pv solar and_hts_trends_a_hunze_irl_-1
TRANSCRIPT
Photovoltaic, solar power and HTS technologies
- status and trends
A.Hunze, R. Badcock,
A. Gardiner, A. Caughley
Industrial Research Limited
Superconductivity and Energy group
Arvid Hunze
Industrial Research Limited
Superconductivity and Energy group
Mail : [email protected]
Web : www.irl.cri.nz
Outline
• The problem (as far as I understand it) – and possible solutions
• Photovoltaic technology – status and trends
• Hydrogen storage for PV – status, trends and NZ experience
• Solar thermal – a brief intro
• HTS opportunities - extremely high power density power cable, generators, cryogenic
systems and RF (long hand) filters
The SKA power problem
– as far as I understand it …How to guarantee …
- power supply and relatively flat load 24/7 in the order of 80-100 MW at the main site
- in one of the most remote areas of the world
- with high (direct) solar radiation and also high temperature values and differentials
- a radio quiet environment is maintained
- a low CO2 footprint, using renewable energy sources up to 100 %
- power of 1 MW at the smaller sites / outer stations
- and a solution that is not too expensive (of course)
Photovoltaic, Solar Power
and Storage
Generating technologies - options
“Both candidate SKA sites are, in fact, exceptionally well placed to use solar-based
generating solutions, provided cost and storage issues are adequately addressed. Early
consideration of solar technologies, including relatively new concentrating solar voltaic
systems, indicate that such solutions may be feasible, given a willingness to invest in a suitable-
scale development program and, most probably, to subsidize the unit cost of SKA renewable power,
at least for the period of the instrument's operational life in which fossil-fuel alternatives are priced
relatively attractively..”
Power Considerations for the Square Kilometre Array (SKA) Radio Telescope
Peter J Hall, 2011 IEEE
Solar PV technologies – Overview
Crystalline Si (wafer)
Thin Film Silicon
Thin Film II – VI
Thin Film III – V
Concentrated PV
New Materials
Monocrystalline (c-Si)
Polycrystalline (c-Si)
Amorphous (a-Si)
Microcrystalline (µc-Si)
Ta
nd
em
/Tri
ple
CuInGaS(e)
CdTe
GaInP / GaAs (2J)
InGaP / InGaAs / Ge (3J)
Organic
Printed PV
Dye Sensitized
… (xJ)
Silicon Wafer, “classic PV”
“Thin Film (Silicon) PV”
a-Si, “micromorph”
“Thin Film PV”
Multijunction cells on III-V group
materials (“inverted LEDs”).
Organic and hybrid materials
Printed semiconductors
Maturity level still very low.
Typ. in field eff.Max. lab.
eff. Low light (dirt)
Temp.
coeff. [%/K]Status and trends
c-S
i
15 % (multi)
20 % (mono)
20.4 % (multi)
25.0 % (mon)
(wafer)++ -0.4 %/K
Std. technology with largest production capacity
worldwide
TF
-Si
10 % 12.5 % ++ - 0.3 %/KImproved efficiency potential with multiple and
micromorph technology.
Cd
Te 11% 17.3 % + - 0,25 %/K
Todays cheapest module technology, but
size limitations due to fabrication process, max GW
limitations due to Te scarcity and end product contains
toxic elements.
CIG
S 12 % 20.3 % 0 -0.4 %/K
Highest efficiency potential of all non-concentrated
technologies, but still no high volume production
process.
CP
V 25% 43.5 % (cell) - -0.2 %/K
Highest efficiency (potential) of all technologies, but
still between R&D and production stage. Requires
light focusing thus high direct normal radiation and
sun tracking.
For high direct normal irradiation and high temperature sites
CPV seems to be best technology choice
esp. with further improvements in the future
Solar PV technologies – comparison
Optical efficiency :
100% x 80 % = 80 %
concentrated light energy
on cell lost due to :
- light reflection
- optical losses at interfaces
- light way misalignment
Start :
100 %
sun light in
Cell effciency :
100% x 80 % x 40 % = 32 %
conversion loss of light energy
to electrical energy due to :
-incomplete spectrum
conversion
- cell temperature loss
Sunspectrum
and 3 layer
absorption
InG
aP
GaA
s
InG
aA
s
Cell to module on tracker :
100% x 80 % x 40 % x 90 % = 30 %
electrical energy loss due to :
- wiring
- module array on tracker
Module
Concentrated PV – How it works
Optical
Also DNI is higher in the
desert
Start
This is good
in the desert
Cell
High T in the desert but lowest T
loss of all PV technologies
Sunspectrum
and 3 layer
absorption
InG
aP
GaA
s
InG
aA
s
Tracker
Tracking enables better and more flat
generation profile
Module
Concentrated PV – what are the advantages
Optical
Due to focusing sensitive to
contamination and dust
so regular cleaning might
be an issue (DI water).
Start Cell
Sunspectrum
and 3 layer
absorption
InG
aP
GaA
s
InG
aA
s
Cell
Tracking = mechanical movement
always sensitive, good maintenance
required
… and it will not work at night
combination of technologies or
storage required
Module
Concentrated PV – what is challenging
PV and storage in the NZ context
ENA Solar CHCH – Inverter
Might be some special needs in CPV
due to fluctuations/ spikes when alignment not perfect, clouds passing …
Storage options
Source: EPRI Study on Commercial Energy Storage
~1 GWh (80 MW/12h) off grid
storage needed with strong
discharge cycles
high energy density storage
so pumped hydro () and CAES worse
options
deep discharge cycles challenging
for most battery technologies
Hot environment
battery technologies
suffer severe heat degradation
problems
Low costs and “proven” technology
hydrogen storage
seems viable option
HYLINK (hydrogen link) concept - IRL
The concept
Storing renewable electrical energy using hydrogen gas
Invisible underground gas pipe (no overhead wires, ~ 1MW easily handled by a single pipe)
Only one other installation worldwide (but not renewable or remote)
The benefits
Good solution for locating renewable energy sources in optimal positions, transport H2
instead of electrical power
could be beneficial for reduced noise
Pipeline cheaper than installing overhead wires for lengths >2km
Pipe part of the volume for energy storage
hydrogen
Fuel
cellelectricity
hydrogenHouse
Grid
• 16mm gas pipeline (MDPE)
provides energy transfer (1MW
capable) AND storage.
• Buried pipeline cheaper than
overhead cables when >2km and
cheaper than batteries.
• Minimal resource consent issues,
invisible, long life
HYLINK example - Totara Valley site
Valley: peak demand smoothed
electricity
• Electrolyser
– Test site for a new in-house design
• Alkaline bipolar cells, 4 barg
• 24V, 100A input
• Fuel cell system
– Field prototype from ITRI, Taiwan
– 2kW, 24V low pressure PEM
• Hydrogen burners (planned)
– Investigate H2 and H2/LPG blending
• Hydrogen distribution and storage
– 315mm dia, standard polymer fuel pipe
– 8kWh HHV at 4 barg
– Inclined moisture purging
– Buried in raised garden
Concentrated solar power - overview
- different technologies but apart from parabolic dish no long term experience
- big advantage over PV is inherent storage possibility
but only experimental technologies can provide full 24 h operation
(e.g. oil vs. molten salt)
Efficiency (%) + -
Pa
rab
olic
15-20 %
most established technology
(> 90 % of installations)
easy to scale
1 axis tracking
flattened area
high water usage
Fre
sn
el
experimental
potentially lower cost
lower complexity
1 axis tracking
R&D stage
efficiency
shadowing
larger area needed
To
we
r
17 %
higher temperature thus higher
efficiency potential
direct steam integration easier
pilot stage
2 axis tracking for every mirror
flat area
Dis
h 30 %
higher temperature, high efficiency
decentralized independent units
(like CPV)
pilot stage
high complexity
(energy unit attached/moving)
no storage possibility
high maintenance
For high direct normal irradiation and high temperature sites
concentrated solar could be viable option
but less experience/ installations than PV
Concentrated solar power – comparison
High temperature superconductivity
and cryogenic refrigeration
Status and trends
• Copper Cables
Equivalent HTS Cable
High Temperature Superconducting Cable
GCS
HTS power cable
Long Island, New York.
609 meter cable system
138 kV, 574 MW
Operating since April 22, 2008
Participants: AMSC, Nexans, Air Liquide,
LIPA
HTS power cable could be viable option for parts of the SKA :
- much higher power density at low impedance
- can be buried underground (safety, noise)
- higher and T-independent efficiency
- inherent fault current limiting properties, reducing damage propagation
- due to constant cooling better lifetime than conventional expected
574 MW
AMSC
Conventional Generator HTS Rotor with air-gap winding stator
(High power density)
a/2
• Smaller footprint/mass
• Higher efficiency at lower load
• No ageing in the rotor expected
• Improved electrical stability, potential to
reduce inductance whilst increasing
current density
• Power rating 100%
• Ageing rotor winding
• Limited power diagram
a
Benefits of Superconducting Utility Generators
Siemens
Converteam
IRL Cryogenic Refrigeration R&D Experience
• Underlying science & capabilities
– Cryocooler design and manufacture.
– Modelling of oscillating thermodynamic systems.
– Computational Fluid Dynamics.
– Cryogenic materials, properties and use.
– Cryogenic Engineering.
– Flexible membrane (diaphragm) design.
– Reciprocating and rotating machinery design.
– Pressure vessel design.
• Diaphragm Pressure Wave Generator technology.
– Unique double metallic diaphragm technology overcomes shortcomings of incumbent technologies.
– Scalable from 500W-30kW input power.
• Pulse Tube Cryocoolers.
– Development of medium to large (10-1000W) pulse tube cryocoolers.
Experience of cryogenic refrigeration systems
might be interesting for custom tailored receiver cooling solution
HTS RF filters
Opportunities for HTS solutions
for high Q RF filters to be explored
• much lower surface
resistance than conventional
materials
• planar design possible
• already tried in deep space
network project for
interference mitigation
HIGH TEMPERATURE SUPERCONDUCTING 8.45-GHz BANDPASS FILTER FOR THE DEEP SPACE NETWORK* G. L.
Matthaei** and G. L. Hey-Shipton (1993)
Summary
• Concentrated PV + Hydrogen storage and/or solar thermal power plant are good
options for powering the SKA but still many challenges on the way
• PV and CSP opportunities for NZ to be explored
• Strong NZ capabilities in Hydrogen storage - HYLINK concept
• Strong NZ capabilities and industrial partnerships in HTS systems that could be
useful for
- underground HTS power cables
- higher efficiency HTS generators (e.g. in a solar thermal plant)
- tailored cryogenic solutions for receiver cooling
- HTS RF filter opportunities
Thank you very much
for your attention