Interesting to hear of the fact that the Gold Coast Desalination plant is going with green energy. I have a few ideas myself on some options. To me it's verging on criminal that we have not yet tapped into our vast solar (and geothermal) resources. Although there is promising work being done using triple junction photo voltaic arrays in South Australia, I think that the best option is still large scale solar thermal arrays, similar to those in California.

Hydrogen:

If you produce hydrogen from electricity you never get anything approaching 100% conversion efficiency (especially using straight electrolysis), so why bother converting it? Well if you have off-peak load, it's a way of storing electricity, so Geothermal or Solar are two examples of where you'd want to store the energy in some way.  

Most hydrogen these days is separated from natural gas and steam using a reformer reaction. If you can reconvert the resulting carbon monoxide to methane using a methaniser, at least you're part of the way there. The carbon footprint is much lower than simply burning natural gas, although the calorific value of hydrogen is much lower (in volume terms)  

Alternatively, think of a Solar Power Station. The main problem with Solar is that it doesn't work too well at night. Storage is an issue. At the moment, the most efficient storage mechanism if you want to get electricity out when the sun isn't shining is an ammonia based thermochemical energy storage system. With such a system, you can have at least two possibilities:

1. A totally closed loop system.
2. A closed loop system for carbon that produces hydrogen (and consumes water)

There is actually a third possibility which I won't discuss here, as this post is starting to get complicated enough as it is. All three are carbon neutral. In design 1 , the ammonia is dissociated to nitrogen and hydrogen using solar-thermal energy. The gases are then recombined catalytically at high pressure and temperature to recover the energy. The energy is used to drive a turbo-generator.

Design 2 uses a steam Reformer (inputs methane, steam and air) to produce excess hydrogen. The nitrogen is separated from the air (using Pressure Swing Absorption). Pressure Swing Absorption is also used to purify the hydrogen. The hydrogen and nitrogen are combined, and the excess hydrogen is used for automotive use. The resultant carbon monoxide is reacted with steam in a methaniser (another catalyst) to produce methane. The methane is recycled back into the Reformer. The ammonia is dissociated using solar-thermal energy.

I won't go into design 3, but the products are hydrogen, ammonia and energy.

The bottom line is that this is all proven technology.

By the way, if anyone still has doubts about anthropogenic global warming, I'd love to talk through the issues. I have a reasonable working familiarity with the chemistry, climate modelling and atmospheric physics, so you can make it as technical as you want.

We can duel with Rayleigh Absorption scattering equations at 20 paces if you so desire  ;D

How accurately are we able to model and predict the impact of emissions on climate? Are the models heavily tuned to measured data, or are we able to build an accurate model based on fundamental principles?

Climate models of today are considerably more accurate than those of the early 80's, but the interesting thing is that using some of the earliest models, we can predict what has happened over the last 20 years or so - with no iteration involved. Long term climate is largely deterministic, whereas short-term weather is stochastic.  

There are some natural influences of course, and the biggest errors are related to polar effects, aerosols and cloud albedo modelling. There are also cyclical effects such the Southern Oscillation Index and the effects of large explosive volcanoes, such as Mt Pinatabo. La Nina episodes such as the one we are currently experiencing generally have a short-term global cooling effect, as do explosive volcanoes.

- but the biggest single factor that we can't model is the response of mankind. How quickly can we curb emissions and develop alternative energy sources? The latest IPCC synthesis reports provides us with a range of possible scenarios.

http://news.smh.com.au/more-money-urged-for-green-energy/20080318-200t.html

Environment groups have urged governments to spend more taxpayers' money on renewable energy than the fossil fuel industry.

Greenpeace released an opinion poll which found a majority of Australians think renewables should receive more subsidies than fossil fuels like coal.

The Australian Conservation Foundation (ACF) issued a report showing federal and state governments are investing nearly 50 times as much on fossil fuels and uranium mining as they do on technologies like solar and wind power.

In another thread, it was mentioned that South Australia could become the Saudi Arabia of Australia. Here's a major contribution that SA is currently making to the field of renewable energy.

http://www.greenandgoldenergy.com.au/

The suncube is a triple junction photovoltaic panel which uses a solar-tracking concentrator to maximise efficiency. They have achieved a peak energy efficiency conversion of just over 40% (typically >35%) with a measured output of 750 Watts per square metre in Adelaide. Suncube was launched at the Green City Festival in Adelaide about four weeks ago.

Triple junction cells are much more efficient than conventional solar panels. Up until now, they have been reserved for space probes, such as the NASA Mars Exploration Rovers Spirit and Opportunity.

As far as cost is concerned, energy production using this technology is currently about the same level of cost as natural gas fueled energy production.

Can we make renewable portable energy sources?
Suitable for the grey nomads.

Are solar panels enough, or is a combination better?
Say a small wind turbine as well.

In another thread, it was mentioned that South Australia could become the Saudi Arabia of Australia.

Umm that analogy is so far off the mark that it borders beyond ridiculous

The other thread I mentioned was talking about Uranium. South Australia has very large reserves of Uranium (and Thorium). Australia has 35% of the world's Uranium and about 70% of the thorium reserves, so if nuclear fission took off in a big way, we could become the new nuke sheiks  ;)

Sprintcyclist wrote on Mar 21^st, 2008 at 11:01pm:

Can we make renewable portable energy sources? Suitable for the grey nomads. Are solar panels enough, or is a combination better? Say a small wind turbine as well.

Conventional Solar Panels have the disadvantage that the total energy derived from them over their life cycle is typically less than the energy (mainly fossil fuel derived)  taken to manufacture them. That is not the case with TJ cells.

If we can develop cellulosic ethanol and biodiesel production facilities using otherwise unused (semi-arid) land, then at least we'll be part of the way towards supplying automotive fuel needs. Then we have enormous solar and geothermal reserves. Find a way of storing that electricity in chemical form, and we could easily be exporting energy.  

One of the new renewable technologies will probably dominate eventually due to market factors, but in the short term, we're going to have a mixture of energy sources.

Conventional Solar Panels have the disadvantage that the total energy derived from them over their life cycle is typically less than the energy (mainly fossil fuel derived)  taken to manufacture them.

I think your information is outdated by a few decades.

wrote on Mar 22^nd, 2008 at 8:37am:

The other thread I mentioned was talking about Uranium. South Australia has very large reserves of Uranium (and Thorium). Australia has 35% of the world's Uranium and about 70% of the thorium reserves, so if nuclear fission took off in a big way, we could become the new nuke sheiks  ;)

Seems a shame we aren't using it for power generation.


wrote on Mar 22^nd, 2008 at 8:37am:

If we can develop cellulosic ethanol and biodiesel production facilities using otherwise unused (semi-arid) land, then at least we'll be part of the way towards supplying automotive fuel needs.

Where is the water going to come from?

Quote:

Seems a shame we aren't using it for power generation.

Every environmentalist with their heads screwed on right should be campaigning for nuclear power in Australia. The trouble is they are few and far between.

Re the water - You don't need much water to grow Jatropha and sweet sorghum, and believe me, I live in the outback and I'm aware of the issues.  Here's a link:

http://en.wikipedia.org/wiki/Jatropha_oil

"Jatropha oil is vegetable oil produced from the seeds of the Jatropha curcas, a plant that can grow in wastelands. Jatropha curcas grows almost anywhere, even on gravelly, sandy and saline soils. It can thrive on the poorest stony soil and grow in the crevices of rocks."

A jatropha bush can live for up to 50 years, producing oil in its second year of growth, and survive up to three years of consecutive drought.

Something went wrong with your quotes. I fixed them up for you. Hope you don't mind.

wrote on Mar 22^nd, 2008 at 4:15pm:

Quote: Seems a shame we aren't using it for power generation. Every environmentalist with their heads screwed on right should be campaigning for nuclear power in Australia. The trouble is they are few and far between.

Why's that? With around 1% of the World's CO2 emissions it will make no tangible difference to the World's emissions if Australia goes nuclear or not.

PJ, any group of 20 million people could make the same argument, but it wouldn't hold water. The fact that you can conveniently draw a line around this particular group of 20 million and say they alone won't change anything is meaningless.

freediver wrote on Mar 22^nd, 2008 at 6:00pm:

PJ, any group of 20 million people could make the same argument, but it wouldn't hold water. The fact that you can conveniently draw a line around this particular group of 20 million and say they alone won't change anything is meaningless.

Its not meaningless at all. Were talking about a country, ie a political and economic entity. Something like a decision to go nuclear will require a government decision - so there you go, there is a line around our population of 20 million.

We might do more developing and exporting clean coal technologies in any case - given that we are a significant coal exporter.  

I've split off the latest posts to a new thread. We might keep this thread for Renewable Energy discussions.

New Thread

freediver wrote on Mar 22^nd, 2008 at 8:37am:

Conventional Solar Panels have the disadvantage that the total energy derived from them over their life cycle is typically less than the energy (mainly fossil fuel derived)  taken to manufacture them. I think your information is outdated by a few decades.

You're right. I should have looked into that further. I was relying on memory. The energy payback for most commercially available arrays is of the order of one year.

recfisher - perhaps we could get water from a device invented in WA, CETO it is called.
Uses wave energy to generate either fresh water or electricity.

Or divert soem of the runoff from the topend to make an inland sea.
Dig a canal from an ocean to a depression, let nature do the work ??

Sprintcyclist wrote on Mar 25^th, 2008 at 10:44am:

recfisher - perhaps we could get water from a device invented in WA, CETO it is called. Uses wave energy to generate either fresh water or electricity.

How far off commercial reality is it?


Sprintcyclist wrote on Mar 25^th, 2008 at 10:44am:

Or divert soem of the runoff from the topend to make an inland sea. Dig a canal from an ocean to a depression, let nature do the work ??

Not robbing Peter to pay Paul?

recfisher - commercial reality ??? hhhmmm, no idea. The trials work well, prob at leastg a few years.

Wonder if they could make a small portable one for grey nomads.
Power and water from the same device ??


most of the monsoon rains go out to sea, divert some inland ??
Even a salty inland sea would give exaporation, clouds, rain locally ???

paint on solar panels

http://www.inhabitat.com/2008/03/24/solar-power-without-a-solar-panel/

Installing solar panels on the roof of every new building in the world would go a long way towards solving our energy needs, but as we all know, solar panels are costly and often difficult to install. But what if the solar panel was an integral part of every building? What if solar cells could be painted on building products? Well, according to a team from Swansea University this type of technology will soon be coming to a hardware store near you.

The Swansea Solar Paint project is led by Dave Worsley, who, together with his team, were researching ways to make make steel last longer. By chance that they started to focus on the degradation of paints in steel surfaces, when they realized that their research could lead them to develop a new way of getting energy from the sun.

The idea is to coat every piece of steel cladding with a solar cell paint. As steel is passed through the rollers multiple coatings of of the solar cell system are applied to it. Based on the preliminary research, the materials that are being applied are suited to capturing low level solar radiation, which means that they should work just as well in areas where the sun doesn’t directly shine on them.

It’s not the first project which aims to develop paint that can convert solar energy into electricity, longtime readers will probably remember this project, from a few months ago. What is interesting about this one, is that the process, if successful, can be scaled massively and quickly. Think about the possibilities of having every roof clad with a durable, electricity-generating steel finish!

If the Solar Paint project gets off the ground, it is expected that they would be able to press around 30 to 40m2 a minute. This may not sound like much, but put it into perspective: according to Dr. Worsley, if all the steel cladding produced by just one manufacturer was produced to be energy generating, at a very conservative energy exchange rate of 5%, it would be the equivalent of 50 wind farms, or roughly 4,500 gigawatts of electricity, per year. If you ask us, this is a project that might be worth looking into.

---

Transparent glass containing solar cells could capture enough energy to power a home

http://www.enn.com/energy/article/34462

Professor John Bell said QUT had worked with a Canberra-based company Dyesol, which is developing transparent solar cells that act as both windows and energy generators in houses or commercial buildings.

He said the solar cell glass would make a significant difference to home and building owners' energy costs and could in fact generate excess energy that could be stored on onsold.

Professor Bell said the glass was one of a number of practical technologies that would help combat global warming which was a focus of research at the ISR.

"The transparent solar cells have a faint reddish hue but are completely see-through," Professor Bell said.

The solar cells contain titanium dioxide coated in a dye that increases light absorption.