Any of several Chemical Engineering processes including hydrogenation, hydrocracking and hydrotrating.
Renewable energy technologies and their potential
Renewable Energy Technologies and their Potential“……the time is running out…soon, there will be nothing left to burn on earth but earth itself…”
Renewable Energy – “any sustainable energy source that comes from natural environment.” It exists perpetually and in abundant in the environment. Ready to be harnessed, inexhaustible. It is a clean alternative to fossil fuels. “energy that is derived from natural process that are replenished constantly” -- defined by the RENEWABLE ENERGY WORKING PARTY of the INTERNATIONAL ENERGY AGENCY
Contribution of Renewable Energy in World Electricity Production
Major Renewable Energy Sources• Wind Energy• Biomass and Biofuel Energy• Solar Energy• Hydro Energy• Geothermal Energy• Ocean Energy
Wind Energy•Wind power is the conversion of wind energy into auseful form of energy.•Wind Turbines are the only present way to harvestwind Energy.•A wind turbine is a device that converts kineticenergy from the wind into mechanical energy. If themechanical energy is used to produce electricity, thedevice may be called a wind generator or windcharger. If the mechanical energy is used to drivemachinery, such as for grinding grain or pumpingwater, the device is called a windmill or wind pump
A wind turbine obtains its power input by converting the force of the wind into a torque (turning force) acting on the rotor blades. PLF of Wind Farm is normally in the range of 20 % to 30% depending upon the site conditions and WTG rating.
The amount of energy which the wind transfersto the rotor depends on the density of theair, the rotor area, and the wind speed P =0.5ρAV3 P - Power ρ - Air Density (kg/m3) A - Blade Area -turbine (m2) V - Wind velocity (m/s)
Types of wind turbineGenerally of two types:1.Can rotate about horizontal axis2.Can rotate about vertical axisthe former being both older and more common
Design of a Wind Turbine 1. Foundation 2. Connection to the electric grid 3. Tower 4. Access ladder 5. Wind orientation control 6. Nacelle 7. Generator 8. Anemometer 9. Brake 10.Gearbox 11.Rotor blade 12.Blade pitch control 13.Rotor hub.
Status quo Current capacity Wind farm(Onshore) (MW) CountryAlta (Oak Creek-Mojave) 720 USABuffalo Gap Wind Farm 523.3 USACapricorn Ridge Wind Farm 662.5 USADabancheng Wind Farm 500 ChinaFowler Ridge Wind Farm 599.8 USAHorse Hollow Wind Energy Centre 735.5 USAMeadow Lake Wind Farm 500 USAPanther Creek Wind Farm 458 USARoscoe Wind Farm 781.5 USASweetwater Wind Farm 585.3 USA
Wind farm(Offshore) Capacity(MW) Country Walney 367 United Kingdom Thanet 300 United Kingdom Horns Rev II 209 Denmark Rødsand II 207 DenmarkLynn and Inner Dowsing 194 United Kingdom Robin Rigg (Solway 180 United Kingdom Firth) Gunfleet Sands 172 United Kingdom Nysted (Rødsand I) 166 Denmark
• World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years.Top 10 countries by nameplate wind power capacity (2010) Country Windpower capacity (MW)China 44,733United States 40,180Germany 27,215Spain 20,676India 13,066Italy 5,797France 5,660United Kingdom 5,204Canada 4,008Denmark 3,734
Fastest growing renewable energy source. Globally, it grew at the average rate of 27 % pa over the past 10 years. In India it grew at the average rate of 33% over the past 9 years. Presently, India is ranked 3rd in the world in terms of Wind Energy Installed Capacity surpassing Germany and Spain in 2011 Drivers of growth • Environmental Awareness and Sustainable Development • Growing Global Energy Demand • Improving Competitiveness of renewable energy • Security of Supply Concerns • New Markets (e.g. India, China etc) • Carbon Trading • Fiscal Benefits by Govt. (PTC, feed in tariffs, etc)
Wind Energy Potential• 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.• Offshore resources experience average wind speeds of ~90% greater than that of land, so offshore resources could contribute substantially more energy .• Max Planck Institute in Germany concluded that 18 TW and 68 TW could be extracted.• A new Carbon Trust study into the potential of small-scale wind energy has found that small wind turbines could provide up to 1.5 terawatt hours (TW·h) per year of electricity saving 0.6 million tonnes of carbon dioxide emission.
No pollution Can satisfy small and large scale needs easily. No non-renewable inputs. Noisy. Undesirable appearance. Vulnerable to thunderstorms.
Solar power is by far the Earths most available energy source, easily capable of providing many times the total current energy demand. Solar power is the conversion of sunlight into electricity. Two main commercial ways of conversion of sunlight into electricity. • Concentrating Solar Thermal Plant (CSP) • Photovoltaic Plants (PV)
CSP and PV both have their markets. PV is very successful in decentralized applications, whereas CSP offers advantages for central and large-scale applications. CSP power plants are the most cost-efficient way to generate and to store dispatch able CO2-free electricity. However, there is no competition between both. Rather, they have to be seen as complementary technologies. PLF of CSP – In the range of 20 % to 30 % PLF of PV – In the range of 15 % to 20 %
Concentrating Solar Thermal Plant (CSP) It contains; • Collector Field • Turbine • Generator • Cooling Tower • TransformerCourtsey – ESP solar
Solar Photovoltaic Plants (PV) It contains; • Solar Arrays • Inverter • Transformer
Solar thermal energy• It is a technology for harnessing solar energy for thermal energy.• Solar thermal collectors(STC) are used to serve this.Types of STC-1. Low-temperature collectors(LTC)2. Medium-temperature collectors(MTC)3. High-temperature collectors(HTC)
Low-temperature collectors(LTC)• Generally installed to heat swimming pools• Can also be used for space heating.• Collectors can use air or water as the medium to transfer the heat to their destination.The two main types of solar air panels are- 1. Glazed 2. Unglazed
Glazed• designed primarily for space heating.• Recirculate building air through a solar air panel where the air is heated and then directed back into the building.• Require at least two penetrations into the building and only perform when the air in the solar collector is warmer than the building room temperature.
Unglazed• Primarily used to pre-heat make-up ventilation air in buildings with a high ventilation load.• Turn building walls or sections of walls into low cost, high performance, unglazed solar collectors
Medium-temperature collectors(MTC)• Common designs are pressurized glycol, drain back, batch systems and newer low pressure freeze tolerant systems using polymer pipes containing water with photovoltaic pumping.• Operational innovations include "permanently wetted collector" operation. This innovation reduces or even eliminates the occurrence of no-flow high temperature stresses called stagnation which would otherwise reduce the life expectancy of collectors.• Applications in Solar Drying , Cooking , Distillation.
High-temperature collectors(HTC)• Solar radiation is concentrated by mirrors or lenses toobtain higher temperatures – a techniquecalled Concentrated Solar Power (CSP) is used.• CSP plant generates heat first of all, it can store the heatbefore conversion to electricity. With currenttechnology, storage of heat is much cheaper and moreefficient than storage of electricity. In this way, the CSP plantcan produce electricity day and night.
Different designs of CSP(a)Parabolic trough design-A Power Tower Design-Flat mirrorschange of position of the focus the light on the top of thesun parallel to the receiver tower. The white surfaces belowdoes not require the receiver are used foradjustment of the mirrors calibrating the mirror positions
Dish Design-A parabolic solar Fresnel Reflectors- Wind load isdish concentrating the suns rays avoided by the low position of theon the heating element of a mirrors. Light construction ofStirling engine. tracking system due to separation from the receiver
Photovoltaic Plants (PV)• Photovoltaic (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect.• Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material like- monocrystalline silicon, polycrystalline silicon, amorphous silicon cadmium telluride copper indium gallium selenide / sulfide.
TECHNOLOGY• The photovoltaic effect refers to photons of light exciting electrons into a higher state of energy, allowing them to act as charge carriers for an electric current.• The term photovoltaic denotes the unbiased operating mode of a photodiode in which current through the device is entirely due to the transduced light energy.• Solar cells produce direct current electricity from sun light, which can be used to power equipment or to recharge a battery• Photovoltaic panels based on crystalline silicon modules are encountering competition in the market by panels that employ thin-film solar cells (CdTe, CIGS, amorphous Si, microcrystalline Si), which had been rapidly evolving.• The most efficient solar cell so far is a multi-junction concentrator solar cell with an efficiency of 43.5%.
The total installed capacity of solar power (Both CSP and PV) as of 2008 is 2826 MW. In India the total installed capacity of solar power is around 2 MW. In India, various government and private players have entered into CSP and PV markets. MNRE has set a target to establish at least 50 MW of solar projects during the 11th plan.
Saves money. Semi-independent. Low maintenance. High Initial Cost of installation. Can’t work during night. Similarly plants can be installed only where there is sufficient sunlight.
BIOMASS AND BIOFUEL• It is a renewable energy source because the energy it contains comes from the sun.• As long as biomass is produced sustainably, with only as much used as is grown, the battery will last indefinitely.• As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel.
Biomass sourcesBiomass energy is derived from five distinct energy sources: Garbage Wood waste landfill gases alcohol fuels
• The largest source of energy from wood is pulping liquor or “black liquor,” a waste product from processes of the pulp, paper and paperboard industry.• Biomass alcohol fuel, or ethanol, is derived primarily from sugarcane and corn. It can be used directly as a fuel or as an additive to gasoline.• Rotting garbage, and agricultural and human waste, release methane gas—also called "landfill gas" or "biogas”.• Biomass to liquids (BTLs) and cellulosic ethanol are still under research.
TECHNOLOGIES FOR BIOMASS CONVERSION TO USEFULENERGY Thermal conversion- These are processes in which heat is the dominant mechanism to convert the biomass into another chemical form. • hydrothermal upgrading(HTU) - converts a large variety of biomass feedstock into a liquid fuel that can be upgraded to a high quality diesel fuel. • Hydro processing • combined heat and power (CHP) - use of a heat engine or a power station to simultaneously generate both electricity and useful heat. • co-firing - combustion of two different types of materials at the same time
Chemical conversion- A range of chemical processes may be used to convert biomass into other forms.A microbial electrolysis cell can be used to directly make hydrogen gas from plant
• Biochemical conversion makes use of the enzymes of bacteria and other micro-organisms to break down biomass. In most cases micro-organisms are used to perform the conversion process : anaerobic digestion, fermentation and composting.• Another way of breaking down biomass is by breaking down the carbohydrates and simple sugars to make alcohol. However, this process has not been perfected yet. Scientists are still researching the effects of converting biomass.
Biomass Energy Overview • Agricultural Crops and Residues • Oil Bearing PlantsBio Mass • Woody BiomassResources • Industrial and Municipal Waste • Harvesting • Collection Supply • Handling System • Storage • Thermo chemical • Physical/ChemicalConversion • Heat Electricity • Transport Fuels End • Solid Fuels Products
BIOENERGY POTENTIAL 20 GW of power may be generated from 300 MT of agro waste (currently produced) 50% currently burnt in the open Less than 3% potential realized Can revolutionize pace of rural electrification Better technologies Dual usage of cattle dung (fuel + manure)
• High initial cost despite subsidy• Space requirement & slurry handling difficulties• High water requirement• Lack of proper maintenance infrastructure
Recent developments • Compact biogas plants • Alternative feedstock Need of Technical Work for • Increasing efficiency of cattle dung based plants • Low cost, user-friendly, optimal plant designs Development of training & service infrastructure
HYDROPOWER• Conversion of kinetic energy of flowing water into useful energy.• Water from the reservoir flows due to gravity to drive the turbine.• Turbine is connected to a generator.• Power generated is transmitted over power lines.
THEORETICAL- The maximum potential that exists. TECHNICAL- It takes into account the cost involved in exploiting a source (including the environmental and engineering restrictions) ECONOMIC- Calculated after detailed environmental, geological, and other economic constraints.
REGION THEORETICAL TECHNICAL POTENTIAL (TWh) POTENTIAL (TWh) AFRICA 10118 3140 N. AMERICA 6150 3120LATIN AMERICA 5670 3780 ASIA 20486 7530 OCEANIA 1500 390 EUROPE 4360 1430 WORLD 44280 19390
Theoretical potential is about 40,500 TWh per year. The technical potential is about 14,300 TWh per year. The economic potential is about 8100 TWh per year. The world installed hydro capacity currently stands at 694 GW. In the 1980s the percentage of contribution by hydroelectric power was about 8 to 9%. The total power generation in 2000 was 2675 Billion KWh or close to 20% of the total energy generation. Most of the undeveloped potential lies in the erstwhile USSR and the developing countries. Worldwide about 125 GW of power is under construction. The largest project under construction is the Three Gorges at the Yangtze river in China. Proposed potential is 18.2 GW and the proposed power output is 85 TWh per year
Flexible. Long Economic lives. Suitable for industrial applications. Failure risk. Methane Emission. High initial and maintenance cost. Loss of Land.