Carbon intensity of electric power sources (Weekly pic)

IPCC (2014) median estimates of life cycle carbon intensity of selected electricity sources. The figure includes mining, raw material and waste disposal impacts, but excludes infrastructure requirements such as energy storage, strengthened transmission grid, or backup generators. As a result, the figures are likely to underestimate emissions from variable sources such as wind and solar power.

To avert dangerous climate change, we will need lots and lots of low-carbon energy sources. Electricity is perhaps the most important of these, as it is wonderfully flexible form of energy that can replace fossil fuels in multiple applications. Furthermore, it is easy to deliver and we know how to generate it in quantity with very low carbon emissions.

Of all the methods of low-carbon electricity generation, nuclear power is still the single most important. It alone produces far more low-carbon electricity than all the “new” renewables combined. This is an inconvenient fact for those who try to oppose nuclear power while simultaneously opposing climate change. As a result, one hears constantly claims that nuclear power produces greenhouse gases – and that this makes it unsuitable for climate mitigation.

The first part of this claim is true: In fact, no energy source produces energy without greenhouse gas emissions of any kind. There are emissions associated with wind power, and there are emissions associated with solar power. The second part, the inference, is false, however. In all the serious research on the subject, the carbon balance of nuclear electricity is found to be very low. It compares well with wind power and, in fact, tends to be lower than that of solar electricity.

The most common counterargument we’ve heard at this point is the obvious: “Wait, what about uranium mining, or building of nuclear power plants? Surely they contribute a lot of emissions?” 

Fortunately, we can say that this counterargument does not hold water. The figures quoted here, and in any serious scientific report, are so-called lifecycle emissions. This means that the figures already include impacts from mining, building of power plants, and so forth. In our opinion, it is somewhat insulting even to think that such obvious emission sources would not be included in any serious calculations.

But one thing that’s not included in these calculations is the additional infrastructure that is required to deliver equivalent level of service. For nuclear power plants, not much additional infrastructure is required, beyond obvious power lines. But if we want to deliver equivalent service – equivalent amount of reliable electricity generation – from variable sources, we most probably are going to need more infrastructure. This can be reinforced electricity grid to transfer energy from places where the wind blows or the sun shines to places where electricity is needed; it can be backup generators that provide power when it’s dark or calm; or it can be wind turbines and solar panels that are part of “overbuild” required to ensure that at least some catch the wind or the sun at all times.

So far, as the share of variable energy sources in electricity grid has remained small, this additional infrastructure is not really needed. The existing grid and existing power plants can cope with the limited variability, although this often incurs extra costs already. But as we expand our low-carbon energy production, we will need more and more infrastructure to cope with increasing variability. This causes both economic and environmental costs, resulting to higher carbon balance than these simple calculations would suggest.

This is one of the reasons why we believe that opposing proven solutions that can provide significant quantities of low-carbon energy is, at this point, a gamble with the climate. For more information, buy our book, Climate Gamble – or come to Paris during the COP21 climate negotiations and get one for free!



Land use of equivalent wind and nuclear power generation (Weekly pic)

Land use of equivalent wind and nuclear power generation. Examples are Olkiluoto nuclear power plant (Finland) and Ranger uranium mine (Australia), and a composite graphic based on Oosinselkä wind farm (3 MW turbines).
Land use of equivalent wind and nuclear power generation (ca. 27 terawatt hours per year). Examples are Olkiluoto nuclear power plant and Onkalo waste repository (Finland) with Ranger uranium mine (Australia), and a composite graphic based on Oosinselkä wind farm (3 MW turbines). Maps are to scale and include only essential roads and power connections.

Besides climate change, one of the major environmental problems of our age is biodiversity loss. As it is caused largely by increased human land use, stopping biodiversity loss requires us to reduce the land footprint of humanity.

A major problem with renewable-heavy or renewable-only energy scenarios is that they essentially do not acknowledge any problem with human land use. In these visions, vast areas are to be dotted with wind turbines, filled with solar panels or (perhaps most problematically) used for biofuel production to produce enough energy and to deal with intermittency of stochastic energy sources: if you’ve ever heard the explanation “it’s always windy somewhere,” you’ve heard a call to build two to five times as many wind turbines as their nominal production would suggest.

Compared to wind, solar and biomass farms of the required scale, the environmental footprint of nuclear energy is very small. The graph above attempts to show this difference, based on real-world projects in Finland (and an Australian uranium mine). Note that this is for similar annual production of about 27 terawatt hours: to produce energy of similar quality – that is, non-intermittent – one would probably require at least three wind farms of equal size, spaced far enough apart, or significant energy storage facilities.

Note also that the figure likely overestimates nuclear land use. The Olkiluoto plant contains a reserved area for fourth reactor, capable of increasing the annual production from same land area by as much as 13 TWh; and the Ranger uranium mine could easily supply many more reactors.

We would like to emphasize that this picture should not be construed as an argument against wind power or other renewables. We almost certainly need all the low-carbon energy we can have, and both wind and solar have, on the whole, much lower environmental footprint than fossil fuels. The only reason we publish this image is to show that the oft-stated claim of nuclear energy’s environmental destructiveness is misleading at best, and outright falsehood at worst.

This series of posts introduces graphics from our book Climate Gamble: Is Anti-Nuclear Activism Endangering Our Future? The book is now available on in Kindle and paperback formats; see also our crowdfunding initiative which aims to deliver a copy of the book to COP21 climate delegates in Paris this December.