processing design capacity, the amount of CO 2 , and the amount of culture. In
addition to insolation other climate-related factors (temperature and cloud cover,
precipitation, wind, etc.) will also affect both the productivity and reliability of algal
production. The optimized temperature for algal biomass growth is in between
20 and 35
C, though strains vary in temperature tolerance. Higher temperatures
can lead to reduced productivity rates, while very low temperature can cause slower
algal growth (Pate 2013). As a result, lower latitude areas are more preferable for
algal growth due to more stable temperature range (Pate et al. 2011; Lundquist et al.
2010; Pate 2013; Quinn et al. 2012). According to requirement the operating
temperature range can be adjusted through the use of different open, closed, and
hybrid cultivation systems for algal culture. In open pond systems, optimum temperature can be affected by evaporative water loss, solar gain during the day, pond
depth, pond mixing, radioactive heat loss at night, the thermal coupling, and
bidirectional heat flow through pond. Comparatively closed photobioreactors
(PBRs) are less sensitive to climate change than open ponds. However, temperature
monitoring is needed in PBRs due to limited evaporative cooling. Availability of
temperature and sunlight (seasonally and annually) will directly affect the algal
productivity, whereas other climate changes (precipitation, evaporation, and severe
weather) will affect quality and demand of water in open systems.
1.5.2 Water
Suitable water is an important factor for algal cultivation. It is dependent on
geographical and local conditions. Most of the areas of the country are suited for
algal culture due to the highest solar resource but it is subject to more limited water
supplies (Wigmosta et al. 2011; Venteris et al. 2013). Instead of geographic location,
algae-based biofuels will also depend on water use and consumption in the cultivation systems (photoautotrophic/heterotrophic/mixotrophic) and growth system
(open vs. closed systems). Different degrees of water usage are incurred if there is
a need to replace water lost by evaporation in open pond systems, or to use water for
evaporative cooling in closed systems. Mixotrophic and heterotrophic systems must
also require water used for upstream production of organic carbon feedstock.
Cultivation of algal feedstock can be dependent on less, the same, or more water
than terrestrial biofuel crops. It all depends on cultivation process, co-products, and
location of systems (Batan et al. 2013).
1.5.3 Land
Open and closed systems will require land availability for photosynthesis-based
biomass feedstock. Various factors such as physical, social, economic, environmental, legal, and political factors affect land availability for algal production. It has
demonstrated that open pond system is required approx. 5.5% land area of the
Continental United States (CONUS) to generate 220 Â 10
9 L/year of oil through
16
N. Maheshwari et al.
addition to insolation other climate-related factors (temperature and cloud cover,
precipitation, wind, etc.) will also affect both the productivity and reliability of algal
production. The optimized temperature for algal biomass growth is in between
20 and 35
C, though strains vary in temperature tolerance. Higher temperatures
can lead to reduced productivity rates, while very low temperature can cause slower
algal growth (Pate 2013). As a result, lower latitude areas are more preferable for
algal growth due to more stable temperature range (Pate et al. 2011; Lundquist et al.
2010; Pate 2013; Quinn et al. 2012). According to requirement the operating
temperature range can be adjusted through the use of different open, closed, and
hybrid cultivation systems for algal culture. In open pond systems, optimum temperature can be affected by evaporative water loss, solar gain during the day, pond
depth, pond mixing, radioactive heat loss at night, the thermal coupling, and
bidirectional heat flow through pond. Comparatively closed photobioreactors
(PBRs) are less sensitive to climate change than open ponds. However, temperature
monitoring is needed in PBRs due to limited evaporative cooling. Availability of
temperature and sunlight (seasonally and annually) will directly affect the algal
productivity, whereas other climate changes (precipitation, evaporation, and severe
weather) will affect quality and demand of water in open systems.
1.5.2 Water
Suitable water is an important factor for algal cultivation. It is dependent on
geographical and local conditions. Most of the areas of the country are suited for
algal culture due to the highest solar resource but it is subject to more limited water
supplies (Wigmosta et al. 2011; Venteris et al. 2013). Instead of geographic location,
algae-based biofuels will also depend on water use and consumption in the cultivation systems (photoautotrophic/heterotrophic/mixotrophic) and growth system
(open vs. closed systems). Different degrees of water usage are incurred if there is
a need to replace water lost by evaporation in open pond systems, or to use water for
evaporative cooling in closed systems. Mixotrophic and heterotrophic systems must
also require water used for upstream production of organic carbon feedstock.
Cultivation of algal feedstock can be dependent on less, the same, or more water
than terrestrial biofuel crops. It all depends on cultivation process, co-products, and
location of systems (Batan et al. 2013).
1.5.3 Land
Open and closed systems will require land availability for photosynthesis-based
biomass feedstock. Various factors such as physical, social, economic, environmental, legal, and political factors affect land availability for algal production. It has
demonstrated that open pond system is required approx. 5.5% land area of the
Continental United States (CONUS) to generate 220 Â 10
9 L/year of oil through
16
N. Maheshwari et al.