Sustainable Energy - Without the Hot Air
- Feb 4, 2018
- 4 min read
How I came across this book: After the recently heated debate about the 'Paris agreement', I was looking for some scientific source on renewable energy to hang my hat on.
Favorite Line from the book:
If everyone does a little, we’ll achieve only a little.
We live at a time when emotions and feelings count more than truth, and there is a vast ignorance of science. James Lovelock
Climate Change is a conspiracy theory??
Did you have a discussion about climate change with anyone recently? One of the responses I get to hear quite often is “why is media targeting USA and UK? China and India is out of control when it comes to pollution!”
If divide the amount of total CO2 produced by the world population, then the average CO2 production in Gigatons will 5 GtCO2 e /year. In the year 2000, Europe’s per-capita greenhouse gas emissions were twice the world average; and North America’s were four times the world average. But it isn’t the rate of CO2 pollution that matters; it’s the cumulative total emissions; much of the emitted carbon dioxide (about one-third of it) will hang around in the atmosphere for at least 50 or 100 years. If we accept the ethical idea that “the polluter should pay” then we should ask how big is each country’s historical footprint. USA and UK are winners when it comes to pollution! Having said that both countries specially UK has done quite a lot to develop it's renewable sources of energy over the last decade.
It has been predicted that a rise in global temperature by more than 2c will have major climate changes and alterations of the ecosystem. Carbon dioxide in combinations with methane and nitrous oxide is the major player in the greenhouse effect and subsequent global warming. Most of the carbon dioxide comes from energy consumption.
The current per-capita emission of CO2 is 11 tonnes per year. If we really want to make a dent in global climate change by 2050, then we have to aim for a CO2 emission of 1 tones per year. I calculated my yearly carbon footprint and I am guilty as most people. My number is around 5 tonnes/year. You can calculate yours from the carbon neutral website.
This book is about 'energy' and not climate change. However, since 90% of our energy comes from fossil fuel, which will ultimately have a major effect on global warming, so it is imperative to understand the concepts of energy. David Mackay puts an excellent argument if we can live on our renewable sources of energy or not. Humans have already reached the peak of fossil fuel utilization. Apart from the fact that fossil fuels are the main cause of global warming, we will soon run out of fossil fuel. He puts numbers and data to back up everything he says. But the book is more than just numbers. It makes you think for yourself and encourages you to do simple calculations to make sense of the numbers. It is a book for skeptics who argue “what’s the point in my doing anything? China’s out of control!”, or pessimists who think 'energy gap' crisis can not be solved.
David Mackay breaks down all the problems of the energy crisis and tries to provide the solution to each one of them. He has used kWh/day/person as a unit consistently throughout the book to make it easy to understand. For example, one 40 W lightbulb, kept switched on all the time, uses one kilowatt-hour per day. An average Brit consumes 125 kWh per day per person. This is equivalent to keeping 125 lightbulbs switched 'on' all day. The average European consumption is similar. An average American consumes 250 kWh per day per person. This reminds me of the line from United States Declaration of Independence 'all men are created equal!'
The author uses simple mathematics and physics to divide consumption and production in two stacks. Most of the consumption comes from transport, heating, and electricity.
Once the numbers are added up, the stacks look like the picture on the right. He was extremely generous with green stacks (renewable source of energy) and yet it could not compete with the red stack (consumption). What was impressive to me is how inefficient our cars are! For example, ‘all the energy saved in switching off your charger for one day is used up in one second of car-driving.’ How some machines like laser printer are consuming a crazy amount of energy while sitting idle if they are left switched on. David MacKay concludes that it is not possible to survive on renewables with current technology. Rising population and poor lifestyle choices will make it more challenging. We have to radically change our technology, efficiency, and supply of energy to meet the demands.
SOLUTIONS:
Electrifying transport including electric cars, using public transport (In 2006–7, the total energy cost of all London’s underground trains, including lighting, lifts, depots, and workshops, was 15 kWh per 100pkm– five times better than our baseline car), electrifying heating of air and water, smarter home heating – thermostat, double glazed houses to reduce leakiness, newer buildings, heat pumps (didn’t catch up because of the cost involved), clean coal (it has its own limitations), nuclear energy (In 2015 nuclear reactors provided about 11% of the world's electricity) and exponentially increasing renewable sources of energy.
The renewables have to be country-sized in order to match demands so the author suggested looking to countries where available renewables are diffuse like deserts (the DESERTEC Concept promotes the large-scale production of solar and wind power in the desert regions of the world, combined with a smart mix of photovoltaics, hydropower, biomass and geothermal energy.)
This book is ten years old, and many things have changed. However, the principles described in this book will be valid for a long time. This is a great starting book to get an idea about energy consumption and production. Unfortunately, David Mackay died prematurely from stomach cancer two years ago, but his legacy will never be forgotten. He made his book freely available because he wanted to spread his message about energy crisis and all of us to act upon it – www.withouthotair.com.
Climate Change is real, and so are the solutions.
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