Lesson Notes By Weeks and Term - Junior Secondary School 3

TERM: 2ND TERM

SUBJECT: BASIC TECH

CLASS: JSS 3

Reference Materials

• NERDC, INTRODUCTORY TECHNOLOGY FOR JSS, BOOK 3
• EVANS, INTRODUCTORY TECHNOLOGY FOR JSS, BOOK 3

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WEEK 10

TOPIC: ENERGY RESOURCES-Solar Powered Devices�

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CONTENT

• Renewable energy
• Solar power
• Solar powered devices

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RENEWABLE ENERGY

Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished). In 2008, about 19% of global final energy consumption came from renewables, with 13% coming from traditional biomass, which is mainly used for heating, and 3.2% from hydroelectricity.[1] New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.7% and are growing very rapidly.[1] The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewables.[1][2]

Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 157,900 megawatts (MW) in 2009,[3][4] and is widely used in Europe, Asia, and the United States.[5] At the end of 2009, cumulative global photovoltaic (PV) installations surpassed 21,000 MW[6][7][8] and PV power stations are popular in Germany and Spain.[9] Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert. The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel. Ethanol fuel is also widely available in the USA.

While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas, where energy is often crucial in human development.[12] Globally, an estimated 3 million households get power from small solar PV systems. Micro-hydro systems configured into village-scale or county-scale mini-grids serve many areas.[13] More than 30 million rural households get lighting and cooking from biogas made in household-scale digesters. Biomass cookstoves are used by 160 million households[13]

Evaluation�

1. Define renewable energy
2. State the percentage of renewable used in recent year.

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SOLAR POWER

Solar power is the generation of electricity from sunlight. This can be direct as with photovoltaic (PV), or indirect as with concentrating solar power (CSP), where the sun's energy is focused to boil water which is then used to provide power. Solar power had the potential to provide over 1,000 times total world energy consumption in 2008,[citation needed] though it provided 0.02% of the total that year. If it continues to double in use every two to three years, or less, it would become the dominant energy source this century. The largest solar power plants, like the 354 MW SEGS, are concentrating solar thermal plants, but recently [clarification needed] multi-megawatt photovoltaic plants have been built. Completed in 2008, the 46 MW Moura photovoltaic power station in Portugal and the 40 MW Waldpolenz Solar Park in Germany appear to be characteristic of the trend toward larger photovoltaic power stations. Larger ones are proposed, such as the 100 MW Fort Peck Solar Farm[citation needed], the 550 MW Topaz Solar Farm, and the 600 MW Rancho Cielo Solar Farm

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Evaluation�

1. Define solar power
2. State and explain the two types of solar power you know

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SOLAR POWERED DEVICES

Solar energy is utilized for:

1. Drying clothes and agricultural products.
2. Distillation of water:
3. Production of hot water and hot air for various purposes.
4. Generating electricity either directly or indirectly�

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SOLAR CROP DRIER

Solar crop drier has been developed to minimize contamination and to maximize effectiveness of incidence solar energy, essentially used to remove moisture in order to dehydrate pepper, vegetables, fish e.t.c.

�It consists of four parts Box, The cover, the Tray and the insulator.

The operation of the drier is simple. The drier cover allows solar radiation to enter into the box but prevents heat from being emitted from interior of the box back to the surrounding. The trapped heat is used to removing moisture fro m the materials to be dried.

Solar drier is faster than ordinary exposure of the material to the sunshine. It also protect dried material from the rain and contaminant�

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Evaluation

1. What is renewable energy? Give examples.�
2. Mention three areas of application of solar energy as a renewable� sources

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Reading Assignment

Read ENERGY RESOURCES-Solar Power Devices

Reference Materials���

1. EVANS, Introductory Technology for JSS, book 3, pages 185 - 190

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Weekend Assignment�

1. The� energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished) is called ___ (a) renewable energy (b) non-renewable energy (c) artificial energy (d) potential energy
2. Solar energy is utilized for the following except (a) Drying clothes and agricultural products. (b) Distillation of water (c) Production of hot water and hot air for various purposes. (d) flying a air plane
3. In 2008, about____of global final energy consumption came from renewables. (a) 19% (b) 29% (c)39% (d) 49%
4. The generation of electricity from sunlight is called __(a) solar power (b) solar conversion (c) solar digester (d) solar engine
5. Solar crop drier has been developed for the following except (a) to minimize contamination (b) to maximize effectiveness of incidence solar energy(c) to remove moisture in order to dehydrate pepper, vegetables and fish. (d) to increase food product�

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Theory

• Mention three areas of application of solar energy as a renewable� sources

• a) Define solar power

1. State and explain the two types of solar power you know