After my last foray into the controversial world of the environment and power generation (which generated some stimulating discussion and research for me) I thought it best to take a look at the renewable means of power generation and which of them have a future. I’ve had a bit of experience with most of the technology in the past with a few of my off site engineering lectures, a requirement for any engineering degree, being held on renewable energy technologies. My father also teaches renewable energy classes at the local TAFE here in Canberra, and I’ve seen quite a few interesting projects he’s been involved with over the years.
When we talk about renewable energy sources we’re looking for something that doesn’t rely on fossil fuels. The main candidates for renewable energy are:
Now not one of these solutions can provide meet all of the energy needs of the entire world and there’s many different factors to consider. The ideal solution will probably end up with a combination of many of these technologies (and some of the ones that are currently under development) just like the power generation we use today.
First the main consideration is base load power generation. Whilst this is usually trotted out as the argument to destroy the idea of using any form of renewable energy it does have raise a key points that need to be addressed. Many of the renewable energies I’ve mentioned (in fact just over half of them) can’t produce stable amounts of power. Solar, wind and oceanic technologies vary their power output significantly depending on their environment. To solve this issue base load generating stations like geothermal and biomass have to be used to supply that base level of power. The other alternative is to invest some storage technologies, like molten salt for solar thermal. For Australia I believe that geothermal and solar thermal are probably the way to go. This is because we have so much uninhabitable land that is very dry and sunny, something that these technologies thrive on. Photovoltaics are nice for smaller installations however they currently do not scale as well as the others, although that might all change when sliver cells take off¹.
Secondly load following plants are also required in order to accommodate variations in power requirements. Biomass and Hydroelectric are both options for this however I’m not entirely sure how well they can scale up. It may be more efficient to have more base load plants and just disconnect them from the grid. Whilst that may sound counter-intuitive it would be perfectly acceptable since the energy is usually not being harnessed anyway.
The last problem I’ve seen with the implementation of renewables is the lack of ideal locations for certain technologies. Geothermal requires geysers to be present or implementation of a hot rocks plant. Wind requires either high altitude or favourable wind environments such as offshore. Solar and solar thermal require a decent amount of sun and a nice flat area. You can see where I’m going with this, there’s a fair amount of work to be done to get these things in and working.
Having said all this, I’m still all for these technologies. All of the problems I’ve put forward are nothing short of solvable and eventually we’ll be forced into implementing these solutions. The great news is a lot of the supposedly big bag oil companies are in fact on board and supporting this kind of technology. The ones who aren’t will eventually fall by the wayside and we can only hope they come around before they pull an Enron and dissolve the company.
I still believe nuclear would be a great transition technology, but only time will tell.
¹I actually had the pleasure of meeting the developer of sliver technology, Andrew Blakers, back when I was a fledgling engineer. His technology does have the potential to change photovoltaics in a way that would make them highly viable. Origin Energy has some great pictures of the cells in development, and hopefully they’ll be commercially available soon.