Solar Power Making a Big DifferenceThe economics of generating electricity are very interesting, and must be kept in mind to truly understand how clean energy can make a difference. When power is generated matters a lot because there can be a huge difference in costs per kWh - it can be an order of magnitude - between a baseload power plant and a peaker plant that is only used during peak demand time.
So if you are generating lots of cheap clean energy in the middle of the night, you won't be able to shut down peaker power plants and you are only displacing energy that was already cheap to produce. Someday plug-in vehicles will be able to absorb, store, and use that off-peak clean energy, but right now we're not quite there yet.
So the bottom line if you want to shut down fossil-fuel powere plants and have good economic returns on your clean energy project, you need to generate lots of power during peak demand time so that the peak becomes lower and peak power plants just aren't needed anymore. Well, that's exactly what has started to happen in Australia where solar PV has been booming. The only hiccup is that lack of storage means that the solar peak isn't exactly the same as the demand peak, and peaker plants are still needed in the evening. If we could just add a bit more storage to the Aussie grid, solar PV - at the rate at which it's growing now - could completely shave off the peak and make many dirty power plants unnecessary.
If you want more details on this, check out what Mike Sandiford (he's the Director of the Melbourne Energy Institute at University of Melbourne) wrote about this. It's a great read if you're an energy-geek.
In any case, it's great to see solar PV growing so fast in Australia (and around the world). That's what happens with exponential growth: For a long time it seems like nothing is happening, and suddenly you get a huge spike.