Solar PV Excel 2020.Pptx

6/3/20

PV Excel – Designer & Installer

2 Day solar PV Excel Course for Designers and Installers of PV systems PQRS Presented by Carel Ballack +27 82 322 2601 [email protected]

General Welcome • Course rules – Please switch oﬀ cell-phones – In case of emergencies, please make and take calls outside • Tea at more or less 10:30 & 15:00 – 15 minutes each • Lunch around 12:00-12:30 – 30 minutes • FaciliVes – Bathrooms

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Content Disclaimer & Feedback • Electricity is dangerous. • The purpose of this training course is to promote the use of solar, for both electrical & plumbing solar technologies. • The instructors cannot be held liable for informaVon presented; or the way in which informaVon has been interpreted through this; or any other training, markeVng or media plaZorm. Please read product instrucVons and comply to manufacturer recommendaVons • Your feedback is important • Please complete the feedback form. • We trust that you will enjoy the course

IntroducVon - Presenter • Presenter: Carel Ballack – Electrician – Plumbing and gas. – Former Ombudsman for SESSA – Tenders, Project management, Electrical infrastructure, Repairs and maintenance. – Consultant – Training & development for energy sector

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IntroducVon PQRS Reports

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IntroducVon PQRS - Network OrganisaVons InsVtuVons and associaVons • Rubicon, ACDC, Ellies • Green Cape • Allelec, Yingli • Western Cape Government • TIA - Test Instruments Africa • Mangosuthu University of Tech. • ABB, PLP, Dixon • Copper Development • Schneider, Enel, Greensun Association • Mustek • SAAEA • Tesla • SAPVIA • AREP

Supplementary free informaVon

• Leonardo Energy - free online training for engineers (advanced) hgp://www.leonardo-energy.org • Assess and determine available solar irradiaVon at a speciﬁc venue hgps://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#PVP • For free training on energy eﬃciency: Easy to Moderate to Advanced hgps://www.schneideruniversiVes.com/ • Free Book - Unlimited Energy – Describes how bageries work hgp://www.victronenergy.com/upload/documents/Book-Energy-Unlimited-EN.pdf • Free Maths & Science Mastery - Training PlaZorm hgps://www.khanacademy.org/ • Calculate solar systems viability hgp://www.retscreen.net

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PV Project Stages & Business OpportuniVes

Development • Identify Funding model • Consider system size • Consider system Type • Oversee municipal requirements • Essentially – project sales & support.

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O & M (OperaVons and Maintenance)

1. Operations 1. Monitoring 30

0 4:50 AM 4:50 AM 5:10 AM 5:30 AM 5:50 AM 6:10 AM 6:30 AM 6:50 AM 7:10 AM 7:30 AM 7:50 AM 8:10 AM 8:30 AM 8:50 AM 9:10 AM 9:30 AM 9:50 1:10PM 1:30PM 1:50PM 2:10PM 2:30PM 2:50PM 3:10PM 3:30PM 3:50PM 4:10PM 4:30PM 4:50PM 5:10PM 5:30PM 5:50PM 6:10PM 11:10 AM 11:10 AM 11:30 AM 11:50 10:10 AM 10:10 AM 10:30 AM 10:50 12:10PM 12:30PM 12:50PM

Current DC (Inverter 1) [A] Current DC (Inverter 2) [A] Current DC (Inverter 3) [A] Current DC (Inverter 4) [A] Current DC (Inverter 5) [A]

O & M (OperaVons and Maintenance) 1. Maintenance 1. Cleaning modules & inverters 2. Checking modules for visible defects 3. Check mounting structures for loose bolts and bi- metallic corrosion 4. Check cables & terminations for wear and tear and hot spots 5. Checking modules for hot spots & non-visible defects 6. Finding faults – See next slides

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O & M (OperaVons and Maintenance)

1. Finding faults 1. Ultra violet light – only works after hours

O & M (OperaVons and Maintenance)

1. Finding faults 1. Infra red cameras – only works when system works

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O & M (OperaVons and Maintenance)

1. Finding faults 1. IV Curve Tests – Expensive testers but thorough

Technology selecVon • Choosing the right technology for the applicaVon – Solar water heaVng vs solar PV – SWH systems are also referred to as Solar Thermal Systems – Solar PV - Solar Photovoltaic

Solar Thermal Eﬃciency 400 - 700w/m2 Available IrradiaVon 2 1000w/m Solar PV Eﬃciency 130 - 180w/m2

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Solar Water HeaVng vs Solar PV

Standard Bank Braamfontein Hybrid 200m2 solar water heaVng system

Energy Eﬃciency 18

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MTN Head Oﬃce Roodepoort 180℃1200kPa 330kW solar cooling system

Energy Eﬃciency 19

University of Pta 52 000 Liter 848m2 Solar water heaVng system

Energy Eﬃciency 20

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BMW Rosslyn 90℃ 200m2 Solar water heaVng system

Energy Eﬃciency 21

Exstrata Elands mine 60 000 Liter 320m2 Solar water heaVng system

hgp://www.blackdotenergy.co.za

Energy Eﬃciency 22

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Photos of faulty installaVons

Only 4% of all issues can be prevented by simply “reading the instrucVons”, a further 95% can be prevented by understanding the instrucVons Pr

How not to install a PV system

•No earth leakage •Bagery stored in ceiling +50’C •No earthing •Incorrect cable terminaVon •Wire sizing?

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How not to install a PV system

• We can see: – Shade to the leu of the panel – Standard twin & earth used – Top leu cable going through the roof material

How not to install a PV system

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How not to install a PV system

• Wood as a mounVng structure(EVA - EC) • Overlap & overhang(MP)

Solar Panels can burn

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Fivng modules

• Not Vght enough. Hoop Iron used to support Modules

• Spacing of mounVng structure

Electrical safety and maintenance • Copper pipe used as lugs • O & M • Photo taken in the Eastern • Cleaning and access? Cape

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Solar Borehole with shading

Submersible cable

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2kWp system Somerset West

Module mismatch in string inverter Module sizing should be equal. Performance severely aﬀected

O&M DomesVc environment do not buy into maintenance agreements, sell remote monitoring device in •Growing culture in SA to use opVmizers in order to monitor order to compensate for shading, hence performance shading is deemed to be “acceptable”. periodically

12kWp System Kyalami

• MC4 couplers were cut and ferruled in order to parallel modules – Not recommended as this may negate module warrantees. – May aﬀect • O&M, tesVng & product durability

Good PV PracVce Electrical InstallaVon suggests 1-3% (volt drop) Standard accepts 5%

SANS 10142-1 6.2.5.2 Once current-carrying capacity has been determined and correction factors had been considered, carry out voltage drop calculations to determine voltage drop which should be within the allowed 5 %. (very inefficient for PV systems)

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30kWp system Franschoek UnintenVonal shading Lack of knowledge

Module life possibly aﬀected by long term overheaVng of cells due to shading O&M Apart from design, this secVon of the installaVon can’t be inspected or maintained with ease, consider leaving space to move between modules. No spacing between modules makes visual inspecVon diﬃcult

Row spacing inadequate, 12 x 300W modules producing 400W

250kWp system JHB IntenVonal shading

The engineer involved in this project combined the same modules aﬀected by shade into the same string

Although deemed good from a design point of view. Could aﬀect long term life & performance of cells / modules O&M Neighboring construcVon site resulted in dust deposits which required regular cleaning. Increase frequency of visual All shaded modules are part inspecVon to ensure opVmum of the same string performance

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500kWp system in Fourways Ongoing maintenance

•No space for cleaning modules •DB Board cb’s overheated & tripped conVnuously •Inverters overheated •Conductors from panels to inverter overheated 230m 6mm2

Program & Content Flow Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect

Oﬀ-Grid BaHeries

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TradiVonal ConnecVon

Normal Eskom InstallaVon

“Grid-Tied” Solar system

Small Scale Embedded Generator

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Oﬀ-Grid Solar System

No connecVon to Eskom Grid

Hybrid System

CombinaVon of both

Huge Grey Area

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Have you heard of: • The latest panels that can generate power at night? – Uhm . . . . • Water bageries – Uhm . . . . • The best solar system

C-Si AbsorpVon

• hgp://www.slideshare.net/Ennaoui/rd-roadmap-ennaoui

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How do I ﬁnd. . . • The best inverter – Service, applicaVon, spares, technical support • The best solar Modules – 3rd party test results vs “Tier 1” • The best bageries – Datasheets • Latest Technology – Breathe, relax, breathe some more. • Contractors – www.arepenergy.co.za, FREE P4 Solar Test

QuotaVons • Find the detail – In system calculaVon – Paperwork / invoices / Quotes – Get references – Do Research – Visit other sites • Phone a friend • Phone another friend – It’s only R100k – R200k and auer all; you can aﬀord it.

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“no worries, no-one can see my roof”

Solar PV Solar Geysers

IrradiaVon Irradia5on PV technologies

Cable calc. Volt drop Series and parallel config Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect Pr Safety & Cos5ng BaHeries Energy Efficiency Off-Grid 48

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InsolaVon vs irradiance

• (Photovoltaic) • PV Power varies based on available insolaVon. • This variaVon could be effected by changes in the atmosphere, weather pagerns and seasonal changes. • InsolaVon is defined as the amount of radiaVon striking the earth • Note the difference in the terms – Irradiance : Intensity of Solar energy kW/m2 – InsolaVon : QuanVty of Solar energy kWh/m2

The solar constant 1367W/m2 – World RadiaVon Centre

ReﬂecVon, DeﬂecVon & AbsorpVon

Reference: Duﬃe Beckman 1991 50

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Sun hours calculaVon • Peak Sun Hours are used to calculate power generaVon of PV modules • Peak Sun Hours can be calculated by dividing annual sun hours by the number of days per year. • e.g. 2000kWhrs/m2 divided by 365 = 5,47kWh/m2 • 5,47kWh/m2/day or 5470Wh/m2/ day •

CalculaVon tools for design conﬁrmaVon

• PVSol • PV Syst • Helioscope

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Link to GRS Solar Tool • hgps://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#PVP • GHI - Global horizontal irradiaVon is used for PV applicaVons • DNI - Direct Normal irradiaVon ﬁgures are used for solar Thermal applicaVons • hgps://www.suncalc.org/ #/-30.8331,24.3049,2.5266666666666775/2019.07.30/14 :30/1/3

Global Horizontal Irradiance (GHI) is the total amount of shortwave radiation received from above by a surface horizontal to the ground. This value is of particular interest to photovoltaic installations and includes both Direct Normal Irradiance (DNI) and Diffuse Horizontal Irradiance (DIF).

Incline

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Trackers • Single axis trackers • Implemented in SA • Shows approx. 30% improvement on yield

• Maintenance Centurion Solar should be considered in feasibility criteria

Sishen 75MW 55

Summer and winter solsVce

63o 43o 33o

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Impact of incline on yield 10 33 8 33

6 53 53 4

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Impact of incline on yield - JHB

9 33oCPT 7 33oJHB 5

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 23 33 43 58

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InsolaVon energy (Bfn 30o) hgp://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php?map=africa

8000

6000

4000

Watts per day per Watts 2000

0 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Due North West & East South Due North 60’ Tilt

Summary - Impact of orientaVon

• 1000W/m2 is used as the reference value and global average. • Solar IrradiaVon varies according to E

region and season. W N

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AC & DC • AC IS NOT COMPATIBLE WITH DC • The frequency of AC in SA is around 50Hz meaning there are 50 ‘waves’ or cycles per second

• To Convert – AC to DC we use a RecVﬁer – DC to AC we use an Inverter • Inverters invert DC to AC. By deﬁniVon Inverters cannot charge ba/eries 61

Harmonics • Both inverters and recVﬁers are sources of Harmonics • Harmonics are caused by non-linear loads • Pre-1970 all loads were linear as they were mostly resisVve • The fundamental, is deﬁned as the lowest frequency of a periodic waveform

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AC & DC • Only some inverters can synchronise to a reference, i.e Grid Ved inverters that feed power back to the grid • MulVple sources of AC need to be synchronised, i.e. Voltage + Frequency + Phase angle

With DC no synchronisaVon is required. 63

Power and Energy • DisVncVon between power and energy is important – When sizing systems • Energy requirement is used to size the bageries or storage devices • Power requirement is used to size the inverter • Understanding the diﬀerence gives the consumer conﬁdence in the knowledge of the sales and installaVon teams

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Power and energy • Solar Modules are rated in Power Capacity

• Loads are rated in Power Capacity

• Li-ion Bageries generally rated in Energy Capacity

• Lead Acid bageries – Energy capacity must be calculated

Power and energy - ConsumpVon

• Example: Let’s take 12 LED downlighters from the previous slide as the load • Each downlighter consumes 23W • 12 x 23W = 276W

• Energy = Power x Time • Energy = 276W x Time • Energy = 276W x 8hrs = 2208Wh or 2,2kWh

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Power and energy - GeneraVon • As per the data sheets - Page B2 – ‘60 cell module’ • Energy = Power x Vme = 260W x 5,5hrs = 1430Wh

• Modules for a site is selected based on: – Roof size – Module orientaVon – Stock availability – Price – Ease of on-site operaVon

Power and energy - Storage

• Power can be calculated by multiplying Volts with Amps • W = Volts x Amps • Energy = Power x time or Wh = W x hrs • Energy = (Volts x Amps) x hr

• When the energy in a Lead Acid battery is calculated the Amp-hour rating of the battery is multiplied by the nominal Voltage • Lead Acid Battery: Energy = Ah x V • 100Ah x 12V = 1200Wh

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ConsumpVon – Storage - GeneraVon

• Energy = Power x time = 260W x 5,5hrs = 1430Wh

• Energy = 276W x 8hrs = 2208Wh or 2,2kWh

• Energy = Ah x V = 100Ah x 12V = 1200Wh

Basic Terminology • What is Volt? – Voltage can be explained as being electrical pressure • What is Amp? – The movement of current is measured in Amps • Nominal voltage • What is Series? See next slide • What is Parallel? See next slide

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Series conﬁguraVon • Voltage increases and the current stays the same

Series ConﬁguraVon • When connecVng in series the voltage is mulVplied by the number of panels to get to the system voltage. • The inverter or charge controller needs to be able to operate in the system voltage temp ranges

Modules in Series Voc Ave. Per cell Module Voc -15℃ 80℃

36 Cell X 8 Modules 0,6 21,6 193 144

54 Cell X 8 Modules 0,6 32,4 290 216

60 Cell X 8 Modules 0,6 36 322 240

72 Cell X 8 Modules 0,6 43,2 387 288 Values are es5mated and have been calculated using a temp co-eﬀ. of 0,30%/℃

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Parallel conﬁguraVon • Current increases and the voltage stays the same

Parallel ConﬁguraVon

• Using Branch connectors • Same power being produced as previous slide • Lower Voltage • Current X 2 of a single string

Modules in Series Voc Ave. Per cell Module Voc -15℃ 80℃ 36 Cell X 4 Modules 0,6 21,6 96 72 54 Cell X 4 Modules 0,6 32,4 145 108 60 Cell X 4 Modules 0,6 36 161 120 72 Cell X 4 Modules 0,6 43,2 193 144

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Parallel ConﬁguraVon • Using a combiner box • Same power being produced as previous slide • Oﬀers the advantage of • individual string disconnecVon • Housing for SPD’s

To Inverter

Ohm’s Law • Ohm's Law is a formula or range of formulas used to calculate the relaVonship between voltage, current and resistance in an electrical circuit.

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Power triangle • The power Triangle is a range of formulas clarifying the diﬀerence between Power, Current and Voltage

System sizing when storage is included

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How bageries charge • Batteries charge with current • The current changes the internal resistance of the battery • The result is an increase in voltage

PV Technology Irradia5on PV technologies

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PV History

1839 - Edmund Becquerel discovers the photovoltaic effect 1883 - Charles Fritz creates first solar cell (gold coated selenium) 1953 - Bell labs create Solar Cells that are 6% efficient 1958 - Solar energy is used in space 1982 - First 1MW plant is built in California 1994 - NREL creates 30% efficient Gallium Indium phosphate 2015 - 5% eff. Flexible Solar cells are printed using a printer

Costs of PV over Vme

1MW CosVng around R13/w Oct 2016 Freight 0,01 Proﬁt Margin 0,02 Cell 0,20 BoM, EVA 0,12 $0,38(US) Manufacturing & Assembly 0,04 Total 0,39 2016

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Basic Electrical Principles Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect

Oﬀ-Grid BaHeries

Diﬀerent PV technologies

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NREL PV Performance over Vme

General PV Module Eﬃciency Cell Material Lab Actual Concentrated pv (Sharp May 2014) 47% -

Mono-crystalline silicon (Panasonic Feb 2014) 24.7% 18%

Poly-crystalline silicon 20.4% 17% CdTe (Cadmium-Tellurid as at July 2015) 21.5% 16%

CIGS (Copper Indium Gallium di Selenide July 2014) 18.3% 13%

Amorphous Silicon (a-Si August 2014) 12% 10%

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Crystalline Silicon Cells

Mono-crystalline

Poly-crystalline

Solar Cells • Cells are approximately 0,2mm thick

Do not stand on modules!!

Grid ﬁngers

Busbars/ Ribbons

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Series cell conﬁguraVon • Ribbons or busbars are soldered onto the face of one cell.

• And then joined onto the back of the next cell

• One side of the cell has one polarity and the other side has the opposing polarity

16W Module - Cell conﬁguraVon

Grid ﬁngers

Busbars/ Ribbons

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Solar Cells conﬁguraVon • 36 Cells - TradiVonally called 12 Volt modules • 54 Cells • 60 Cells • 72 Cells - TradiVonally called 24 Volt Modules

Module ConstrucVon • Some modules consist of 5 layers • Globally most module manufacturers use 3.2mm tempered low-iron glass • Hydrofobic & Hydrophilic coaVng • AnV-reﬂecVve coaVngs • AnV-dust / water • Nano CoaVngs

• Hail tesVng done with 25mm hailstones at approx. 80km/h

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Thin-film - CIGS & CdTe • CIGS – Solar FronVer moved out of SA in 2016 • CdTe – First Solar Barloworld • Material and workmanship warranty for ten (10) years and a power output warranty of 90% of the nominal output power raVng (PMPP+/- 5%) during the first ten (10) years and 80% during twenty-five (25) years subject to the warranty terms and condiVons.

Cell, Module, String, Array • Cell, module, string, array 1 x Cell

1 x Module

1 x String

1 x Array

Image is an example only Induced Voltages – Do not connect this way

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PV Cell Electrical parameters • Current changes along with cell size • 100 x 100 cell = approximately 4.5Amp • 150 x 150 cell = approximately 8.7Amp • Voltage of cells remain more or less the same at

• 0.5Voc(open circuit) to 0.7Voc(open circuit) • Under varying temperature condiVons

PV Cell Electrical parameters

• Calculate the voltage of the string of cells above? • If the cells were 100 x 100, what would the Current be that can be produced?

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Main PV technologies Thin-Film

Silicon wafers Major Issues (Mono & Poly) Major Issues Micro Cracks (snail trails) (CIGS) DelaminaVon DelaminaVon

Thermal images: courtesy Sinani Energy 97

Understanding the Data Sheet

• Power output tolerances • Cells vary in performance. SorVng limits relate to possible variances in panel performance

• ISC – The short-circuit current is the maximum current through the solar cell (i.e., when the solar cell is short circuited). • Voc – Open-circuit voltage is the diﬀerence of electrical potenVal between two terminals of a device when disconnected from any circuit. – There is no external load connected. – No external electric current ﬂows between the terminals.

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All values in speciﬁcaVons are at STC & NOCT

• STC corresponds to: NOCT is the temperature • 1000W/m2 reached by open circuit cells in a • At 25°C cell temperature, module under the conditions as listed below: • with an Air Mass 1.5 (AM1.5), • Open back mounted module • At a 45° Vlt angle from the horizontal • as deﬁned in IEC 60904-3 • Total irradiance of 800 W/m2 and • 20°C ambient temperature where a • 1 m/s wind speed is available • on a panel in an open circuit condiVon

Air Mass • One and a half Vmes the spectral absorbance of the Earth’s atmosphere. It refers to the amount of light that has to pass through Earth’s atmosphere before it can hit Earth’s surface, and has to do mostly with the angle of the sun relaVve to a reference point on the earth.

evaluaVng spectrally selecVve • Modules used in space are PV materials with respect to tested against AM=0 as the performance measured under atmosphere is not a factor in varying natural and arVﬁcial space. sources of light with various spectral distribuVons. 100

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PV Panel DegradaVon

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Electron Flow

• Benjamin Franklin – Glass & Silk Experiment – Kite experiment • Electrons – Charged ‘negaVve’ – Move from areas of abundance to areas of depleVon • The same principles can be seen in solar modules

102

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Current ﬂow in a cell - video

103

By-Pass diodes in panels No Visible Diodes

Polarity: PosiVve is always on the right and negaVve always on the leu in crystalline modules

104

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How to overcome the eﬀect of shading • Most good quality panels are factory ﬁged with Diodes. • A diode can be explained as a one way valve for current. • These diodes are referred to as bypass diodes • Bypass diodes do not have an impact in reverse current

Typical bypass diode wiring conﬁguraVon

Centre pin connected to posiVve Long pins connected to negaVve

105

Spacing of rows - rule of thumb

• Rule of thumb for panel installaVon in CT, EL & PE= 1,9 X height • Rule of thumb for panel installaVon in DBN & BFN = 1,8 X height • Rule of thumb for panel installaVon in JHB = 1,6 X height

106

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IV Curves explained • IV characterisVcs show the current and voltage generated across the terminals of a module. • With a variable resistor connected between the terminals, the operaVng point can be determined from the resulVng IV characterisVcs. • When R is small the module is a constant current source • When R = 0, Isc condiVons result. At Isc, voltage is 0 • When R is large (approaching inﬁnity, modules behave as a voltage source creaVng the max Voc. At Voc current is 0

107

Eﬀect of temp. on PV panels

108

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Hot vs Cold days - String Voltage 700 650 600 Max 660V 550 500 450 400 Min 460V 350 300 15 Jun 2015: Coldest 250 winters day. 200 5 Jan 2016: Heat 150 wave in summer. 100 50 0

20 modules in a string - 4 strings / mppt - 3 mppt’s per inverter

109

Temp co-eﬃcient calculaVons • ObjecVve: Calculate the module’s summer and winter voltages • Summer Voltage is the lowest possible voltage at the highest temperature • Winter Voltage is the highest possible voltage at the lowest temperature

Module Voltages are High

Module Voltages are Low

Winter Summer

Temperatures are low Temperatures are high

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Temperature co-efficient calcs • -0,45%/℃ 260W 60 cell Maximum Voltage (VDC-max) • Eff of temp = 30,9Vmp x 0,45%/℃ = Vmp Max_STC (Solar PV) x 1.15 • = 0,139V =Vmp Min_STC*0.75 Add co-efficient 36Vmp 30,9Vmp Deduct co-efficient

23Vmp

-15℃ 0℃ 5℃ 25℃ 46℃ ±2 60+℃ 70℃ 80℃ Molteno NC PE & CT EL STC NOCT CT GP NC Actual Cell Temperature - Values based on resident survey

111

Sunny vs rainy days 62,500 8th January 2016 5th January 2016 4th May 2015 Clear Summer : 50,000 Produced 386kWh Cloudy Summer : for the day. Produced 316kWh for the day. 37,500

25,000

Clear Winter : 12,500 Produced 248kWh for the day.

112

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Eﬀect of Light intensity on current and voltage

113

Min & Max Current - Edge of cloud eﬀect

A maximum value of 1195W/m2 was observed on 31/7/2015(PE) 114

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Standards Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect

Pr Safety & Cos5ng BaHeries Energy Eﬃciency Oﬀ-Grid 115

Consumer point of supply

116

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Dedicated Feeder NRS 097

< 75%

117

Shared Feeder NRS 097 • Maximum PV System sizes • LSM > 7 < 75% • < 50 % conversion to PV • Shared liability

< 25% < 25%

118

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Typical demand curve for residenVal installaVon

Evening Peak Demand

Morning Peak Demand

PV Power generaVon vs convenience

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Inverter / system size selecVon

Typical demand curve for oﬃce block installaVon

Mid day Peak Demand

PV Power generaVon

120

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Solar PV Service Technician(Separate Trade)

1. Occupational Tasks

2. Planning and preparing for maintaining, testing, diagnosing, repairing and replacing PV system electrical and mechanical components (Level 4)

3. Inspecting, testing, diagnosing, replacing and maintaining PV panels (Level 5)

4. Inspecting, testing, diagnosing, replacing, repairing and maintaining inverters in PV systems (Level 5)

5. Inspecting, testing, diagnosing, replacing and maintaining batteries and charge controllers and repairing charge controllers in PV systems (NQF Level 5)

6. Inspecting, testing, diagnosing, replacing, repairing and maintaining transformers in PV systems (Level 5)

7. Inspecting, testing, diagnosing, replacing and maintaining cables, cable inter-connections, smart boxes, PV junction/string boxes, string diodes, connectors and fuses in PV systems (Level 5)

8. Inspecting, testing, diagnosing, replacing, repairing and maintaining switchgear and control gear in PV systems (Level 5)

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How do i qualify as an electrician

• Inﬂux of diverse range of occupaVons in energy sector – Many not skilled in electrical trade – RPL vs standard apprenVceship route – 4 years experience with >N2 Electrical – 6 years experience with no academic electrical background – Merseta, Ceta, EWseta – Same cerVﬁcate & Red Seal – Register with D.o.L – = single phase tester – Electrical trade = N4 – Unlocks more opportuniVes, i.e. N4 electrical academic online

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Legal, Standards & Regulatory Framework • Commissioning report – Installer tested system and it was working – Line diagram • Should accompany design but could become as-built – Standard operaVng procedure • Manuals and documents – Maintenance Procedure • Improve overall performance (up-sale SLA) – Lock out or disconnecVon procedure • What happens when the system – Stops working – Needs to be maintained – Electrical C.o.C

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Compulsory Standards related to solar

▪ LOA’s are required by all manufacturers and importers of commodities that fall under the scope of the compulsory specifications prior, to the sale of the product. • NaVonal Regulator for Compulsory Standards – Leger Of Authority • SANS IEC 61010 - Safety requirements for electrical equipment for measurement,control and laboratory use • SANS IEC 61558 - Safety requirements for power transformers, power supplies,reactors and similar products • VC8075 - Compulsory SpeciﬁcaVon for the Safety of Electric Cables with Extruded Solid Dielectric InsulaVon for Fixed InstallaVons (300/500V to 1900/3300V) • VC8077 - Compulsory SpeciﬁcaVon for the Safety of Medium-Voltage Electrical Cables.

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Solar standards developed by UVliVes ECB & ECA Eskom AMEU 277 177 NRS

SANS

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Labelling - NRS 097-2-1:2017 • 4.2.7 Labelling • 4.2.7.1 A label on the distribuVon board of the premises where the embedded generator is • connected, shall state: “ON-SITE EMBEDDED GENERATION (EG) CONNECTED. THE EG IS • FITTED WITH AN AUTOMATIC DISCONNECTION SWITCH WHICH DISCONNECTS THE EG IN • THE CASE OF UTILITY NETWORK DE-ENERGIZATION.” • 4.2.7.2 The label shall be permanent, coloured red, and with white legering of height at least 8 mm.

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Harmonics - NRS 097-2-1:2010 • 4.1.6.4 Total harmonic current distorVon shall be less than 5 % at rated generator output in accordance with IEC 61727. Each individual harmonic shall be limited to the percentages listed in table 1.

Current distorVon limit as a funcVon of harmonics (Source: IEC 61727:2004) 1 2 Odd harmonics DistorVon limit 3rd through 9th Less than 4,0 % 11th through 15th Less than 2,0 % 17th through 21st Less than 1,5 % 23rd through 33rd Less than 0,6 % Even harmonics DistorVon limit 2nd through 8th Less than 1,0 % 10th through 32nd Less than 0,5 %

127

UVlity compaVbility – NRS 097-2-1:2017 • 4.1.1.6 The maximum size of the embedded generator is limited to the raVng of the supply point on the premises. • 4.1.1.7 Embedded generators larger than 13,8 kVA shall be balanced three-phase type. • A customer with a mulVphase connecVon shall split the embedded generator over all phases if the EG is larger than 6 kW.

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SynchronisaVon - NRS 097-2-1:2010 • 4.1.8.2 AutomaVc synchronizaVon equipment shall be the only method of synchronizaVon. • 4.1.8.3 The limits for the synchronizing parameters for each phase are • a) frequency difference: 0,3 Hz, • b) voltage difference: 5 % = 11,5 V per phase, and • c) phase angle difference: 20°.

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NRS Standards applied

• hgp://resource.capetown.gov.za/documentcentre/Documents/Forms,%20noVces, %20tariﬀs%20and%20lists/Approved%20Photovoltaic%20(PV)%20Inverter %20List.pdf

• Product: KLNE • Model: Solartec D15000 • Test House: TUV Rheinland • Requirement: RCD Type B required on the supply side

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Solar standards developed by Industry

ECB & ECA Technical SABS Eskom Commigee Industry associaVons

ECB & ECA Working Eskom Group Industry associaVons Specialist Reps.

131

Standards issued or being developed • SANS 60364-7-712 (Fuse and cable sizing) • SANS 61215 PV Module standard • SANS 62040 UPS systems • IEC 62930 Electric cables for photovoltaic systems (Feb 2018) • Local standard development – Same colour cable on DC – TesVng procedure on PV – AddiVonal DB – Surge protecVon before and auer – Level of electrician to sign-oﬀ bagery installaVons • Hazardous locaVons

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Bageries Irradia5on PV technologies

C-RaVng of bageries • Both Lead-acid and Li-ion Bageries have C raVngs • “C” indicates 3 important criteria. – Energy Capacity – Charge rate – Discharge rate

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Bagery Capacity

• Capacity of the bagery provides the storage capacity of a bagery, e.g. 100Ah

• Bageries are usually marked as C10, C5, C2, C1 or C0.5. The subscripts 10, 5, 2, 1 or 0.5 gives the charge/discharge rate

• If we have a bagery denoted by C10, having a capacity of 40 Ahr, then (40/10) = 4 Amps of current can be drawn from such a bagery for 10 hours.

135

Cost of energy equaVon - Life cycle cost Bagery Price Cost of Energy = ______(Energy(Ah*V) x DoD x #Cycles x Round trip eﬃciency) R1200 Cost of Energy (SMF) = ______(1,2kWh x 50% x 120 x 90%)

Cost of Energy (SMF) = R18,52/kWh

• Energy = Power x Time • Power = Volt x Current

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D.o.D & RTE • D.O.D • R.T.E – Depth Of Discharge – Round Trip Eﬃciency

Four main storage technologies • Flow bageries • Li-ion bageries • Lead acid bageries • Super capacitors

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Redox Vanadium Flow

Performance not aﬀected by temperature Can be drained 100% over full service life Life unlimited or 10 years Charge Voltage 54VDC System weight 1800kg - 3000kg 5 year standard warranty WxDxH 2.20 x 1.22 x 2.15 m 2,7m2 139 hgp://www.cesa.org/webinars/showevent/ﬂow-bagery-basics-part-1-what-they-are-how-they-work-where-they-re-used?d=2014-06-19

Li-ion Chemistries

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Li-ion bagery layouts

Li-Fe Bagery technology

• Lithium Iron Phosphate • No signiﬁcant heaVng during charging and discharging process. • Larger bagery architecture.

• Lithium Iron NMC (Nickel Manganese Cobalt) Tesla • Signiﬁcant heaVng – Tesla - Water cooled system • approx. 880 small bageries to create 48V packs stepped up to 400V(DC-DC Converter) • 6,4kWh per day at a max of 3,3kW peak.(18MWh) • Full closed loop recycling by 2020

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Lead Acid Family • Lead acid bageries are not an exact science – The energy storage and draw-oﬀ is as a result of a chemical reacVon subjected to external factors

Lead Acid

VLA (Vented Lead-Acid) VRLA (Valve Regulated) Flooded (Non Spillable)

Absorbed Glass Standard Maintenance Free Gel Mat (AGM) Lead Antimony Lead Calcium Lead Calcium Lead Calcium Higher level of gassing Calcium = Lower level of gassing & self discharge Requires higher charge **Tip -Compare voltage weight 143

Lead Acid ConstrucVon

• Bageries have posiVve and negaVve plates separated from one another to prevent short Deep cycle posiVve plate circuit condiVons. – Standard lead acid (car bagery) • 2,2mm posiVve & • 1,4mm negaVve plate • Deep Cycle (brand dependent) • 3,3mm posiVve & Car bagery posiVve plate • 2,3mm negaVve plate

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Lead Acid ConstrucVon • 12 Volt bagery = 6 x 2V cells • 2 Volt bageries – Which always produce • (photo: 1000Ah x 2V cells) approx. 2,1 - 2,3 Volts/Cell • Series & Parallel regardless of size of cell. 1 2 3 4 5 6

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Bageries • Bageries with a high power density and low energy density – Good for delivering large volumes of power over a Car short period of Vme • Good for vehicles

• Semi-TracVon Bageries (a happy medium) – Good for delivering smaller volumes of energy over Leisure a longer period of Vme in light duty applicaVons • Also referred to as “Leisure” Bageries • Bageries with a low power density and high energy density Deep Cycle – Good for delivering smaller volumes of energy over a longer period of Vme • Good for solar

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Bageries – D.o.D, End of life • Cycle life – Number of cycles it was designed to deliver • End of life – A fully charged bagery that can only deliver 60-80% of its rated capacity may be considered to be at the end of its cycle life • Design life – See next slide

147

Design life under ﬂoat condiVons • Bageries remaining in a ﬂoaVng state may or may not last longer than bageries that are cycled • When not in service all bageries self-discharge at a rate of about 1-15% per month depending on the type of bagery.

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Live fast die young • Higher temperatures = Lead acid bagery being more eﬃcient • Hoger bageries die faster • The rate of self- discharge increases as the temperature increases.

149

Depth of Discharge vs Cycles

12000 M-Solar Cell FNB Omnipower 10000 Trojan J185 Hoppecke OPzV Energizer Victron Li-ion 8000

6000

4000

2000

0 10 20 30 40 50 60 70 80 90 100

• If only cycled to 10% DOD, a bagery will last about 5 Vmes as long as one cycled to 50%. 150

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Bageries - Storage • Myth: Storing bageries on concrete ﬂoors will cause them to discharge. – About 100 years ago, bagery cases were made up of wood and asphalt. The acid would leak from them, and form a slow- discharging circuit through the now acid- soaked and conducVve ﬂoor. – Wood is not used in modern bagery cases

• Bageries should not be placed directly onto concrete during operaVon in order to prevent large temperature diﬀerences between the upper and lower regions.

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Li-Fe Brands for Solar sector

• Local landscape (Brands Available) • SolarMD (MyPower24) • Blue Nova • Freedomwon • i-G3N • REVOV • LG Chem • Li-ion bageries need to be managed • BagCo. by a BMS in order to prevent thermal • Icon runaway and damage to the bagery • Tesla • BMZ • Zegajoule • Extra2000 (SolaX) • Python (Pylontech)

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Lead Acid Charging cycle - 3 stages Voltage Current

AbsorbVon

Voltage Float

Bulk

Time Bulk charge (aka constant current charge) Current stays constant and voltage increases

Absorbtion Charge (aka Topping charge) Voltage remains constant and current drops consistently until battery is fully charged Float stage Charge voltage is reduced to between 13 & 13,8V and held constant while the current is reduced to less than 1% of battery capacity.

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Charging and discharge

• Discharge takes place through the posiVve terminal • Charging takes place through the negaVve terminal

VS.

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Bagery charging • Recommended Charging current – 10% of bagery capacity in Grid assisted areas – 20% of bagery capacity in certain oﬀ-grid areas – 30% of bagery capacity in all other oﬀ-grid areas

• (Sonnenschein) The charge current must not exceed 35A / 100 Ah nominal capacity. (35%) • Higher currents will not lead to relevant gain of recharging 9me. Lower currents will prolong the recharging Vme signiﬁcantly. • The cell / bloc temperature must never exceed 45°C. If it does, stop charging or switch down to ﬂoat charge to allow the temperature to decrease

155

Why are these conﬁguraVons incorrect? Charging into the ﬁrst row only Charging cable lengths

EqualizaVon

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Correct InstallaVon

Why 12 / 24 / 48V

Show series & parallel Charging & discharging across bank

Equal cable lengths

EqualizaVon taken care of with busbars

157

Busbar & Disconnector Layout

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Bus bar calculaVon - Rule of thumb

Please double check busbar thickness for safety & applicaVon

• Bus bar calculaVon as a rule of thumb • width x height x 2 should = bagery capacity • 5mm x 20mm x 2 should be suﬃcient for a 200Ah bagery bank. • (SANS10142-1 6.6.2) for current >1600A = 1,6A per mm2 • current <1600A = 2Amps per mm2

159

Bagery charging

• Very important for background sevngs. • Adjust the cable resistance in order to ensure the correct charging voltage. • (grid Ved hybrid inverters) Some can be controlled not to feed back into the grid (Grid-LimiVng) • AddiVonal equipment • Meter • Modbus • costs about R4k

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Bagery - Summary • Minimize voltage drop • Use the correct size cables • Locate bagery and load close to PV panel • Choose a large enough bagery to store all available PV current • VenVlate or keep bagery cool, respecVvely, to minimize storage losses and to minimize loss of life • The 744 rule: Is a genset/grid available for boost charge ?

161

Oﬀ-grid Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Charge Inverter controller Voltage Calcula5ons DC Disconnect

Pr BaHeries

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System sizing when storage is included

Step 1 - Calculate consumpVon

Step 1.a) Power Requirement in W Step 1.b) Daily ConsumpVon in Wh

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Step 2 - Bagery Sizing

•Lead Acid System Losses vary 5 between ±22 to 30% •Li-ion System Losses vary between ±18 to 22% 15 5 • hgp://www.bagerysizingcalculator.com

2 Inverter Charge controller Cabling System (Batteries + connections)

Inverters 165

Bagery Sizing – Lead Acid

Step 2.a) Multiply Daily requirement with losses (as a factor) = 7994Wh x 1,27 = 10152Wh Daily Storage required This value represents 27% Losses

Step 2.b) Divide Daily storage by DC voltage = 10152Wh / 48V = 211Ah of Average Daily Ah needed The “48V” value is found in the datasheet Step 1.a showed us we need 3576W of Power. At least a 5000W inverter would be required. From the datasheet Page B1, we will see the 5000W inverter uses a 48V bagery / bagery bank.

Step 2.c) Adjust to depth of discharge = 211Ah / 0,5 = 422Ah Sub Total of storage required Use 0,5 for 50% D.o.D, 0,4 for 40% D.o.D and so on . . . . .

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Bagery Sizing – Lead Acid

Step 2.d) Make provision for rainy days =422Ah x 2 days = 844Ah Total Storage required This value is just a guess and would vary based on the number of rainy days for that area The battery bank needs to be 48V 844Ah according to our calculations. Step 2.e) Select battery to match both 48V and 844Ah as close as possible.

12 Volt Bagery 200Ah

2 Volt Cell 840Ah

4 in series to reach 48V 200Ah 24 in series to reach 48V 840Ah

167

Bagery Sizing – Lead Acid

Step 2.f) Check to ensure that the chosen battery can handle the rate of discharge (c-rating)

Step 3.a) Calculate Power required to charge batteries. (Group Exercise) Power = Volts x Amps

Step 3.b) Select modules to match Power Requirement, roof space and ease of handling (Group Exercise)

Step 3.c) Module layout and design is done according to charge controller power, voltage and current limitations. (Group Exercise)

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Step 4 - Select Charge Controller

• Microcare vs Victron recommended chart • Please check other manufacturer speciﬁcaVons

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Bagery Fuse calc’s Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect

Pr Safety & Cos5ng BaHeries Energy Eﬃciency Oﬀ-Grid 170

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Bagery SCC

• The short circuit current of a bagery (considered to be a ﬁnite power source) depends on: – the resistance of the path, and – the state of charge and – internal resistance of the bagery which depends on variables, such as: • the material and dimensions of the grids and terminal posts, • the surface area and composiVon of acVve material, • the speciﬁc gravity, and • the thickness of the separators • REf : StaVonary Bagery and DC Power System Electrical ProtecVon Design ConsideraVons; K. Uhlir

171

Bagery PSSC SANS 10142-1:2012 • The prospecVve short-circuit current of bageries can be calculated using the following values in a formula: (I=V/R) • EB is the open-circuit voltage of the bageries; if this informaVon is not known, then use • EB = 1,05 x UNB V (where UNB = 2,0 V/cell); • RBBr is the total resistance of the upstream network, in ohms, including the internal resistance of the bagery and the resistance of the conductors; • RBBr = 0,9 x RB + RBL + Ry Ω (see ﬁgure 8.1); • RB is the internal resistance of the bagery; • RBL is the resistance of the bagery connecVons; • Ry is the resistance of the conductors. • NOTE The internal resistance of the bagery can be obtained from the manufacturer’s data.

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Bagery PSCC • A conservaVve approach in determining the short-circuit current that the bagery will deliver at 25°C is to assume that the maximum available short-circuit current is 10 Vmes the 1 minute ampere raVng (to 1.75 V per cell at 25°C and speciﬁc gravity of 1.215) of the bagery • Ref:hHps:www0.bnl.gov/isd/documents/88634.pdf • Page 10 Sec5on BaHeries 10 X 38 PV fuse

173

Bagery Fuses • Varied Philosophies on fuse sizing – Could be based on: • RecommendaVon by Manufacturer, or; • Calculated based on current consumpVon, and on potenVal short circuit current, or; • Various rules of thumb.

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Basic bagery discharge principles

= P I __ V 230W @ 48V 230W @ 230V = 4,79A = 1A Inverter + Losses TV

48 Volt Battery Bank 175

Cable sizing for bageries - 0.259V drop max.

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Conductors Irradia5on PV technologies

Conductor resistance • InternaVonal Annealed Copper Standard (IACS) Metal / Material Conductance IACS Silver 105% Copper 100% Gold 70% Aluminium 61% Brass 28% Zinc 27% Nickel 22% Iron 17% Iron 17% Tin 15% Phosphor Bronze 15% Lead 7% Nickel Aluminium Bronze 7% Steel 3 to 15%

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Solid or stranded? • Solid wire is cheaper, but does not put up with the constant ﬂexing of power cords. • Solid core wire in our walls where it does not need to move and cost magers • Stranded wire in our power cords where a solid wire would quickly harden and break from conVnuous ﬂexing. • Why would wire work harden, embrigle and break? • Strand diameter relaVve to the bend radius is what determines how much strain is imparted into the wire. Solid wires have large strand diameters and see lots of strain. Stranded wires have strands with small diameters. • Welding & bagery cables use thin strands to compensate for movement

179

Solar cable & conductors • General Cable • Halogen-free wiring will typically have a higher conVnuous use temperature raVng, and is more suitable for pv operaVng environments.(Popular sizes 4 & 6mm) • Rated from 900 – 1500V Crosslinked Special Polyoleﬁn • Flexible Vnned mulV stranded wire • XLPO • 36 Shore D • Halogen free • Weather- and UV-resistant • Ozone resistant

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Avoid loops - Induced voltages

181

TerminaVng Solar cable • MC4 type connectors are rated

• 22A-30A 4mm2-6mm2(please check parVcular brand) • For safety reasons do not cross mate coupler brands • Use only PV cerVﬁed cables (Vnned mulV-stranded, double insulated) • Avoid colour cables (long term UV resistance)

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ConnecVng solar Cable

183

Volt drop CalculaVon

• AssumpVons & Figures correspond to SANS 10142-1 Page 305 & table 6.2 Convert from mV to Volts.

Max distance = 20m @ 110V

• 4mm cable volt drop = 11mV/a/m • 6mm cable volt drop = 7.3mV/a/m

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Combiner boxes Irradia5on PV technologies

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AC & DC Combiner boxes • Black cable only in a DC network. Is it allowed?

187

Combiner boxes – Examples

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Combiner boxes – DC Combiner • Combine mulVple strings in parallel • Design is based on – Inverter requirements – Site/safety requirements – Designer/ client preference

189

AC Combiner boxes • Combine mulVple inverters onto the same AC connecVon point • Design is site / client / safety and applicaVon speciﬁc • Moulded case breakers recommended for commercial installaVons

95 6/3/20

Tips & Trends • Tip **BT Consult conducted a study to determine the temperature inside housings for electrical equipment. Findings were that internal housing temperature was between 8-10oC higher than outside ambient temperature. This value has reference to the fuse deraVng temperature as per the next slide. • Tip **Use molded case breakers in larger systems

• Trend *Use fuse box opposed to a combiner box on installaVons where the inverter comes ﬁged with a combiner box

191

Fuse deraVng ▪ Fuse calculations:

▪ Isc x 1,56

▪ Edge of cloud

▪ Fuse Derating

▪ 1 string not required

▪ 2 string not required ▪ 3 string maybe

▪ 4 string yes

▪ (n-1)Isc * 1,25

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CalculaVng String fuses

• Capability of the fuse should be • Where • Voc = Open Circuit Voltage • Ns = Number of modules in a string • Fuse Voltage Capability

• = 1,2 x Voc x Ns • Current Capability • = 1,56 x Isc

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Earthing, LPS & SPD’s Irradia5on PV technologies

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Earthing / Grounding • The simple deﬁniVon of an earth is: • to connect the electric circuit or equipment to the earth’s conducVve surface. • Systems are earthed because of: • personal safety and protecVon in the event of accidental contact • equipment safety and protecVon in the case of a lighVng strike, surge and or fault condiVons.

195

Surge protecVon without LPS (62305)

Class 2

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Surge ProtecVon with LPS

Class 2

197

Surge ProtecVon with LPS

Class 1&2

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AC vs DC Switching Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect

Pr Safety & Cos5ng BaHeries Energy Eﬃciency Oﬀ-Grid 199

Breaking the current

• Fuse Wire / Fuses – Melt or disintegrate • Circuit breakers – Can be reset – Do not use a CB with an AC raVng on a DC Circuit

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Circuit breakers • Diﬀerence between AC & DC CB’s – How they exVnguish an arc • Arc chutes may be spaced further apart. – Whenever a load is connected and disconnected, an arc is produced. – The arc generated in DC is much larger than AC. – AC Breakers not rated for DC will fail in a DC network – Technical term is ‘spark gap technology’

201

The diﬀerence in breaking AC & DC - video

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Arc Flashes • Electrical arcs produce some of the highest temperatures known to occur on earth, up to 19426oC • Arcs spray molten droplets of metal at speeds that exceed 1120km/h which can easily penetrate the body. • Fatal burns can occur even more than a meter away with clothing being ignited up to 3 meters away. • The arc blast can have a sound magnitude of 140dB at a distance of 60cm from the arc resulVng in hearing loss. • Arc ﬂash can be caused by something as simple as a rodent, tool or other element in the breaker area which compromises the distance between energized components, • 2 out of 3 electrical injuries are the result of inappropriate acVon of a worker.

203

Bi DirecVonal Chargers • MPPT’s can be added to increase charging capacity

• Courtesy suncolect.com 204

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Bi-direcVonal chargers

• Bi-direcVonal charging • 2 x 5kW Axpert inverters paralleled • Master vs slave conﬁg

205

AC Coupled Grid Ved inverter • The purpose of connecVng a system • What is the maximum AC in this way is for the current that can be pushed mulVplus to provide through the MulVplus? a reference voltage • In this conﬁg, the Inverter will to keep the grid Ved keep the loads switched on. inverter switched on

Main DB • Transfer switch • 2kW - 30A • 3kW - 50A • 5kW - 100A

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Support Structures Irradia5on PV technologies

Cable calc. Volt drop Series and parallel conﬁg Moun5ng Structures Combiner Boxes PV Fuse Inverter calc Voltage Standards Calcula5ons SPD’s, LPS & Earthing DC vs AC Disconnect

Pr Safety & Cos5ng BaHeries Energy Eﬃciency Oﬀ-Grid 207

Bi-Metallic reacVons 8 month old installaVon - JHB

208

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PowAsnap - ARaymond - Video

209

Structural support and ﬁtment

• Pitched roof structural support • Video by Solarworld

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Only in the Northern Cape

211

References • Earthing SecVon:

• hgp://www.nla.org.za/webﬁles/conferences/2012/Papers/Monday,%203%20September/M206%20-%20High%20voltage%20pylon%20earth%20measurements.pdf

• hgp://www.ijser.org/researchpaper%5CSOIL-RESISTIVITY-AND-SOIL-pH-PROFILE-INVESTIGATION-A-CASE-STUDY-OF-DELTA-STATE-UNIVERSITY-FACULTY-OF- ENGINEERING-COMPLEX.pdf

• www.copper.org

• hgp://electrical-engineering-portal.com/how-to-determine-correct-number-of-earthing-electrodes-strips-plates-and-pipes-part-1

• hgp://www.solarabcs.org/about/publicaVons/reports/module-grounding/pdfs/IssuesRecomm_Grounding2_studyreport.pdf • Bypass diodes SecVon

• hgp://www.V.com/lit/ds/symlink/sm74611.pdf

• hgp://www.cooperindustries.com/content/dam/public/bussmann/Electrical/Resources/technical-literature/bus-ele-an-10191-pv-app-guide.pdf

• hgp://www.solar-facts.com/panels/panel-diodes.php • Bageries

• hgp://fortune.com/2015/05/18/tesla-grid-bageries-chemistry/ • PV Fuse selecVon SecVon:

• hgp://solar.org.au/papers/08papers/408.pdf

• hgp://www.bre.co.uk/ﬁlelibrary/pdf/rpts/Guide_to_the_installaVon_of_PV_systems_2nd_EdiVon.pdf

• hgp://www1.cooperbussmann.com/pdf/4897c8Ü-c785-4993-a4d6-1fddf120cf70.pdf

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THE END

THANK YOU!!

(Please see supplemental slides)

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