Biofuels: Global Impact on Renewable Energy, Production Agriculture, and Technological Advancements

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Though these drawbacks can be partially compensated by higher productivities, they still limit the cost-effective production of microalgae biomass on required scale for biodiesel production. Comparison between open ponds and photobioreactors [ 51 , 52 , 58 , 66 — 71 ]. In these hybrid systems both open ponds and close photobioreactors are used together in combination to get better results.

In these systems, the required amount of contamination free inocula obtained from photobioreactors is transferred to open ponds or raceways to get maximum biomass yield [ 72 , 73 ]. Olaizola [ 74 ] and Huntley and Redalje [ 75 ] used these hybrid systems for the production of astaxanthin from Haematococcus pluvialis. However this is not suitable for biofuel production because this system is more expensive and it is also a batch culture system rather than a continuous culture system. In heterotrophic cultivation, instead of photosynthetic process, microalgae utilize organic carbon for their growth and development.

As photosynthetic organisms, microalgae are usually light-limited at high cell densities during large scale cultivation [ 76 ] or they experience photoinhibition if the light is too intense, both of which lead to slow growth and production [ 77 ]. Based on these drawbacks associated with phototrophic cultivation, heterotrophic cultivation of microalgae can be considered favourably [ 78 ]. The major advantages associated with heterotrophic cultivation over phototrophic cultivation are the good control on cultivation procedure, elimination of light necessity, and low cost of biomass harvesting [ 79 ].

However, heterotrophic cultivation also has some limitations. Until now only four types of heterotrophically grown microalgae such as C. However the utilization of plant-based glucose leads to food versus fuel feud because this is also used for human consumption [ 85 ]. Therefore, there is a necessity to develop an alternative technology to use lignocellulose and glycerol derived glucose. Therefore, more comprehensive LCA studies and proactive research for heterotrophic cultivation of microalgae are highly required. Most of the microalgae utilize both the autotrophic and heterotrophic pathways for their growth and development, indicating that they are able to photosynthesize and utilize organic material [ 87 , 88 ].

In mixotrophic growth system microalgae cannot depend entirely on photosynthesis because light is not a complete limiting factor, as either light or organic substrate can be utilized for growth [ 78 , 89 ].

Microalgae which exhibit mixotrophic metabolism are Spirulina platensis cyanobacteria and Chlamydomonas reinhardtii green algae [ 78 ]. In these organisms, photosynthesis takes place by utilizing light, whereas aerobic respiration uses an organic carbon source for growth [ 87 ]. Here the growth of the organism is influenced by the media supplemented with glucose during the light and dark phases; hence, biomass loss during the dark phase is less [ 89 ].

A subtype of mixotrophy is called amphitrophy. This type of organisms can survive either autotrophically or heterotrophically, depending on the availability of organic carbon source and light intensity [ 90 ]. Chojnacka and Noworyta [ 91 ] compared the growth of Spirulina sp. Their observation indicated that cultures grown in mixotrophic conditions showed reduced photoinhibition and enhanced growth rates as compared to autotrophic and heterotrophic culture conditions.

Therefore, fruitful mixotrophic production of microalgae permits the incorporation of photosynthetic and heterotrophic compounds during diurnal cycle. Mixotrophic cultivation reduces the impact of biomass loss during dark respiration and decreases the utilization of a number of organic matters during growth. Based on these features, mixotrophic cultivation plays a significant role in microalgae biofuel production. Photoheterotrophy is also known as photometabolism or photoorganotrophy or photoassimilation.

In this cultivation system, organic substrate is utilized as carbon source in the presence of light. There is no clear differentiation between photoheterotrophic and mixotrophic metabolisms, but they can specifically be defined according to the requirement of energy source for growth and particular metabolite production [ 90 ]. Manipulation of metabolic pathways by using genetic engineering in microalgae is relatively easy due to its unicellular formation.

The main objective of applying genetic engineering to microalgae is to improve the biomass and biodiesel production. The progress in genetic engineering of microalgae was extremely slow until recently. Availability of the microalgae genome sequences greatly facilitates the genetic engineering technology. To date genome sequencing projects were completed for several microalgae species [ 92 ] and the sequencing projects for some other microalgae species such as Fragilariopsis cylindrus , Pseudo-nitzschia , Thalassiosira rotula , Botryococcus braunii , Chlorella vulgaris , Dunaliella salina , Galdieria sulphuraria and Porphyra purpurea are under progress [ 93 , 94 ].

In addition to this, several sequencing projects for different species of microalgae plastids and mitochondria were completed and some projects are continuing [ 92 , 95 — 97 ]. The development of methodologies for microalgae genetic transformation has progressed considerably in the last 15 years. Advanced methodologies were developed for green, red, and brown algae, diatoms, euglenoids, and dinoflagellates, and until now 30 microalgae strains have been successfully transformed [ 92 ]. Most of the transformation experiments were made on a model green alga Chlamydomonas reinhardtii at both nuclear and chloroplast levels [ 98 , 99 ].

Microalgae growth is generally influenced by various environmental stress conditions such as temperature, light, salt concentration, and pH. These conditions can be controlled by engineering and manipulations of growth characteristics, but these manipulations increase the total growing costs of microalgae. Thus, it will be beneficial if the genetic engineering strategies can be developed to control these environmental stress conditions. The light intensity above this level reduces the microalgae growth.

Renewable energy

Because of this, microalgae growth efficiency during day time is less. Therefore, several studies were carried out to improve the microalgae photosynthetic efficiency and also to reduce the effect of photoinhibition. Most of these studies were carried out by reducing the number of light-harvesting complexes LHC or lowering the chlorophyll antenna size to decrease light absorbing capacity of individual chloroplasts [ ]. In an experiment, LHC expression in transgenic C. This alteration allowed C. In another study conducted by Huesemann et al.

Genes that are able to withstand other stress conditions such as temperature, pH, salt concentration, and other stimuli have also been identified. Genetic engineering application in the improvement of microalgae biofuel production is still in the initial stage. Some important advances have been made in the past few years such as development of genetic transformation strategies; sequencing of nuclear, mitochondrial, and chloroplast genomes; and establishment of expressed sequence tag EST databases [ 92 ]. The current molecular strategies required to improve microalgae biodiesel production include blocking energy rich compounds e.

Microalgae produce extracellular products for the development of matrix like substance on their surfaces, which encourages and provides the environment for the formation of bacterial biofilms [ , ]. To date, only limited studies have been carried out about the existence of interactions between bacterial biofilms and microalgae [ — ]. These studies suggest that the bacteria encourage the growth of microalgae by producing the vitamins and other growth factors, and the organic matters produced by the microalgae simultaneously encourage bacterial growth.

They also have negative interactions between each other; microalgae inhibit the bacterial growth by increasing the temperature, pH, and dissolved oxygen concentration DOC or by producing inhibitory metabolites [ , ], and in the same manner bacteria also can inhibit the microalgae growth by secreting algicidal compounds [ ] Figure 2. Recent reports suggested that the presence of these positive interactions between microalgae and bacteria enhances the microalgae biomass and biodiesel production [ , ].

Possible interactions between microalgae and bacteria: After attaining sufficient biomass, the microalgae cells are separated from water and prepared for downstream processing. Generally one or more solid-liquid separation steps are required for microalgae biomass separation [ 23 , , ]. Biomass harvesting and drying processes may constitute major energy consumption in microalgae biofuel production [ ]. Therefore, there is a need to reduce energy consumption in microalgae biomass harvesting and drying processes; otherwise, it may cause major cost increase in the overall processes of microalgae biofuel production [ , ].

Several methods such as presses, supercritical carbon dioxide extraction, ultrasonic-assisted extraction, osmotic shock, solvent extraction, and enzymatic extraction are available for oil extraction from microalgae biomass. The first three methods are used only at laboratory scale. The most important aspects to be considered for selection of appropriate oil extraction process are the cost, efficiency, toxicity, and ease of handling. Supercritical carbon dioxide and osmotic shock are not commercially viable methods due to high operation costs [ ]. Enzymatic extraction method is commercially possible, but some efforts are needed to reduce the costs [ , ].

However, some commercially viable methods are needed to minimize the cost, maximize the extraction of desirable lipid fractions, and reduce the coextraction contaminants. Microalgae biomass conversion technologies are classified into different types such as biochemical conversion, thermochemical conversion, chemical reaction, and direct combustion [ ] Figure 3. Biochemical conversion can be applied to produce methanol anaerobic digestion and ethanol fermentation from microalgae biomass [ 28 ].

Thermochemical conversion processes can be categorised into pyrolysis bio-oil, charcoal , gasification fuel gas , and liquefaction bio-oil [ — ].

The energy stored in microalgae cells can be converted into electricity by using direct combustion process. In chemical conversion technologies transesterification process can be employed for the conversion of extracted lipids into biodiesel [ 16 ]. Transesterification process is quite a sensitive process as it depends on different parameters such as free fatty acids FFAs , water content, molar ratio of alcohol to oil, catalyst, reaction temperature, and stirring [ ].

Catalytic processes are more appropriate in converting biomass to biodiesel, especially nanocatalysts which have the good capacity in improving product quality and attaining best operating conditions [ ]. Microalgae biomass conversion processes [ 23 , ]. In addition to many advantages, microalgae biofuels also have some disadvantages.

The main limitations involved in microalgae biofuel production are the low concentration of biomass in the culture and low oil content.

In addition, small size of microalgae cells makes the harvesting process quite costly. Harvesting and drying of microalgae biomass from high volume of water are an energy consuming process. Compared to the conventional agriculture practice, microalgae farming is more costly and complicated. These difficulties can be minimized or overcome by the improvement of the harvesting technology.

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Some of the cost effective technological strategies suggested to develop microalgae biofuel production are 1 development of biorefinery or coproduct strategy, 2 designing high photosynthesis efficiency photobioreactors, 3 development of cost-effective technologies for biomass harvesting and drying, 4 development of genetic engineering technology to modify metabolic pathways for microalgae biomass and lipid production, and 5 understanding of symbiotic interactions between microalgae and bacteria that also affects the biomass and lipid production in microalgae.

Economy plays an important role in the commercial feasibility of microalgae biofuel production [ ]. Microalgae oil production cost depends on various factors, such as biomass yield, oil content, scale of production systems, and cost of recovering oil from microalgae biomass. It also depends on the petroleum oil price. According to Gallagher [ ], the economic feasibility of microalgae biofuel production seems to be fair and dependent on government subsidies and the future prices of oil. In addition to optimized biomass yields, the requirement of carbon neutral renewable alternatives makes microalgae one of the best future sources of biofuels [ 16 ].

The resulting biomass production costs for these three systems including dewatering were 4. The factors which influence production costs are irradiation, mixing, photosynthetic efficiency, culture medium, and CO 2. Generally the following formula can be used to estimate the cost of algal oil where it can be a competitive substitute for petroleum diesel [ 16 ]:. The biodiesel competitiveness depends mainly on the microalgae biomass production costs. Competitiveness can be calculated by estimating the maximum price that could be paid for microalgae biomass with a given content of oil, if crude petroleum can be purchased at a given price as a source of energy.

This estimated price can then be compared with the current cost of producing the algal biomass. According to Chisti [ 44 ] the quantity of algal biomass M , tons , which is the energy equivalent to a barrel of crude petroleum, can be estimated as follows:. Keeping with average values for organic wastes, E biogas and q are expressed to be around Using these values in 2 , M can be calculated for any selected value of W. Assuming that converting a barrel of crude oil to various useable transport energy products costs roughly the same as converting M tons of biomass to bioenergy, the maximum acceptable price that could be paid for the biomass would be the same as the price of a barrel of crude petroleum; thus,.

The feasibility of microalgae biofuel can be enhanced by designing advanced photobioreactors, developing cost-effective technologies for biomass harvesting and drying, improving molecular strategies for more biomass and lipid production, and understanding of biotic and abiotic interactions with algae. Microalgae have the potential to be important and sustainable renewable energy feedstock that could meet the global demand. In spite of the many advantages, microalgae biofuels also have some disadvantages such as low biomass production and small cell size that makes the harvesting process costly.

These limitations could be overcome by designing advanced photobioreactors and developing low cost technologies for biomass harvesting, drying and oil extraction. In addition, application of genetic engineering technology in the manipulation of microalgae metabolic pathways is also an efficient strategy to improve biomass and biofuel production. Genetic engineering technology also plays an important role in the production of valuable products with minimal costs.

Biotic interaction with bacterial biofilms is also an important aspect in microalgae biomass and biofuel production.

1. Introduction

However, these technologies are still in the early stages and most have not been applied on a commercial scale. Therefore, further research in the development of novel upstream and downstream technologies will benefit the commercial production of biofuels from microalgae. The authors declare that there is no conflict of interests regarding the publication of this paper. National Center for Biotechnology Information , U. Journal List Biomed Res Int v. Published online Mar Srikanth Reddy Medipally , 1 Fatimah Md.

Shariff 1 , 3. Author information Article notes Copyright and License information Disclaimer. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article has been cited by other articles in PMC. Abstract The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources.

Introduction World energy crisis and global warming are the two major problems human kind faces today, which are mainly due to the more population growth, fast industrialization, and increased use of fossil fuels [ 1 ]. Table 1 Comparison of oil content, oil yield, and biodiesel productivity of microalgae with the first and the second generation biodiesel feedstock source [ 17 , 18 , 21 , 22 ].

Open in a separate window. World Market for Biofuel Production Large scale commercial production of microalgae began in Japan in the early s by culturing Chlorella as food additive. Production of Microalgae Biomass and Biofuel Microalgae biomass and biofuel production can be developed at two major phases that involve upstream and downstream processes Figure 1. Different strategies involved in microalgae biomass and biofuel production. Microalgae Cultivation Technologies Production of microalgae biomass can be carried out by three different types of culture systems such as batch, semi-batch, and continuous systems.

Table 2 Biomass and lipid productivities of some microalgae under phototrophic, heterotrophic, and mixotrophic conditions. Table 3 Comparison between open ponds and photobioreactors [ 51 , 52 , 58 , 66 — 71 ]. Molecular Strategies to Improve Microalgae Biomass and Biofuel Production Manipulation of metabolic pathways by using genetic engineering in microalgae is relatively easy due to its unicellular formation. Harvesting and Drying of Microalgae Biomass After attaining sufficient biomass, the microalgae cells are separated from water and prepared for downstream processing.

Typically full load hours of wind turbines vary between 16 and 57 percent annually, but might be higher in particularly favorable offshore sites. Wind energy was the leading source of new capacity in Europe, the US and Canada, and the second largest in China. Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand, assuming all practical barriers needed were overcome. This would require wind turbines to be installed over large areas, particularly in areas of higher wind resources, such as offshore.

In hydropower generated There are many forms of water energy:. Hydropower is produced in countries, with the Asia-Pacific region generating 32 percent of global hydropower in For countries having the largest percentage of electricity from renewables, the top 50 are primarily hydroelectric.

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China is the largest hydroelectricity producer, with terawatt-hours of production in , representing around 17 percent of domestic electricity use. There are now three hydroelectricity stations larger than 10 GW: Wave power , which captures the energy of ocean surface waves, and tidal power , converting the energy of tides, are two forms of hydropower with future potential; however, they are not yet widely employed commercially. A demonstration project operated by the Ocean Renewable Power Company on the coast of Maine , and connected to the grid, harnesses tidal power from the Bay of Fundy , location of world's highest tidal flow.

Ocean thermal energy conversion , which uses the temperature difference between cooler deep and warmer surface waters, currently has no economic feasibility. Solar energy , radiant light and heat from the sun , is harnessed using a range of ever-evolving technologies such as solar heating , photovoltaics , concentrated solar power CSP , concentrator photovoltaics CPV , solar architecture and artificial photosynthesis.

Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air. Active solar technologies encompass solar thermal energy , using solar collectors for heating, and solar power , converting sunlight into electricity either directly using photovoltaics PV , or indirectly using concentrated solar power CSP. A photovoltaic system converts light into electrical direct current DC by taking advantage of the photoelectric effect.

Commercial concentrated solar power plants were first developed in the s. CSP-Stirling has by far the highest efficiency among all solar energy technologies. In , the International Energy Agency said that "the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries' energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability , reduce pollution, lower the costs of mitigating climate change , and keep fossil fuel prices lower than otherwise.

These advantages are global.

Renewable Energy Production on Farms

Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared". High Temperature Geothermal energy is from thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals in currently uncertain [56] but possibly roughly equal [57] proportions. The geothermal gradient , which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface.

The adjective geothermal originates from the Greek roots geo , meaning earth, and thermos , meaning heat. Heat conducts from the core to surrounding rock. Extremely high temperature and pressure cause some rock to melt, which is commonly known as magma. Magma convects upward since it is lighter than the solid rock. From hot springs , geothermal energy has been used for bathing since Paleolithic times and for space heating since ancient Roman times, but it is now better known for electricity generation.

Low Temperature Geothermal [29] refers to the use of the outer crust of the earth as a Thermal Battery to facilitate Renewable thermal energy for heating and cooling buildings, and other refrigeration and industrial uses. In this form of Geothermal, a Geothermal Heat Pump and Ground-coupled heat exchanger are used together to move heat energy into the earth for cooling and out of the earth for heating on a varying seasonal basis.

Low temperature Geothermal generally referred to as "GHP" is an increasingly important renewable technology because it both reduces total annual energy loads associated with heating and cooling, and it also flattens the electric demand curve eliminating the extreme summer and winter peak electric supply requirements. Biomass is biological material derived from living, or recently living organisms. It most often refers to plants or plant-derived materials which are specifically called lignocellulosic biomass.

Introduction

Conversion of biomass to biofuel can be achieved by different methods which are broadly classified into: Wood remains the largest biomass energy source today; [66] examples include forest residues — such as dead trees, branches and tree stumps —, yard clippings, wood chips and even municipal solid waste. In the second sense, biomass includes plant or animal matter that can be converted into fibers or other industrial chemicals , including biofuels.

Industrial biomass can be grown from numerous types of plants, including miscanthus , switchgrass , hemp , corn , poplar , willow , sorghum , sugarcane , bamboo , [67] and a variety of tree species, ranging from eucalyptus to oil palm palm oil. Plant energy is produced by crops specifically grown for use as fuel that offer high biomass output per hectare with low input energy.

Some examples of these plants are wheat, which typically yield 7. Plant biomass can also be degraded from cellulose to glucose through a series of chemical treatments, and the resulting sugar can then be used as a first generation biofuel. Biomass can be converted to other usable forms of energy such as methane gas or transportation fuels such as ethanol and biodiesel. Crops, such as corn and sugarcane, can be fermented to produce the transportation fuel, ethanol.

Biodiesel, another transportation fuel, can be produced from left-over food products such as vegetable oils and animal fats. Once harvested, it can be fermented to produce biofuels such as ethanol, butanol , and methane, as well as biodiesel and hydrogen. The biomass used for electricity generation varies by region. Forest by-products, such as wood residues, are common in the United States. Agricultural waste is common in Mauritius sugar cane residue and Southeast Asia rice husks. Animal husbandry residues, such as poultry litter, are common in the United Kingdom. Biofuels include a wide range of fuels which are derived from biomass.

The term covers solid , liquid , and gaseous fuels. Gaseous biofuels include biogas , landfill gas and synthetic gas. Bioethanol is an alcohol made by fermenting the sugar components of plant materials and it is made mostly from sugar and starch crops. These include maize, sugarcane and, more recently, sweet sorghum.

The latter crop is particularly suitable for growing in dryland conditions, and is being investigated by International Crops Research Institute for the Semi-Arid Tropics for its potential to provide fuel, along with food and animal feed, in arid parts of Asia and Africa. With advanced technology being developed, cellulosic biomass, such as trees and grasses, are also used as feedstocks for ethanol production. Ethanol can be used as a fuel for vehicles in its pure form, but it is usually used as a gasoline additive to increase octane and improve vehicle emissions.

Bioethanol is widely used in the United States and in Brazil. The energy costs for producing bio-ethanol are almost equal to, the energy yields from bio-ethanol. However, according to the European Environment Agency , biofuels do not address global warming concerns. It can be used as a fuel for vehicles in its pure form, or more commonly as a diesel additive to reduce levels of particulates, carbon monoxide, and hydrocarbons from diesel-powered vehicles.

Biodiesel is produced from oils or fats using transesterification and is the most common biofuel in Europe. Pollutants such as sulphurous oxides SO x , nitrous oxides NO x , and particulate matter PM are produced from the combustion of biomass; the World Health Organisation estimates that 7 million premature deaths are caused each year by air pollution. Energy storage is a collection of methods used to store electrical energy on an electrical power grid , or off it.

Electrical energy is stored during times when production especially from intermittent power plants such as renewable electricity sources such as wind power , tidal power , solar power exceeds consumption, and returned to the grid when production falls below consumption. Costs of lithium ion batteries are dropping rapidly, and are increasingly being deployed as fast acting sources of grid power i.

Renewable power has been more effective in creating jobs than coal or oil in the United States. The EIA has predicted that almost two thirds of net additions to power capacity will come from renewables by due to the combined policy benefits of local pollution, decarbonisation and energy diversification.

According to a projection by the International Energy Agency, solar power generators may produce most of the world's electricity within 50 years, reducing the emissions of greenhouse gases that harm the environment. Cedric Philibert, senior analyst in the renewable energy division at the IEA said: In , worldwide installed photovoltaics capacity increased to gigawatts GW , sufficient to supply 1 percent of global electricity demands. Ethanol fuel is also widely available in the United States. As of , American electric utility companies are planning new or extra renewable energy investments.

These investments are particularly aimed at solar energy, thanks to the Tax Cuts and Jobs Act of being signed into law. The law retained incentives for renewable energy development. Other companies, including Xcel Energy Inc.

Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A IEA report said: Hydro-electricity and geothermal electricity produced at favourable sites are now the cheapest way to generate electricity. Renewable energy costs continue to drop, and the levelised cost of electricity LCOE is declining for wind power, solar photovoltaic PV , concentrated solar power CSP and some biomass technologies.

As the cost of renewable power falls, the scope of economically viable applications increases. Renewable technologies are now often the most economic solution for new generating capacity. Where "oil-fired generation is the predominant power generation source e. New projects take the form of run-of-the-river and small hydro , neither using large reservoirs. It is popular to repower old dams thereby increasing their efficiency and capacity as well as quicker responsiveness on the grid. Countries with large hydroelectric developments such as Canada and Norway are spending billions to expand their grids to trade with neighboring countries having limited hydro.

Wind power is widely used in Europe , China , and the United States. As of the end of , China, the United States and Germany combined accounted for half of total global capacity. The United States conducted much early research in photovoltaics and concentrated solar power. When commissioned it was the largest parabolic trough plant in the world and the first U. The solar thermal power industry is growing rapidly with 1. Spain is the epicenter of solar thermal power development with MW under construction, and a further MW under development.

The Ivanpah Solar Power Facility being the most recent. Worldwide growth of PV capacity grouped by region in MW — Photovoltaics PV uses solar cells assembled into solar panels to convert sunlight into electricity. It's a fast-growing technology doubling its worldwide installed capacity every couple of years. PV systems range from small, residential and commercial rooftop or building integrated installations, to large utility-scale photovoltaic power station. The predominant PV technology is crystalline silicon , while thin-film solar cell technology accounts for about 10 percent of global photovoltaic deployment.

In recent years, PV technology has improved its electricity generating efficiency , reduced the installation cost per watt as well as its energy payback time , and has reached grid parity in at least 30 different markets by At the end of , worldwide PV capacity reached at least , megawatts.

Photovoltaics grew fastest in China , followed by Japan and the United States , while Germany remains the world's largest overall producer of photovoltaic power, contributing about 7. By , worldwide capacity is projected to reach as much as gigawatts. This corresponds to a tripling within five years. As the cost of solar electricity has fallen, the number of grid-connected solar PV systems has grown into the millions and utility-scale solar power stations with hundreds of megawatts are being built. Solar PV is rapidly becoming an inexpensive, low-carbon technology to harness renewable energy from the Sun.

Many solar photovoltaic power stations have been built, mainly in Europe, China and the United States. Many of these plants are integrated with agriculture and some use tracking systems that follow the sun's daily path across the sky to generate more electricity than fixed-mounted systems. There are no fuel costs or emissions during operation of the power stations.

However, when it comes to renewable energy systems and PV, it is not just large systems that matter. Building-integrated photovoltaics or "onsite" PV systems use existing land and structures and generate power close to where it is consumed. Since the s, Brazil has had an ethanol fuel program which has allowed the country to become the world's second largest producer of ethanol after the United States and the world's largest exporter.

By the end of there were 35, filling stations throughout Brazil with at least one ethanol pump. By mid, there were approximately 6 million ethanol compatible vehicles on U. Geothermal power is cost effective, reliable, sustainable, and environmentally friendly, [] but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation.

Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. IGA projects this will grow to 18, MW by , due to the large number of projects presently under consideration, often in areas previously assumed to have little exploitable resource.

In , the United States led the world in geothermal electricity production with 3, MW of installed capacity from 77 power plants; [] the largest group of geothermal power plants in the world is located at The Geysers , a geothermal field in California. Renewable energy technology has sometimes been seen as a costly luxury item by critics, and affordable only in the affluent developed world.

Renewable energy can be particularly suitable for developing countries. In rural and remote areas, transmission and distribution of energy generated from fossil fuels can be difficult and expensive. Producing renewable energy locally can offer a viable alternative. Technology advances are opening up a huge new market for solar power: Even though they are typically very poor, these people have to pay far more for lighting than people in rich countries because they use inefficient kerosene lamps. Solar power costs half as much as lighting with kerosene.

More than 30, very small solar panels, each producing 1 [] 2 to 30 watts, are sold in Kenya annually. Micro-hydro configured into mini-grids also provide power. Alcohol fuels ethanol and methanol can be produced sustainably from non-food sugary, starchy, and cellulostic feedstocks. Renewable energy projects in many developing countries have demonstrated that renewable energy can directly contribute to poverty reduction by providing the energy needed for creating businesses and employment.

Renewable energy technologies can also make indirect contributions to alleviating poverty by providing energy for cooking, space heating, and lighting. Renewable energy can also contribute to education, by providing electricity to schools. Many national, state, and local governments have also created green banks. A green bank is a quasi-public financial institution that uses public capital to leverage private investment in clean energy technologies.

The military has also focused on the use of renewable fuels for military vehicles. Unlike fossil fuels, renewable fuels can be produced in any country, creating a strategic advantage. It aims to provide concrete policy advice and facilitate capacity building and technology transfer. As of , countries have some form of national renewable energy policy target or renewable support policy.

National targets now exist in at least 98 countries.

United Nations' Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity. The Intergovernmental Panel on Climate Change has said that there are few fundamental technological limits to integrating a portfolio of renewable energy technologies to meet most of total global energy demand.

Renewable energy use has grown much faster than even advocates anticipated. Pacala and Robert H. Socolow have developed a series of " stabilization wedges " that can allow us to maintain our quality of life while avoiding catastrophic climate change, and "renewable energy sources," in aggregate, constitute the largest number of their "wedges". In Mark Z. They found producing all new energy with wind power , solar power , and hydropower by is feasible and existing energy supply arrangements could be replaced by Barriers to implementing the renewable energy plan are seen to be "primarily social and political, not technological or economic".

As already explained in previous chapter, the EU biofuel policy coincided with the initial commodity price volatility in before the EU biofuel sustainability criteria were introduced through the Renewable Energy Directive. After , this common trend is no longer visible with biofuel consumption continuing to rise while commodity prices have moved in the opposite direction. Developing countries as net importers are often most vulnerable for transmission of price fluctuations and in those countries also the impact on food security is more severe than for developed countries, even if the latter are also net importers.

The way domestic and global price fluctuations impact local consumers also differs for different countries. With crops comprising a small share of the final cost of food in high-income countries, the impact of price effects on food consumers is smaller In low-income countries, where expenditure on raw grains and vegetable oils comprises a much larger share of the household food budget, a given increase in crop prices will have a much larger impact on food consumers.

In the longer term, however, high prices are beneficial since they provide opportunities and higher profitability for agricultural markets which are, most of the time, also in developing rural regions. Biofuel consumption may continue to have some influence on the global food prices and food affordability, but according to the EU monitoring since , this impact is marginal compared to other factors such as oil prices, weather and climate induced stress, and speculation impacts. Availability and prospects of renewable energy technologies for transport by The majority of double counted biofuels in the EU are produced from used cooking oil or animal fat.

The biofuel industry argue that double-counting provisions have so far only assisted the deployment of inexpensive conversion of used oils and fats, whereas an advanced ethanol development would require respective mandatory sub-targets A number of EU production facilities have already been producing advanced biofuels since , often in conjunction with other bio-based products Despite the important and continuous progress during the past 5 years, including the opening of commercial production facilities, the development of large-scale production capacity for advanced biofuels in the EU is still slow.

It was hampered by technological challenges, feedstock availability, financing and political uncertainty. The most viable business model will in most cases be based on an integrated biorefinery approach that produces both biofuels and a range of other bio-based products. The share of renewable electricity is expected to increase significantly until and beyond. Given the move towards a low carbon electricity mix, both electrification of transport and the use of renewable hydrogen could contribute to the decarbonisation options of the transport sector.

The largest number of registrations was recorded in France more than 10 vehicles , Germany around 8 vehicles and the UK around 6 vehicles. Nevertheless, electric vehicles continue to constitute only a very small fraction of new registrations 0. Indeed, the amount of electricity used in non-road transport, e. Fuel cell propelled cars start to be commercially available and major car manufacturers have announced that they will produce such cars at commercial scale in the future.

Currently, the use of hydrogen in transport is negligible and also no significant contribution is expected for Some Member States have national strategies for the deployment of hydrogen infrastructure for the coming years, therefore some market uptake could still be expected. In some countries, also biomethane is used as a transport fuel.

Currently, its contribution is very limited but its use might have potential. Other alternative GHG-poor fuels are currently in development phase. Fuel production from synthetic gas generated water, CO2 and solar energy or green electricity is developed for application to cars and aviation fuel. Another alternative are marine biofuels, however, further research in this area is still required. Cost-efficiency of the measures to be implemented to achieve the transport target.

In most of the Member States the current remuneration ranges cover the gap in the generation costs between fossil fuels and biofuels. The overall trend towards is that most Member States will use obligations as their main policy measure to ensure sufficient biofuel consumption. Tax reductions and subsidies have been phased out or reduced in several Member States over the past years and it is expected that this trend will continue towards Obligations are cost-effective measures to ensure a certain amount of biofuels on the market.

For governments it is a policy measure with low direct budgetary impact, which ensures the desired amount of biofuels to reach the market, as long as the fine or buy-out price is sufficiently high. A more technical element which could limit the total amount of biofuels used in the transport sector is the blending percentage possible. However, public acceptance and industry implementation of higher blends would be necessary steps for increased use of biofuels through the current infrastructure. Achieving the target for renewable energy in transport certainly remains technically feasible and the remarkable progress achieved already in some Member States testifies to this.

The provision in the Renewable Energy Directive that waste and residue-based biofuels count double towards the transport target has proven to be effective in some Member States in achieving the transport targets. An increase in the share of renewable electricity in non-road transport together with a minor contribution from electrification of road transport could further contribute to progress in the next years. However, given the debate about conventional biofuels and the fact that there are no alternatives to biofuels in heavy duty road transport and aviation, additional initiatives will be required, as of Member States must therefore do more to promote advanced biofuels and enable electrification of their transport fleet.

Electrification will also help integration of variable renewable electricity, if administered in a clever manner. Improved funding of research, development and demonstration, cooperation between Member States but also partnerships within the industry, involving both fuel suppliers and consumers, will help fostering the necessary transition. This site uses cookies to improve your browsing experience. Would you like to keep them? Skip to main content.

This document is an excerpt from the EUR-Lex website. EU case law Case law Digital reports Directory of case law.

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