I have a different view to Klare.
I work as a risk analyst in the energy business. I was once an energy quant in investment banking, and now I have my own business producing software to analyse investment risk.
The relationship between renewable and fossil fuels, and therefore in effect the relationship between high and low carbon energy sources, is driven almost entirely by the market. No matter how well-meaning the intentions of policy makers, the only real effect they can have on what type of energy source is used depends on the price.
Most of the conservationist (as opposed to conservative!) actions of lawmakers are therefore aimed at changing the price, and they have been more or less successful. For example, the Australian carbon tax has had a substantial effect on the mix of investment in the Australian energy market, simply because it has changed the price.
Sadly, the policies of lawmakers come and go. In Australia a conservative government may soon be elected who will undo this good work.
But all is far from lost. The long-term prognosis for the cost of energy produced from renewable sources is excellent. For example, the cost of electricity generated from solar and wind is already at 5c per kw/h in the United States, and if projections are to believed, they will fall to 1c per kw/h over the next 50 years.
This isn't driven by policy, or politics, but the cost of technology. Fuel from the sky or the wind is inherently cheap, because we don't have to pay for it or ship it to plants.
Never forget, the energy from the sun is free. All we need is the technology. And we have the technology now. So don't despair: oil companies may be a potent bogeyman, but the market is a category 5 hurricane that will blow them away.