The current extensive research and development activities on microalgae as commercial sources of renewable fuels and energy rely on the basic and applied research on biology, physiology, cultural methods,cultural systems etc undertaken in the past . The oil content of microalgae can be very high which is one of its many features that have attracted scientist and engineers alike to continue research and development of this technology. Oil content of some microalgae can be as hig has 90% of dry biomass weight under extreme growth conditions, and the potential high oil content and dense biomass makes algae an interesting renewable fuel source .The diverse range of microalgae growing conditions and large number of species offers many methods and possible locations to grow microalgae, but to be viable and obtain a highest possible yield the effort must be taken to choose the most productive species whilst maintaining optima conditions to suit that species.The best approach would likely be to screen for highly productive oleaginous strains at selected sites, optimizing growth conditions for large scale culture,4x8ft rolling benches and optimizing productivity and lipid production through genetic manipulation or biochemical manipulation of the timing of lipid accumulation in the selected strains .

Many different countries in the world have trialed different species of microalgae such as the “Algae Species Program ” which was launched in the USA in 1980. The ASP program demonstrated that some species of microalgae could be cultivated reliably on a large scale for relatively long periods .Some species of microalgae have shown consistent potential and are considered reliable sources of biofuel. According to Solar Energy Research Institute report,the most promising species for biofuel production are Botryococcus braunii due to its rich quantities of hydro-carbons, Nannochloropsis salina for its high quantities of esters, and Dunaliella salina for its fatty acid content . See Table 1.Successful microalgae cultivation requires specific environmental conditions which vary from species to species   to achieveI deal cultivation conditions many factors need to be taken into account. The major parameters influencing biomass production include light of proper intensity and wavelength, temperature, CO2 concentration, nutrient composition, salinities and mixing conditions .In selecting a suitable location to grow microalgae efficiently it is important to take into account light and temperature as being paramount, as creating these conditions artificially can be a very expensive and difficult challenge.

Light and temperature are probably most important and well studied factors limiting the lipid and fatty acid composition of algae .Growing algae for biomass is also becoming useful system for wastewater treatment as the algae captures carbon dioxide, releases oxygen.The use municipal wastewater in microalgaecultivation can not only save water and cost but the water itself my offer some advantages particularly if it is high in nitrogen and phosphors and the production whilst also doubling as a method of wastewater treatment. A great deal of money and effort is being spent on the removal of pollutants such as biochemical oxygen demand,flood and drain table turbidity, nitrogen and phosphorus . Algae have been part of the process degrading organic compounds in aerobic water treatment systems along with playing a part in nutrient removal. Wastewater treatment ponds rely on algae photosynthesis to harness sunlight energy and provide oxygen to drive aerobic bacterial degradation of organic compounds . Utilizing algae as part of a water treatment process combined with growing algae as a biofuel feedstock offers a natural solution to two problems in a very environmentally friendly way. The concept of producing biofuel from algae harvested from wastewater treatment HRAP effluent is a niche opportunity that could be economical today .

There are several different cultivation methods for growing Microalgae, the main ones being an open pond systems, closed systems or hybrid systems. Determining the best system depends largely on the local environment and local weather conditions with regions of high levels of sunlight and warm temperatures offering the best conditions. The most influencing factors of algae growth light intensity, photosynthetic rate, temperature, nutrient availability, and PH. Closed systems offer much better environmental control and enables microalgae production to take place in locations a wider range of locations but at a must higher cost in both infrastructure and operational cost. Algae grown in an open system is prone to various environmental uncertainties like temperature fluctuation,weather change, consumption of the nutrients by other organisms in the pond, and stray pathogens .