Wind and solar PV are not enough

Wind and solar PV have made great leaps forward in recent years. But to make the ground necessary to avoid dangerous climate change, we must put more effort into other clean technologies.

Thanks to significant levels of government support, wind power and solar PV have progressed in leaps and bounds over the past decade. They have now reached a scale that they represent a major component of new power supply additions in the developed world.  But while these two low emission energy sources are making good progress, they aren’t enough to solve dangerous climate change. 

The other near zero carbon options for meeting our energy needs are pretty much stalled or barely out of the starting blocks. Meanwhile additions of coal in China and India have been overwhelming a great deal of the progress in renewables.

The chart below from Bloomberg New Energy Finance illustrates how global investment in wind and solar is an order above all the other renewable energy technologies. In lumping solar thermal together with solar PV in the chart it hides the fact that solar thermal represents a tiny fraction of investment. Last year solar thermal power generation capacity increased by 460MW, by comparison solar PV expanded by 30,000MW.

Annual Investment (US$billions) and annual growth in investment - 2011

Looking beyond renewables to other low carbon technologies, nuclear’s much talked about renaissance has been absolutely gutted by the Fukushima debacle. Now rather than a renaissance, we’re talking about a nuclear recession.

And carbon capture and storage is still proceeding at a snail’s pace. It hasn’t been helped by the dramatic drop in the price of gas in the United States, which has reduced the pressure on that country to find a way to decarbonise coal-fired power.

In Australia we confront a similar story. Last year we installed more solar PV capacity at 800MW, than any other fuel type including fossil fuels. And wind is now lined up to deliver several thousand megawatts over the next few years (subject to the RET not being altered). 

But the biomass power project pipeline is tiny, the geothermal sector has pretty much gone back to the drawing board, the major solar thermal project Solar Dawn has had its funding withdrawn, and we seem no further advanced in carbon capture and storage than we were in 2008. There is some small scale activity occurring in batteries and electric vehicles but it’s largely experimental or very small scale trials, although recent news today about the e-Commodore is promising. Also while Carnegie is making progress with its wave technology, other projects don't seem to be much closer to injecting megawatts into the grid, in spite of government grants.

While a lot of poorly researched claims are made about the limits of wind and solar PV, eventually pushing further increases in their capacity will be like pushing on a piece of string. Research by University of NSW academics exploring the feasibility of a 100 per cent renewables scenario in Australia shows the incredible importance of solar thermal with storage and the use of biomass to balance out the variation from wind and solar PV.

Their work also found examples of weather systems that would lead to extended periods of low amounts of wind or solar over large geographic areas. At a more localised level, which is what matters for managing distribution networks, solar PV’s true potential can only be realised if battery costs can be substantially reduced. 

The modelling work recently kicked-off by AEMO examining 100 per cent renewables scenarios, if done well, should help explore in an informed manner the limits of wind and solar PV, and value of other technologies.

It is essential that we debate how to accelerate the progress of low emission technologies beyond just wind and solar PV, as well as energy storage. As part of the review of the RET there is the obligation to consider the extent to which the scheme is encouraging a diversity of technologies. This is extremely important.

Unfortunately we’re not getting any kind of constructive dialogue on this issue. With fossil fuel interests seeking an aggressive scale-back in the RET, the renewables industry has felt the need to retreat into a defensive bunker.

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