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CAN ENERGY EFFICIENCYSOLVE SAs PROBLEMS ?Prof Ernst UkenHead: Energy InstituteCape Peninsula University of Technologyukene@cput.ac.za

English/Afrikaans ik ConfusionEfficiency: doeltreffend, vaardig‐ Bosman, vdMerwe, Hiemstra(afdoenig, geskik, doelmatig,werkend, saaklik, k nuttig, waarde))Effective: effektief, geskik, treffend, werkend,doelmatig, bekwaam.(doeltreffend).d)

GENERAL DEFINITIONS‐ Oxford Dictionary & www.yourdictionary.comyEFFICIENCY• Ability to produce a desired effect/product with minimumeffort/expense/waste• Ratio of useful/effective work to total energy expended inproducing; or heat taken in• Output divided by InputEFFECTIVENESS / EFFICACY• Able to bring about the intended/desired d/d i d effect/result• Making a striking/remarkable impression• Fit for work/service

DEFINITIONS in MARKETINGEFFICIENCY‐ www.smartinsights.com,• “Doing the thing right” iht” by minimising i i i resources or the timeneeded to complete a process,ie. keeping the costs low• Costs include: purchases, conversion rateEFFECTIVENESS• “Doing the right thing” on a broader scale• Customer satisfaction by numbers or lifetime

Marketing (cont.)‐ Hasan H and Tibbits H. Internet Research,vol 5, no10, 2000, p439‐450•Internal process measures areconcerned with Efficiency•Customer and Business valueperspectives relate to Effectiveness

ENGINEERING DEFINITIONSFor Energy Systems (generation/conversion):Efficiency ή = Output(kW) ÷ Input(kW) in %For Lighting :Effectiveness/Efficacy = Lux ÷ Watt“A system becomes more energy efficient, if ituses less energy to maintain the same servicelevel” l” ‐ Wikipedia

GENERATION EFFICIENCIES (%)1009080706050403020100‐ Eurelectric & VGB PowerTech, 2003

REASONS FOR CHOOSING SUCHLOW EFFICIENCIES• Coal and fossil fuels dominate, due to their generalavailability and cost‐effective usage in large central units• Nuclear avoids large‐scale greenhouse gas emissions• Renewable energy with fuel cells will form future pillars offuel mix, because of fuel preservation‐ Eurelectric & VGB PowerTech,2003• “Energy Efficiency is an important strategy for reducing thedependence d on fossil fuels”‐ http://www.ecomii.com/ecopedia/energy .

BUSINESS ‘TIPS’“Efficiency is a comparison of what is actually producedor performed with what can be achieved with the sameconsumption of resources (money, time, labour, etc)BUT, in a rapidly growing market, do not worry toomuch about efficiency. It’s more important to growfast” ………. (and be effective ?)‐ http://www.businessdictionary.com

POSITIONINGRENEWABLE ENERGY SOURCES• Small Hydro and Tidal @ 90% Efficiency• Wind, Nuclear and Biomass @ 35%close behind hid Coal @ 42%• PV is low at 15%BUTHOW DO COSTS OF GENERATIONCOMPARE ?

ENERGY INTENSITY orENERGY EFFICIENCY ?• Often we say ‘Energy Efficiency’ when we actually mean‘Energy Intensity’. Intensity.• A system becomes more energy efficient, if it usesless energy to maintain the same service level‐ Wikipedia• Energy Intensity is the ratio of Energy Consumption tosome measure of demand df for energy services (DemandIndicator)• Energy Intensity may mask structural t and behaviouralchanges, which do not refer to ‘true’ efficiencyimprovements.

(a) % EFFICIENCY1009080706050403020100(b) COST IN $/Kw120001000080006000p400020000EFFICIENCY & COSTOF GENERATION;1. PV has lowefficiency and ismost expensive2. Wind hasreasonableefficiency and ischeapest

USER ENERGY EFFICIENCY‐ http://www.ecomii.com/ecopedia/energyEnergy Efficiency measures, having the potential ofreducing electricity use, while saving the users money inthe long run, include :• Advanced industrial processes• High efficiency motors• Lighting• Appliances, cars, whole buildings, etc• Anything using fuel will improve the environment and• Anything using fuel, will improve the environment andclimate change if less fuel is burnt

AVE LIGHTING EFFICACY(lumen/Watt) ‐ www.mge.com/home120100806040200

EFFICACY & AVERAGE LIFE‐ http://sewelldirect.comLamp Efficacy Ave life(lumen/Watt)(hours)Incandescent 17 750CFLs 62 8 000LEDs 77 >50 000

DECISION MAKING FORLIGHTINGMust consider:• Light effectiveness/efficacy (lum per Watt, to maintainservice level) +• Average lifespan (eg decay factor) +• Cost per lamp, p,pus plus fitting +• Energy consumption in kWh.Only then can an informed decision be made !Energy savings are determined by M&V by measuring andverifying the impact a new installation has made,relative to a previously measured baseline, retaining theservice levell

WATER HEATING COSTS ($ pa)‐ www.efficientheating.co.nzco nz120010008006004002000

SOLAR WATER HEATINGAbsorber b size: 3 sq.m(kWh/sq.m/d)/d)1614121086420http://en.wikipedia.orgEvac tube, dirEvac tube, indir dil Flatplate, l dil dir Flatplate, l indir

GEYSERS vsHEAT PUMPS vsSWHs‐ Rankin & van Eldik, NWUElectricity consumption (kWh) per annumGeyser Electric: H/Pump: SWHtype3kW(150L)13 1,3kW Electric200L4kW(200L) 3,6 kW Thermal 300L2 users 3 740 1 450 1 1704 users 7 400 2 940 2 7306 users 10 729 4 320 5 970

RULE OF THUMB OF SOLARTHERMAL INSTALLATIONS – Weiss, IEA• For Swimming pool heating: Use unglazed, open blackcollector• For small household : Use flat‐plate, glass‐covered collectorwith small tank (direct circulation)• For medium household : Use flat‐plate, glass‐coveredcollector with small tank and direct circulation + electricback‐up + timer• For large household : Consider evacuated tubes with smalltank (indirect circulation) + back‐up + timer. Heat pumpmay become competitive !

HOME‐MADE IMBAULA STOVEMore holes in the cylindrical stove, lead to :• Higher power outputs, but• Lower thermal efficiency, and• Lower specific CO emissionsQUESTION :‐ dkimemia@gmail.comWhich variant will describe Energy Efficiency ?

GENERAL CRITERIA FOR ENERGYIf concerned about :USAGE ‐ www.eia.doe.gov/emeu• Wealth lhand Economic well‐being ?• Improved Productivity ?• Increased Employment ?• Reducing Poverty ?• Resource conservation ?• Improved Environment ?Then use other, more appropriate criteria !

ENERGY INTENSITY – ‘SUROGATEFOR ENERGY EFFICIENCY’ ?Energy Efficiency can only be expressedrelative to one criteria – hopefully themost important energy indicator.Criteria which include national policies andpriorities, move beyond the scope of energyefficiency.iNOTE: ENERGY INTENSITY MASKSSTRUCTURAL & BEHAVIOURALCHANGES (eg. Shift away from sports carsto SUVs).

MEASURING RELATIVE CHANGESFor Energy Efficiency, always ask :‘Efficient ‐ relative to what ?’MEASUREMENT APPROACHES :• Market‐Basket for set of controlled services• Comprehensive for all energy use, removingunrelated changes until energy efficiency remains• Best Practice merely shows what is possible• Site versus Primary Energy showing• Site versus Primary Energy showinggeneration, transmission and distribution losses.

ENERGY EFFICIENCY C AS DRIVER‐ WikipediaReducing energy use ofappliances, buildings, industrial i processesand vehicles may also• Reduce costs• Rd Reduce level l of energy imports• Slow down rate at which domestic energyresources are depleted• Reduce greenhouse gas emissions