Physical Insights

An independent scientist’s observations on society, technology, energy, science and the environment. “Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.” – Carl Sagan

We Support Lee!!

 Duke Energy last week submitted a combined construction and operating license application to the U.S. Nuclear Regulatory Commission (NRC) for the proposed two-unit William States Lee III Nuclear Generating Station in Cherokee County, S.C, with a capacity of 2.23 GW.

Duke Energy is the fourth company to submit a COL application to the NRC under the revised licensing process, and the first to submit an application for a greenfield site. The Duke Energy application uses TVA’s Bellefonte COL application as the Westinghouse AP1000 reference application.

http://www.world-nuclear-news.org/newNuclear/Duke_files_COL_application_for_Lee_plant-141207.shtml

This sounds like good news for the people of SC, and everyone else in the US community.

Gee, Ruth, I guess this means you’ll need to update the information on your blog now!

December 17, 2007 Posted by Luke Weston | Uncategorized | | No Comments Yet

Electric cars and fossil fuels.

I’ve recently heard a bit of debate centred around the question of electric cars – in a society such as Australia, where essentially all electricity generation comes from extremely polluting, carbon dioxide emissions intensive coal-fired plants, is there any environmental benefit to using electric vehicles?

First and foremost, of course, petroleum is one of our most finite and limited energy resources – concerns about the limits to conventional petroleum extraction are oft discussed, and the geopolitical insecurity associated with dependence on foreign oil also needs to be taken into account.

Gasoline/petrol has an energy content (calorific heating value) of 44.4 MJ/kg, and a mass density of about 737 g/l, and therefore a heating value of 9.1 kWh per litre.

A typical small car uses about 7 litres/100 km at an average of 90 km/h in highway use, and about 8.5 litres/100 km in city use.

In highway use, the engine uses about 1 litre of fuel – 9.1 kWh – to generate 1.7 kWh at the wheels – 18.7% efficiency. In city use, due to frequent braking, this overall efficiency in energy consumption is greatly reduced – let’s say 5-10%.

Averaging out highway and city use, let’s take – just rough approximations, remember – an overall efficiency of 12%, giving 1.48 kWh generated at the wheels per kilogram of fuel.

With an electric car, assuming 90% efficiency in the charger, and 90% efficiency in the control electronics, combined with regenerative braking, then we need to input 1.83 kWh of electricity from the grid, to get 1.48 kWh at the wheels. For 1 kg CO2 equivalent per kWh of electricity generated – this seemingly very high figure is typical for Australia – we have 1.83 kg of CO2 generation, for the equivalent of the use of 1 kilogram of fuel in a gasoline engine.

If we assume that the fuel is a mixture of only octane and its isomers (a rough assumption, but it will do), then the complete combustion of 1 kg must generate 3.08 kg of carbon dioxide – clearly the electric car is significantly ahead in this regard.

Electric cars are a technology we should at least give full, rational scientific thought to. Whilst the burning of coal to generate 80% of our  electricity needs is clearly unacceptable and cannot continue, as we replace the coal-fired base of the grid with  cleaner technology, maybe electric vehicles are potentially a technology where, in theory at least, benefits are to be had, especially if combined with a scalable, high-capacity, strong power grid, powered by clean nuclear electricity.

December 17, 2007 Posted by Luke Weston | electricity generation, fossil fuels, nuclear energy, transportation | | No Comments Yet

Anti-nuclear photo of the day.

I found this interesting photo headlining a post on an established emotionally-motivated full-of-sound-and-fury-signifying-nothing anti-nuclear activism blog today. I won’t mention it by name, but I’m sure you know the one I mean.

Look – it’s clearly obvious! Simpsons-esque concrete hyperboloidal cooling towers – it’s a Nuclear plant!

Nuclear power – obviously equates to dead people! Vast numbers of people, all dead because of the evils of the nuclear plant!

That is, until the reader notices the smoke-belching stacks clearly present in the photograph. Nuclear plants don’t have those!

Unless I’m very much mistaken, that looks like a coal-fired power plant to me.

December 17, 2007 Posted by Luke Weston | anti-nuclear movement, dangerous fossil fuels | | No Comments Yet