorized lamp
Heater Water purifier
generator Pump
water heater
In-line duct fan,
coupled to lights
Oscillating fan Room fan
carbon filter
Fig. 1. Carbon footprint of indoor Cannabis production.
Table 1
Carbon footprint of indoor Cannabis production, by end use (average U.S
Energy intensity
(kW/h/kg yield)
Emissions factor (kgCO
emissions/kg yield)
Lighting 2283 1520 33%
Ventilation &
1848 1231 27%
Air conditioning 1284 855 19%
Space heat 304 202 4%
injected to
increase foliage
93 82 2%
Water handling 173 115 2%
Drying 90 60 1%
Vehicles 546 12%
Total 6074 4612 100%
Note: The calculations are based on U.S.-average carbon burdens of 0.666 kg/kW/h.
injected to increase foliage’’ represents combustion fuel to make on-site CO
Assumes 15% of electricity is produced in off-grid generators.
E. Mills / Energy Policy 46 (2012) 58–6760
If improved practices applicable to commercial agricultural
greenhouses are any indication, such large amounts of energy are
not required for indoor Cannabis production.
The application of
cost-effective, commercially-available efficiency improvements to
the prototypical facility modeled in this article could reduce
energy intensities by at least 75% compared to the typical-
efficiency baseline. Such savings would be valued at approxi-
mately $40,000/year for a generic 10-module operation (at
California energy prices and $10,000/year at U.S. average prices)
(Fig. 2(a)–(b). These estimated energy use reductions reflect
practices that are commonplace in other contexts such as more
efficient components and controls (lights, fans, space-condition-
ing), use of daylight, optimized air-handling systems, and reloca-
tion of heat-producing equipment out of the cultivation room.
Moreover, strain choice alone results in a factor-of-two difference
in yields per unit of energy input (Arnold, 2011).
5. Energy intensities in context
Policymakers and other interested parties will rightfully seek
to put these energy indicators in context with other activities in
the economy.
One can readily identify other energy end-use activities with
far greater impacts than that of Cannabis production. For example,
automobiles are responsible for about 33% of U.S. greenhouse-gas
emissions (USDOE, 2009), which is100-times as much as those
produced by indoor Cannabis production (0.3%). The approxi-
mately 20 TW/h/year estimated for indoor Cannabis production
is about one/third that of U.S. data centers (US EPA, 2007a,
2007b), or one-seventh that of U.S. household refrigerators
(USDOE, 2008). These shares would be much higher in states
where Cannabis cultivation is concentrated (e.g., one half that of
refrigerators in California (Brown and Koomey, 2002)).
On the other hand, this level of energy use is high in compari-
sion to that used for other indoor cultivation practices, primarily
owing to the lack of daylighting. For comparison, the energy
intensity of Belgian greenhouses is estimated at approximately
1000 MJ/m
(De Cock and Van Lierde, No date), or about 1% that
estimated here for indoor Cannabis production.
Table 2
Indoor Cannabis production consumesy3% of California’s total
electricity, and
9% of California’s
household electricity
1% of total U.S.
2% of U.S.
U.S. Cannabis production & distribution
energy costsy
$6 Billion, and results in the
emissions of
15 Million tonnes per
year of greenhouse
gas emissions (CO
Equal to the
emissions of
average cars
U.S. electricity use for Cannabis
production is equivalent to that ofy
1.7 Million average U.S.
or 7 Average U.S. power
California Cannabis production and
distribution energy costs...
$3 Billion, and results in the
emissions of
4Million tonnes per
year of greenhouse
gas emissions (CO
Equal to the
emissions of
average cars
California electricity use for Cannabis
production is equivalent to that ofy
1Million average California
A typical 4 48-ft production module,
accomodating four plants at a time,
consumes as much electricity asy
1Average U.S. homes, or 2Average California
or 29 Average new
Every 1 kilogram of Cannabis produced
using national-average grid power
results in the emissions ofy
4.3 Tonnes of CO
lent to
7Cross-country trips
in a 5.3 l/100 km
(44 mp g) car
Every 1 kg of Cannabis produced using a
prorated mix of grid and off-grid
generators results in the emissions
4.6 Tonnes of CO
lent to
8Cross-country trips
in a 5.3 l/100 km
(44 mp g) car
Every 1 kg of Cannabis produced using
off-grid generators results in the
emissions ofy
6.6 Tonnes of CO
lent to
11 Cross-country trips
in a 5.3 l/100 km
(44 mp g) car
Transportation (wholesaleþretail)
226 Liters of gasoline per kg or $1 Billion dollars
annually, and
546 Kilograms of
kilogram of
final product
One Cannabis cigarette is like drivingy37 km in a 5.3 l/100 km
(44 mpg) car
2kg of CO
, which is
equivalent to
operating a 100-watt
light bulb for
25 Hours
Of the total wholesale pricey49% Is for energy (at average
U.S. prices)
See, e.g., this University of Michigan resource:
E. Mills / Energy Policy 46 (2012) 58–67 61
Energy intensities can also be compared to those of other
sectors and activities.
Pharmaceuticals Energy represents 1% of the value of
U.S. pharmaceutical shipments (Galitsky et al., 2008) versus
50% of the value of Cannabis wholesale prices. The U.S.
‘‘Pharma’’ sector uses $1 billion/year of energy; Indoor Canna-
bis uses $6 billion.
Other industries Defining ‘‘efficiency’’ as how much energy is
required to generate economic value, Cannabis comes out the
highest of all 21 industries (measured at the three-digit SIC
level). At 20 MJ per thousand dollars of shipment value
(wholesale price), Cannabis is followed next by paper (14),
nonmetallic mineral products (10), primary metals (8),
petroleum and coal products (6), and then chemicals (5)
(Fig. 3). However, energy intensities are on a par with Cannabis
in various subsectors (e.g., grain milling, wood products, rubber)
and exceed those of Cannabis in others (e.g., pulp mills).
Alcohol The energy used to produce one marijuana cigarette
would also produce 18 pints of beer (Galitsky et al., 2003).
Other building types Cannabis production requires 8-times
as much energy per square foot as a typical U.S. commercial
building (4x that of a hospital and 20x that of a building for
religious worship), and 18-times that of an average U.S. home
(Fig. 4).
6. Outdoor cultivation
Shifting cultivation outdoors can nearly eliminate energy use
for the cultivation process. Many such operations, however, require
water pumping as well as energy-assisted drying techniques.
Moreover, vehicle transport during production and distribution
remains part of the process, more so than for indoor operations.
A common perception is that the potency of Cannabis pro-
duced indoors exceeds that of that produced outdoors, leading
Table 3
Energy indicators (average U.S. conditions).
per cycle, per
per year, per
Energy use
Connected load 3,225 (watts/module)
Power density 2,169 (watts/m
Elect 2756 12,898 (kW/h/module)
Fuel to make CO
0.3 1.6 (GJ)
Transportation fuel 27 127 (Gallons
On-grid results
Energy cost 846 3,961 $/module
Energy cost 1,866 $/kg
Fraction of wholesale price 47%
emissions 1936 9,058 kg
emissions 4,267 kg/kg
Off-grid results (diesel)
Energy cost 1183 5,536 $/module
Energy cost 2,608 $/kg
Fraction of wholesale price 65%
emissions 2982 13,953 kg
emissions 6,574 kgCO
Blended on/off grid results
Energy cost 897 4,197 $/module
Energy cost 1,977 $/kg
Fraction of wholesale price 49%
emissions 2093 9,792 kg
emissions 4,613 kgCO
Of which, indoor CO
9 42 kgCO
Of which, vehicle use
Fuel use
During production 79 Liters/kg
Distribution 147 Liters/kg
During production 77 $/kg
Distribution 143 $/kg
During production 191 kgCO
Distribution 355 kgCO
Worst Average Improved
Carbon Footprint (kgCO2/kg finished Cannabis)
Water handling
CO2 injected to increase foliage
Space heat
Air conditioning
Ventilation & Dehumid.
Worst Average Improved
Electricity Cost ($/kg finsihed Cannabis)
California residential
65% (energy cost as % of wholesale value)
electricity price
US residential
electricity price
Fig. 2. Carbon footprint and energy cost for three levels of efficiency. (a) Indoor
cannabis: carbon footprint. (b) Indoor cannabis: electricity cost. Assumes a
wholesale price of $4400/kg. Wholesale prices are highly variable and poorly
Fig. 3. Comparative energy intensities, by sector (2006).
E. Mills / Energy Policy 46 (2012) 58–6762
consumers to demand Cannabis produced indoors. Federal sources
(National Drug Intelligence Center, 2005) as well as independent
testing laboratories (Kovner, 2011) actually find similar potencies
when best practices are used.
Illegal clearing of land is common for multi-acre plantations, and,
depending on the vegetation type, can accordingly mobilize green-
house-gas emissions. Standing forests (a worst-case scenario) hold
from 125 to 1500 t of CO
per hectare, depending on tree species,
age, and location (National Council for Air and Soil Improvement,
2010). For biomass carbon inventories of 750 t/ha and typical yields
(5000 kg/ha) (UNODC, 2009), associated biomass-related CO
sions would be on the order of 150 kg CO
/kg Cannabis (for only one
harvest per location), or 3% of that associated with indoor produc-
tion. These sites typically host on the order of 10,000 plants,
although the number can go much higher (Mallery, 2011). When
mismanaged, the practice of outdoor cultivation imposes multiple
environmental impacts aside from energy use. These include defor-
estation; destruction of wetlands, runoff of soil, pesticides, insecti-
cides, rodenticides, and human waste; abandoned solid waste; and
unpermitted impounding and withdrawals of surface water
(Mallery, 2011;Revelle, 2009). These practices can compromise
water quality, fisheries, and other ecosystem services.
7. Policy considerations
Current indoor Cannabis production and distribution practices
result in prodigious energy use, costs, and unchecked greenhouse-
gas pollution. While various uncertainties exist in the analysis,
the overarching qualitative conclusions are robust. More in-depth
analysis and greater transparency of the energy impacts of this
practice could improve decision-making by policymakers and
consumers alike.
There is little, if any, indication that public policymakers have
incorporated energy and environmental considerations into their
deliberations on Cannabis production and use. There are addi-
tional adverse impacts of the practice that merit attention,
including elevated moisture levels associated with indoor cultiva-
tion that can cause extensive damage to buildings,
as well as
electrical fires caused by wiring out of compliance with safety
codes (Garis, 2008). Power theft is common, transferring those
energy costs to the general public (Plecas et al., 2010). As noted
above, simply shifting production outdoors can invoke new
environmental impacts if not done properly.
Energy analysts have also not previously addressed the issue.
Aside from the attention that any energy use of this magnitude
normally receives, the hidden growth of electricity demand
in this sector confounds energy forecasts and obscures
savings from energy efficiency programs and policies. For exam-
ple, Auffhammer and Aroonruengsawat (2010) identified a
Fig. 4. Comparative energy intensities, by U.S. building type (2003).
Table A1
Configuration, environmental conditions, set-points.
Production parameters
Growing module 1.5 m
walking area)
Number of modules in a room 10
Area of room 22 m
Cycle duration 78 days
Production continuous throughout
the year
4.7 cycles
Illumination Leaf phase Flowering
Illuminance 25 klux 100 klux
Lamp type Metal halide High-pressure
Watts/lamp 600 1000
Ballast losses (mix of magnetic &
13% 0.13
Lamps per growing module 1 1
Hours/day 18 12
Days/cycle 18 60
Daylighting None none
Ducted luminaires with ‘‘sealed’’
lighting compartment
150 CFM/1000 W
of light (free
Room ventilation (supply and
exhaust fans)
30 ACH
Filtration Charcoal filters on
exhaust; HEPA on
Oscilating fans: per module, while
lights on
Application 151 liters/room-
Heating Electric submersible
Space conditioning
Indoor setpoint day 28 C
Indoor setpoint night 20 C
AC efficiency 10 SEER
Dehumidification 7x24 hours
production target
concentration (mostly natural gas
combustion in space)
1500 ppm
Electric space heating When lights off to
maintain indoor
Target indoor humidity conditions 40–50%
Fraction of lighting system heat
production removed by
luminaire ventilation
Ballast location Inside conditioned
Space conditioning, oscillating fans,
maintaining 50% RH, 70–80F
7 Days
Electricity supply
grid 85%
grid-independent generation (mix
of diesel, propane, and gasoline)
For observations from the building inspectors community, see http://www.
E. Mills / Energy Policy 46 (2012) 58–67 63
statistically significant, but unexplained, increase in the growth
rate for residential electricity in California during the years when
indoor Cannabis production grew as an industry (since the mid-
Table A2
Assumptions and conversion factors.
Service levels
25–100 1000 lux
Airchange rates
30 Changes per hour
Cycle duration
78 Days
4.7 Continuous
96 Cubic feet per
minute, per module
Leafing phase
Lighting on-time
18 hrs/day
18 days/cycle
Flowering phase
Lighting on-time
12 hrs/day
60 days/cycle
24 hrs
7 days/cycle
Average air-conditioning age 5 Years
Air conditioner efficiency [Standards
increased to SEER 13 on 1/23/2006]
Fraction of lighting system heat production
removed by luminaire ventilation
Diesel generator efficiency
27% 55 kW
Propane generator efficiency
25% 27 kW
Gasoline generator efficiency
15% 5.5 kW
Fraction of total prod’n with generators
Transportation: Production phase (10
25 Miles roundtrip
Daily service (1 vehicle) 78 Trips/cycle. Assume
20% live on site
Biweekly service (2 vehicles) 11.1 Trips/cycle
Harvest (2 vehicles) 10 Trips/cycle
Total vehicle miles
2089 Vehicle miles/cycle
Transportation: Distribution
Amount transported wholesale 5 kg per trip
Mileage (roundtrip) 1208 km/cycle
Retail (0.25oz 5 miles roundtrip) 5668 Vehicle-km/cycle
6876 Vehicle-km/cycle
Fuel economy, typical car [a] 10.7 l/100 km
Annual emissions, typical car [a] 5195 kgCO
0 kgCO
Annual emissions, 44-mpg car
2,598 kgCO
0.208 kgCO
Cross-country U.S. mileage 4493 km
Propane [b] 25 MJ/liter
Diesel [b] 38 MJ/liter
Gasoline [b] 34 MJ/liter
Electric generation mix
Grid 85% share
Diesel generators 8% share
Propane generators 5% share
Gasoline generators 2% share
Emissions factors
Grid electricity U.S. [c] 0.609 kgCO
Grid electricity CA [c] 0.384 kgCO
Grid electricity non-CA U.S. [c] 0.648 kgCO
Diesel generator
0.922 kgCO
Propane generator
0.877 kgCO
Gasoline generator
1.533 kgCO
Blended generator mix
0.989 kgCO
Blended on/off-grid generation CA
0.475 kgCO
Blended on/off-grid generation U.S.
0.666 kgCO
Propane combustion 63.1 kgCO
Electricity price grid
(California PG&E) [d]
0.390 per kW/h (Tier 5)
Electricity price grid (U.S.) [e] 0.247 per kW/h
Electricity price off-grid
0.390 per kW/h
Electricity price blended on/off CA
0.390 per kW/h
Electricity price blended on/off U.S.
0.268 per kW/h
Propane price [f] 0.58 $/liter
Gasoline price U.S. average [f] 0.97 $/liter
Diesel price U.S. average [f] 1.05 $/liter
Table A2 (continued )
Wholesale price of Cannabis [g] 4,000 $/kg
Plants per production module
Net production per production module [h] 0.5 kg/cycle
U.S. production (2011) [i] 10,000 metric tonnes/y
California production (2011) [i] 3,902 metric tonnes/y
Fraction produced indoors [i] 33%
U.S. indoor production modules
Calif indoor production modules
Cigarettes per kg
Average new U.S. refrigerator 450 kW/h/year
173 kgCO
/year (U.S.
Electricity use of a typical U.S. home 2009
11,646 kW/h/year
Electricity use of a typical California home
2009 [k]
6,961 kW/h/year
Trade and product literature; interviews with equipment vendors.
Calculated from other values.
Notes for Table A2.
[a]. U.S. Environmental Protection Agency., 2011.
[b]. Energy conversion factors, U.S. Department of Energy,
energyexplained/index.cfm?page=about_energy_units, [Accessed February 5, 2011].
[c]. United States: (USDOE 2011); California (Marnay et al., 2002).
[d]. Average prices paid in California and other states with inverted-block tariffs are
very high because virtually all consumption is in the most expensive tiers. Here the
PG&E residential tariff as of 1/1/11, Tier 5 is used as a proxy for California http://, (Accessed February 5, 2011). In practice a
wide mix of tariffs apply, and in some states no tier structure is in place, or the
proportionality of price to volume is nominal.
[e]. State-level residential prices, weighted by Cannabis production (from Gettman.
2006) with actual tariffs and U.S. Energy Information Administration, ‘‘Average
Retail Price of Electricity to Ultimate Customers by End-Use Sector, by State’’, http://, (Accessed February 7, 2011)
[f]. U.S. Energy Information Administration, Gasoline and Diesel Fuel Update (as of
2/14/2011) – see Propane prices –, (Accessed
April 3, 2011).
[g]. Montgomery, 2010.
[h]. Toonen et al., 2006); Plecas et al., 2010.
[i]. Total Production: The lower value of 10,000 t per year is conservatively retained.
Were this base adjusted to 2011 values using 10.9%/year net increase in number of
consumers between 2007 and 2009 per U.S. Department of Health and Human
Services (2010), the result would be approximately 17 million tonnes of total
production annually (indoor and outdoor). Indoor Share of Total Production:The
three-fold changes in potency over the past two decades, reported by federal
sources, are attributed at least in part to the shift towards indoor cultivation See and (Hudson, 2003). A
weighted-average potency of 10% THC (U.S. Office of Drug Control Policy, 2010)
reconciled with assumed 7.5% potency for outdoor production and 15% for indoor
production implies 33.3%::67.7% indoor::outdoor production shares. For reference,
as of 2008, 6% of eradicated plants were from indoor operations, which are more
difficult to detect than outdoor operations. A 33% indoor share, combined with per-
plant yields from Table 2, would correspond to a 4% eradication success rate for the
levels reported (415,000 indoor plants eradicated in 2009) by the U.S. Drug
Enforcement Agency (
Assuming 400,000 members of medical Cannabis dispensaries in California (each
of which is permitted to cultivate), and 50% of these producing in the generic 10-
module room assumed in this analysis, output would slightly exceed this study’s
estimate of total statewide production. In practice, the vast majority of indoor
production is no doubt conducted outside of the medical marijuana system.
[j]. Total U.S. electricity sales: U.S. energyinformation administration, ‘‘retail sales of
electricity to ultimate customers: Total by end-use sector’’
cneaf/electricity/epm/table5_1.html, (Accessed March 5, 201 1)
[k]. California Energy Commission, 2009;2011.
E. Mills / Energy Policy 46 (2012) 58–6764
Table A3
Energy model.
Penetration Rating
(Watts or %)
Number of
modules served
Input energy per
Units Hours/day
(leaf phase)
Days/cycle (leaf
(flower phase)
kW/h/cycle kW/h/year per
Lamps (HPS) elect 100% 1,000 1 1,000 W 12 60 720 3,369
Ballasts (losses) elect 100% 13% 1 130 W 12 60 94 438
Lamps (MH) elect 100% 600 1 600 W 18 18 194 910
Ballast (losses) elect 100% 0 1 78 W 18 18 25 118
Motorized rail motion elect 5% 6 1 0.3 W 18 12 18 60 0 1
Controllers elect 50% 10 10 1 W 24 24 18 60 2 9
Ventilation and moisture control
Luminare fans (sealed from conditioned
elect 100% 454 10 45 W 18 12 18 60 47 222
Main room fans supply elect 100% 242 8 30 W 18 12 18 60 31 145
Main room fans exhaust elect 100% 242 8 30 W 18 12 18 60 31 145
Circulating fans (18’’) elect 100% 130 1 130 W 24 24 18 60 242 1,134
Dehumidification elect 100% 1,035 4 259 W 24 24 18 60 484 2,267
Controllers elect 50% 10 10 1 W 24 24 18 60 2 9
Spaceheat or cooling
Resistance heat or AC [when lights off] 90% 1,850 10 167 W 6 12 18 60 138 645
Carbon dioxide Injected to Increase foliage
Parasitic electricity elect 50% 100 10 5 W 18 12 18 60 5 24
AC (see below) elect 100%
In-line heater elect 5% 115 10 0.6 W 18 12 18 60 1 3
Dehumidification (10% adder) elect 100% 104 0 26 W 18 12 18 60 27 126
Monitor/control elect 100% 50 10 5 W 24 24 18 60 9 44
Irrigation water temperature control elect 50% 300 10 15 W 18 12 18 60 19 89
Recirculating carbon filter [sealed room] elect 20% 1,438 10 29 W 24 24 18 60 54 252
UV sterilization Elect 90% 23 10 2.1 W 24 24 18 60 4 18
Irrigation pumping elect 100% 100 10 10 W 2 2 18 60 2 7
Fumigation elect 25% 20 10 1 W 24 24 18 60 1 4
Dehumidification elect 75% 1,035 10 78 W 24 7 13 61
Circulating fans elect 100% 130 5 26 W 24 7 4 20
Heating elect 75% 1,850 10 139 W 24 7 23 109
Electricity subtotal elect 2,174 10,171
Air-conditioning 10 420 W 583 2,726
Lighting loads 10 W 259 1,212
Loads that can be remoted elect 100% 1,277 10 W 239 1,119
Loads that can’t be remoted elect 100% 452 10 W 85 396
CO2-production heat removal elect 45% 1,118 17 W 18 12 18 60 ——
Electricity Total elect 3,225 W 2,756 12,898
FUEL Units Technology
Number of
modules served
Input energy per
(leaf phase)
Days/cycle (leaf
(flower phase)
GJ or
GJ or kgCO
On-site CO
Energy use propane 45% 11,176 17 707 kJ/h 18 12 18 60 0.3 1.5
CO2 production –4emissions kg/CO
20 93
Externally produced Industrial CO
5% 1 0.003 liters
18 12 18 60 0.6 2.7
Weighted-average on-site/purchased kgCO
E. Mills / Energy Policy 46 (2012) 58–67 65
For Cannabis producers, energy-related production costs have
historically been acceptable given low energy prices and high
product value. As energy prices have risen and wholesale com-
modity prices fallen, high energy costs (now 50% on average of
wholesale value) are becoming untenable. Were product prices to
fall as a result of legalization, indoor production could rapidly
become unviable.
For legally sanctioned operations, the application of energy
performance standards, efficiency incentives and education,
coupled with the enforcement of appropriate construction codes
could lay a foundation for public-private partnerships to reduce
undesirable impacts of indoor Cannabis cultivation.
There are
early indications of efforts to address this.
Were such operations
to receive some form of independent certification and product
labeling, environmental impacts could be made visible to other-
wise unaware consumers.
Two anonymous reviewers provided useful comments
that improved the paper. Scott Zeramby offered particularly
valuable insights into technology characteristics, equipment con-
figurations, and market factors that influence energy utilization in
this context and reviewed earlier drafts of the report.
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E. Mills / Energy Policy 46 (2012) 58–67 67
... Reviews suggested that workers at Cannabis cultivation facilities (CCFs) are exposed to organic dust (molds, pollens, bacteria, other allergens, and bioaerosols), VOCs, fungicides, and pesticides . An interview of Cannabis cultivation facilities (CCFs) workers found that 71% presented some work-related symptoms, and the majority of symptoms (65%) was respiratory (76)(77)(78)(79)(80). Workers in indoor cultivation of Cannabis are mostly in contact with "raw" material, whereas consumers are exposed to processed or combusted material (70)(71)(72)(73)(74)(75)(76)(77)(78)(79)(80). ...
... Raw Cannabis material is often composed of larger particles (e.g., organic dust, allergens, impurities) that are filtered by airway defences, while combusted material is composed of smaller particles and gases that are inhaled and penetrate deeper in the respiratory system (70)(71)(72)(73)(74)(75)(76)(77)(78)(79)(80). Emissions from Cannabis cultivation facilities (CCFs) may affect public health at the community scale through exposures to: (1) High concentrations of terpene oxidation products, (2) High concentrations of particulate matter and ...
... Page 29 ozone, and (3) Odour. However, studies point to a broad range of symptoms, such as burning eyes and throat, problems sleeping, nausea, and headache (65)(66)(67)(68)(69)(70)(71)(72)(73)(74)(75)(76)(77)(78)(79)(80). ...
Full-text available
This review paper highlights about the emission of volatile organic compounds (VOCs) of Cannabis plants. Volatile organic compounds (VOCs) are a large group of chemicals harmful to human health that are readily released into the atmosphere and participate in atmospheric photochemical reactions. Floral Volatile organic compounds (VOCs) are often involved in defence and pollinator attraction. Cannabis cultivation and consumption may lead to additional environmental impacts. Studies found out that Cannabis plants emit a significant amount of biogenic volatile organic compounds (BVOCs) which could cause indoor air quality issues. Indoor Cannabis cultivation is energy-consuming, mainly due to heating, ventilation, air conditioning, and lighting. Energy consumption leads to greenhouse gas emissions. Common compounds to all the tested hemp cultivars include β-myrcene, ϒ-caryophyllene, α-pinene, β-pinene and limonene, reflecting species specificity in the emission of these compounds. β-Myrcene was the most abundant compound in most of the outside hemp cultivars. The terpenes had an earthy musky, and fruity smell may contribute to the odour in Cannabis samples at the vegetative stage, flowering stage, and drying/curing stage. All hemp cultivars are the prolific emitters of terpenoids. The oxidation of highly reactive Biogenic Volatile organic compounds (BVOCs) from Cannabis plants can lead to the formation of ozone and secondary Volatile organic compounds (VOCs) (e.g., formaldehyde and acrolein). In hemp production, considerable odorous emissions occur during field retting. However, more research is needed to address how outdoor air quality is influenced by Cannabis cultivation facilities (CCFs) emissions.
... It is well-established that indoor cannabis cultivation (including environmentally controlled greenhouses) is highly energy intensive (Mills 2012;Summers et al. 2021). With increasing voluntary and mandatory measures being implemented to stem the release of energy-related greenhouse gasses, facilities of all types are moving towards zero-net-energy goals (i.e., all energy provided with on-site renewable energy systems, primarily solar photovoltaic panels). ...
... One outdoor land-intensity datapoint is off-scale (90 sf/pound). Sources:Arnold (2011;2013),Backer et al, (2019),3 Caulkins et al., (n/d),Knight et al., (2010),Leichliter et al., (2018), NFD (2018),Rodriguez-Morrison et al., 2021),Vanhove et al., (2011 and2012),Wilson et al., (2019), and numerous company reports. ...
... Yields have been found to vary by a factor of two as a function of plant genetics(Vanhove et al., 2011;2012 andArnold 2011). ...
Technical Report
Full-text available
Key distinctions between indoor and outdoor cannabis cultivation include energy, land, and water use. It is well established that indoor cultivation is vastly more energy-intensive than outdoor cultivation. In contrast, indoor-based practices are widely asserted to be less water- and land-use-intensive. However, these claims are based on an “apples-and-oranges” comparison of highly optimized indoor production methods to outdoor methods representing typical rather than best practices. To develop a more balanced assessment, this study pools land use, water use, and yield data from the literature representing 188 sources and 503 specific cultivation sites or trials representing 29.8 million square feet of canopy area. When best practices are examined – utilizing compost-enriched soils with high water retention properties together with intensive plantings to minimize evaporation -– it appears that outdoor cultivation can readily be more land- and water-efficient than indoor practices. In particular, land-use intensity (square feet per pound of marketable flower per year) for typical outdoor cultivation is 5-fold greater than that of indoor cultivation, falling to less than twice that level with demonstrated best practices and about 25% less than indoor intensities per current targets. This is conservatively assuming only one harvest per year for outdoor production. Similarly, water use intensity (gallons of water per pound of marketable flower) for typical outdoor cultivation is about 50% greater than that of indoor cultivation, falling to about 50% less than indoor intensities with demonstrated best practices and 75% less per current targets. Moreover, boundary conditions set by previous analysts — the dividing line between what is and isn’t included in the comparative assessments — routinely skew the analysis. This results from excluding water evaporated in the generation of electricity used in indoor cultivation facilities or, where sustainable energy is used to achieve a “net zero” on-site energy profile, the land area required to support the required solar electricity arrays. When these factors are included, even “typical” outdoor cultivation requires less water and land per unit yield than indoor cultivation.
... Popular media speculation about environmental impacts of cannabis agriculture in this region, especially impacts on water, is widespread (Bland, 2014, Harkinson, 2014, Ryzik, 2014, [77][78][79] but empirical research is limited (Carah et al., 2015). [69] The small body of scientific research points to profound negative consequences, including decreased stream flows , [80] rodenticide poisoning of rare carnivores (Gabriel et al., 2012), [81] and high carbon emissions from greenhouses (Mills, 2012). [82] ...
... [69] The small body of scientific research points to profound negative consequences, including decreased stream flows , [80] rodenticide poisoning of rare carnivores (Gabriel et al., 2012), [81] and high carbon emissions from greenhouses (Mills, 2012). [82] ...
... Accelerated electricity demand growth has beens observed in areas reputed to have extensive indoor cannabis cultivation (Durkay and Freeman 2016). To control and maintain consistent and desired environmental conditions throughout cultivation, cannabis facilities require highly energy-intensive processes (Mills 2012). Some of these key environmental conditions are temperature, humidity, and air movement. ...
... The literature on cannabis flowering rooms across the US reports air change values as high as 60 ACH and as low as 12 ACH in these facilities (Summers, Sproul, and Quinn 2021), which on average translate to around 6-times the air change rate in high-tech laboratories, and 60-times the air change rate in a modern home (Mills 2012). In most cases, the high air change rates to achieve consistent and desired indoor environmental conditions could be lowered by adding supplemental equipment like oscillating fans and changing the layout of intake, exhaust systems, and grow lights. ...
Conference Paper
With increased legalization, cannabis cultivation is no longer a basement industry and cannabis cultivators are calling for improved indoor environmental conditions to produce high yields (Humphreys 2017). The economic laws of supply and demand will drive this industry and only those growers that produce high yields at low operating costs will survive. Cannabis growers prefer indoor grow facilities over outdoor for environmental control, security, and pest and disease management (Taylor 2013). Cannabis plants have varying sensitivities to temperature, air velocity, humidity, and lighting levels in different stages of their growth. It is important to maintain consistent and desirable uniform environmental conditions in grow rooms as any sudden changes can shock the plants and ultimately lead to crop damage and product loss. To maintain these desired indoor environmental conditions, the flowerings rooms require a regular supply of conditioned air. The literature on cannabis flowering rooms reports air change values as high as 60 ACH and as low as 12 ACH across the facilities in the US (Summers, Sproul, and Quinn 2021). The widespread use of high air change rates, without any scientific reasoning, in indoor cannabis facilities is one of the key reasons these facilities are energy intensive. Current indoor cannabis production results in prodigious energy use and costs which might be reduced with the use of additional equipment and room air distribution layout design (Summers, Sproul, and Quinn 2021). There are some conflicting recommendations for air changes and good air distribution layouts in cannabis flowering rooms (Daugherty and Bonnville 2020), ("How to Ensure Proper Airflow at Your Indoor Cannabis Cultivation Facility" 2020) but no scientific evidence to support these recommendations. These guidelines include rule of thumbs to calculate ACHs, and the arrangement of inlets, outlets, supplemental fans, and grow lights in the flowering room. This paper introduces a study to evaluate the aforementioned guidelines by testing variations in air distribution layouts for a flowering room in Las Vegas using Computational Fluid Dynamics (CFD) simulations. The base case air distribution arrangement is varied in this study through multiple design iterations, which are briefly mentioned, and six design iterations that are discussed in depth. The results demonstrate the variations of temperature, humidity, and airspeed levels in the flowering room with different air distribution layouts. Optimal air distribution layouts to achieve desired indoor environmental conditions and minimum air changes for a test case flowering room are discussed. The findings of the study will benefit growers and designers in energy and cost savings considering that there is little to no previous relevant scientific research on air distribution design in cannabis grow facilities.
... The reported environmental impact and carbon footprint (Mills, 2012) associated with the fast increase of commercial cannabis cultivation draw attention toward a more efficient use of fertilizers (Wartenberg et al., 2021). The response of plant growth to an increase in fertilizer concentration often follows a convex bellshaped curve. ...
Full-text available
Indoor medicinal cannabis cultivation systems enable year-round cultivation and better control of growing factors, however, such systems are energy and resource intensive. Nutrient deprivation during flowering can trigger nutrient translocation and modulate the production of cannabinoids, which might increase agronomic nutrient use efficiency, and thus, a more sustainable use of fertilizers. This experiment compares two fertilizer types (mineral and organic) applied in three dilutions (80, 160 and 240 mg N L−1) to evaluate the effect of nutrient deprivation during flowering on biomass, Cannabidiol (CBD) yield and nutrient use efficiency of N, P and K. This is the first study showing the potential to reduce fertilizer input while maintaining CBD yield of medicinal cannabis. Under nutrient stress, inflorescence yield was significantly lower at the final harvest, however, this was compensated by a higher CBD concentration, resulting in 95% of CBD yield using one-third less fertilizer. The higher nutrient use efficiency of N, P, and K in nutrient-deprived plants was achieved by a larger mobilization and translocation of nutrients increasing the utilization efficiency of acquired nutrients. The agronomic nutrient use efficiency of CBD yield – for N and K – increased 34% for the organic fertilizers and 72% for the mineral fertilizers comparing the dilution with one-third less nutrients (160) with the highest nutrient concentration (240). Differences in CBD yield between fertilizer types occurred only at the final harvest indicating limitations in nutrient uptake due to nutrient forms in the organic fertilizer. Our results showed a lower acquisition and utilization efficiency for the organic fertilizer, proposing the necessity to improve either the timing of bio-availability of organic fertilizers or the use of soil amendments.
... In the greenhouse industry, light-emitting diodes (LEDs) have been widely used for plant cultivation, as they are rated more energy-efficient over other conventional light sources, including high-pressure sodium (HPS) lamps [20,21]. Fixture efficacy plays an important role in C. sativa production as lighting represents one of the highest operating costs and associated environmental performance [22]. The impact of the light spectrum on C. sativa cultivation has been reported with different lighting systems, including HPS [23,24] and LEDs [25][26][27]. ...
Full-text available
Light is one of the most crucial parameters for enclosed cannabis (Cannabis sativa) production, as it highly influences growth, secondary metabolite production, and operational costs. The objective of this study was to investigate and evaluate the impact of six light spectra on C. sativa (‘Babbas Erkle Cookies’ accession) growth traits and secondary metabolite (cannabinoid and terpene) profiles. The light spectra evaluated included blue (430 nm), red (630 nm), rose (430 + 630 nm, ratio 1:10), purple (430 + 630 nm, ratio 2:1), and amber (595 nm) LED treatments, in addition to a high-pressure sodium (HPS, amber-rich light) treatment as a control. All the LED light treatments had lower fresh mean inflorescence mass than the control (HPS, 133.59 g plant−1), and monochromatic blue light yielded the least fresh inflorescence mass (76.39 g plant−1). Measurement of Δ9-tetrahydrocannabinol (THC) concentration (%) and total yield (g plant−1) showed how inflorescence mass and THC concentration need to be analyzed conjointly. Blue treatment resulted in the highest THC concentration (10.17% m/m), yet the lowest THC concentration per plant (1.44 g plant−1). The highest THC concentration per plant was achieved with HPS (2.54 g plant−1). As with THC, blue light increased cannabigerol (CBG) and terpene concentration. Conversely, blue light had a lesser impact on cannabidiol (CBD) biosynthesis in this C. sativa chemotype. As the combined effects of the light spectrum on both growth traits and secondary metabolites have important ramifications for the industry, the inappropriate spectral design could cause a reduction in cannabinoid production (20–40%). These findings show promise in helping producers choose spectral designs that meet specific C. sativa production goals.
Full-text available
Environmental impacts need to be taken into account in the cannabis regulation debate, because the high carbon footprint of indoor grow facilities could jeopardize policy aims to meet climate goals. Given the global climate and energy crisis, there is a compelling case to encourage sustainable outdoor cultivation and to enable certified imports from traditional Southern producers.
Full-text available
The increasing demand for food, the lack of natural resources and arable land, and the recent restrictions on energy consumption require an immediate solution in terms of agricultural activities. This paper’s objective was to review hydroponics (a new soilless cultivation technology) and compare it with conventional agriculture (soil cultivation) regarding its environmental impact and water and energy consumption. The soil loss, the crop/soil contamination, and the greenhouse gas emissions were the criteria for the environmental comparison of conventional agriculture and hydroponics. As for resource consumption, the water consumption rates (L/kg), energy consumption rates (kWh), and energy required (kW) were the criteria for comparing conventional agriculture with hydroponics. Tomato and cannabis cultivation were used as case studies in this review. The review results showed that the advantages of hydroponics over conventional cultivation include zero-soil cultivation, land-use efficiency, planting environment cleanliness, fertilizer and resource saving, water consumption reduction, and conservation. The disadvantages of hydroponics versus conventional cultivation were found to include the high investment costs, technical know-how requirements, and higher amount of demanded energy.
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In this study, the thermal, energy, economic, and environmental perspectives of a smart Cannabis plantation are investigated. A commercial R-32 air conditioning at a cooling capacity of 12,300 BTU/h is implemented for the 5-lighting sets. One 300 We-violet-light-emitting diode (LED) and two 100 We-daylight-LEDs are designed for one lighting set at a photosynthetic photon flux density of 100 µmol/m²⋅s. A smart watering system is designed to automatically control a watering period of 62 hours, an operating time of 40 minutes, and a watering rate of 41.5 L/time. The smart Cannabis plantation can produce a fresh inflorescence of 250 g and a dried inflorescence of 46.3 gdy, respectively. A power consumption of 126.9 kWh/plant is mainly driven the environmental impacts of a climate change of 6.22E+02 kg CO2 eq/kgdy. The economic result of a levelized cost is approximately 262.85 USD/kgdy.
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The motor vehicle industry in the U.S. spends about $3.6 billion on energy annually. In this report, we focus on auto assembly plants. In the U.S., over 70 assembly plants currently produce 13 million cars and trucks each year. In assembly plants, energy expenditures is a relatively small cost factor in the total production process. Still, as manufacturers face an increasingly competitive environment, energy efficiency improvements can provide a means to reduce costs without negatively affecting the yield or the quality of the product. In addition, reducing energy costs reduces the unpredictability associated with variable energy prices in today?s marketplace, which could negatively affect predictable earnings, an important element for publicly-traded companies such as those in the motor vehicle industry. In this report, we first present a summary of the motor vehicle assembly process and energy use. This is followed by a discussion of energy efficiency opportunities available for assembly plants. Where available, we provide specific primary energy savings for each energy efficiency measure based on case studies, as well as references to technical literature. If available, we have listed costs and typical payback periods. We include experiences of assembly plants worldwide with energy efficiency measures reviewed in the report. Our findings suggest that although most motor vehicle companies in the U.S. have energy management teams or programs, there are still opportunities available at individual plants to reduce energy consumption cost effectively. Further research on the economics of the measures for individual assembly plants, as part of an energy management program, is needed to assess the potential impact of selected technologies at these plants.
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The U.S. pharmaceutical industry consumes almost $1 billion in energy annually. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. pharmaceutical industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy efficient technologies that can be implemented at the component, process, system, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. pharmaceutical industry is provided along with a description of the major process steps in the pharmaceutical manufacturing process. Expected savings in energy and energy-related costs are given for many energy efficiency measures, based on case study data from real-world applications in pharmaceutical and related facilities worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. The information in this Energy Guide is intended to help energy and plant managers reduce energy consumption in a cost-effective manner while meeting regulatory requirements and maintaining the quality of products manufactured. At individual plants, further research on the economics of the measures?as well as their applicability to different production practices?is needed to assess potential implementation of selected technologies.
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This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, or The Regents of the University of California.
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Annually, breweries in the United States spend over $200 million on energy. Energy consumption is equal to 38 percent of the production costs of beer, making energy efficiency improvement an important way to reduce costs, especially in times of high energy price volatility. After a summary of the beer making process and energy use, we examine energy efficiency opportunities available for breweries. We provide specific primary energy savings for each energy efficiency measure based on case studies that have implemented the measures, as well as references to technical literature. If available, we have also listed typical payback periods. Our findings suggest that given available technology, there are still opportunities to reduce energy consumption cost-effectively in the brewing industry. Brewers value highly the quality, taste and drinkability of their beer. Brewing companies have and are expected to continue to spend capital on cost-effective energy conservation measures that meet these quality, taste and drinkability requirements. For individual plants, further research on the economics of the measures, as well as their applicability to different brewing practices, is needed to assess implementation of selected technologies.
Energy consumption and energy efficiency are topical matters in the Belgian glasshouse horticulture. In Belgium only a few data on energy consumption in the agricultural and horticultural sector are available. To fill this gap of information, the Centre of Agricultural Economics developed an extrapolation model that uses data from the Farm Accountancy Data Network of the Centre and data of the Agricultural Census of the National Institute of Statistics to monitor the energy consumption in the glasshouse horticultural sector from 1980 till now. The model is developed in such way that for each holding of the population the energy consumption is estimated. This allows us to estimate the energy consumption for different aggregates. The estimation of the share of the different energy sources in the total energy consumption makes it possible to estimate emissions due to the heating of the glasshouses. On the other hand the model creates an instrument for researchers and policy makers to evaluate the impact of energy saving actions on the energy consumption of the glasshouse horticultural sector.
Life cycle inventories of four industrial carbon dioxide production processes are reported. The inventory data were calculated using design-based methodology. Energy consumptions and critical emissions of the four processes are compared. Quasi-microscopic allocation was applied to processes with multiple products. The inventory data of this study are transparent and can be used in other life cycle studies. Copyright © 2007 Society of Chemical Industry
This paper provides a general overview of electricity consumption and peak load in California, by both sector and end use. We examine the growth in electricity demand between 1980 and 2000, as well as the composition of electricity end uses in 1999. One of the main conclusions from this analysis is that electricity use in California in the 1990s did not grow explosively, nor was the amount of growth unanticipated. In both absolute and relative terms, growth in electricity use was greater in the 1980s than the 1990s. During the 1990s, most of the growth in electricity use has been in the buildings sector, particularly commercial buildings. In 2000, the building sector accounted for 2/3 of annual electricity consumption and 3/4 of the summer peak load.