Exam 2 fa - Name Fall 7,0901 Sellfiigfl ECE 333 Exam#2...

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Unformatted text preview: Name: Fall 7,0901 Sellfiigfl ECE 333 Exam #2 Thursday, November 19, 2009 Closed book, closed notes Two note sheets allowed, 1. /26 2. /25 3. /l6 4. /15 5. /18 Total / 100 l. (26 points total) Suppose a project in ChampaignfUrbana/ Savoy deploys smart meters on 80,000 homes. The initial cost to equip each home is $1000 (Suppose this includes an in-home display and a home area network). Electricity costs $0.07/kWh. The project lifetime is 20 years and the discount rate is 10%. Economic tables are given on the last page of the exam, in case you need them. If the annual energy demand from these homes is reduced from 480x106 kWh to 400x106 kWh, what are the annual savings in $/yr? A Baxtob awhgrxgoej/Wa —. “e fiswwaw‘ir W mew» Mum» .Mww Assume the demand reduction given in part a. Find the net present value of the project assuming- and state Whether it is a net gain or a net loss. , .3005) x W hone: + 9% 5000 Obggr“ X C‘HA; 100/6; E‘ig’tfle, NPV WMNWM.WWM—W " " I WWW—w What is the IRR for tfiiéloiéjééfié d mm" mm NW ; 0 <3le mmmw ‘ mcfiwfimwsm $5é00000‘ this lsa t‘tQ-t’ £053. What amount of annual savings is required for the project to break even? NW 0.- » amoeeam Mas-51% SBWU ‘l" A: saw amalgmss get/gm 5mm ward “ms: gage/1*— lgreak €V€W Assume the annual savings found in part a. What total equipment cost for each home is required for the project to break even? NW ot'C xgeeem iameeojymg, C flags-1 L4; MAX“ swag“ mm 4 $3}? We comet rectum aw: WWW £119?” 96‘! men/as m be was W6) Jrne weft/9% emits gnaw ‘so‘ie Sitar? \Wfi" 2. (25 points total) Site measurements of wind speed (Fig. 1) over one year reveal the following probability distribution of wind speeds at a 60m height. Assume the standard air density of 1.225kg/m3. A 1.5 MW wind turbine with a 64 m diameter placed at the sight has characteristics given by Fig. 2. Fig. 1 Fig. 2 Turbine Output (kW) 5 6 10 15 20 5 6 10 15 20 windspeed v (m/s) —> windspeed v (m/s) ——> a. What is the average velocity? / . ('3‘ng 4; 0,35% warm + DAME” 905% 10 'V f ‘5 8 t ('9 m S W b. How much energy (per square meter) is there in this wind in one year? Express your result in MWh/yr (per square meter). JEW ; 3:2 F 3}“; X 8 7 $0 , 3 61 3L5: oazgzir 0:35x8t03wg trill x283 +63%ng ix ‘ * 22g Kai gem-*1?" % 7‘3 G h“ a, i3 Beat :- 6353108139 W WW a) r (a mama {WK/m e c. What would the annual energy yield for this turbine be in these winds? (await + mecca-3% auto .3; i: Marja .13 t 23% to. 633) x87“) Mi?) (WW. Wmmem Hitsam Wk d. What is the overall average efficiency of the turbine? b - Wrgw = We M23 ma W a... 23.60 A) “lax are amt/s MD M v may? 6. Assuming the annual energy yield in c, what is the capacity factor of {he turbine? Emmi W it‘stfi «s. 0‘ 3 .5333 CF "5‘ a {Bro mimosa. '4 a {mi , 25*»; 3‘} M 3 Short Answer, four points each (16 points total) a. Using the equation discussed in class, approximately how much greater is the 5 windspeed at 60m then at 10m in an open area with tall grass (0!. =@? a“ i {V “a (00 \x‘31 E? v a ‘ , t a!" a— g.” a," 1.3,» {VD ‘3 f w -“:_','::‘:7.. ’ b. Briefly explain two demand-side management strategies. D l‘fij‘ifié’vméidfi’b (Och {Q RAM 13 Rebates ow gmlfikf- mg? l1 i 33 was com-mi 9'03er 3 Ln firm-wallets e rode: 5) malvfimefl foul” etc, o. A 30 kW microturbine with an elecgical efficiency of 30% is used in a combined heat and power (CHP) application illustrated in the figure below. Assume that 50% of the input fuel ends up as useful heat. The heat offsets the need for fuel for a 75% efficient boiler. Find the displaced boiler input in Btu/hr. Note, one Btu is 1055 J. d. As discussed in class, explain how an induction motor works. 4m? sting S E siCWQF i’mw syflUL/i Wow W5 $9230}. Claw?) MC‘QW fifiicfi m {$292145}? is organise: ‘m the, 3525 . _ l - n fl}. 3338’“ \ Caug’gc. Q,ijm~¢§,§%% ‘34:} “3&6 i J w . r W. 2m fumed awe—é \ , I Y V much imarwtg wf smear infiwmgpgg Vi cause; 4% met «in 39} tflig’lg‘ag, stiecwéwi t 4 Short Answer,three points each (15 points total) a. A l-MW wind turbine yielded about 3.5 million last year. What is its capaCity factor? 3 fl 4‘5” ‘ WE X ‘ £4”: 0" a ' éffiéciaqiij b. In a thermodynamic system, the m— must always increase. r Wm Lb c. In general, if the wind speed doubles, what happens to the output power of a wind turbine1 a It doubles. Lb) It goes up by 8x» (cifi‘pisngtpossiblewtosa‘y/ tfis’in't‘ormation. rovide a short justification for your choicbfwm 3 0 wk If) - ‘3 Q) pa v3 3 b 5% a w“ aorta , ’ , :J- [V N) W§£§+ef§fi$§ : jfi’figigiwlg 3 #5.? W3 \8 év‘f \‘ég‘ggis . Eflwflzji ,,,,,,,,,,,,,,,, Ir- d. Consider a power plant with a heat rate of 10,800 kJ/kW-hr burning bituminous coal with 75% carbon and a heating value (energy released when burned) of 27,300 kJ/kg. How many kg of carbon dioxide are emitted per kW-hr of electricity generated? I Dfim M y A /, _ O 26; £4; a“? @675 k \QN'A 7.3300 ‘95:? ' ' ‘ ‘ 4%?“ .i {:0 ‘. (3,20. (:97 la C x [ 2 d as 1 £13» \ w. a j e. Your non-technical friend has just heard a news story that hydrogen fuel cell based cars will run on water. He asks you if this is true. Provide a technically correct response about what role water would play in the operation of this car, and a likely source for the hydrogen used in the car (hint: mining hydrogen from the Sun is not a correct source). Waclex‘ks a Produd‘ 019 OLqu cw ) via-l an MPM' “a “New? \3 h? myAkt Hyéwmm can firm: {93m decantj 3:73 W N“ WVMA‘? U L658 in b“ch we. ream-s1) E6 to: kg 5. i; '13" ‘3 r. a , .. Hi we (a K 5 (18 points total). T rue/False — Two points each. Circle T if statement is true, F if statement is False. o F 1. Assuming a positive interest rate, the present worth of an investment is never greater than its future worth. A Increasing the assumed lifetime of’i'enewable generator will increase its interal rate of return. For industrial and commercial customers, the demand charge is usually based on their highest kWe over some time period (often monthly). '" Mauve One ton of cooling is equal to 12,000 Btu heat removal per hour, the same as from melting a one ton block of ice in 24 hours. In order to encourage the development of wind energy, the State of Illinois has decided wind turbines are excempt from local property taxes. Ground source heat pumps can be used for heating and cooling. The smart grid TV ad shown in class featured the cartoon character Sponge Bob exploring how the smart grid could help him reduce his electric load. Q E twill-ii if)? ’1’} 5-?“ use a downwind desi n in order to avoid the need-for complex yaw control. \23 «r»ng 5w w m... QQVA‘fié4 Mean A key advantage of synchronous generators is their speed can be easily controlled by changing their dc rotor current. Possibly useful tables: TABLE 5.5 Capital Recovery Factors as a Function of Interest Rate and Loan Term Years 3% 4% 5% 6% 7% 8% 9% 10% 11% 12% 13% 5 10 15 20 25 30 0.2] 84 0.1 172 0.0838 0.0672 0.0574 0.05 1 0 0.2246 0. 1233 0.0899 0.0736 0.0640 0.0578 0.2310 0.2374 0.1295 0.1359 0.0963 0.1030 0.0802 0.0872 0.07101 0.0782 0.0651 0.0726 0.2439 0. 1424 0. 1098 0.0944 0.0858 0.0806 0.2505 0. 1490 0.1 168 0. 10 [9 0.0937 0.0888 0.2571 0.2638 0.2706 0.2774 0.2343 0.1553 0.1627 0.1698 0.1770 0.1343 0.1241 0.1315 0.1391 0.1468 0.1547 0.1095@ 0.1255 0.1339 0.1424 0.1018 0.1102 0.1137 0.1275 0.1364 0.0973 0.1061 0.1150 0.1241 0.1334 Periods 1 coco-40“):th 10 12 13 1.4 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 35 37 38 39 40 41 42 43 45 47 48 49 50 Present Value 01 Ann—01137 Fact0rs (Ordinary Anhuity) 1% .9901 '1 .9704 2.9410 . 3.9020 4.3534 5.7955 6.7262 7.5517 8.5660 9.4713 10.3676 11.2551 12.1337 13.0037 13.6551 14.7179 15.5623 16.3963 17.2260 1 6.0456 16.6570 19.6604 20.4558 21.2434 22.0232 22.7952 23.5696 24.3164 25.0653 25.6077 26.5423 27.2696 27.9897 28.7027 29.4066 30.1075 30.7995 31.4347 32.1630 32.6347 36.4997 34.1561 34.3100 35.4566 36.0945 36.7272 37.3537 37.9740 36.5661 39.1 961 2% .9804 1.9416 2.8839 3.8077 4.7135 5.6014 6.4720 7.3255 8.1622 8.9826 9.7868 10.5753 11.3484 12.1062 12.8493 13.5777 14.2919 ' 14.9920 15.6785 16.3514 . 17.0112 17.6580 18.2922 18.9139 19.5235 20.1210 . 20.7069 21.281 3 21 -8444 22.3965 22.9377 23.4683 23.9886 24.4986 24.9986 25.4888 25.9695 26.4406 26.9026 27.3555 27.7995 28.2348 28.6616 29.0800 29.4902 29.8923 30.2866 30.6731 31 .0521 31 .4236 3% 4% .9709 .9615 1.9135 1.6661 2.8286 2.7751 3.7171 3.6299 4.5797 4.4516 5.4172 6.2421 6.2303 6.0021 7.0197 6.7327 7.7361 ' 17.4353 6.5302 3.1109 9.2526 6.7605 9.9540 9.3851 10.6350 ’ 9.9656 11.2961 10.5631 11.9379 11.1164 12.5611 11.6523 13.1661 12.1667 13.7535 12.6593 14.323 " 13.1339 .8775 - 15.4150 15.9369 15.4436 16.9355 17.4131 17.8768 13.3270 16.7641 19.1635 19.6004 20.0004 20.3366 20.7658 21.1316 21.4672 21.6323 22.1672 22.4925 22.6032- 23.1143 19.7926 23.4124 19.9931 23.7014 20.1656 23.9319 20.3706 24.2543 20.5466 24.5137 20.7200 24.7754 20.8847 25.0247 21.0429 25.2667 21.1951 25.5017 21.3415 25.7296 21.4822 14.0292 14.451 1 14.8568 15.2470 . 16.6221 15.9326 16.3296 16.6631 16.9637 17.2920 17.5885 17.6736 16.1476 16.4112 . 16.6646 16.9033 19.1426 19.3679 19.5645 5% .9524 1 .6594 2.7232 3.5460 4.3295 5.0757 5.7564 6.4632 7.1073 7.7217 6.3064 6.6633 9.3966 9.3966 10.3797 10.3373 11.2741 11.6396 12.0653 12.4622 12.8212 13.1630 13.4666 13.7986 14.0939 14.3752 14.6430 14.6961 15.141 1 15.3725 16.5928 15.6027 16.0025 15.1929 16.3742 16.5469 16.71 13 16.3679 17.0170 17.1591 17.2944 17.4232 17.5459 17.6626 17.7741 17.6601 17.9610 18.0772 16.1667 16.2559 6% .9434 1 .8334 2.6730 3.4651 4.2124 4.9173 5.5824 6.2098 6.8017 7.3601 7.8869 8.3838 8.8527 9.2950 9.7122 10.1059 10.4773 10.8276 11.1581 11 .4699 11 .7641 12.0416 12.3034 12.5504 12.7834 13.0032 13.2105 13.4062 13.5907 13.7648 13.9291 14.0840 14.2302 14.3681 14.4982 14.6210 14.7368 14.8460 14.9491 15.0463 15.1380 15.2245 15.3062 15.3832 15.4558 15.5244 15.5890 15.6500 15.7076 15.7619 7% .9346 1 .8080 2.6243 3.3872 4.1002 4.7665 5.3893 5.9713 6.5152 7.0236 7.4987 7.9427 8.3577 8.7455 9.1 079 9.4466 9.7632 10.0591 10.3356 10.5940 10.8355 11.0612 11.2722 11 .4693 11 .6536 11 .8258 1 1 .9887 12.1371 12.2777 12.4090 12.5318 12.6466 12.7538 12.8540 12.9477 130352 13.1 170 13.1935 13.2649 13.3317 13.3941 13.4524 13.5070 13.5579 13.6055 13.6500 13.6916 13.7305 13.7668 13.8007 Periods 1 mmummxuwm 10 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 35 36 37 as 39 40 41 42 43 45 46 47 48 49 50 Present Value Of Annuity Factors (Ordinary Annuity) 8%- .9259 1.7833 2.5771 3.3121 3.9927 4.6229 5.2064 5.7466 6.2469 6.7101 7.1390 7.5361 7.9038 8.2442 8.5595 8.8514 9.1216 9.3719 9.6036 9.8181 10.0168 10.2007 10.371 1 10.5288 10.6748 10.81 00 10.9352 11.051 1 11 .1584 11.2578 11.3498 11.4350 1 1.5139 1 1.5869 1 1.6546 1 1.7172 1 1.7752 11.8289 ' 11.8786 11.9246 11.9672 12.0067 12.0432 12.0771 12.1084 12.1374 12.1643 12.1891 12.2122 12.2335 9% .9174 1.7591 2.5313 3.2397 3.8897 4.4859 5.0330 5.5348 5.9952 6.4177 6.8052 7.1607 7.4869 7.7862 8.0607 8.3126 8.5436 8.7556 8.9501 9.1285 9.2922 9.4424 9.5802 9.7066 9.8226 9.9290 10.0266 10.1 161 10.1983 10.2737 10.3428 10.4062 10.4644 10.5178 10.5668 10.61 18 ' 10.6530 10.6908 10.7255 10.7574 10.7866 10.81 34 10.8380 10.8605 10.8812 10.9002 10.9176 1 0.9336 10.9482 10.9617 10% .9091 1.7355 2.4869 ~ 3.1699 3.7908 4.3553 4.8684 5.3349 5.7590 6.1446 6.4951 6.8137 7.7034 7.3667 7.6061 7.8237 8.0216 8.2014 8.3649 8.5136 8.0487 8.7715 8.8832 . 8.9847 8.0770 9.1609 9.2372 9.3066 9.3696 9.4269 9.4790 9.5264 9.5694 9.6086 9.6442 9.6765 9.7059 9.7327 9.7570 ‘ 9.7791 9.7991 9.8174 9.8340 9.8491 9.8628 9.8753 9.8866 9.8969 9.9063 9.9148 11% .9009 1 .7125 2.4437 3.1 024 3.6959 4.2305 4.71 22 5.1461 5.5370 5.88 92 6.2065 6.4924 6.7499 6.981 9 7.1909 7.3792 7.5488 7.7016 7.8393 7.9633 8.0751 8.1757 8.2664. 8. 3481 8.4217 8.4881 8.5478 , 8.6016 8.6501 8.6938 8.7331 8.7686 8.8005 8.8293 8.8552 8.8786 8.8996 8.9186 8.9357 8.951 1 8. 9649 8.9774 8.9886 8.9988 9.0079 9.0161 9.0235 9.0302 9.0362 9.0417 12% .8929 1.6901 2.4018 3.0373 3.6048 4.1 1 14 4.5638 4.9676 5.3283 5.6502 5.9377 6.1944 6.4235 6.6282 ’ 6.8109 1 6.9740 7.1196 7.2497 7.3658 7.4694 7.5020 7.6446 7.7184 7.7843 7.3431 7.8957 7.9420 7.9844 8.0218 3.0552 8.0850 8.1116 3.1354 8.1566 8.1755 8.1924 8.2075 8.2210 8.2330 8.2438 8.2534 8.2619 8.2696 8.2764 8.2825 8.2880 8.2928 8.2972 8.3010 8.3045 13% .8850 1.6681 2.3612 2.9745 3.5772 3.9976 4.4226 4.7988 5.1317 5.4262 5.6869 5.9176 6.1218 6.3025 6.4624 6.6039 6.7291 6.8399 6.9380 7.0243 7.1016 7.1695 7.2297 7.2829 7.3300 7.3717 7.4086 7.4412 7.4701 7.4957 7.5183 7.5383 7.5560 7.5717 7.5856 7.5979 7,0007 7.6183 7.6268 7.6344 7.6410 7.6469 7.6522 7.6568 7.6809 7.6645 7.6677 7.6705 7.6730 7.6752 14% .8772 1.6467 2.3216 2.9137 3.4331 3.8887 4.2883 4.6389 4.9464 5.2161 5.4527 5.6603 5.8424 6.0021 6.1422 6.2651 6.3729 6.4674 6.5504 8.6231 6.6870 6.7429 6.7921 6.8351 6.8729 6.9061 6.9352 6.9607 6.9830 7.0027 7.0199 7.0350 7.0482 7.0599 7.0700 7.0790 7.0868 7.0937 7.0997 7.1050 7.1097 7.1138 7.1173 7.1205 7.1232 7.1256 7.1277 7.1296 7.1312 7.1327 Present Value Of Annuity Factors (Ordinary Annuity) Periods 1 com-qmcnxxww 10 11 12 13 14 15 16 17 18 '19 20 21 23 24 25 26 27 28 29 30 31 32 33 35 37 - 39 40 41 42 43 45 46 47 49 50 15% .8696 1 .6257 2.2832 2.8550 3.3522 3.7845 4.1604 4.4873 4.7716 5. 01 88 5.2337 5.4206 5.5831 5.7245 5.8474 5.9542 6.0472 6. 1280 6.1982 6.2593 6.3125 6.3587 6.3988 6.4338 6.4641 6.4906 6.51 35 6.5335 6.5509 6.5660 6.5791 6.5905 6.6005 6.6091 6.61 66 6.6231 6.6288 6.6338 6.6380 6.641 8 6.6450 6.6478 6.6503 6.6524 6.6543 6.6559 6.6573 6.6585 6.8596 6.6605 16% ‘ .8821 1 .8052 2.2459 2.7982 3.2743» 3.8847 4.0388 4.3436 4.6065 4.8332 5.0288 5.1971 5.3423 5.4675 5.5755» 5.6685 5.7487 5.8178 8.8775 5.9288 5.9731 6.01 13 8.0442 8.0728 8.0971. 6.1 182 8.1384 8.1 520 8.1858 8.1772 6.1872 8.1959 6.2034 6.2098 ' 6.2153 6.2201 . 6.2242 8.2278 8.2309 , 6.2335 6.2358 6.2377- 6.2394 6.2409 6.2421. 6.2432 6.2442 6.2450 6.2457 6.2463 17% .8547 1 .5852 2.2096 2.7432 3.1993 3.5892 3.9224 4.2072 4.4506 4.6586 4.8364 4.9884 5.1 1 83 5.2293 5.3242 5.4053 5.4746 5.5339 5.5845 5.6278 5.6648 5.6964 5.7234 5.7465 5.7662 5.7831 5.7975 5.8099 5.8204 5.8294 5.8371 5.8437 5.8493 5.8541 5.8582 5.8617 5.8647 5.8673 5.8695 5.8713 5.8729 . 5.8743 5.8755 5.8765 5.8773 5.8781 5.8787 5.8792 5.8797 5.8801 18% .8475 1 .5656 2.1743 2.6901 3.1 272 3.4976 3.81 15 4.0776 4.3030 4.4941 4.6560 4.7932 4.9095 5.0081 5.0916 5.1624 5.2223 5.2732 5.3162 5. 3527 5.3837 5.4099 5.4321 5.45 09 5.4669 5.4804 5.491 9 5.5016 5.5098 5.5168 5.5227 5.5277 5.5320 5.5356 5.5386 5.541 2 5.5434 5.5452 5.5468 5.5482 5.5493 5.55 02 5.551 0 5.5517 5.5523 5.5528 5.5532 5.5536 5.5539 5.5541 19% .8403 1.5465 2.1399 2.6386 3.0576 3.4098 3.7057 3.9544 4.1633 4.3389 4.4865 4.6105 4.7147 4.8023 4.8759 4.9377 4.9897 5.0333 5.0700 5.1009 5.1268 5.1486 5.1668 5.1822 5.1951 5.2060 5.2151 5.2228 5.2292 ‘ 5.2347 5.2392 5.2430 5.2462 5.2489 5.2512 5.2531 5.2547 5.2561 5.2572 5.2582 5.2590 5.2596 5.2602 5.2607 5.2611 5.2614 5.2617 5.2619 5.2621 ' 5.2623 ...
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This note was uploaded on 03/04/2011 for the course ECE 333 taught by Professor Overby during the Fall '09 term at University of Illinois, Urbana Champaign.

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Exam 2 fa - Name Fall 7,0901 Sellfiigfl ECE 333 Exam#2...

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