Solar Hydrogen Project

mewlingfawnSemiconductor

Nov 2, 2013 (3 years and 11 months ago)

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Solar Hydrogen Project


Group Update




23
rd

June 2009

Solar Hydrogen



The techno
-
economics

for distributed generation of
hydrogen

from solar energy

The trouble with the sun


Irradiation not on demand


Poor temporal correlation with demand


PV / solar thermal don’t displace generation capacity


?

?

Can H
2


storage

h
elp?

Irradiation

Demand

24h

24h

The trouble with
(average)

humans

24h

kWh 5min
-
1

Data: Courtesy of Adam Hawkes

24h

30 days of one month

1 day (high and low res.)

Temporal resolution

The drawback of
limited ramping
and
finite power
rating is only
revealed with high
temporal resolution
data!

18%

8%

Model

Thermal

Demand

Profile

Power

Demand

Profile

Irradiation

Profile


η

el.

η

th
.

η

H
2




Input Data

Parameters

Generation

H
2



el


£ kW
-
1



Conversion

η

charge



£ Wh
-
1



Storage

Commercial

E
l
.
R
ate

FIT

Gas
price

IRR



NPV

Model structure

Demand


Demand


G
as boiler

Grid

Model structure

Thermal

H
2

Electr
.

Demand


Demand


Model structure

Thermal

H
2

Electr
.

Available


Demand


Available


Demand


Storag
e



Model structure

Thermal

H
2

Electr
.

Available


Demand


Demand


Storag
e

Available


Demand


Demand


Storag
e



Model structure

Thermal

H
2

Electr
.

Available


Demand


Demand


Storag
e

Fuel
Cell

Available


Demand


Demand


Output


Storag
e



Model structure

Thermal

H
2

Electr
.

Available


Demand


Demand


Storag
e

Fuel
Cell

Unmet


Available


Demand


Demand


Excess


Unmet


Output


Storag
e



G
as boiler

Feed in

Grid

Model structure

Thermal

H
2

Electr
.

Available


Demand


Demand


Storag
e

Fuel
Cell

Unmet


Available


Demand


Demand


Excess


Unmet


Output


Storag
e



Electrolys
er

G
as boiler

Feed in

Grid

Excel’s solver is useless!


Instead

-

2 or more control variables

-

model scans all combinations

-

plots NPV over control variables



Optimum Storage
Capacity

H
2
Storage [kWh]

Thermal Storage Capacity [kWh]

20%

15%

10%

0, 5%

Net Present Value [£]

H
2

conversion efficiency

Thermal conversion efficiency

0 kWh

10 kWh

20
-
40 kWh

Conversion Efficiency

Net Present Value [£]

P
RELIMINARY

R
ESULTS

-

E
XAMPLES

How does a PEC device compare to

-

PV

-

PV + electroyser

-

Solar Thermal

T
HE

B
IG

Q
UESTION


To get meaningful model outputs we need good input
data

F
UTURE

W
ORK

Model

Thermal

Demand

Profile

Power

Demand

Profile

Irradiation

Profile


η

el.

η

th
.

η

H
2




Input Data

Parameters

Generation

H
2



el


£ kW
-
1



Conversion

η

charge



£ Wh
-
1



Storage

Commercial

E
l
.
R
ate

FIT

Gas
price

IRR













?

?



Christopher Carver

Dr Klaus Hellgardt

SMR

3
tC
/tH
2

Electrolysi
s

8
tC
/tH
2

Other

Benefits

Fossil fuel
reliance

Green house
gases

Abundant
resources

Durable &
low
maintenance

Energy
security

Challenges

Infrastructure

Storage

Perception


Design flexible test
-
bed reactor


Maximise photon absorption


Obtain high mass transfer rate coefficients


Effectively separate hydrogen and oxygen products


Run experiments for hydrogen production


Semiconductor


Configuration


Good absorption


Stable in alkali


Recombination


Stable in
acid/alkali


UV absorption
only


Good efficiency


Stable in acid

titanium

PVDF

quartz

LIGHT

A

C

B

Nafion


Polymer membrane


Chemically resistant to attack


Ionically conducting

PEC
REACTO
R

Testing unit


-

hydrogen sensor


-

pH


-

temperature

Pump

Bubbles

Gravity
extraction

Light
dispersion

Dissolve
d

Pumped

Clear

Future Work


photoanode

quartz
window

cathode

membrane

electrolyte

LIGHT

A

B

C

current
distribution

Summary of Future Work


Set up reactor


Experiments


Different semiconductors


Electrode configuration


Analyse data


Compare configurations and parameters


Deliver report

QUESTIONS?

Solar Hydrogen Project:
SD


Solar Simulator: awaiting developments



Doctor Blade machine: initial
experiments underway (see below)



Electrchem09: abstract submitted

Solar Hydrogen Project:
SD


Doctor blading:



Height setting requires calibration



Fabricated films with range of thickness (by
measurement of blade height)



Analysis of films underway


Solar Hydrogen Project:
SD

Film from ~20 micron thick coating, after annealing

Solar Hydrogen Project:
SD

Film from ~2 (?) micron thick coating, after annealing

Solar Hydrogen Project:
SD


Initial electrochemistry of doctor bladed
WO
3
:



Characteristic WO
3

behaviour, but no
photoresponse



Looking at thinnest film next.