| World Insolation
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|---|
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| Acknowledgement WorlyParsons - EcoNomics
|
The map on the right shows insolation rates on the world's land areas;
the units, I believe, are kilowatt-hours per square metre per year.
The desert areas get the most sunlight because they have less cloud cover
than the better watered areas.
The map indicates that Australia has very high levels of solar power
available for development, the SW part of the US is the only other part of
a developed nation that comes close.
Insolation in Australia is shown in greater detail below.
| Australian Insolation
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|---|
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| Acknowledgement WorlyParsons - EcoNomics
|
The map on the right, using the same colour-coding as that above, shows
insolation within Australia.
Any of the areas coloured red would be very well suited for solar power.
By far the greatest problem in the economic use of solar power is due to the
low intensity at which it reaches the surface of the Earth.
Whatever is used to collect it must cover a large area and therefore must
be low in cost per unit of area covered.
In some applications the radiation is collected direct (eg. the common photo
voltaic panels) and in others the radiation is concentrated in some way.
Several methods of collecting solar power are (the links are to examples
illustrated on this page):
- Photo voltaic
- Flat pannel
collectors
- Crystaline silicon
- Amorphous silicon
- Gallium arsenide
- Dish concentrators (shine concentrated sunlight
onto relatively small PV panels that need to be actively cooled)
- Thermal
- No concentration
- Linear concentrators
- Trough concentrators
- Fresnel concentrators
- Array concentrators
- Power tower (a single collector in a large array of reflectors)
- Modular power towers (an array of power tower modules)
- Dish concentrators
- Repeated modules (many dishes of moderate size)
Photo voltaic systems generate electricity directly.
Thermal energy collectors heat something - usually a fluid, but possibly
something like a Stirling engine - as an intermediate step toward the
production of useful energy.
Several of the above methods have been brought to the stage of commercial
viability, the others have gone only to the pilot stage.
Also see the section
Off-beat applications.
There are many scattered installations of solar photovoltaic power in
Australia, on isolated homesteads, homes of environmentally conscious
people scattered across the nation, powering the long optical-fibre
telecommunication cables that criss-cross the land, powering local equipment
on railways or pumps on wells and dams,
supplementary power in remote tourist attractions and towns, etc.
These range in capacity from a few Watts to a few hundred kilowatts.
The chart at the right shows approximate installed solar power by states
and territories (from DEWHA, 2009/02/20).
These figures are the totals of the listed solar power installations on
the downloadable DEWHA spreadsheet; and does not include any installation
less than 3kW, which would exclude most domestic photovoltaic installations.
The DEWHA data also mention that total Australian photovoltaic in
2005 was 60 600kW; presumably this includes domestic installations.
|
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| State | kW
|
|---|
| ACT | 101
| | NSW | 5972
| | NT | 1678
| | Qld. | 516
| | SA | 2382
| | Tas. | 120
| | Vic. | 764
| | WA | 745
| | Total | 12 278
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|---|
|
|
The DEWHA data listed the Liddell station as 25 000kW solar; so far as
I can find out the actual figure is 2000kW.
This makes a huge difference to the NSW total; I have used 2000kW for
Liddell here.
12.3MW of installed solar power would generate about 26GWh/yr,
60.6MW would generate about 127GWh/yr.
Note that the 60 600kW (60.6MW) figure for solar power generating
capacity in Australia is very small compared to the installed wind energy
capacity (at January 2009) of 1494MW.
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Record of domestic power consumption and generation; on my house as it
happens.
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An example case
The pink symbols on the graph above shows the power consumption
record for a 30-year-old electrically boosted solar water heater in
Mid-North South Australia (200km north of Adelaide).
This 16-month record shows that the solar energy is sufficient to heat all
the water required in the home for all but two or three months in winter.
The yellow curve is power sold-back to the grid from a 1kW set of PV
panels - see domestic photovoltaic
generation, elsewhere on this page.
|
|
Solar water heating has long been popular in Australia, although its
take-up has varied from place to place, not necessarily with any
relationship to the local availability of sun light.
It is most often used on private homes, but also on hospitals, camping
ground toilet blocks, hotels, and other public buildings.
It can also be used for heating swimming pools and has industrial uses.
There is generally some backup heating combined with the solar water
heater so that hot water continues to be available in very cold weather
or when the sun doesn't shine.
The backup, in Australia, is usually gas or electric, but sometimes
wood-fired.
Electric backup is being discouraged by government in order to reduce
greenhouse gas production (most Australian electricity is generated by
polluting coal-fired power stations).
Wood-fired water heating combines well with solar because the wood fire
will generally be used in winter when the solar water heater is at its
least effective.
Some solar water heaters use a pump to move the water (or some other heating
fluid) through the solar panels to the hot water storage tank.
Research has shown that the power used by such a pump can be quite
significant and therefore negates, to some extent, the point of using solar
heat; this depends on the design of the unit.
Solar water heater rebates are discussed
elsewhere on this page.
Wikipedia has many articles on
Solar hot water
and related subjects.
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Record of my domestic power consumption and generation
| |
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Domestic Photovoltaic generation
The yellow symbols on the graph at the right shows the record of the power
fed into the electrical grid from a home with 1kW of solar photovoltaic
panels on its roof (in SA 200km north of Adelaide).
The blue and pink symbols record the electricity being drawn from the grid.
Interestingly the amount of sell-back in this case is fairly constant
year-round.
It seems that while the power generated by the PV panels must be lower in
the cloudy winters, with their shorter days, this is offset by lower
power consumption in the house by the refrigerator and freezer at that
time of year; and of
course there is no need for air-conditioning in the winter.
I use wood-fired heating and have practically no need for electrical
heating.
Photovoltaic rebates are discussed
elsewhere on this page.
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Off-grid photovoltaic generation installation in a national park
Wilpena in South Australia
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The Wilpena solar power station in its beautiful setting
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A part of the Wilpena solar power station
Diesel generators are in the containers in the background
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The combined diesel and photovoltaic power station at Wilpena in South
Australia's north is an example of solar power in use in an environmentally
sensitive area.
The South Australian (Olsen) Government constructed it as a demonstration
project.
It was commissioned in December 1998 and is now (2008) owned and
operated by AGL.
The photovoltaic part of the power station generates up to 100kW, the
diesel generators can produce several times that amount and are used
whenever the solar power is insufficient to provide the needed
generation.
AGL has a
page
on the power station, in which they say that it has an estimated output
of 100MWh; one would assume that this is per year.
(Interestingly, if one calculates five hours per day at 100kW, which seems
conservative, the year's total is 183MWh.)
The Array consists of 1250 panels, each with a capacity of 80 Watts.
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Off-grid photovoltaic applications in a national park
Wilpena in South Australia
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A tracking solar power unit for a well pump.
(The panels are rotated about the diagonal axis through the day to follow
the apparent movement of the Sun across the sky.)
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Solar powered telephone
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Solar powered street light
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Solar photovoltaic power has been used in many places in Australia.
Often it is used because the point where the power is needed is a relatively
long way from a power line; sometimes it is used because the local
power supply is limited and expensive to generate; sometimes because sunlight
is locally abundant, the application requires little power, and it is
cheaper than connecting to the local grid.
The applications in the photographs on the right are used because of a
combination of all these things.
Some of the uses to which off-grid PV power has been put to in Australia are:
- Home/homestead power;
- Water pumping from wells and dams;
- Powering communications equipment including public telephones and
repeater stations on fibre-optic cables;
- Railway signals;
- Street lights.
If you buy 5kW (5000 Watts) of solar panels in Australia don't expect
them to generate 5kW of power that you can use or feed into the
electrical grid most of every sunny day.
They may get up to near 5kW in the middle of a sunny day in November if
you are lucky.
If you have an off-grid system and will be charging batteries the situation
is even worse.
What retailers will sell you as 5kW of panels are, I believe, capable of
generating 5kW under ideal conditions; the conditions under which your
panels will be working are rarely, if every, ideal.
Is this 'truth in Advertising'?
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| Solar & wind-powered shipping
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|---|
| |
Skysails - credit GmbH
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| |
Windship - credit Knud E. Hansen
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|
While this bit comes from the USA it is very applicable in Australia.
The following was extracted from
Wikipedia.
"Sterling Energy Systems is building a 4,500-acre (18 km2) sun
farm to supply 500 MW by 2012.
Output will go to Southern California Edison and San Diego Gas and Electric.
Annual output is expected to be 1,047 gigawatt-hours (GWh)."
The heat produced by the solar dishes is converted into electricity by
Sterling engines and generators.
ABC
On-line news reported on 2008/10/29 that the Sydney-based renewable
energy company Solar Sailor had contracted to supply two Chinese commercial
ships with high-tech energy generating sails.
The sails are shaped to harness wind energy and are covered with solar PV
panels to generate electricity.
Australian governments have encouraged the fossil fuel industries in
spite of the harm they have done to our atmosphere.
The coal industry in particular is still advantaged by
subsidies
totaling billions of dollars per year.
Even now, in 2008, Australian governments continue to protect the coal
industry, when they should be doing the opposite.
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Solar photovoltaic panels and 30-year old solar water heater on an Australian
house (mine, as it happens).
Appearance to the contrary, the tree does not shade either PV panels or
water heater significantly.
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The Australian Federal Government introduced a solar-photovoltaic rebate
for systems installed on private homes and community use buildings (other
than schools) several years ago.
It has had a faltering and inconsistent history.
At first it was capped at $8000, this was later reduced to $4000, then
progressively reduced to $3500, and raised again to $8000.
The Rudd Government put in place a means-test, limiting access to the
rebate to those having a household income of less than $100 000
per annum.
Schools can receive grants of up to $50 000 to install solar power
"and other measures".
The old rebate is now to be replaced by the
Solar
Credits Scheme (which has dubious
carbon accounting
connotations).
A Federal Government
rebate of
$1000 is available "in eligible circumstances" for the installation of
a solar or heat-pump water heater.
One of the criteria is that it must replace an existing electric storage
hot water system; for the full criteria use the 'rebate' link above.
Several states provide a rebate payable to anyone installing a solar
water heater in addition to the Federal Government rebate.
Solahart has a useful site that provides details
about the rebates provided by various state governments.
According to this there are no rebates available for the territories or
for Queensland or Tasmania.
The maximum rebates in the other states are...
| State/Territory | Max. rebate
|
|---|
| New South Wales | $1200
|
| South Australia | $500
|
| Victoria | $1500
|
| Western Australia | $700
|
I have not gone into details on the above rebates because it is probably
better if you get it from someone nearer the source of the information.
At least two local governments,
Whyalla in South Australia,
and Brisbane City Council in Queensland,
offer a further rebate on solar water heating.
There is a description of what a
feed-in tariff
is in the glossary; it also explains the difference between gross and net
tarriffs.
All Australian states and territory governments other than NSW have either
promised or implemented feed-in tariff schemes at the time of writing
(October 2008).
The Clean Energy Council, Australia's peak renewable energy body, is pressing
for a national feed-in tariff.
ABC On-line News reported on 2009/03/13 that the ACT will pay
"a 'gross' feed-in tariff where the property owner is paid 3.8 times the
retail price for all electricity produced from solar panels up to a 10 kW
capacity."
The Northern Territory situation is more complicated.
Alice Springs residents can receive a net feed-in tariff rate of $0.45/kWh.
In other areas of the Northern territory, the rate is $0.1438 (14.38c).
The New South Wales government is not offering a feed-in tariff.
In South Australia $0.44 will be paid for each
kWh fed from a domestic solar installation
into the electricity grid; the legislation is for a period of 20 years.
This is a 'net' tariff.
Queensland's scheme provides for a payment of $0.44/kWh to domestic
generators.
Tasmania currently has a net tariff of $0.20/kWh.
Victoria's feed-in tariff will begin operation in 2009 and will
be set at $0.60/kWh net.
Western Australia has just gone through an election at the time of
writing and has changed to a Liberal-National coalition government.
I believe that the Liberals, when in opposition, promised a feed-in scheme.
Much of the information in this section was extracted from the
Energy Matters Net page.
The areas with the
greatest solar power
potential are in the drier, less populated areas of Australia.
In general there are few high-capacity power lines in these places.
Power transmission lines at government expense have been used to encourage
the development of major remote mines and
governments have traditionally financed the building of power lines to
fossil fueled power stations; they should also be willing to build
high-capacity power lines where needed for sustainable power development, but
so far seem not to be.
This subject is covered in more detail in my page on
sustainable
energy in Australia.
The Rudd Federal government has promised a renewable energy target for
electricity of 20% by 2020, but has not yet put this, or the very important
intermediate targets, into law (as of October 2008).
The previous
Howard Government refused to
increase MRET from a pathetic 2%.
I have dealt with the MRET in greater depth in
FailAust.
