Where will the electricity come from?

by Jeremy on 15-May-2011

Patrick Donnelly calculates the energy required to power HS2 and considers how long our energy resources will last.  Read on. 

Our modern civilisation is reliant on electricity. It is a taken for granted assumption that the electricity supply grid is like a tap that can be turned on or off at will, providing an infinite stream of energy. We only realise how much we depend on it when it goes down for some reason. Perhaps it’s because we take electricity so much for granted that the subject of how much would be required for HS2 has not been raised in the debate so far.

Figures from the office for national statistics show that in 2010, 91.3% of our electricity came from gas, coal and nuclear power stations. 6.9% came from renewables and 1.8% from ‘other’.  Britain, along with many other countries, has agreed to ambitious carbon reduction targets. By 2020 the government aims to generate one third of our electricity from renewables. Energy minister Chris Huhne has said that Britain must build thousands more wind turbines to cope with energy demands.

In the transport sector, Philip Hammond has said that the next 30 years will see a shift from high carbon to low carbon based road travel. Rail travel requires less energy per passenger kilometre than road or air, and as the proportion of fossil fuels used in power generation decreases there will be a corresponding reduction in CO2 emissions from electrically powered trains.

It is difficult to estimate how much energy HS2 trains would draw down from the electric grid. Actual consumption would depend on the weight of the trains, gradients, maximum speeds and stopping patterns. Also, when operating in tunnels more energy is consumed than on an open line.

The HS2 Traction Energy Modelling carried out at Imperial College shows the power consumption pattern for Euston – Birmingham, and for Birmingham – Euston. For most of the journey time, the power drawn down from the grid would be about 12MW.

A wind turbine produces electricity 75-85% of the time, but it generates different outputs depending on the wind speed. Over the course of a year it will typically generate about 33% of the theoretical maximum output. A modern commercial wind turbine of the type currently installed in off shore wind farms can generate 3.0MW.  Therefore, average electricity produced = 1.0MW.

A train drawing 12 MW of power would require the output of 12 wind turbines. HS2 would accommodate 10 trains per hour in each direction in off peak hours, rising to 14 trains per hour during peak periods. So running in peak mode at 360 km/h, 14 trains in each direction would require the output of 336 wind turbines.

To put this in perspective, our largest off shore wind farm off Thanet in Kent, consists of 100 turbines which can each generate 3.0MW of electricity. Enough to power 240,000 homes or 4 HS2 trains per hour in each direction.

There are those who say that we should be building more coal, gas and nuclear power stations, and that pollution and climate change is a risk we have to take. But more and more people are now realising that problems with CO2 emissions are just one side of the coin. On the other side is the problem of resource depletion.

Fossil fuels and uranium are finite non renewable resources. Industrial societies have consumed more than half of the earth’s fossil fuel resources in a spectacularly short time period. Now, with globalisation, they are being consumed at an ever increasing rate. At the same time they are becoming more difficult and costly to extract. The glass really is half empty and there’s no way it can be re-filled. Sip from it slowly and it can last a bit longer, but sooner or later it will be empty.

The world is facing major uncertainty regarding energy supplies. Experts and academics are now pointing out a stark reality “…there will be NO combination of alternative energy solutions that might enable the long term continuation of economic growth, or of industrial societies in their present form and scale.”  Richard Heinberg.

Numerous books and reports have been written about how serious and far reaching this could be. One thing they all agree on is that we will all have to adapt to less consumption of material resources and energy, less globalisation, and more localisation. Renewable energy sources might be able to sustain us, but not in the manner to which we have become accustomed.

Given that this scenario will play out one way or another, we cannot regard the electricity grid as a tap to be turned on and off at will, supplying an infinite stream of energy. Resource analysts cannot predict exactly when the ‘energy crunch’ will happen, but within two or three decades we are likely to see energy conservation measures on an unimaginable scale, comparable with world war two.

Ultimately, rather than seeing an ever increasing demand for travel as projected by HS2 ltd, the future holds less travel in store, regardless of the means of transport. Economic survival will require reducing the need for transportation by moving producers, workers and consumers closer together – i.e. localisation.

From this perspective, to use vast quantities of energy and resources to build an ultra high speed railway that is designed to consume large amounts of energy on an on-going basis is not the right way to prepare for the ‘post carbon’ future. To squander precious non renewable resources on a scheme that is not sustainable over time, and to destroy good agricultural land in the process, would be extremely unwise and to the detriment of the younger generation.

HS2 would be wrong because we would waste energy and materials building it, there will not be enough energy to run it, and there won’t be the people who need or want to use it. The most worrying aspect is that we’re even thinking about it.  The scientists at Imperial College who did the traction data modelling pointed out that operating at 360 km/h consumes 23% more energy than at 300 km/h. In other words saving just over 3.5 minutes requires 23% more energy or 63 wind turbines. It’s insane when you think about it. Our politicians are sleep walking into the future.

Mr Hammond has said that we need HS2 in order to meet the challenges of the 21st century. Does he know what the challenges of the 21st century really are? His prediction that “the next 30 years will see a shift from high carbon to low carbon based road travel” is most likely to come true. But we won’t be driving electric cars: we’ll be walking and riding bikes!

Further reading.

Heinberg, Richard (2003). The Party’s Over: Oil, War, and the Fate of Industrial Societies. Gabriola, BC: New Society Publishers. ISBN 0-86571-482-7.

300 years of Fossil Fuels in 300 seconds. www.youtube.com

Richard C. Duncan (2000). The Peak of World Oil Production and the Road to the Olduvai Gorge

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