PV Testing and Thermal Management: Qatar Perspective

15/05/2017

Abdelhakim HassabouBen FiggisAhmed AbotalebAmir Abdallah

Agenda

Part I (Ben Figgis):

Outdoor & Indoor Solar Test Facilities

Outdoor Solar Test Facility Indoor Test Facilities

Part II (Abdelhakim Hassabou)

Thermal Management of PV Panels

Part I

Outdoor & Indoor Solar Test Facilities

QEERI Solar Test Facility

Purpose:

• Identify solar technologies suited to Qatar’s climate

• Determine how to manage dust and heat for PV

• Field testing for QEERI research projects (energy & water)

Timeline:

2010: Initiated by QSTP

2011-12: Systems installed

2013-03: Testing commenced

2016-01: Transitioned to QEERI

2017-03: 4 years of continuous testing

Solar Energy Research Program @ STF

Solar energy technologies

Photovoltaic: Crystalline, thin film, concentrating

Thermal: Linear Fresnel collector

Applications: Battery storage, desalination

Operation technologies

1- and 2-axis tracking

Anti-soiling coatings & machines

Performance modeling

Environmental data

Irradiation: GHI, DNI, POA, UV

Soiling: Aerosols, condensation

Weather parameters

STF Meteo Conditions

Peninsula in Arabian Gulf with carbonate geology

Köppen cat. BWh (hot desert)

Hot summers. Mild, very humid winters

3-4 rainy periods per year

Occasional dust storms but not sand storms. No visible abrasion after 4 years

Median PM10 = 0.11 mg/m3

Dominant wind from N-NW, over sea and then ~100km of land

Source (local vs. “imported”) not certain

Left: PM (μg/m3). Right: Wind Direction. Summer averages.C. Fountoukis, QEERI.

Soiling Research Focus

Real-time microscopy of soiling

“Outdoor soiling microscope” developed

Monitoring of individual dust particles > 4 μm, every 10 minutes

Greased/ungreased coupons distinguishes deposition, rebound and resuspension

Monitoring of condensation on dust at microscopic level

Condensation & cementation

Capillary adhesion and cementation thought to dominate PV soiling

Field and lab investigation of condensation on soiled surfaces

Parameters being investigated: RH, Tsurface – Tdew

point, hygroscopic matter, surface wettability

Select Findings from STF

Solar technologies

Because of Qatar’s diffuse irradiation skies, flat-plate PV modules perform better than concentrating PV

C-Si and thin film PV modules have different efficiencies but similar yields (kWh/kWp)

Dust

Cleaned every 2 months (plus rain), soiling loss of PV modules in Qatar averages ~8%

Depending on project economics, optimal strategy is to clean PV when soiling reaches ~10%

Heat

Annual average heat losses (relative to 25⁰C) were 9% for both crystalline silicon PV, and 6% for thin-film modules

Trackers

1-axis trackers (N-S axis) increased energy yield ~10% compared to 22°tilt

2-axis trackers increased it 48% (partly because of elevation), however have low ground coverage ratio

Capabilities @ QEERI: PV module indoor testing

Under Preparation

Climate Chamber (Atlas SEC 2100)

Wet leakage and rain penetration setup

Climate chamber:Thermal cycling, Damp Heat and Humidity freeze

Steady-state sun simulator: high capacitance technology, Nominal Module Operating Temperature NMOT, module temperature coefficient

UV irradiance chamber

Insulation resistance & Wet-leakage Current

Mechanical loading

Capabilities @ QEERI: Laboratories

Photovoltaic laboratories

Silicon growth line

Crystallization furnace, squarer, scrapper,

inspection (IR, resistivity & carrier lifetime),

grinding & chamfering, cropping, wafering and

ultrasonic clean

Solar cell characterization

Solar cell IV measurements

Surface Photovoltage SPV

Deep Level Transient Spectroscopy DLTS

Hall Effect

4-point probe

Thin films lab

Molecular Beam Epitaxy MBE

DC/RF Sputtering

Thermal Evaporation

Perovskite lab

Core Lab

Microscopy

Scanning Electron microscopy SEM

Transmission Electron Microscopy TEM

Confocal Microscopy

Focused Ion Beam FIB

Atomic Force Microscopy AFM

Surface Science Lab

Profiliometer

UV-Vis spectroscopy

FTIR

Raman

X-Ray Diffraction XRD

Thermal Analysis

TGA, DSC, DMA, TMA, and Rheology

Modelling

FEM ABAQUS, thermo-mechanical, COMSOL

Part II

Thermal Management of PV Panels

Passive Cooling of PV Panels by PCM-Matrix Absorber

Utilization of (PCM) to:

Shave temperature peaks during day time

Keep PV warm above dew point during night time

to prevent condensation

Alum. Fiber + PCM

PV Panel

Outdoor Testing & Proof of Concept

Proof of concept and examination of the solution

effectiveness under Sun in Qatar

Site infrastructure ready

Outdoor test setup will be commissioned by end of

June 2017

PCM-Absorber with Fins

PCM-Absorber Without Fins

Sample of Numerical Modeling Results

Temperature PV Electrical Instantaneous Efficiency

Successfully model PV and PCM matrix Absorber to shave PV module peak temperature

Module Peak temperature could be reduced by 16 °C

Depending on the temperature coefficient of the PV modules, the power production can be increased

up to 6-8% for mono and poly crystalline cells and up to 5% for thin film

Module Instantaneous efficiency increased by more than 1-2%

Study the effect on the PV module life time is ongoing – first results shows 30% increase in life time

Active Cooling of PV Modules - Innovative Hybrid PV-T Collector

Why PV-T is important in GCC & MENA

• Provides active cooling of PV cells, which increases

its efficiency and life time

• Most of potential applications of solar energy

requires both electricity and heat, e.g. solar

desalination, cooling, food processing and drying,

EOR with steam generation, domestic ,

• Hybrid PV-T increases the overall conversion

efficiency from ~ 20% to ~ 80%

• Combine heat & power (CHP) is an option that

contributes substantially to energy efficiency

• Reduces land footprint and cost, are major barriers

for accelerated deployment of solar energy in many

applications

Limitations of Existing PV/T Collectors

Trade-Offs

Electrical

efficiency

Thermal

energy

Tfluid ηth

TPV ηel

Tfluid ηth

TPV ηel

• Hybrid PV-T collectors are designed only for low temperature applications below 40 °C.

• The low temperature (below 40 °C), not suitable for process heat (100-250 ° C)

• Hybrid PV-T collectors that deliver medium temperatures do not exist at all worldwide

Innovative Hybrid PV-T Collector

Much more efficient - > 85% compared to 18%

Electrical Efficiency of PV alone)

Delivers temperature up to 140 °C yet very

simple, non tracking, non evacuated, low tech

Short lead time for the project (60%) compared

to CSP

Automated cleaning with water sprayers with >

80% water recycling

Single axis tracking

Low cost incurred for the new design

Prototype and outdoor test setup will be

commissioned by end of June 2017

Thank you