Sustainable Energy – Without the Hot Air (2009)

A lot of the previous writers I have reviewed have used great rhetorical skills or grand verbiage to convey their message and unique slant on the multifaceted environmental movement.  In Sustainable Energy – Without the Hot Air, author David JC MacKay (Professor of Physics at the University of Cambridge) attempts no such ingratiation or smooth posturing.  To his credit, MacKay has quite simply written an extremely practical, numerical investigation of the energy debate.  He has taken the question of renewable energy, plugged it into the conceivable UK power supply, and calculated a no-nonsense renewable energy debaters’ handbook.

MacKay explains that as an empirical scientist he became interested in the renewable energy debate when he read two seemingly credible books that came to shockingly differing conclusions – David Goldstein’s Out of Gas and Bjorn Lomborg’s The Skeptical Environmentalist.  Consequently, Professor MacKay admirably decided he would put that physics doctorate to further good use and write a freely downloadable book that, devoid of emotions, asks the question: How much renewable energy could the UK theoretically produce and would it be enough to power the country/achieve energy independence? http://www.withouthotair.com/

What follows is a source by source dissection of the theoretical sustainable energy production this country could achieve versus current energy consumption levels here in the UK.   In order to do so, MacKay helpfully converts everything into a single unit of measurement that we can then use to easily compare all the variables.  This is where you’ll have to take my word, or alternatively check the science for yourself (if, unlike me, you studied physics past the age of 18); the magic unit we shall use to further the discussion is:

kWh/day/person (kilowatts per day per person).

Now, before the bespectacled jump on my back, it is worth noting that all the following calculations are approximations, rounded to whole numbers for ease of understanding and discussion.  So take a moment to consider the two following tables so that we can begin to investigate the interesting implications of MacKay’s findings.

Energy Consumption Source	Energy Used in kWh/day/person	Comments
Cars	40	Assuming the average person drives 30 miles per day, obtaining a fuel efficiency of 33 miles per gallon (without considering the energy used to manufacture the vehicle).
Planes	30	Assuming 1 trans-continental flight per person per year (for the frequent flyer – 60 kWh/day/person)
Heating & Cooling	37	This includes the heating & cooling related to the home, workplace and cooking.  More specifically hot water is responsible for 12 kWh, hot air 24 and cooling 1 kWh (this is so low only because the UK has so few days per year when we require cooling).
Lighting	4	Including lighting at home, in the workplace, street lights and traffic lights.
Gadgets	5	Here we’re talking about fridges, freezers, computers, TVs, Xbox, etc.
Food & Farming	15 E.g. Eggs – 1,  Meat – 8, Fertiliser – 2.	This includes the energy used to grow a crop and the energy spent/consumed by the animal that provides/is the food (but not the energy of transporting or processing the food).
Stuff	48 E.g. Drinks containers – 3 Other packaging – 4 Car-making – 14 Road freight – 7 Shipping – 4.	This includes the extraction of raw materials and the production, use and disposal of consumables.
Public Services	4	This primarily consists of the energy used in providing for the country’s armed defence (Army, Navy, etc.).
TOTAL	195	In comparison, the U.S. total for energy consumption is roughly 250 kWh/day/person.

Before moving on I would like to mention that this list demonstrates the effect of what I call “token environmentalism.”  Don’t get me wrong, using energy efficient light bulbs and becoming best friends with your “bag for life” is the right thing to do, it’s just that they don’t really make that big of a dent in the total!  The above list demonstrates that such behavioural changes likely do more to reduce cognitive dissonance rather than actually addressing the problem in a meaningful way.

 

Anyway, I digress.  We now have an idea of what consumption behaviours take up the largest proportion of our energy use (travel, heating, manufacturing, etc.) but it doesn’t really provide much context until we understand how much energy we can generate.

Renewable Energy Source	Conceivable Output in kWh/day/person	Comments
Wind	20	This calculation presumes that we cover 10% of the entire country with wind farms (extremely optimistic given that the current global wind power generation is 10 kWh/day/person).
Solar (Photovoltaics)	5	This is assuming that every person in the country could install 10m2 (south-facing) of 20% efficient (high-end) solar PV panels.
Solar Thermal	13	Where normal solar panels convert sunlight into electricity (a high-grade energy), solar panels can do a much more efficient job of converting the energy into heat (a low-grade energy) to heat water and thus produce more output but with fewer applications.
Biomass	24	This is again a very optimistic calculation based on using all current crops (neglecting the need for crops as food) as biofuel.
Hydroelectricity	1.5	Hydroelectricity requires altitude and rainfall.  The UK actually already receives 0.2 kWh/day/person and the exploitation of the remaining areas would be potentially expensive and disruptive.
Offshore Wind (Shallow)	16	Shallow mean coastal areas less than 30 miles from the coast, which actually means you would have to build in international waters, presenting several legal problems.
Offshore Wind (Deep)	32	Deep means more than 30 miles from the coast.  At present no such windmills exist.  Their economic viability is questionable due to transmission and maintenance costs.
Wave	4	This calculation assumes that we line half of the Atlantic coastline (500km) with deep sea wave absorbers.
Tidal	11	Using a mixture of barrages, lagoons and tidal stream farms, it would be possible to harness the tidal power of the sea and ocean should land owners agree and public opposition be minimal.
Geothermal	1	Unfortunately the UK does not have too many geothermal sources (being so far from tectonic boundaries).  Currently a geothermal plant in Southampton produces 0.1 kWh/day/person.
TOTAL	180	Other predictions of total conceivable renewable energy production include: 27 – Institute of Electrical Engineers (2002) 38 – Centre for Alternative Technology (2007)

CONSUMPTION 195 v THEORETICAL RENEWABLE PRODUCTION 180

Thus we can clearly see that even with the most optimistic of calculations the UK could not shut off the energy supplied by coal, oil and natural gas tomorrow and be able to power the country with clean electrons.  As a staunch environmentalist I wish I could deliver different news, but the numbers must be respected and the pragmatists must prevail over the idealists at this moment in time.

So what conclusions can we draw and where can we go from here?

• Firstly, to make a difference, renewable projects need to be country-sized!  I am a big proponent of micro-generation (e.g. installing your own solar panels/ decentralising energy generation), but it appears that at present levels of efficiency, the best an individual could hope for would be to cover then own electricity bill.  Micro-generation could not currently provide for the energy needed for transportation, manufacturing, etc. 
• Every little does not help! Well it does, but what I mean is that if we are to balance the energy budget (either by reducing consumption or increasing renewable production), we must do something big.

Before we give up on renewable energy technologies, there are however some exciting technologies and plans (even if two of them aren’t technically renewable) that could buoy the mood:

1. The DESERTEC Plan – just because the UK doesn’t have great potential for solar energy production doesn’t mean we couldn’t buy some.   MacKay analyses an exciting plan to create 65 solar parks each of which consists of 1500km² of solar panels in northern African desert (97,500 km² in total).  Enough sunlight falls on the North-African desert that, using a High-Voltage Direct-Current (HVDC) transmission line, renewable energy could then be distributed to the majority of Europe and Africa to provide 125 kWh/day/person.  Such a plan is obviously incredibly ambitious but nonetheless incredibly appealing.  Issues regarding the covering of such a large area with man-made objects, international agreements on how to pay for the manufacture, installation and maintenance of the solar panels, and how the energy would then be shared would all need to be carefully considered and negotiated.  Nonetheless, an incredible humanitarian goal that I think everyone should learn more about: http://www.desertec.org/concept/ .
2. Nuclear Fission – hate or love it, nuclear fission is a form of energy that could produce an extremely helpful 420 kWh/day/person for the next 100 years if we extracted all available Uranium and all countries agreed to the safe and ubiquitous deployment of nuclear plants. Currently, Sweden and France lead the world in nuclear production, generating 19 kWh/day/person.  Of course concerns regarding the safe disposal of radioactive Uranium after use and the effective safeguarding of these materials so as to prevent the proliferation of nuclear arsenals across the world are problems that cannot be ignored, but from a mathematical point of view it is clear that our fears of nuclear power must be kept in perspective as the potential is just so great.
3. Nuclear Fusion – now we enter the realm of science fiction and can begin to talk about some truly mind-blowing numbers.  At present scientists are not confident that the science of nuclear fusion, in which Lithium or Deuterium are used instead Uranium, will ever be perfected.  But if the theory is correct and the technology could be successfully developed we are talking about an energy source that could provide 30,000 kWh/day/person for 1,000,000 years for 60 billion people!

Should we be able to perfect nuclear fusion then all bets are off and we’ll have such an abundance of energy on this planet that no one would every pay for, or fight over, energy again.  Yet, the pragmatist in me is screaming not to get carried away; we must push forward without the magic bullet in mind.

With that said, I think MacKay has written an extremely helpful book.  Regardless of how optimistic the numbers presented are it is essential to create context in any debate.  Having studied the numbers he has presented I have come to grips with the reality that fossil fuels will have to part of our energy portfolio for many decades to come should the country wish to maintain its current economic  output and standard of living. 

I hope MacKay updates this book every decade and we can see how technology improves and whether we will ever be able to achieve energy independence.  For now, I encourage everyone to read Without the Hot Air this year.  No matter your political persuasion or motivation, this book forms an excellent starting point for debate on a topic that has become far too stifled by grand rhetoric and out of context numbers.  It’s time we all started talking about renewable energy, without the hot air.

Score: 82/100