Solar and Wind Energy

Transcription

1 Jerry Hudgins Solar and Wind Energy Department of Electrical Engineering 1

2 Average Irradiation Data (Annual) from Solarex. The units on the map are in kwh/m 2 /day and represent the minimum case values at an optimum tilt angle. Based on cloud cover data from satellite images. 2

3 Passive Solar Buildings designed with large-area South-facing windows for passive heating. Wall and floor materials that absorb the sunlight and later release heat back to the room. Sunspace: A sunspace (which is much like a greenhouse) is built on the south side of a building. As sunlight passes through glass or other glazing, it warms the sunspace. Proper ventilation allows the heat to circulate into the building. Trombe Wall: a wall that is very thick, south-facing wall, painted black and made of a material that absorbs a lot of heat. A pane of glass or plastic glazing, installed a few inches in front of the wall, helps hold in the heat. The wall heats up slowly during the day. Then as it cools gradually during the night, it gives off its heat inside the building. Daylighting is the use of natural sunlight to brighten up a building's interior. 3

4 Concentrating Solar Power (CSP) Heliostats (guided mirrors) concentrate the solar energy to heat molten salt; a mixture of 60% sodium nitrate and 40% potassiumnitrate. (photos courtesy Sandia National Laboratories) Central Receiver Test Facility at Sandia National Laboratories can produce up to 5 MW h (1.5 MW e ). Footprint: 9 acres 4 Cost: 21M$ (1978)

5 Concentrating Solar Power (CSP) Parabolic trough mirrors concentrate the solar energy to heat oil. The heated oil produces steam in a heat exchanger to drive a turbine. One of nine solar electric energy generating systems at Kramer Junction, California, with a total output of 354 MW e. (photo courtesy Kramer Junction Operating Company) 5

6 Solana (SW Arizona) 280 MW APS will pay about 14 /kwh. The Solana plant will cost an estimated $2 billion. The plant will employ a trough technology and will cover an area of 1,900 acres (770 ha). Construction is expected to create about 1,500 construction jobs; once completed, the plant will employ 85 full-time workers. Solar thermal plants use substantially more water for cooling than other solar generating technologies. Advantage of CST is that storage can be provided efficiently (99%/day) so that 24 hour output can be provided, and output can be scheduled to meet demand requirements. The Solana Generating Station is designed to provide six hours of storage. 6

7 PV Arrays 1 Cell produces V for Temperatures from 50 to -25 o C (122 to -13 o F) at about 1.5 W (2 to V) Cells connected in series for more voltage Commonly operated in multiples of 12 V Cells connected in parallel for more current 7

8 Photovoltaics (PV) Single-crystal, large-area planar cells (Usually Silicon) Single-crystal, small-area concentrator silicon cells yield higher efficiencies under concentrated light (from suns) III-V Semiconductors (GaAs, etc.) have efficiencies >25% (Space Applications) Polycrystalline silicon cells are less expensive, but also less efficient than single-crystal cells 11-14% Efficiency (19.8% Max. Efficiency Reported) Can make rectangular ingots or ribbons Thin film semiconductor materials are available including: Amorphous Silicon (a-si), Cadmium Telluride (CdTe), Copper- Indium-DiSelenide (CIS), and CIGS. *Efficiencies measured at 1 kw/m 2, 25 o C, and AM1.5 solar spectrum. 8

9 Photovoltaics (PV) Amorphous silicon modules are used extensively in consumer products. Available as Roofing Material Multiple-layer (Tandem-layer) amorphous with Germanium added to several layers improves efficiency Available for terrestrial applications CdTe also has stability and manufacturing challenges, in addition to potential environmental concerns over the use of cadmium. CIGS technologies have potentially high efficiencies, but face manufacturing challenges. 9

10 Photovoltaics (PV) Multi-junction cells consisting of several layers of different semi-conducting materials are being produced primarily for space applications. Achieved record-setting efficiencies as high as 41.6% under concentrated light, but are more complex to manufacture. Titania (TiO 2 )- Organic Dye on Glass Window coatings 8-11% Efficiency 10

11 Rare Earth Solar Thin film solar panels utilizing rare earth elements. Zinc and Sulfides can replace Indium Indium tin oxide (ITO) (InSnO) 11

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13 Footprint for PV Arrays Diffuse nature of sunlight Sunlight to electrical energy conversion efficiencies of photovoltaic devices THUS Surface area requirements for PV array installations are on the order of 8 to 12 m 2 (86 to 129 ft 2 ) per kw of installed peak array capacity. Use rule of thumb of 0.1 ft. 2 per Watt (peak) 13

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15 Dual-Axis Tracking 15

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18 Fixed Latitude Tilt vs. Dual-Axis Dual-axis tracking can increase energy output by 29 to 42% over fixed installations. 18

19 Fixed vs. Dual-Axis Systems A comparison of fixed (4 kw) and dual-axis (3.2 kw) systems producing the same amount of annual energy indicated that the tracked system cost an additional $1.33/W for installation. However, due to the lower peak power rating needed, the dual-axis tracking system was less expensive for installation as long as the fixed system installation cost exceeds about $4.00/W. Fixed Dual-Axis NOTE: This does not include O&M Expense. 19

20 ROOFTOP PV SYSTEMS Roof mounted arrays operate at a higher temperature and can suffer up to a 5% loss of power in the summer. The rooftop of an existing building might not have optimum orientation. The topography, trees and views might also override the ability to provide practical electric generation. 20

21 PV Costs Installed cost of solar PV systems in the United States fell substantially in 2010 and The average installed cost of residential and commercial PV systems fell mainly due to drops in PV cells/modules costs. Systems rated greater than 5 MW ranged from $2.90/W to $6.20/W in Consistent with continued cost reductions, current utility scale projects appear to be in the range of $3.00 to $4.00 per Watt. Systems smaller than 2 kw (residential) averaged $9.80/W as of Small systems (4-8 kw) currently are priced at about $5.00/W 21

22 Solar Energy Jobs Utility Scale Ivanpah project is a CSP facility to generate 392 MW It will create approximately 1,000 construction jobs and 86 operations and maintenance (permanent) jobs. Supply Chain ripple effects 22

23 Wind Energy 23

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25 Wind-Turbine Physics Power available in the wind is proportional to the Air Density, r Swept Area of the Rotor, A Cube of the Air Velocity, (v x v x v) (P w = ½ rav 3 ) V 1 Vavg Betz Limit theoretical maximum power V2 that can be extracted from the wind is 0.59 or 59% A

26 Big Wind/Small Wind Definition By common practice, small wind is defined as nameplate power rating of 100 kw or less. Large wind is considered to be for turbines with a nameplate rating greater than 100 kw. Sometimes a further refinement of turbine classifications occurs into small, intermediate, and large.

27 Sizes and Applications Very Small ( 10 kw) Homes Farms Remote Application Small ( kw) Village Power Hybrid Systems Distributed Power Large (660 kw - 2+MW) Central Station Wind Farms Distributed Power Community Wind

28 Turbine Prices decline to about $1.20/W in

29 Installed Cost dropped in 2012 to an average of $1.80/W 29

30 Construction Construction takes about a year It takes ~2500 person-hours to construct each turbine or approx 1.25 full-time jobs for one year The crawler crane takes 18 semitruckloads to deliver to the site Each foundation is a continuous pour needing cement truck loads One full-time job created for every MW s A typical 80 MW windfarm generates enough power for 24,000 houses Photo Credit: Mark Grundmayer

31 Economic Development Impacts - Summary Land Lease Payments: 2-3% of gross revenue $2500-$4000/MW/year Local property tax revenue: 100 MW generates $500K-$1 million/yr jobs/100 MW during construction 2-6 permanent O&M jobs per MW Local industry: concrete, towers, electrical services Manufacturing and Assembly plants expanding in U.S. (e.g. IL, CA, ND, PA) A large amount of information on state, local, utility and federal incentives and policies that promote renewable energy and energy efficiency can be found at

32 Economic Impact Model (JEDI)

33 Installed Costs ($/Watt) Summary and Comparison of Relative Installation Costs $8.00 $7.00 $6.00 $5.00 $4.00 $3.00 $2.00 $1.00 $0.00 Wind Small (< 50 kw) Solar PV Small (<50 kw) Wind Large (>650 kw) Solar PV Large (>650 kw) Solar CSP 33