Why the new RET is nothing more than political grandstanding

The Australian government recently updated its Renewable Energy Target (RET) to aim for 20% of our energy to be created from supposedly 'renewable' sources by 2020. On the surfaces this seems to be a good move forward (even if it is a little lacklustre in scope) but when you actually look closely at the amendment to the RET legislation it is clear that there has been a fair bit of bargaining and comprise going on to actually pass this as law.

The main change has obviously been to change the law to increase the RET to 45,000 GWh by 2020, but it should be noted that from 2021-2030 (the length of time defined in the legislation) the RET stays at 45,000 GWh, even though the national energy usage will probably increase! Even if the law is to be revisited before then, it makes sense that it should at the very least maintain the RET at 20% instead of decreasing with time as stated in the law.

Secondly, there has been a wording change from "eligible renewable energy source" to "eligible energy source". This allows for a new definition of the 'energy source' to include waste coal methane gas (WCMG). This is clearly a ploy to bring appease current providers as the definition of eligible WCMG providers only include those currently producing energy from WCMG. It seems to me that if the government really considered this a renewable energy source then providers should be eligible even if they start producing energy from WCMG after the law was passed.

But WCMG is not a renewable energy source. WCMG is a by-product of coal mining and is released when pressure on the coal seam is reduced. In no way is it 'renewable' in that it cannot be regenerated over time (unless your time scale is the same of that for coal regeneration!). WCMG should be looked on as a way of making producing energy from coal slightly more efficient, by using 'waste' gas from the seam the provider is simply getting more energy from mining the coal. I'm not entirely sure how the coal provider making bigger profits also makes them greener in this case.

The other worrying part of this change is that by changing the wording to 'eligible energy source' their is essentially an open door to include other so-called 'renewable' energy sources into the law. Proposals have already been put forward by the Australian natural gas industry to be included in the RET and given the definition of the law there is very little to stop them.

Overall, this law may generate some movement in the renewable energy sector, but to create a real meaningful industry the government needs to create stronger legislation and avoid political lobbying. Of course there are serious vested interests at stake here, but once the movement has begun, even the coal industry in Australia will realise that they actually stand to benefit from these laws, by using there considerable knowledge and resources to create greener, renewable energy.

CHP systems... so many possibilities!

A combined heat and power (CHP) system is one where either the byproduct (or waste) of a power system is used to generate heat or vice versa. By using waste products as the source for heat or power, the efficiency of the system as a whole is raised and it presents new revenue possibilities for an existing powerplant or industrial heating system. But is the concept behind CHP systems just limited to large systems, or can it be efficiently used in more common, smaller applications around the home or workplace environments?

In the true sense of CHP, the waste energy of a system is reused to create a more thermally efficient system. I can think of quite a few systems at home that have produce large amounts of waste heat every day, to name a few there are ovens, showers, cars, appliances and air conditioners but I'm sure if you dig into it some more you could find loads of different systems in your home that just sit there wasting energy. Ovens and showers are good examples because we typically actually physically extract the heat as part of their use anyway through ceiling fans and kitchen extractors. Where does this heat go after we extract it... nowhere! Just into the roof and then it's lost to the atmosphere. Now I know the idea of using this energy is not new, there are plenty of places around the world where it is commonplace to use secondary heat sources to keep the house warm. The problem in Australia is that we mostly have the other problem of trying to cool our houses down. But there are still ways we could use this waste heat, by using it to heat our hot water for example or by converting it to electricity, it would even be possible (in a cleverly designed system) to use this waste heat to actually cool the house down!

But I would like to see systems designed to reuse waste energy down to a small appliance level. For example, how could you use the heat from your toaster or light energy from your tv to power/heat/cool your home? Perhaps we could use light and heat sensitive products (paint would be a good one) to capture this energy... I realise that per appliance this would amount to a very small quantity of energy but in a whole house over time I think it would add up. Another idea might be to gather this energy while the appliance is on to power it while it is off, instead of wasting energy from plugged in, unused appliances.

To me this kind of design and thought process embodies the key to green/sustainable engineering, while it is nice to be saving the planet the more interesting part is about making our existing, wasteful systems more efficient and hence do more with less energy.

Ocean Thermal Energy Conversion

Ever since I was a little kid I have had a certain respect for the power of the sea. I used to sit with my granddad looking out over the ocean and he would tell me that I should never take things for granted when I was in the surf, that the sea could change in an instant and many people had lost their lives because they didn't respect the ocean enough. He would know, both him and my dad were commercial fisherman for a while and had seen their fair share of some of the sea's might.

It wasn't until many years later that I began to think that maybe the power of the ocean could be harnessed in some ways to provide us with energy. In many ways, the ocean is just a gigantic, constantly charging and discharging battery. It stores wind energy in the form of waves, and solar energy in the form of heat and even gravitational power in the form of tides. It then discharges these by crashing into land and by creating immensly powerful currents, so powerful that they influence the world's weather and stop many parts of the world from freezing over entirely.

The ocean is also a very difficult environment. As I learnt from my granddad, it can be highly unpredictable, but it is also very corrosive and provides an excellent environment for all forms of life, some more frustrating than others. Any ocean reliant energy technology, while having the potential to produce huge amounts of green power, is generally limited by the environment it is to be built in.

There are a few prominent technologies that harness power from different parts of the great ocean battery, these are, in no particular order,

• Wave Energy
• Tidal Energy, and
• Ocean Thermal Energy Conversion (OTEC)

I hadn't actually even heard of OTEC until a couple of days ago when I came across this article. To me it seems like a great idea, pretty much the ocean version of geothermal power. Unfortunately, for the reasons I mentioned above, the practicality of it all is very difficult and is made even more so by the fact that the parts of the world that are well suited to it, are also well suited to very unpredictable weather... like hurricanes!

Nonetheless, it made me wonder exactly how it all works and what the real challenges are. Basically, OTEC works by utilising the temperature difference between the deep, cold water and the warmer surface water in the ocean. Unfortunately, these temperature differences are not nearly as great as they are with hot rock geothermal (15-20 degrees vs 100-200 degrees!) although it does have the advantage of being truly renewable (unlike geothermal which has a lifetime of around 20 years). This small temperature difference means that the thermodynamic efficiency is very low, somewhere around 3%. This in turn makes the return on investment quite small even in the long run due to the high maintenance costs (to stop things rusting).

However the real power of OTEC is that by pulling up cold seawater (using an open cycle system, which also avoids using chemicals such as ammonia) you have the opportunity to create unique biosystems that would otherwise be unsustainable in the region. Concepts such as aquaculture for cold water environments in the tropics and chilled soil agriculture allow plants and animals that would otherwise not grow very well because of the heat.

Of course, playing god like this can have very serious consequences, but when you combine new foods with coal and oil free power, clean water (desalination is also possible using OTEC technology) and the possibility of exportable products (minerals and even hydrogen production are possible) then you have a very real opportunity to improve the quality of life for those living in small islands and other equatorial nations.

In the end I think that OTEC is not the most promising renewable energy technology available and this is perhaps the reason why there has been very little progress in developing it on a mass scale. There are however, a few good proposals of it in use on a small scale, for example military bases in Diego Garcia and Guam. As with all renewable and new technologies in general, all it needs is something to kick start it and get the research going!

WorldChanging and TED

Ok, time for a break from the tech for a little inspiration. I read somewhere that whenever we do something that fills us with enthusiasm, we are going in the right direction, and as far as I can see it, inspiration is the source of enthusiasm.

The first site is a blog I have been following for a while and is a place where I have discovered loads of the things that people are doing to make the world a better place. For those who haven't been to WorldChanging you should definitely drop in for a visit sometime, there are some great ideas there and it is updated daily with more and more from around the world.

The second site is one that I've only discovered recently and that is TED (Technology, Entertainment, Design - Ideas worth sharing). TED has a ton of videos recorded from some of the worlds best designers, engineers, academics, entreprenuers etc talking about what they are really passionate about. This site isn't necessarily devoted to climate change or any particular topic, it is just a collection of ideas from some very bright people.

Anyway, I just thought that I should share these to sites with you all so that you can enjoy them too. I have already had a heap of ideas about kite powered wind energy, electric cars on mobile phone style plans and the fundamentals of design to name a few :)

Algae as a Biofuel?

I was reading a blog the other day about a Chinese company looking to use algae as a way of absorbing carbon from their coal power stations. The idea is that given that algae needs only sunlight, carbon dioxide and salt water to grow it can be grown in mass quantities using the CO₂ from the coal station. This would in theory produce 'cleaner' coal and a useful by-product as algae can be used as both a fertiliser and as be converted into biofuel.

My problem with this is that are you really saving any carbon from entering the atmosphere?

After digging around for a bit, I came across some useful information in wikipedia. When biomass is burnt as fuel, it releases less carbon than was used in its growth for two reasons,

1. Approximately one third of the carbon absorbed by the plant during its life is sequestered in its roots, which are left in the soil to rot and fertilize nearby plant life, and
2. Combustion of biomass produces 1-10% solid ash (depending on type of plant used), which is extremely high in carbon (this ash is commonly used as fertilizer)

So given that we can convert the biomass into a usable fuel without consuming too much energy (or using energy from other renewable sources) then the net outcome is more power output for only slightly more carbon output. So really this comes down to a question of efficiency... are we better off spending the money researching and developing an algae based carbon absorption plant which then converts the algae into a usable fuel, or are we simply better off using that same money to improve the efficiency of our existing coal power station, or even investing in other renewable technologies?

The graph below gives some idea of the relative carbon intensity (carbon output per unit of energy output) of biofuels against fossil fuels. While it doesn't include algae fuels it does show that it requires less carbon dioxide to extract energy from biofuels in general. This, coupled with the fact that our primary source of food for growing the algae comes from a process that is also generating power, makes for a more efficient process than simply doing either independently and makes a better case than existing biofuels.

It really is hard to say without seeing the numbers. But given that the by-product of the algae may also be used as a fertiliser, and more importantly, that there is a significant amount of R&D in an entirely new field, then I am tempted to say that it is worthwhile. Because even though it may cost more to develop the algae technology, there are other advantages to broadening our approach to energy. For example, algae may be used as a natural source of hydrogen and it is possible to extract ethanol without having to harvest the algae.

In researching all of this I was pretty amazed to realise that biofuels really are becoming an established industry in themselves. I guess this is because they offer a solution that doesn't require major infrastructure changes and they offer a significant solution to the transport industry, which is one of the major (and in some ways hardest to fix) contributors to global CO₂ levels. The things is though, that although we are talking about a more efficient process, the use of biofuels (whether algae or otherwise) still never gets past the key point that we are still putting carbon into the atmosphere at an unsustainable rate. While biofuels may all make us feel a bit better about 'doing our bit', they will never be enough to reduce our carbon output to sustainable levels.

Geothermal Power in Australia

This week saw me attend 'Geothermal Energy - Current Projects and Future Directions', a presentation hosted by the Brisbane chapter of the Institute of Engineers (Society for Sustainability and Environmental Engineering). The presentation included two points of view; one from GeoDynamics, an Australian company that (in conjuction with Origin Energy) has recently completed 'proof of concept' for energy production using 'hot rock' geothermal, the other from a government sponsored research and development centre (in conjuction with UQ), the Queensland Geothermal Energy Centre of Excellence (QGECE).

Geothermal power can be generated using one of two methods. The first, traditional, method generates energy from hydrothermal systems, where fluids circulate through rock fractures where high heat flow is present, typically near active tectonic plate boundaries. Hydrothermal systems are generally used for direct applications and not electricity generation as they may be located in unstable areas and have problems with maintaining sufficient fluid to generate power over time.

The second method, which was discussed in the presentation, involves pumping fluid deep into the ground (3km and below), extracting heat from rocks before retrieving it above ground for use in a heat exchanger. The rocks underground can be very hot, upwards of 200ºC, due to the decay of radioactive material and the kilometers of insulation above them. This provides an excellent source for baseload energy.

Obviously, using the aptly named 'hot rock' (method two) process has complications, not the least of which is having to drill more than 3km underground. But never fear, we have the technology! The oil and gas industry has been developing deep drilling techniques for decades now and it is possible to buy equipment for drilling a long way down. Another problem is finding rocks that are hot enough and over a large enough area. In this case, we are very lucky here in Australia as there are huge regions containing rocks with temperatures greater than 250ºC!

As a side note, while geothermal power is technically 'renewable' it takes many thousands of years for these rocks to heat up once they have been cooled from extracting the heat for energy. Fortunately for us, to reduce the temperature by around 40 degrees (resulting in an approximate 50% loss of efficiency) would take between 25 and 50 years and that would occur over a relatively small area. Given this is a huge resource (albeit out in the middle of nowhere for the most part), investment in geothermal power makes a lot of sense for Australia.

The process to extract energy from hot rocks involves drilling an 'injection' well down into the hot granite approximately 3-5km below the surface. This granite has natural horizontal fractures (due to horizontal compression). These are expanded over a wide area by pumping high pressure fluid into them and forcing the fractures open further. Then a second (and possibly more) 'production' well is drilled to the same depth within the expanded fracture region. Once this is established, fluid is pumped down the injection well, heated by the rock below and retrieved up the production well(s), passed through a heat exchanger and sent back down again. Since the heat of the rocks is so high, the heat exchanger produces enough energy to drive a turbine which in turn generates electricity.

Anyway, back to the presentation. Gerry Grove-White, the Managing Director of Geodynamics, described the process that their business had been through to come to the proof of concept milestone they achieved in early 2009. Their journey was not without difficulty. Gerry described some of the difficulties they had, for example, obtaining equipment as a 'small consumer' in the world of mining, or that there was actually a surprisingly large amount of water under very high pressure (to the order of 70MPa!) down there. This was alongside understanding many of the risks involved in hot rock geothermal power. Things like the ability to create a horizontal fracture, using air condensing rather than Australia's precious water resources, how to manage multiple production wells and whether corrosion (due to radioactive material or otherwise) would be an issue.

Despite all of this, the project has continued with only one major setback - a well blowout in April 2009. This was a fairly major incident although, as Gerry explained, it is not entirely uncommon incident in the oil and gas industry. While the reason for the blowout has not been resolved, there doesn't seem to be any specific concerns regarding the continuation of the project, however there will be some delays in reaching a commercial demostration plant (of the order of 6-12 months).

Gerry finished off with a very interesting note about energy distribution in GeoDynamics' business model. Obviously, having power generated so far from its end consumers creates problem for distribution. One ingenious solution to this was to (particularly in the initial stages) provide the power to consumers willing to use it on or near the site. Examples given for this were data centres and high quality silicon producers, both of which use large amounts of power (which could become very costly when an ETS is introduced) and could be co-located with the plant.

Next up was Professor Hal Gurgenci from the QGECE and it was time to put our theory hats on. It really was quite amazing to hear the difference in the two presentations. One focused on the practicalities of creating a business and the process required to actually create energy (and hence money) from it, while the other was devoted to the theory behind creating a more efficient cycle. Professor Gurgenci described the difference between the standard rankine cycle (commonly used in steam turbines), and a theoretical supercritical cycle using CO₂ as the fluid for heat extraction.

Unfortunately, my memory of 2^nd year thermodynamics failed me and I spent a large section of his presentation trying desperately to follow what was going on! One point I did catch onto though, was the necessity for dry rocks to allow the supercritical cycle to work. Given what Gerry had said regarding the high pressure liquid underground it got me wondering whether there may have been a disconnect between the academic world and the real world as is so often the case. On the plus side however, Professor Gurgenci did present some excellent points on increasing the efficiency of the entire process using concentrated solar power to further heat the fluid once it reaches the surface before going into the heat exchanger.

All in all I thought it was an excellent presentation from both speakers. For someone who knew very little about the entire hot rock geothermal process it was very well explained and was, for the most part, taken from an engineering point of view.

Sources:

Geoscience Australia

GeoDynamics Limited

'Direct use of Geothermal Energy: Opportunities for Australia', GEOCAT #65454, Geoscience Australia

'Electricity Generation from Geothermal Energy in Australia', GEOCAT #65455, Geoscience Australia

'The Power Beneath Our Feet', Tim Flannery, Sydney Morning Herald, April 2005

Greenfest 2009

This weekend saw the second annual Greenfest to be held in Brisbane. I headed down on the last day (Sunday) and was lucky enough to catch some of the great weather we enjoyed this weekend. For those who don't know, Greenfest is a free event with three key elements, purpose, education and production -

Purpose: Accelerate the rate of change in consumer behaviour
Education: Throughout the event from exhibitors to speakers and film
Production: Walking the talk in our own production

This all amounted to a respectable number of stalls, live music and educational talks held in the Brisbane botanical gardens.

As is typical of these kinds of events, there was an interesting cross-section of exhibits. There were the small companies advertising predominantly different solar solutions for consumers, a range of environmentally friendly products and foods, politcal groups and a minor presence from some of the bigger companies focusing in the environmental field in Australia. Aside from the environmental products and foods, which I see as the reason people get dubbed 'greenies' when they mention sustainable engineering, corporate sustainability or the like, most exhibitors seemed very professionally set up and it was great to see just how much interest and room there is in the Australian market for green companies.

However, one of the things I was most impressed with, was the involvement of the Queensland government in Greenfest. I wasn't really aware of just how many programs were being run by the government and the level of thinking (and money) that had gone into them. I must admit that I tend to dismiss state government programs as being generally inefficient and missing the point, but there were some fantastic ideas being pushed at Greenfest, everything from state-wide ethanol initiatives (sugar cane, not corn), to green car guides, to free (for Brisbane city residents) energy monitoring and efficiency audits for your home. I haven't yet looked fully into the details and progress of these programs, but from the surface they look very promising and if nothing else are a very positive step in the right direction. I can only hope that they are not just 'crowd pleasing' programs and that they are the first step in the direction of real green policies and improvements, not only in Queensland but Australia wide.

Another good thing was to see the presence of some serious corporate consulting companies in this space, again I saw this as evidence of a growing industry in Australia for green technology and corporate sustainability.

Unfortunately, I was very disappointed to see a distinct lack of any really big companies/organisations in the green technology sector. For example there was no presence from the Australian Institute of Engineers which have some active societies and projects in Queensland, nor were there any major corporations with green programs. I think if companies are really serious about gaining the most benefit from their green programs then they need to be active in events such as this, otherwise how do people know what's going on? It's the same as the Queensland government's presence, it highlights some of the major programs that they have going and provides people with a chance to understand them a bit better. The only reason I could think of is that Greenfest is simply not big enough yet, nor does it have a big enough following in the corporate world to warrant the presence of these big companies an organisations. Hopefully, as the festival grows over the coming years it can begin to merge these bigger organisations into its lineup.

Having said that, there was a presence from a couple of auto companies, including Mini (BMW), Suzuki, Saab and Telsa all of which had some excellent ideas that came from very different lines of thought. Again though, it was interesting to see that Honda and Toyota, both of which have some obviously great hybrid vehicles weren't present. I particularly liked some of the smart computing technology built into the Saab biofuel demo car, which allows the car to adapt to different ethanol mixes in fuels, anywhere from 0-85% ethanol. This is already an old concept in Europe where the car was introduced in 2006, but this kind of car hasn't reached the Australian market yet, largely due to the lack of high ethanol fuels available.

Anyways, all in all I thought it was a great event, well organised and with a decent turnout. I can only see this event growing in the years to come as more organisations get involved with it and community interest grows.