RENEWABLE ENERGY

Renewable & Non renewable Energy

Renewable energy is a kind of energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable.

Non-renewable energy is energy that comes from the ground and is not replaced in a relatively short amount of time. Fossil fuels are the main category of non-renewable energy. Fossil fuels include; coal, oil and natural gas.

Positivity & Negativity of Renewables

Use as long as you want : it is renewable it is therefore sustainable and so will never run out.

Green & Harmless : no green house gases, almost zero pollution to the environment, reduce carbon footprint, mix up with nature without affecting anything

Less maintenance : require less maintenance than traditional generators. Their fuel being derived from natural and available resources reduces the costs of operation.

Economic Benefits

Positive sideLow productivity : that it is difficult

to generate the quantities of electricity that are as large as those produced by traditional fossil fuel generators.

Reliability of supply : Relies on the weather for its source of power. This can be unpredictable and inconsistent.

Costly : The current cost of renewable energy technology is also far in excess of traditional fossil fuel generation. This is because it is a new technology and as such has extremely large capital cost.

Negative side

Mainstream forms of Renewable Energies

Bio fuelBiomassGeothermalHydroelectricitySolar PhotovoltaicWave powerWind power

Bio Fuel Basic mechanism : Biofuel is a type

of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion.

Types : Solid biomass -- wood, sawdust,

domestic refuse, charcoal, agricultural waste, non-food energy crops, and dried manure.

Liquid fuels – Bioethanol , Bio diesel Biogas -- Gas from manure,

Biodegradable waste gas.

Costing : 60-80 (£/MWH)

Payback period : 15 years on average

Disadvantages: Food vs fuel debate Carbon emissions Huge amount of land needed Deforestation Not environmentally friendly

Bio mass Basic Mechanism: Biomass, as a

renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products. Biomass is carbon, hydrogen and oxygen based. Biomass energy is derived from five distinct energy sources: garbage, wood, waste, landfill gases, and alcohol fuels.

Conversion Types: Thermal conversion Chemical conversion Bio chemical conversion

Costing : 65-70 (£/MWH)

Payback Period: 17 years average

Disadvantage: Pollution & carbon emission Land usage Expensive technology Limited potentiality

Geothermal Basic Mechanism: Geothermal

energy is thermal energy or heat generated and stored in the Earth.

Types: Dry steam power plant Flash stem power plant Binary steam power plant

Costing: 150 – 350 (£/MWH) Payback Period: 8-10 years Disadvantages: Not widespread energy source High installation cost Suited to particular

region( tectonic plate boundaries) Toxic gases

Hydroelectricity Basic mechanism: The production

of electrical power through the use of the gravitational force of falling or flowing water (hydropower). It is the most widely used form of renewable energy.

Types: Pumped storage : different elevations

between two reservoirs for water pumping

Run of the river : It is continuously moving and should not remain static.

Tidal power: Use ocean tidal waves. Underground system Micro hydro system Costing : 30-35 (£/MWH) Payback period : 10-12 years Disadvantages: Ecosystem damage & loss of land Siltation and flood Relocation Failure risk

Solar photovoltaic (PV) Basic mechanism: Physical process where

photons are absorbed into materials rather than being re-emitted. The energy from that photon is transferred into an electron in the material, which then contains enough energy to escape its atom and become part of an electrical current.

Types : Monocrystalline panel: Most efficient & expensive Polycrystalline panel: Less expensive Amorphous panels: thin layer of silicon's & much

cheaper Concentrated PV : concentrate a large amount of

sunlight onto a small area of solar photovoltaic materials

Costing : 2 - 3.50 (£/watt) average Payback period : 10 years or less average Disadvantages: toxic chemicals, like cadmium and arsenic, are

used in the PV production process

Setup & installation cost is high Very Low efficiency (12% - 18%)

Wave power Basic Mechanism: Wave power is

the transport of energy by ocean surface waves, and the capture of that energy to generate electricity.

Types of wave energy converter

Disadvantages: not currently a widely

employed commercial technology

Super expensive Ocean environment

threat

Fig : Oscillating water columns

Fig: Buoyant moored device

Fig: Overtopping devices

Fig : Hinged Contour device

Wind Power Basic Mechanism : A wind turbine is

a device that converts kinetic energy from the wind, also called wind energy into mechanical energy ;a process known as wind power.

Types: Vertical axis wind turbine (VAWT) Horizontal axis wind turbine (HAWT) Onshore wind turbine Offshore wind turbine

Costing: 150 – 200 (£/MWH) Payback period : 5 to 3 year on

average for big scale. Less than 1 year for small scale.

Disadvantages: Heavily depends on wind velocity Cant produce enough electricity Betz law limitation (only convert 59.3%

kinetic energy to mechanical energy ) Unpleasant look and heavy noise.

HYDROGEN ENERGY• Hydrogen is the simplest element. An atom of hydrogen consists of only one

proton and one electron. It's also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth - it's always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O).

• Hydrogen is also found in many organic compounds, notably the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane. Hydrogen can be separated from hydrocarbons through the application of heat - a process known as reforming.

• Currently, most hydrogen is made this way from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen. This process is known as electrolysis.

• Some algae and bacteria, using sunlight as their energy source, even give off hydrogen under certain conditions.

• Hydrogen is high in energy, yet an engine that burns pure hydrogen produces almost no pollution. NASA has used liquid hydrogen since the 1970s to propel the space shuttle and other rockets into orbit. Hydrogen fuel cells power the shuttle's electrical systems, producing a clean byproduct - pure water, which the crew drinks.

• A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Fuel cells are often compared to batteries. Both convert the energy produced by a chemical reaction into usable electric power. However, the fuel cell will produce electricity as long as fuel (hydrogen) is supplied, never losing its charge.

• In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier moves and delivers energy in a usable form to consumers. Renewable energy sources, like the sun and wind, can't produce energy all the time. But they could, for example, produce electric energy and hydrogen, which can be stored until it's needed. Hydrogen can also be transported (like electricity) to locations where it is needed.

Important info In the photoelectric effect, electrons are ejected from a material's

surface upon exposure to radiation. The photovoltaic effect differs in that electrons are transferred between different bands (i.e., from the valence to conduction bands) within the material, resulting in the build-up of voltage between two electrodes.

The most efficient solar cell so far is a multi-junction concentrator solar cell with an efficiency of 43.5% produced by the National Renewable Energy Laboratory in April 2011. The highest efficiencies achieved without concentration include Sharp Corporation at 35.8% using a proprietary triple-junction manufacturing technology in 2009

According to researchers at Japan’s National Institute of Industrial Science & Technology, some of the coldest geographic locations on earth have some the greatest potential in the world for capturing solar energy using PVs.

• Green Certificate also known as Renewable Energy Certificate (RECs) is a tradable commodity proving that certain amount of electricity (normally sold to the customer) is generated using renewable energy sources

• A 1-kilowatt home solar system will prevent approximately 170 lbs. of coal from being burned, 300 lbs of CO2 from being released into the atmosphere and 105 gallons of water from being consumed each month!

• Enough sunlight falls on the earth every hour to meet the world’s energy demands for an entire year.

• If we covered a small fraction of the Sahara desert with photovoltaic cells, we could generate all the world’s electricity requirements.

• intermittent energy source is any source of energy that is not continuously available due to some factor outside direct control

• A carbon footprint has historically been defined as "the total set of greenhouse gas (GHG) emissions caused by an organization, event, product or person at a predictable time.

• Ocean Thermal Energy Conversion (OTEC) uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity.

• Firm capacity is the amount of energy available for production or transmission which can be (and in many cases must be) guaranteed to be available at a given time. Firm energy refers to the actual energy guaranteed to be available. Nonfirm energy refers to all available energy above and beyond firm energy. Energy producers such as hydroelectric plants and wind farms may have nonfirm energy available due to unexpected weather or seasonal conditions.

Conclusion

European Union currently using 10% renewable energy & agreed to produce 20% of their final energy from renewable source by year 2020.

USA is currently using 14.3 % & aiming to achieve 25% within year 2025. $257 billion already invested & Over 0.6 million jobs will create only in

europe .