please do q 7 8 9 asap

7. 5. Is your lifestyle sustainable? If not, what changes would make it so? (50-100 words) 6. Can we expect renewable energy supplies to be universally applicable? Clarify your answer by explaining which renewables are most applicable in your home area. (50-100 words) (a) Show that the average solar irradiance absorbed during 24 hours over the whole of the Earth's surface is about 230 W/m2 (see Fig. 1.2). (b) Using devices, the average local power accessible can be increased e.g. by tilting solar devices towards the Sun and by intercepting winds. Is it reasonable to state that each square metre of the Earth's habitable surface is crossed or accessible to an average flux of about 500W"? 8. Compare the direct costs to the consumer of using: (a) a succession of ten 100 W incandescent light bulbs with an efficiency for electricity to visible light of 5%, life of 1000 hours, price 0.5 Euro; (b) one compact fluorescent lamp (CFL) giving the same illumination at 22% efficiency, life of 10,000 hours, price Rs. 600: use a fixed electricity price of Rs. 20/kWh; (c) Calculate the approximate payback time in lighting hours of (b) against (a). Repeat the calculation of Question 8, with prices of your local lamps and electricity. Both the price of CFLs in local shops and of electricity vary markedly, so your answers may differ significantly. Nevertheless, it is highly likely that the significant lifetime savings will still 9. occur. Infrared radiation to space Solar water heaters Solar buildings Solar dryers Ocean thermal energy Reflected to space 50 000 80 000 Sensible heating 40 000 Latent heat of water evaporation Hydropower Osmotic power From Sun Solar 120 000 radiation Absorbed on Earth 300 Kinetic energy Wind and wave turbines 100 Photon processes Biomass and biofuels Photovoltaics 30 From Earth Geothermal Heat Geothermal heat Geothermal power 3 From planetary motion Gravitation, orbital motion Tidal motion Tidal range power Tidal current power Fig. 1.2 Natural energy currents on the Earth, showing renewable energy systems. Note the great range of energy flux (1:105) and the dominance of solar radiation and heat. Units terawatts (1012W). 7. 5. Is your lifestyle sustainable? If not, what changes would make it so? (50-100 words) 6. Can we expect renewable energy supplies to be universally applicable? Clarify your answer by explaining which renewables are most applicable in your home area. (50-100 words) (a) Show that the average solar irradiance absorbed during 24 hours over the whole of the Earth's surface is about 230 W/m2 (see Fig. 1.2). (b) Using devices, the average local power accessible can be increased e.g. by tilting solar devices towards the Sun and by intercepting winds. Is it reasonable to state that each square metre of the Earth's habitable surface is crossed or accessible to an average flux of about 500W"? 8. Compare the direct costs to the consumer of using: (a) a succession of ten 100 W incandescent light bulbs with an efficiency for electricity to visible light of 5%, life of 1000 hours, price 0.5 Euro; (b) one compact fluorescent lamp (CFL) giving the same illumination at 22% efficiency, life of 10,000 hours, price Rs. 600: use a fixed electricity price of Rs. 20/kWh; (c) Calculate the approximate payback time in lighting hours of (b) against (a). Repeat the calculation of Question 8, with prices of your local lamps and electricity. Both the price of CFLs in local shops and of electricity vary markedly, so your answers may differ significantly. Nevertheless, it is highly likely that the significant lifetime savings will still 9. occur. Infrared radiation to space Solar water heaters Solar buildings Solar dryers Ocean thermal energy Reflected to space 50 000 80 000 Sensible heating 40 000 Latent heat of water evaporation Hydropower Osmotic power From Sun Solar 120 000 radiation Absorbed on Earth 300 Kinetic energy Wind and wave turbines 100 Photon processes Biomass and biofuels Photovoltaics 30 From Earth Geothermal Heat Geothermal heat Geothermal power 3 From planetary motion Gravitation, orbital motion Tidal motion Tidal range power Tidal current power Fig. 1.2 Natural energy currents on the Earth, showing renewable energy systems. Note the great range of energy flux (1:105) and the dominance of solar radiation and heat. Units terawatts (1012W)