Tag Archives: Renewable


Stretching our Carbon Budget with Nuclear Power

By John Gorman
Originally published by MediaPlanet, December 17, 2019

Nuclear power is a practical and inexpensive technology, and it’s essential to avoiding the worst effects of climate change in the coming decades.

Modelling our climate is complex, but the big picture is simple: to keep global warming under 1.5°C, as proposed under the Paris Agreement, there’s only so much carbon we can pour into the atmosphere – about 580 gigatonnes of carbon dioxide.

Humanity is burning about 37 gigatonnes per year, which means that the time left to stave off catastrophic change is short. By the time we burn through the budget, we’ll have to be taking out as much as we put in.

Limited national progress

Through the Paris Agreement, countries around the world committed to target limits on their total carbon emissions. If kept, these should keep us within the carbon budget.

But they aren’t. Many countries are not even coming close to their targets, partly because of increased demand for power and rapid industrialization. Germany, for example, has had to increase its fossil-fuel use because of the closure of nuclear power plants. And China is massively increasing coal-fired electricity generation. Even Canada is not on track to meeting its target of reducing carbon emissions by 30% from 2005 to 2030. According to the International Energy Agency, greenhouse-gas pollution has risen worldwide for two consecutive years.

Green alternatives

There have been hopeful signs. Prices of low-carbon renewable energy, such as wind and solar, have dropped substantially in recent years, and there’s been a corresponding increase in use. In 2017, solar power reached a global capacity of 398 GW. And carbon capture and sequestration, the only technology proven to remove carbon from industrial operations, has been demonstrated in Weyburn, Saskatchewan. We can expect these technologies to continue to advance. But can this be done in the decade or so we have left in the carbon budget?

Nuclear power: clean and affordable

Given how short our timeline is, nuclear power offers a practical way ahead, and it’s already doing a lot to keep carbon out of our atmosphere.

The lifecycle carbon emissions of nuclear power are comparable to wind and even lower than for solar. According to the World Nuclear Association, the world’s 445 reactors are saving 2.5 gigatonnes of carbon-dioxide emissions every year. This is why Ontario, which generates almost 60% of its electricity through nuclear, has seen a steady drop in air pollution since 2003. It’s why countries such as Sweden and France have been able to decarbonize their economies. It’s also why provinces such as New Brunswick and Saskatchewan, and many countries around the world, are taking a closer look at what we call the “new nuclear” – small modular reactors that can power industrial activities and remote communities.

Environmentalists look to a future powered by renewables, but there is also increasing recognition of nuclear power as part of that future, or at least a bridge to it. This is partly because the transformation of our energy sector is going to be expensive, while nuclear power delivers electricity at competitive prices. This, along with the increasing capacity of nuclear technologies to support variable sources of electricity like wind and solar, makes nuclear an attractive option for decarbonizing our electricity grids.

As our climate crisis deepens, and our needs for clean electricity increase, nuclear power is emerging as our most practical, clean technology choice.

Nuclear Education Nuclear Energy

How is your Energy Systems Literacy?

Last week we blogged about the need for a conversation about energy and a pan-Canadian energy strategy.
June 28-29th in Calgary, Pollution Probe is holding an Energy Systems Literary  in Canada workshop as part of its ongoing series about engaging Canadians in dialogue about energy. According to the workshop’s overview,

Pollution Probe’s workshop series on Energy Systems Literacy in Canada is a national initiative designed to promote a new approach to engaging Canadians in a dialogue about energy – a dialogue that is firmly rooted in a “whole-systems” perspective that recognizes the interconnections between the energy sources we draw on to deliver the energy services we demand.

The regional workshops are taking place from February to September 2011 and are for energy stakeholders to convene and take a forward-looking approach to energy systems in Canada. They are intended to build the foundation of a longer-term program to build energy systems literacy in Canada, supportive of national energy priorities.

Pollution Probe produces the Primer on Energy Systems in Canada which is meant to “identify the opportunities for improving the way that we produce, distribute and use energy.” It is important to understand the energy mix.

The CNA is a proud sponsor of the Pollution Probe workshop series. We understand the energy mix. Because nuclear power plants operate all the time, they play an important role in Canada’s energy portfolio — and with electricity demand projected to increase by 34% by 2025 (due to population growth and new technology developments), meeting this demand will required increased capacity to produce reliable electricity.

Nuclear provides reliable, clean, non-emitting base load power that is a great start for other renewables like wind and solar. Nuclear is also a better alternative to burning fossil fuels which contribute to climate change.

What energy generating technologies do you think should be part of Canada’s energy mix?

June 28h-29th, 2011

Pollution Probe  is

  • A Canadian charitable environmental organization that
    • Defines environmental problems through research;
    • Promotes understanding through education; and,
    • Presses for practical solutions through advocacy.

IPCC Finds Nuclear Emits Less CO2 than Solar Panels

The recent Special Report Renewable Energy Sources by the IPCC contains an interesting graph that shows nuclear energy emits less CO2 over its lifecycle than solar panels, and about as much as wind (on average). Unfortunately, the report  does not consider the viability of nuclear power to replace fossil fuels for generating electricity. Still – it’s good to see that the IPCC confirms what our own research has shown for quite some time: nuclear is among the cleanest sources of electricity. Maybe the next IPCC report will look at nuclear by itself?

Figure SPM.8. | Estimates of lifecycle GHG emissions (g CO2-eq / kWh) for broad categories of
electricity generation technologies, plus some technologies integrated with CCS.

You can access the entire IPCC report here.

Nuclear Education Nuclear Energy Statistics

Comparing Wind and Nuclear in Terms of Space

One of the reasons I support nuclear power is that it seems to require relatively little space to generate a huge amount of power. Some of Canada’s most powerful reactors can produce up to 881MW (electricity), or 7,717,560,000 kw/h annually. That’s enough to power about 643,000 households 24/7 (Average household consumption in Ontario is about 12,000 kw/h annually).

The Darlington nuclear power station – which has 4 such reactors – is about as big as one of the shopping malls in Whitby, ON (including the parking lots). Not bad, considering the plant produces power for up to 2.5 Million households, day in, day out.


Based on that alone, I always thought that nuclear power would be a pretty good option for replacing much of the electricity currently produced globally by burning coal and gas.

But, a recent story published at PhysOrg.com suggests that, according to a study written by Derek Abbott (a professor at the University of Adelaide), it would be impossible for nuclear energy to supply the entire global demand for energy because all these nuclear plants would take up far too much space.

Abbott addresses other factors,  too, but for the time being, I’ll just focus on the question on size.

I haven’t read the actual study, since it is not yet published (but will be soon in the Proceedings of the IEEE), so I have to go by what the reporter says about Professor Abbott’s findings.

Abbott estimates that

One nuclear reactor plant requires about 20.5 km2 (7.9 mi2) of land to accommodate the nuclear power station itself, its exclusion zone, its enrichment plant, ore processing, and supporting infrastructure.

I’m not entirely sure where he got this number from (I suspect the final article will provide the sources), but it seems he does not allow for multiple reactors on a single site.

The Darlington plant, for example, is a little less than 2 km long (including the parking lot), and roughly 800m or so across. That’s just about 1.6 km2, though my method of measuring that is – admittedly – a little crude. However, there are no less than 4 reactors at that site alone. Even after OPG is done adding another two, the site is not going to get much bigger.


Be that as it may, I will – just for the sake of argument – accept Abbott’s numbers for the time being.

Professor Abbott then calculates how many nuclear reactors it would take to supply the entire global energy demand of 15 Terawatt by generously assuming that each nuclear reactor can supply 1GW (e). That makes for easy math, and results in no less than 15,000 reactors globally. At 20.5 km2 each, the resulting space requirement is 307,500km2 – just a little less than Poland, or a little bit more than Italy.

That does, indeed, seem like a lot – all of Poland or Italy covered end-to-end in nuclear reactors, supporting facilities, fuel manufacturing plants, etc. etc. to supply the entire global energy demand (that is, all the power currently provided by fossil fuels, hydro electricity, nuclear , and other sources combined).

But how would that compare to other sources of energy under the same assumptions? While Prof. Abbott appears to like solar best, I’m going to do it for wind – simply because I have spent more time analyzing the spatial requirements for wind (mostly because wind power is the only low-carbon, non-hydro, source of electricity cost-competitive with nuclear).

Calculating the space requirements for wind is tricky business. The actual footprint of a wind turbine is not that much: if one includes the swept area, it’s anywhere from .2 – 2 acres (based on data from Enercon, and a little basic geometry. For those who want to dig deeper, the NREL has some good information on this).

Let’s assume we are going to use Enercon’s E101 turbine, which has a nominal capacity of 3,000 kW. Let’s further assume that we can expect an average output is about 25% of rated capacity ( though some studies indicate it is much less, and may be as low as 21%). The turbine has a diameter of 101m – or 331.4 ft – and therefore sweeps an area of about 1.98 acres. Since turbines need to be spaced several times their diameter apart, let’s assume we space them about 10x their diameter apart on average over a perfectly even plane, with nothing breaking the pattern (as I did with the nuclear plants above).

How big would a wind farm with such an arrangement have to be to generate 15TW of electricity?

16,023,693 km2 – a little less than the entire territory of Russia. Or about twice the size of Australia.


Or Canada and Greenland with a chunk of the US:


Even if we reduce the distance between the wind turbines to just 5x their diameter, we’d still end up with a space requirement of 4,005,923 km2 – 22% bigger than India.


What about a bigger turbine, like Enercon’s E126, rated at 7,500 kW a piece (spaced 10x diameter)?

Well, that would require 25,335,374 km2more than Russia and Australia combined.


If spaced only 5x diameter, it would still require 6,333,843 km2 – almost twice the size of India.


[The reason is that the E126 has a diameter of 127m, which results in much greater space requirements even though the output is that much greater than the smaller turbine].

But this would just be the size of the wind farm itself. It would NOT include:

  • all the infrastructure needed to supply the farms
  • all the land lost to mining for the materials from which to build the turbines
  • all the land needed for the manufacturing facilities
  • the housing for all the people who will have to work continuously to maintain the wind farm.

These numbers also assume that

  • no wind turbine will ever fail (because that would reduce the average output),
  • electricity can be stored without any loss of power (because sometimes the wind blows just right, and sometimes not so much – or too much -, and the surplus energy from when it blows just right has to be stored to make up for the other times),
  • electricity can be transmitted without any loss of power (which won’t be the case until we figure out cheap super-conductivity).

So, the space requirements I calculated significantly underestimate the territory required for wind farms, if we wanted to supply all global energy needs with wind alone, while Prof. Abbott’s calculations for the nuclear power seem to significantly overestimate the territory required.

While I admit that supplying all the world’s energy exclusively from nuclear would be a stupendous task, it pales before the challenges of trying to supply it with wind (the only other cost-effective low-carbon, non-hydro source of power).