So we only produce small amount of oil and have to import it, we have no good quality, easily accessible coal but we have plenty of gas. Why don’t we just use gas for everything? We could generate electricity, make plastics, fertiliser, clothes etc, heat our homes and cook on our stoves and barbies.
There is no reason why we couldn’t. We have converted vehicles to run on gas (LPG) and buses to run on Compressed Natural Gas (CNG). Sydney buses proudly advertise that they run on natural gas, but as NSW don’t allow their gas to be produced, they import it all from us. The cheapest way to make hydrogen (and ammonia) is from natural gas.
In the long run though, fossil fuels are a luxury and a finite luxury at that. Even though natural gas is not toxic it is a GHG and when burned creates CO2, another GHG. Gas production can also industrialise rural areas, create subsidence and water issues. Luckily in Australia our sedimentary rocks are old and are already highly compressed and consolidated, so we do not have a problem with subsidence caused by gas or water extraction.
Global warming is all a scam I hear some people say, just made up by politicians. Well, the basic physics has been known for a hundred years and satellite measurements have verified the process. We just don’t have a good understanding of how all the complex processes will pan out. There are some upsides as more CO2 helps plants grow, but there are many more severe downsides. There is little doubt that we are all better off by minimising our GHG output.
Besides, solar and wind are the cheapest fuel when the collectors (windmills and solar panels or mirrors) are set up and operating, so why not take advantage of the cheap, less polluting renewables. The problem with renewables is their intermittency and the need to have alternate systems in place, storage and frequency control. Renewables can also industrialise our rural areas.
We can and will have sustained periods of little sun and wind and need complete backup systems in place. Gas and diesel are the best bets and there is also an argument for coal (not in SA though). Natural gas needs a pipeline in place and maintained or portable LNG units while LPG can easily be shipped in. For short term, occasional emergencies, diesel is the best bet. Diesel generators are easily available, easy to install and for occasional use have the least environmental footprint. We use a lot more diesel on our roads and farms than in occasional use backup generators.
Batteries are great for their frequency control and for smoothing out energy input. They can also supply electricity backup, but currently short term only (ie an hour or so). They are great for the instant hit and SA’s big battery saved Victoria’s power when their coal input crashed. Their most environmentally friendly use is for these activities but not for large scale backup.
There are currently about a billion road vehicles on the planet and if we could somehow replace all of these with Tesla EVs, it would require about 60 MT of Lithium Carbonate Equivalent, a little less cobalt and maybe 200 MT of aluminium. That is about our total current known reserve of lithium and about our annual production of aluminium. It is estimated that an EV uses about double the GHG to build than a conventional car. If we also use batteries to back up the world’s electricity supplies it all gets unwieldy pretty quickly with current technology.
Lithium has been produced from high altitude lakes, in evaporation ponds, just like you would for salt. With our increased demands Australia now supplies about half of the world’s lithium needs from hard rock minerals which need mining, cooking in a blast furnace and washing in acid.
Which is why I suggest that a diesel motor turned on a few times a year is cleaner than full scale battery backup. It is also why I suggest that we won’t all be driving electric cars in ten years’ time.
Long Term Storage
Current batteries are minerals intensive and have fairly short lives. Long term storage needs something better and the best bets currently are pumped hydro, hot silica (or salt), compressed air and possibly flywheels.
Local Company 1414 degrees is in the process of developing a system where they use molten silica to store electrical energy as heat and various companies around the world are investigating large flywheels as energy storage systems.
Compressed air is another good storage system, at least in the small scale. Air is compressed and stored in tanks when you have excess energy and the compressed air used to run machinery and tools. Whyalla steel works currently uses the system.
Pumped hydro has been around for about a hundred years but is now coming into its own in areas where water and hills are plentiful. Our Snowy Mountain pumped hydro is a fairly expensive scheme and won’t be ready for ten years or so and still needs to get over some engineering hurdles. It should be good when it is up and running, but perhaps it would not be built today, if starting from scratch with too many environmental issues.
Note that pumped hydro uses whatever energy is available to pump water to an upper reservoir and if it uses coal fired power it is storing coal fired energy. If it uses solar energy to do the pumping it is storing solar energy.
In South Australia our fresh water is perhaps a bit too precious although a scheme has been proposed for an abandoned dam within the bounds of Adelaide. The scheme for Whyalla is proposed as a salt water, pumped hydro plant, with a salt water dam to be built at Cultana.
Is this a good idea? The major issue with the fraccing process in the US is disposing of saline waters, and here we have a solar storage system creating a large salt water storage pond!
There has only been one commercial, salt water, pumped hydro plant built previously, in Okinawa, Japan. They had all sorts of problems with corrosion in the pumps and generators and shut down in 2016 after running at a loss for about 15 years.
So we have a while to go before we have effective wide spread storage systems. My personal favourite is the 1414 Degrees system and believe we should support them when they float the company later this year. Batteries are a good idea, especially if used sparingly as we develop better systems.
For transport systems, battery run EVs will have their place but I can’t see them dominating the market. One big problem is that the average age of our current vehicles is about ten years and this is about the maximum useful life of our EVs being manufactures today. As the vehicle is mostly battery and electronics, it is hard to see how a battery will be replaced at the end of the vehicles life. These batteries weigh about half a tonne and are essentially the car chassis.
On the other hand, our vehicles can easily be converted to burn LPG, hydrogen or ammonia. LPG still has a carbon footprint and hydrogen is perhaps just as environmentally damaging. Large scale hydrogen use will lead to large scale leaks and when it reaches the upper atmosphere, hydrogen reacts with ozone, once again destroying it.
Ammonia on the other hand has no significant environmental footprint and burns to N2 (Nitrogen) and H20 (water). With a few tweaks it can be used in our current vehicles and with a bit of research could become a trouble free solution. Ammonia is readily produced from methane or from hydrogen with the latter available from hydrolysis of water from solar energy.
Renewables are the way of the future and we should do well being early adopters in SA. We have plenty of gas for backup and should support our local gas exploration companies. I have a feeling that we will still be substantially driving petrol and diesel vehicles in ten years’ time and that we will have large scale solar and wind farms with backup gas fired generators. We will still be cooking and heating with gas.
Recent talk of 50% renewable energy increasing to 75% is for electricity from renewable sources. We use plenty of additional oil and gas to produce energy for use in transport, cooking and heating. Our total energy use is still by far, mostly from fossil fuels. Having 75% of our energy requirements from renewable sources in the next ten years is probably an impossibility.
Is nuclear power an option, large scale or modular, fission or fusion. Do we need another interconnector? Why is our power so expensive and what can we do about it? Can we increase to 75% of our electricity from renewable sources without breaking the bank?