Download Why are Greenhouse Gas Emissions Important

Greenhouse Gas Emissions and Renewable Energy in
Alberta
Why are Greenhouse Gas Emissions Important?
Over the last century, modern industry and lifestyles have rapidly increased amounts of greenhouse gas (GHG)
in the earth’s atmosphere. Most scientists who study this topic believe that increased GHG amounts are
causing the climate to change. Changes in climate are expected to lead to more severe weather events, such
as prolonged droughts and flooding, with associated impacts that may include reduced availability of quality
water supplies.
Canada has committed to reducing GHG emissions to 17% below 2005 levels by 2020 and 30% below 2005
levels by 2030. Alberta has also made its own commitments to reduce emissions and was the first province to
design rules for cutting GHGs. Provinces and territories have been taking steps to address climate change
according to their specific circumstances. Businesses and individuals are also reducing emissions by using
resources more efficiently and adopting new, cleaner technologies.
Alberta’s agricultural industry already has many beneficial management practices that can reduce GHG
emissions and capture and store carbon. By showing leadership and taking initiative, farmers and ranchers in
Alberta can remain competitive, increase efficiencies, adapt to climate change and may be able to capture
new opportunities in emerging environmental markets.
Fossil Fuel Energy in Agriculture
Alberta’s economy is largely based on fossil fuels and GHGs are emitted when fossil fuels are burned.
Comparing Alberta’s various industry sectors, the majority of Alberta’s GHG emissions originate from the
energy sector. In 2013, Alberta’s agricultural industry accounted for approximately 8 % of the province’s
total GHG emissions, while the oil sands (22%), other oil and gas (24%), electricity (17%), and
transportation (11%) sectors accounted for 74% (Alberta Environment and Parks, 2014).
What is Renewable Energy?
Renewable energy is generated from sources that are replenished in nature at a sufficient rate that they
can be used by humans indefinitely. Renewable energy technologies convert renewable resources into
forms of energy that can complement or replace conventional energy sources such as fossil fuels into
forms of energy with significantly reduced carbon dioxide emissions. Wind, solar, earth energy systems,
small scale hydro and biomass (straw, wood, corn) are all sources of renewable energy. Table 1 outlines
the various sources of energy in Alberta relative to fossil fuel soures (coal and natural gas), as well as costs
and rates of emissions.
Ongoing research and development has made many renewable technologies economical, reliable, and
environmentally friendly. However, renewable energy technologies are site specific, and what works well
on one farm may not work on another (e.g. small scale hydro requires a farm with a stream running
through it).
Greenhouse Gas Emissions
Wind, solar, and small-scale hydro systems have zero GHG emissions. Biomass sources of energy are
considered GHG neutral because the carbon dioxide (CO2) generated in producing energy is compensated
for by the CO2 used by the growing crop.
Table 1. Alberta generation costs and carbon dioxide equivalents (CO2e) emissions by technology
Technology
Cents/kWh*
Tonnes CO2e /MWh**
Coal, with Carbon Capture and Storage (CCS)
23.7
0.11
Coal, without CCS
4***
0.76
Natural gas, simple cycle
11
0.37
Natural gas, combined cycle
8.2
0.37
6.9 to 10.6
0.37
Wind
8.9
0
Hydro
10.5
0
PV solar
17.6
0
Cogeneration
* AESO Long Term Outlook 2014
** Source: IPCC 2005, MWh = Megawatt hour
*** Aydin et al. 2013
Wind
Wind turbines capture wind energy and convert it to electricity. Wind energy systems range greatly in
capacity, from small, stand-alone ‘off-grid’ systems to utility-scale towers that contribute to the provincial
power grid. Wind power systems require an average annual wind speed greater than 15 kilometres per
hour. Alberta is endowed with abundant wind energy resources (Table 2). In Alberta, wind energy
currently has over 1,100 megawatts (MW) connected to the grid or about seven percent of installed
capacity (Alberta Energy, 2014). This is enough to serve close to half a million houses.
Table 2. Wind generation capacity in Alberta.
Value
Units
Hours in the year
8760
hours
Capacity factor
0.34
%
1,100,000
kW
3,276,240,000
7,200
kWh
Capacity of generating unit
Electricity per year
Average Alberta residence electricity demand per year
Number of Alberta houses
kWh/year
455,033
Solar
There are three types of solar energy systems that can be used to generate heat or electricity:
• Passive solar systems - collect and store solar energy and distribute it by natural processes such as
convection and radiation.
• Active solar systems - use solar collectors to heat water or air, and a pump to circulate it throughout
the building. A typical system will reduce the need for conventional water heating by about twothirds. Dairy, swine and poultry producers, as well as aquaculture operations, are examples of
agricultural businesses using solar systems in Canada.
•
Photovoltaic systems - convert sunlight directly into electricity. Photovoltaic arrays (10 to 20 PV
modules, each made up of approximately 40 cells) can provide enough power for a household. For
large applications, hundreds of arrays can be interconnected to form a single PV system.
Earth energy systems
Earth energy systems can provide heating in winter, cooling in summer and year-round hot water for
home use. These systems use heat pumps to move heat between the earth and buildings as needed. Heat
pumps cost about twice as much as conventional heating systems to install, but on average the operating
cost is approximately two-thirds less than traditional systems. More than 30,000 heat pumps or "earth
energy" installations in Canada are being used in residential, commercial, institutional and industrial
applications. They are considered to be the most energy-efficient, environmentally clean and costeffective heating systems available.
Small-scale hydroelectric power
Small-scale hydroelectric power technologies use free flowing water to produce electricity. Most micro
hydros are run-of-stream systems that divert water through a pipe or channel. The water is directed
through a turbine and then allowed to flow back to the river or creek. Because they typically do not
require large storage dams, they can be sited, built and operated with minimal environmental impact.
Biomass
Biomass resources are any plant-derived organic matter available on a renewable basis. This includes
forestry and agricultural crops, in addition to animal, food-processing, and municipal wastes. Table 3
outlines the relative effectiveness of a range of biomass feedstocks relative to fossil fuels.
There are four ways in which biomass is converted into energy:
• Incineration - the thermal conversion of biomass into heat energy and ash through complete
combustion.
• Gasification - the conversion of biomass into gases (carbon monoxide and hydrogen) at high
temperatures with a controlled amount of oxygen and/or steam.
• Pyrolysis - the decomposition of biomass in the absence of air and presence of extreme heat, to
produce a higher-carbon fuel product
• Anearobic Digestion – the decomposition of biomass in the absence of oxygen to produce energy
rich gas.
Agriculture operations can benefit from the use of biomass as an energy source because many biomass
resources can easily be produced locally and they can be used to produce on-farm energy or sold to
producers of bio-energy products. However, for biomass resources to be renewable, sustainable cropping
practices are necessary. It is also important to recognize that food crops diverted to produce energy
decrease food production for human and animal consumption.
Wood
Burning wood instead of natural gas or propane can substantially lower heating costs if it is readily
available. Wood is more labour-intensive than fossil fuels, which must be taken into account when doing
cost comparisons. Depending on the efficiency of the stove or furnace, burning wood emits unburned
hydrocarbons, smoke and entrained ash at varying levels.
Straw
Shredded, loose, and densified straw (pellets, briquettes, cubes, straw logs), square bales and round bales
can be burned to heat water, buildings or dry grain. A straw burning system is economical in meeting
demands for large heat load. Most bale-burning boilers are about 40 percent efficient. However, the
availability of straw varies considerably between regions and between years due to variations in climate
and livestock requirements for feed and bedding. Transportation costs from fields to biomass facilities
must be taken into account. Sufficient straw must also remain on fields to return crop nutrients and
protect soil from erosion by wind and water. Alberta Agriculture and Forestry recommends that 30
percent of the soil surface be covered by crop residue to prevent soil erosion.
Switchgrass
Switchgrass (Panicum virgatum) is a native perennial grass that once dominated the North American
tallgrass prairie. It grows with minimal inputs of water and fertilizer, can grow on marginal lands and does
not require specialized production equipment. A switchgrass plantation can last from 5 to 15 years. The
grass is harvested annually, then chopped and pelleted for use in specialized stoves and furnaces.
Switchgrass is suitable for production in some parts of Alberta.
Grain
Grains such as wheat are starch crops that can either be used as a heating fuel or converted to
bioethanol. However, grains may not be a good fuel source because it diverts needed foodstuffs, requires
large fertilizer, herbicide and pesticide inputs for production, and has a high ash content, making it
difficult to burn.
Biogas
Biogas is generated by the anaerobic (no oxygen) digestion of organic material such as manures and
municipal wastes. Biogas can be burned to produce heat, electricity or both. Liquid manure systems work
best for anaerobic digestion. The installation and operation of an anaerobic digester requires considerable
monetary and manpower investments. The feasibility of anaerobic digestors depends on type of livestock,
type of manure management system, and heat and electricity requirements. The feasibility of digestors in
terms of cost and continuity of feedstock supply requires careful evaluation.
Biofuels
Biofuels include biogas, alcohols, ethers, esters and other chemicals made from biomass resources.
Biofuels can be used as a supplement or an alternative to fossil fuel to produce electricity, heat and/or
transportation fuel. In the short-term, biofuels can be used as blending agents to dilute CO2 emissions
from fossil-based fuels. In the long-term, technological advances are expected to allow greater use of
biofuels in vehicles.
Bioethanol (fuel alcohol) is made from starch (grain crops, corn); sugar (sugar beet or sugar cane); and,
although still in the preliminary stages, from cellulose (wood, straw, grass or municipal solid waste).
Bioethanol is widely used in Brazil and the USA today. Ethanol-blended fuels such as E85 (85 percent
ethanol and 15 percent gasoline) can reduce net greenhouse gas emissions by as much as 37 percent, and
E10 (10 percent ethanol and 90 percent gasoline) can reduce net greenhouse gas emissions by almost
four percent.
Biodiesel is manufactured from most vegetable oils such as canola or soybean, animal fats, recycled
grease, as well as low quality oilseeds and tall oil produced from wood pulp waste. Biodiesel can be
blended with conventional diesel fuel or used ‘straight’ (100 percent biodiesel).It is typically added to
petroleum diesel in 20 percent blends (B20) for diesel engines and is a direct fuel substitute for #2
petroleum diesel. Biodiesel used as a fuel or additive requires little or no engine modification and biodiesel fueled engines deliver similar mileage, torque and horsepower. Compared to fossil fuels, is that it
degrades quickly in the environment and is nontoxic.
The combination of improved technological efficiencies, scientific advances, increased environmental
awareness and environmental protection regulations have turned biomass conversion into a cleaner,
more efficient process. As the biomass energy market grows, so will the market for biomass resources,
which may provide farms with another stream of income.
Table 3. A comparison of Lower Heat Values (LHV) for burning different energy sources.
Fuel
Lower Heat Values
BTU/lb
MJ/kg
Natural Gas
22865
53.18
Propane
19940
46.37
Gasoline
18831
43.80
Diesel (#2)
18401
42.80
Biodiesel
16251
37.80
Fuel Oil (#1)
15910
37.00
Ethanol
11479
26.70
Coal
10318
24.00
Coal (sub-bituminous)
9000
20.93
Flax straw (dry)
8587
19.97
Wood Pellets
8512
19.80
Wheat straw (dry)
7680
17.86
Corn straw (dry) *
7540
17.50
Shelled corn (15% moisture) *
7000
16.20
Flax straw (20% moisture)
6635
15.43
Wood (15% moisture)
6450
15.00
Wheat straw (20% moisture)
5908
13.74
Biogas
55159
17.25
PAMI Research Update #719. 1995.
*OMAFRA Agdex #111.768. 1997
Incentives for Energy Improvements
In Alberta, carbon credits can also be created from voluntary management improvements that have a
sound science basis for lower greenhouse gas emissions, are above and beyond business as usual, and can
be verified by independent third parties. Companies who are regulated under Alberta’s Specified Gas
Emitters Regulation (2002) can use carbon credits as way to meet their requirement to reduce
greenhouse gas emission intensities each year. There are a number of carbon offset protocols that
provide incentives to support the generation of renewable energy. These protocols outline the science,
policy and verification basis for management improvements that are eligible to create carbon credits for
sale to regulated companies. More information about agricultural carbon offsets is available at:
www.agricuture.alberta.ca/agcarbonoffsets.
Summary
Renewable energy can complement or replace conventional and reduce GHG emissions at the same time.
Wind, solar, and small-scale hydro systems have zero GHG emissions. Biomass resources are considered
GHG neutral because the CO2 generated during combustion is offset by the CO2 used by the growing
biomass crop. Reducing emissions can improve the industry’s production efficiencies, conserve soil and
water resources, and help slow global warming.
Sources
Alberta Electric Systems Operator. 2014. AESO 2014 Long-term Outlook
Alberta Environment and Parks. 2014. Climate Leadership Discussion Document. 62pp. Available at:
http://www.alberta.ca/albertacode/images/Climate-Leadership-Discussion-Document.pdf
Alberta Energy, 2014. Electricity Statistics. Available at: http://www.energy.alberta.ca/electricity/682.asp
Aydin, O. and Graves, F. and Celbbi, M. 2013. Coal Plant Retirements Feedback Effects on Wholesale
Electricity Prices. The Brattle Group
IPCC, 2005. IPCC Special Report on Carbon Dioxide Capture and Storage. Prepared by Working Group III of
the Intergovernmental Panel on Climate Change [Metz, B., O. Davidson, H. C. de Coninck, M. Loos, and L.
A. Meyer (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 442
pp.
Kralovic and Mutysheva. 2006. The Role of Renewable Energy in Alberta’s Energy Future. Canadian Energy
Research Institute, Calgary.