14 kW 11 kW 44 solar PV modules near Consort Solar Electricity 7 … · 67 solar PV modules near...
Transcript of 14 kW 11 kW 44 solar PV modules near Consort Solar Electricity 7 … · 67 solar PV modules near...
#1
Gordon Howell, P.Eng.
©2006-2014Edmonton
14 kW67 solar PV
modulesnear Okotoks
6 kW27 solar PV modulesnear Lamont
7 kW30 solar PV
modulesnear Spruce Grove
6 kW24 solar PV modulesnear Lacombe
Millet2014 March 06
Solar ElectricitySolar Electricity……coming to a farm or acreage coming to a farm or acreage
near younear you
4.5 kW21 solar PV modules
near Devon
11 kW44 solar PV modulesnear Consort
#2
Intro: Me
my house: 2.3 kW PV systemmy house: 2.3 kW PV system44thth gridgrid--connected PV house in Canada in 1995connected PV house in Canada in 1995
~100% solar electricity~100% solar electricity
I am a professional engineerI am a professional engineer
I am a solarI am a solar--electric system project developerelectric system project developerworking with solar energy since 1977 and working with solar energy since 1977 and with solar electricity since 1983with solar electricity since 1983
I develop, design, supply and commission solarI develop, design, supply and commission solar--electric systemselectric systems
I have no vested interests in any one solarI have no vested interests in any one solar--electric technologyelectric technology
I want you to make your decisions I want you to make your decisions with your eyes wide open with your eyes wide open
so that you can decide so that you can decide what may be right for youwhat may be right for you……
#3
Information… energy, power, solar
A lot of information to be aware ofA lot of information to be aware of
A lot of A lot of mismis--information and information and disdis--informationinformation
You need to understandYou need to understand……
basics about solar energybasics about solar energy
basics about energy basics about energy vsvs powerpower
your electricity bill and its pricesyour electricity bill and its prices
#4
Intro: Solar Electricity
OverviewOverview
What are the components?What are the components?
How does it work?How does it work?
What angles are best?What angles are best?
How much can it reduce your electricity bill? How much can it reduce your electricity bill?
What would it cost for your house or farm?What would it cost for your house or farm?
Photo credit: Great Canadian Solar, Edmonton
#5
To start:The basics about solar electricity…
Every great movement must experience three stages: John Stuart Mill…ridicule, discussion, adoption.
#6
Uses of Solar Energy in a House…
Part of a solar ventilation air pre-heating system
Part of a solar
domestic hot water heatingsystem
Part of a solar electricity-generating system
Direct gain passive
solar space heating windows
Solar illumination windows
#7
Solar Heating and Solar Electricity
are NOT the same…
Solar electricity– Much like a computer chip– Photons of light bump
electrons out of an atom– Wires carry electrons away
Solar heatingA dark surface sitting in the sun lightWater or air flows past solar-heatedsurface and carries heat away
#8
Solar heating Solar heating thermal thermal collectorscollectors
Solar electricity Solar electricity photovoltaic photovoltaic modulesmodules
Solar panel Solar panel mechanical configuration mechanical configuration several solar PV modules attached several solar PV modules attached on a mounting rackon a mounting rack
What words do we use?
#9
Solar ElectricityThe technology is called "The technology is called "photovoltaicsphotovoltaics", but we only call it "PV".", but we only call it "PV".
solar PV cell
solar PV module
solar PV panel (because the modules are all
fastened together on one contiguous rack)
array of solar PV modules
#10
PV Terms
Solar PV
Solar PV Solar PV ArrayArray
PV can generate any amount of electricity.Large PV systems = more PV modules.
Solar PV Solar PV ModuleModuleSolar PV Solar PV CellCell
30,000 modules, 6000 kW
5,000 modules1000 kW
170,000 modules34,000 kW
#11
Solar PV System – Major Components…
Solar PV module…to generate
DC electricity
Inverter…to convert to
AC electricity
Battery…to store
DC electricity
maybe… but not usually
#12
Solar Photovoltaic (PV) System
1. Array of solar PV modules
2. DC disconnect switch
3. DC to AC Inverter
4. Customer service box and panelboard
1
2
3 4
7. Electrical utility wires
8. Distribution transformer(dedicated or shared with other customers)
© 2011 Jim Dunlop Solar (modified)
7
8
DC
AC
Notes:DC = direct currentAC = alternating currentComponents #2, 3, 4 are usually inside a house
6. Electrical utility revenue meter
6
5
5. House loads
#13
PV Module Technologies
multimulti--crystalline crystalline
siliconsilicon
single single crystal crystal siliconsiliconTechnologies:Technologies:
singlesingle--crystal silicon (Si)crystal silicon (Si)multimulti--crystalline silicon (Si)crystalline silicon (Si)amorphous silicon (Si)amorphous silicon (Si)(no crystalline structure)(no crystalline structure)thinthin--film (film (CdTe/CdSCdTe/CdS, CIGS, CIS, , CIGS, CIS, GaAsGaAs..)..)
thinthin--filmfilm
CdTe/CdSCdTe/CdS
Myth Myth ---- RareRare--earth metals ???earth metals ???NONO, PV does not contain , PV does not contain rarerare--earth metals.earth metals.RareRare--earth metals do not have the earth metals do not have the correct atomic characteristics for correct atomic characteristics for the the ““photovoltaicphotovoltaic”” effect to work.effect to work.
#14
Continuous silicone seal
Tempered glassEVA embedding
Solar cellsTough polymer back sheet
High strength frame
Typical PV Module Construction
SolarWorld USA
#15
PV Module Manufacturers
Module manufacturers and countries:Module manufacturers and countries:America: America:
First Solar, Evergreen, First Solar, Evergreen, UniUni--Solar, Solar, SunPowerSunPower ++++Canada:Canada:
Day4EnergyDay4Energy, Canadian Solar, , Canadian Solar, EclipsallEclipsall, , SilfabSilfab ++++China:China:
SolarfunSolarfun, Suntech, Trina, , Suntech, Trina, YingliYingli, , AstronergyAstronergy, LDK ++++, LDK ++++France:France:
PhotowattPhotowattGermany:Germany:
ConergyConergyJapan:Japan:
Kyocera, Sharp, Sanyo, Mitsubishi ++Kyocera, Sharp, Sanyo, Mitsubishi ++Korea:Korea:
LG, Samsung, HyundaiLG, Samsung, HyundaiSpain:Spain:
IsofotonIsofoton, , HelieneHeliene++ many ++ many manymany more countries andmore countries and
manufacturersmanufacturers……
50,000 solar PV modules available from50,000 solar PV modules available from
1164 module manufacturers1164 module manufacturers……! **! **** http://www.photon.info/photon_site_db_solarmodule_en.photon
#16
PV Module Standards
18 tests including:Hail test – 25 mm at 83 km/hTemperature cycling test, -40°C to +85°CDamp-heat testUV testWind, snow, ice loading testRated performancePerformance at low irradianceOutdoor exposureHot-spot endurance testHumidity-freeze testWet insulation resistance test
Design, certified and tested to international standard IEC 61215do not buy a PV module that does not have this testing designation shown on the brochure…
#17
Inverters convert DC electricity (produced by the solar array)to AC electricity (used by any AC loads)
Xantrex GT Canada
grid-dependentstring inverter
3.8 kW
Fronius IGAustriagrid-dependentstring inverter2 kW to 5.1 kW
SMA Sunny Boy Germanygrid-dependentstring inverter3 to 11 kW
Xantrex XWCanada
grid-connectedinverter/charger
4 kW to 6 kW
EnphaseAmericagrid-dependentmodule inverter0.2 kW
DC to AC Inverters
#18
DC to AC Inverter Banks…
Each: 0.2 kW to 11 kW, 1 phaseEach: 0.2 kW to 11 kW, 1 phase
Each: 1Each: 10 kW to 1000 kW, 3 phase0 kW to 1000 kW, 3 phase
8200 solar inverters available from8200 solar inverters available from
364 inverter manufacturers364 inverter manufacturers……! **! **** http://www.photon.info/photon_site_db_wechselrichter_en.photon?ActiveID=1241
#19
4 major components:PV arrayDC switchSolar inverterAC switch (maybe)
No energy storage
Typically simpleto design, install, operate
Most commongrid-connected configuration (99.9%)
Solar PVarray1
23
4
Grid-dependent Solar PV System
#20
Importregister
kWh
kWh
Export register
kWh
kWh DC
Electric Wires Company’s electrical distribution grid
AC
All electrical circuits in a building
1
2
3
4
Inverter
Exports to the grid when there is a site surplus.Imports from the grid when there is a site shortage.Typically 50% to 90% is exported over the year from a house.
Generating solar electricity into a building
and also back into the grid…
©1995-2014
Solar electric array
DC to ACInverter
Solar PVarray
Panelboard
Breakers
#21
PV Array
Inverter
DC
AC
All electrical circuits in a house
1
2
3
4
The inverter senses that there is a electrical outage and turns itself off.
When electric power returns, the inverter turns itself on automatically.
What happens during an electrical outage?
Electric Wires Company’s electrical distribution grid
kWh
kWhImportregister
Export register
kWh
kWh
©1995-2014
Panelboard
Breakers
DC to ACInverter
Solar electricarray
#22
Grid-Connected System – with batteries
7 major components
Includes energy storage
Not common at all25 in Canada?
#23
PV Array
DC
Electric Wires Company’s electrical distribution grid
AC
1
2
3
4
This configuration has a battery bank but it is not common.
How about energy security?
AC
5
Battery BankDC
6
7
kWh
kWhImportregister
Export register
Inverter/charger
ChargeController
©1995-2014Main electrical circuits in a house
Main Panelboard
Breakers Essential circuit panelboard
Breakers
kWh
kWh
#24
PV Array
kWh
kWhImportregister
Export register
1
The inverter senses that there is a electrical outage. It disconnects itself from the main breaker panel but continues to run the essential circuits.
During an electrical outage…
Essential circuit panelboard
AC
Battery BankDC
3
DC 2
4
5
6
7
ChargeController
Inverter/charger
Electric Wires Company’s electrical distribution grid
©1995-2014
AC
Main electrical circuits in a house
Main Panelboard
Breakers
Breakers
kWh
kWh
#25
Planning Decisions…
Fit within dimensions and area of available space
#26
Planning Decisions…
Minimise obstructions from other equipment, buildings
#27
Planning Decisions…
Minimise shading from buildings and trees
#28
Technical Decisions…Engineering
Energy● Goal: maximise annual energy generation
Electrical ● Match modules to inverter (voltage, current, power)
at max. and min. module temperatures
Angles● Maximise energy production and generation● Minimise snow cover
Structural fastening ● Minimise extra structural loading on building● Maximise passive cooling and minimise module
temperature to increase module efficiency
#29
What tilt angle to use?
0
2
4
6
8
1 2 3 4 5 6 7 8 9 10 11 12
Annual
0°, horizontal
Month #s
Edmonton
Daily incoming solar radiation
sun-hours= kWh/m2/day
Solar radiation – horizontal surface
#30
What tilt angle to use?
0
2
4
6
8
1 2 3 4 5 6 7 8 9 10 11 12 Annual
Month #s
27°, 6/12 roof pitch
0°, horizontal
Edmonton
In many ways our future is passing us by, Gary Lamphier… and our energy riches may one day look like fool's gold. Edmonton Journal
Daily incoming solar radiation
sun-hours= kWh/m2/day
#31
What tilt angle to use?
1 2 3 4 5 6 7 8 9 10 11 12 Annual
Month #s
0
2
4
6
8
27°, 6/12 roof pitch
0°, horizontal
53°, = latitude
Edmonton
Daily incoming solar radiation
sun-hours= kWh/m2/day
#32
What tilt angle to use?
1 2 3 4 5 6 7 8 9 10 11 12 Annual
Month #s
0
2
4
6
8
27°, 6/12 roof pitch
0°, horizontal
53°, = latitude
90°, = vertical
Edmonton
Daily incoming solar radiation
sun-hours= kWh/m2/day
#33
Optimal Annual Solar Tilt Angle(to use when you’re connected to the grid)
maximum annual solar energy production occurs at around a 50° tilt.tilt angle can be from 18° to 80° and still be within 10% of maximum energy
precise optimum tilt and orientation to collect maximum amount of solar energywide degree of flexibility to orient and tilt solar equipment and still not be too far off the optimum
% of energy
reduced from
optimal annual
tilt angle (and
facing due
south)-30%
-25%
-20%
-15%
-10%
-5%
0%0 13 23 33 43 53 63 73 83 90
Horizontal Vertical
4.8sun-hours/day= kWh/m2/day
3.6
4.0Edmonton
data from simulation software
#34
Optimal Winter Solar Tilt Angle (to use when you’re off grid)
Edmonton
% of energy
reduced from
optimal winter tilt
angle (and
facing due
south) -80%
-70%
-60%
-50%
-40%
-30%
-20%
-10%
0%0 13 23 33 43 53 63 73 83 90
Horizontal Vertical
3.8sun-hours/day
1.0
3.4 3.75
maximum winter solar energy production occurs at around a 83° tilt.tilt angle can be from 50° to 90° and still be within 10% of maximum winter energy
Reduction from snow cover?Enhancement from reflection off snow fields?
data from simulation software
#35
-12%
-10%
-8%
-6%
-4%
-2%
0%230 220 210 200 190 180 170 160 150 140 130
SW SESouth
Orient PV array up to 45° either side of south and still be within 10% of maximum energy
SW South SESSESSW
% of energy
reduced from
optimal annual
orientation angle
(at tilt angle = latitude)
Edmonton
Optimum Annual Solar Orientation Angle
data from simulation software
#36
Solar Window
Sunpath ChartThe solar window:Where most of the sun's energy comes from…
Path of the sun Path of the sun across the skyacross the sky
Sun's pathDecember 21 Sun's path
June 21
NorthSouth
East
West
3pm
10am
#37
Get a sun path chart for your area Site your PV array where there is little or no shading between 10am and 3pm
Sun Path
Make a sun path chart fromhttp://solardat. uoregon.edu/SunChartProgram.html
solar window
#38
Shading Analysis
from the PV system at the Kerry Wood Nature Centre, Red Deer
Huge tree
Solmetric SunEyeshading analysis instrument solar window
#39
SunEye – Monthly Solar Access
from the PV system at the Kerry Wood Nature Centre, Red Deer
100%
93%
76%
67%65%
82%
71%
64%69%
Annual solar access prorated across the
energy availability per month= 88%
#40
What about snow?
What about snow cover?
Do I have to push the snow off my PV array?
What difference does it make?
#41
PV covered with snow works PV covered with snow works just as well as it does at nightjust as well as it does at night
Of course, when the big light in the sky turns off, Of course, when the big light in the sky turns off, solar PV systems donsolar PV systems don’’t work t work so instead we draw electricity from the electricity grid.so instead we draw electricity from the electricity grid.
Riverdale NetRiverdale Net--Zero Energy houseZero Energy house2008 November 20, 19:262008 November 20, 19:26
#42
Snow can stick at lots of angles…
53° tilt angle
Riverdale Net-Zero-Energy House2008 December 30, noon, -20°C
#43
PV Compromises – Snow Cover
Belgravia Green near NZE Belgravia Green NZE Belgravia Green NZE-ready
60°
23°
50° tilt angle
Snow can easily stick and stay… depending on air temperature Over-size the PV system to accommodate unclearedsnow cover
focus on amount of energy generated over the whole year, not generated only in the winter
#44
Reduction in Generation due to Snow Cover – typical year
tilt angle from horizon
Huge variation in depth and duration of snow cover from year to year
data from my observations and guesses
… this data is an informal approximation… it is way better than ignoring snow…
Reduction in annual generated amount
#45
PV Array Mounting Systems
Can be mounted in many ways
Ground-mounted arraysRacks, poles and sun-tracking mounts
Roof-mounted arraysRacks for flat roofsStandoffs for sloped roofsDirect or flush
Orientation typeFixed-tilt, adjustable and sun-tracking arrays
#46
PV Array Mounting – Ground
Need protection from physical harm, module theft, and safetyby fencing or elevating the array
#47
PV Array Mounting – Rack
Can be installed on the ground using concrete footingson roofs, or on the sides of buildings
#48
PV Array Mounting – Pole
Pole-mounted arrays are used for many applications. Larger arrays require substantial foundations to resist winds
#49
Need space for thisLikely will never be used in a cityWould work well on a farm
PV Array Mounting – Pole
#50
PV Array Mounting – Roof Standoff
Standoff mounts are the most common way PV arrays are attached to sloped rooftops.
Many many products available for stand offs.
Sharp Solar
#51
PV Array Mounting – Fixed-Tilt
fixed orientation toward the sunmost common PV array mounting
#52
Tracking the Sun
Single axis trackingpitch function = E-W axis, facing due south, tracking up-down13% more annual energy than array at optimum fixed-tilt angle
Single axis trackingyaw function = vertical axis, optimum array tilt, tracking E-W33% more annual energy than array at optimum fixed-tilt angle
Usuallythe cost of the PV array tracker and a system's increase in energy production is comparable to a fixed tilt system with a bigger PV array!
#53
Single axis trackingroll function = N-S axis, horizontal axis tilt, tracking E-W9% more annual energy than array at optimum fixed-tilt angle
Roll-Axis – Axis Not Tilted
340 kW, California
#54
Single axis – angled axisroll function = N-S axis, axis tilt = 64°, tracking E-W21% more annual energy than array at optimum fixed-tilt angle
Roll-Axis – Tilted Axis
#55
Feeds a house west of Edmonton16.8 kW totalOperational since August2-axis tracking38% more annual energy than array at optimum fixed-tilt angle
Two-Axis Tracking
#56
Economics
Let’s look at costs and economics
#57
Benefits of Solar PV…
Savings on utility bills
Energy price securityalmost all the costs are paid upfrontonly maintenance cost is inverter replacement in 20 years
Energy supply security and independenceonly if you have a battery bank
No noise
No operating emissions (air, water, soil)
Does not incur any new real estate or site development costs (if you mount it on a building)
#58
Exported electricity diagram
SellBuy kWh
1 kWh 1 kWh 1 kWh
PV system owner
Bi-directional kWh meter
Ordinary kWh meter
Electricity is delivered to your neighboursby your Electricity Delivery Company for their normal delivery fee.
Imported electricity
paid in full
Energy Retailer sells your exported energy to your neighbour for full retail price.
1
3
4
1 kWh supplied, 1 kWh paid for
kWh
©1995-2014
Where does exported electricity go?Energy Retailer, Electricity Delivery
Company
Electricity delivery wires
Neighbour
Exported electrical energy credit
Imported electricity paid in full
2
no PV system (yet)
#59
Understanding Electricity Bills:Energy vs. Power
0.3 0.4 0.3 0.4 0.40.5
1.1
1.4
0.70.5 0.5
1.0
0.5 0.5 0.5 0.5
1.5
3.0
1.2
0.8 0.8 0.70.5
0.3
0.75
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Avg
Time of Day [hour]
Pow
er [k
W] BUT they only get paid
for delivering this much electrical energy
Electric companies need to design and build their electricity generating, transmitting and delivery systems to generate and deliver this much electrical power… (plus a safety margin)
Area of brown bars = total energy= 18 kWh/day= 6600 kWh/year
#60
DERS + ATCO Electric Pricesfor an Acreage or House
Prices: charge for energy + charge for gridDERS E1 purchase: 7.78 ¢/kWh $109 /year (March 01)
ATCO D11 delivery: 10.52 ¢/kWh $517 /year (April 01)
Total charges: 18.30 ¢/kWh $627 /year
Bill for 7200 kWh/year: ¢/kWh x kWh/year = $ for energy + $ for grid
DERS E1 purchase: 7.78 x 7200 = $ 560 + $109 /yearATCO D11 delivery: 10.52 x 7200 = $ 757 + $517 /yearTotal charges: 18.30 x 7200 = $1318 + $627 /year
68% 32%--------------------------------------------------------------------------------------
Total bill = $1944 /year(appearance: $1944 / 7200 = 27 ¢/kWh, which is not correct)
GST included in all prices
#61
Time-based connection fee + energy-based feeEnergy fee = amount of electricity purchased and delivered + GSTFor a typical house, the potential savings are $1318 (68% of your bill).
}Amount of electricity used (kWh)
Electricity bill ($)
Annual connection fee ($627 per year, 32% of bill)
Actual price of electricity including purchase, delivery, taxes & GST (18.30 ¢/kWh)
Average household consumption
Average household electricity billAverage
household bill: $1944 per year
7200 kWh/year0$0
Energy fee $1318
Electricity bill = Grid-connection fee
} Connection fee $627
+ (Electricity consumption x electricity price)
Electricity Bill – House
#62
DERS + ATCO Electric Pricesfor a Farmhouse
Prices with 10 kVA transformer: charge for energy + charge for gridDERS E5 purchase (incl GST): 7.88 ¢/kWh $116 /year (March 01)
ATCO D56 delivery (all included): 1.52 ¢/kWh $1216 /year (April 01)
Total charges: 9.40 ¢/kWh $1332 /year
Bill for 7200 kWh/year: ¢/kWh x kWh/year = $ for energy + $ for grid
DERS E5 purchase: 7.88 x 7200 = $567 + $ 116 /yearATCO D56 delivery: 1.52 x 7200 = $110 + $1216 /yearTotal charges: 9.40 x 7200 = $677 + $1332 /year
34% 66%--------------------------------------------------------------------------------------
Total bill = $2009 /year(appearance: $2009 / 7200 = 28 ¢/kWh, which is not correct)
GST included in all prices
#63
Time-based connection fee + energy-based feeEnergy fee = amount of electricity purchased and delivered + GSTFor a typical farm, the potential savings are $677 (34% of your bill).
}
Amount of electricity used (kWh)
Electricity bill ($)
Annual connection fee ($1332 per year, 66% of bill)
Actual price of electricity including purchase, delivery, taxes & GST (9.4 ¢/kWh)
Average household consumption
Average household electricity billAverage
household bill: $2009 per year
7200 kWh/year0$0
Energy fee $677
Electricity bill = Grid-connection fee
Connection fee $1332
+ (Electricity consumption x electricity price)
Electricity Bill – Farm Rate
(D56)
#64
DERS + ATCO Electric Pricesfor a Farm (and its operations)
Prices with 7.5 kVA transformer: charge for energy + charge for gridDERS E5 purchase (incl GST): 7.88 ¢/kWh $116 /year (March 01)
ATCO D56 delivery (all included): 1.52 ¢/kWh $977 /year (April 01)
Total charges: 9.40 ¢/kWh $1093 /year
Bill for 25,000 kWh/year: ¢/kWh x kWh/year = $ for energy + $ for grid
DERS E5 purchase: 7.88 x 25,000 = $1970 + $ 116 /yearATCO D56 delivery: 1.52 x 25,000 = $ 380 + $ 977 /yearTotal charges: 9.40 x 25,000 = $2350 + $1093 /year
68% 32%--------------------------------------------------------------------------------------
Total bill = $3444 /year(appearance: $3444 / 25,000 = 13.8 ¢/kWh, which is not correct)
GST included in all prices
#65
Comparison: a house and farmusing 25,000 kWh/year
A house using 25,000 kWh per yearDERS E1 purchase: 7.78 x 25,000 = $1945 + $109 /yearATCO D11 delivery: 10.52 x 25,000 = $2630 + $517 /yearTotal charges: 18.30 x 25,000 = $4575 + $627 /year
88% 12%--------------------------------------------------------------------------------------
Total bill = $5202 /year
A farm using 25,000 kWh per yearDERS E5 purchase: 7.88 x 25,000 = $1970 + $ 116 /yearATCO D56 delivery: 1.52 x 25,000 = $ 380 + $ 977 /yearTotal charges: 9.40 x 25,000 = $2350 + $1093 /year
68% 32%--------------------------------------------------------------------------------------
Total bill = $3444 /year
#66
0.00.20.40.60.81.01.21.41.61.82.02.22.42.6
0 3 6 9 12 15 18 21 24Time of day
[hours]
Act
ive
Pow
er [k
W]
PV system generation
House electricity consumption
Avg
Avg
Exported energyValue: 7.9 ¢/kWh
PV energy used on siteValue: 7.9 + 1.5 = 9.4 ¢/kWh
Imported energyValue: 7.9 + 1.5 = 9.4 ¢/kWh
Imported energy Value: 7.9 + 1.5 = 9.4 ¢/kWh
Time of day [hours]
Consumption without PV: 18.6 kWh = $1.75Deficit electricity imported: 72% 13.3 kWh = $1.25PV used on site: 5.3 kWh = $0.50PV electricity exported: 30% 2.2 kWh = $0.17Total PV generation: 7.5 kWh = $0.67Savings (energy) ($): 40% 38%
Farm Export and Import Prices (¢/kWh)Actual measured PV and house
performance, 1997 February
#67
0.00.20.40.60.81.01.21.41.61.82.02.22.42.6
0 3 6 9 12 15 18 21 24Time of day
[hours]
Act
ive
Pow
er [k
W]
PV system generation
House electricity consumption
Avg
Avg
Exported energyValue: 7.8 ¢/kWh
PV energy used on siteValue: 7.8 + 10.5 = 18.3 ¢/kWh
Imported energyValue: 7.8 + 10.5 = 18.3 ¢/kWh
Imported energy Value: 7.8 + 10.5 = 18.3 ¢/kWh
Time of day [hours]
Consumption without PV: 18.6 kWh = $3.40Deficit electricity imported: 72% 13.3 kWh = $2.43PV used on site: 5.3 kWh = $0.97PV electricity exported: 30% 2.2 kWh = $0.17Total PV generation: 7.5 kWh = $1.14Savings (energy) ($): 40% 34%
Acreage Export and Import Prices (¢/kWh)Actual measured PV and house
performance, 1997 February
#68
What to look for with PV prices…
Modules (~30% of total system cost)Price divided by rated power: $/ WExample: 250 W PV module for $250 is $1 / WTypical range: $0.85 to $1.10 / W wholesale,
$1.00+ / W retailInverter
Example: 3000 W inverter for $1350 is $0.45 / WTypical range: $0.55 to $1.00 / W
Installation labourTypical range: $0.50 to $0.70 / W
Other costs: design, development, permits and approvals, racking, wiring, disconnects
Total grid-connected system, range: $2.80 to $4 /W
#69
How much solar PV do you need?(house)
1. Add up your electric energy consumption (kWh) in a year from your monthly bills
● e.g. 7200 kWh/year● cost is likely $1944 /year = 7200 x 18.3 ¢/kWh / 100 + $627
2. Divide by the PV system annual yield● e.g. 7200 kWh/year / 1200 kWh/year / kW
3. Gives you PV array capacity (kW)● e.g. 6 kW to generate the same amount of electric energy as
you use over the year
#70
4. Multiply by typical price of installed PV system● e.g. 6 kW x 1000 x $3 /W● $3 /W for typical installations (some installers can do it for a bit less)
5. Gives you the cost of your PV system to generate 100% of your annual electric energy
● e.g. = $18,000
6. Value of annual PV electrical energy = $790 (= 10.94 ¢/kWh x 7200 kWh)● (10.94 ¢/kWh is based on 70% energy exported,
7.78 ¢/kWh energy purchase price,10.52 ¢/kWh ATCO Electric delivery price)
● (you don’t have to generate 100%, you can easily generate any amount less than 100%)
How much solar PV do you need? (house)
#71
What are the economics of PV? (house)
7. Divide initial cost by 1st-year savings● e.g. $18,000 / $790 /year = 23 years
This is only a simple way to do an economic analysis. This is not the correct way to do an economic analyses…● Economic analyses need to include:
20-year analysis periodfinancing costsincrease in electricity pricesdiscount rate, consumer inflation ratesmall performance decrease from PV system (0.5% /year)replacement of inverter after 20+ years
#72
Price of solar PV electricity (house)
8. Divide initial cost by 23-year amount of electricity generated● For example:
$18,000 initial cost7200 kWh /year x 23 years = 165,600 kWhminus 5% for module aging = 157,000 kWh$18,000 / 157,000 = 11.4 ¢/kWh
fixed price for 23 years, then free electricity after that…
● Comparison: today’s price for grid electricity:Edmonton ~13 ¢/kWh (energy purchase + delivery)Fortis ~14 ¢/kWhATCO ~18 ¢/kWh
is rising at 4% to 10% per year
#73
Full economics analysis(house)
analysis period: 20 years for bank loanfinancing costs: 3% per yeardiscount rate: not considered because you are using
the bank’s money not your ownincrease in electricity prices: 4% per year (can range up to 10%)consumer inflation rate: 2% per yearPV performance decrease: 0.5% per yearinverter replacement life: 20 yearssystem insurance cost: $50 per year (0.3% of system cost)maintenance cost: $0 per yearportion of energy exported: 70% per year (reasonable estimate)price of PV electricity: 21 ¢/kWh over 20 yearsprice of grid electricity: 27 ¢/kWh over 20 years
#74
How much solar PV do you need?(farm)
1. Add up your electric energy consumption (kWh) in a year from your monthly bills
● e.g. 25,000 kWh/year● cost is likely $3444 /year = 25,000 x 9.40 ¢/kWh / 100 + $1093
2. Divide by the PV system annual yield● e.g. 25,000 kWh/year / 1200 kWh/year / kW
3. Gives you PV array capacity (kW)● e.g. 21 kW to generate the same amount of electric energy as
you use over the year● What is the size of your transformer’s breaker?
This is a limiting factor…
#75
4. Multiply by typical price of installed PV system● e.g. 21 kW x 1000 x $3 /W● $3 /W for typical installations (some installers can do it for a bit less)● could be down to $2.20 /W if you install it yourself
5. Gives you the cost of your PV system to generate 100% of your annual electric energy if you install it yourself
● e.g. = $46,000
6. Value of annual PV electrical energy = $2160 (= 8.65 ¢/kWh x 7200 kWh)● (8.65 ¢/kWh is based on 50% energy exported (???),
7.9 ¢/kWh energy purchase price,1.5 ¢/kWh ATCO Electric delivery price)
● (you don’t have to generate 100%, you can easily generate any amount less than 100%)
How much solar PV do you need? (farm)
#76
What are the economics of PV? (farm)
7. Divide initial cost by 1st-year savings● e.g. $46,000 / $2160 /year = 21 years
This is only a simple way to do an economic analysis. This is not the correct way to do an economic analyses…● Economic analyses need to include:
20-year analysis periodfinancing costsincrease in electricity pricesdiscount rate, consumer inflation ratesmall performance decrease from PV system (0.5% /year)replacement of inverter after 20+ yearsAccelerated Capital Cost Allowance (50% per year)
#77
Price of solar PV electricity (farm)
8. Divide initial cost by 21-year amount of electricity generated● For example:
$46,000 initial cost25,000 kWh /year x 21 years = 525,000 kWhminus 5% for module aging = 500,000 kWh$46,000 / 500,000 = 9.2 ¢/kWh
fixed price for 21 years, then free electricity after that…
● In comparison: today’s price for grid electricity:Fortis (not calculated yet)ATCO ~9.4 ¢/kWh
is rising at 4% to 10% per year
#78
Full economics analysis(farm)
analysis period: 20 yearsfinancing costs: 3% per yeardiscount rate: not considered because you are using
the bank’s money not your ownAccelerated CCA: 50% per year capital cost allowancemarginal tax rate: 18% (wild guess)increase in electricity prices: 4% per year (can range up to 10%)consumer inflation rate: 2% per yearPV performance decrease: 0.5% per yearinverter replacement life: 20 yearssystem insurance cost: $130 per year (0.3% of system cost)maintenance cost: $0 per yearportion of energy exported: 50% per year (wild guess)price of PV electricity: 11.8 ¢/kWh over 20 yearsprice of grid electricity: 14.0 ¢/kWh over 20 years
#79
Farm near Villeneuve
46 PV modules, 240 W each11 kW$4 /W = $44,000
Solar project designed and installed by: Great Canadian Solar, Edmonton
#80
Farm near Lacombe
24 PV modules5.8 kW$4 /W = $23,000
Solar project designed and installed by: Great Canadian Solar, Edmonton
#81
Farm near Consort
44 PV modules of 240 W each10.6 kW$3.80 /W = $40,000
Solar project designed and installed by: Great Canadian Solar, Edmonton
#82
Farm near Lamont
27 PV modules of 240 W6.5 kW$4 /W = $26,000
Solar project designed and installed by: Great Canadian Solar, Edmonton
#83
Acreage near Okotoks
67 PV modules of 200 W each13.4 kW
Solar PV system installed by homeowner
#84
How many PV systems are there?
Off-grid:Thousands of tiny 2- to 4-module off-grid systems throughout oil and gas fields
Grid-connected:177 in Edmonton (2013 October), increase by ~115 over the last 2 years
780+ in Alberta (2013 October)
30,000 (equivalent) in Canada (???)
11 million (equivalent) around the world… (???)
1000 kW5000 solar PV
modulesNapa Valley
California
#85
Geiseltalsee SolarparkGermany 4000 kW. 25,000 PV modules
Solar PV Farms
Solar prospectors look for rentable farm land
Typically: 6 acres / MW
#86
Caveat…
Solar PV is technical subject and a high-voltage electrical system. Safety and proper design are critical.
There are many factors to be considered in its design, grid-connection approvals and economic calculations.
Be aware of hearsay, products that are not used widely, and wild performance claims.
Do your research well.
Hire someone who knows what they are doing, with qualifications, references, and proven experience.
#87
The dawn of a new era…
……we allwe allcan be part of it
Anyone who thinks they are too small to make a difference… Africanhas never spent the night with a mosquito. Proverb
Solar Electricity
#88
Solar PV ElectricitySolar PV ElectricitySimple Simple –– Clean Clean –– Reliable Reliable –– AffordableAffordable
Local Local …… UnsubsidisedUnsubsidised ... Democratic ... Democratic …… NowNow
Gordon Howell, P.Eng.Howell-Mayhew Engineering
EdmontonPhone: +1 780 484 0476
E-mail: [email protected]©1995-2014Photo credits: Gordon Howell and several others
Other PV presentations are
available atwww.hme.ca
/presentations
We welcome any feedback, questions, suggestions, comments and challenges to anything we present.