Friday, October 30, 2015

EddingtonSafety - Part 4: Comparison of Huntingdon Road with similar maj...

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EddingtonSafety 3 - the Bunker's Hill / Girton Road Crossing

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Sunday, October 11, 2015

How to design climate negotiations: use the science of cooperation!

Price Carbon – I will if you will

David J C MacKay FRS, Peter Cramton,
Axel Ockenfels, and Steven Stoft

Nature Vol 526 Page 315-316 | 15 October 2015

I think this is the most important piece of writing I have ever been involved in.


International negotiations can and should be designed in way that takes into account the science of cooperation.

Reciprocity is the key to realigning self-interests and promoting cooperation.
"Individual commitments" and "reviews" will not solve the tragedy of the commons.
A common commitment ("I will if you will") can.

What sort of common commitment would work best?
We argue that a global carbon-price commitment could yield a strong treaty, especially if coupled to Green Fund transfers, incentivizing low-emitting countries to support a high carbon price.

Read the comment on Nature's website, and for further details see

Tuesday, September 15, 2015

2016 Breakthrough Paradigm Award!

I've been awarded the 2016 Breakthrough Paradigm Award -- here is the nice letter I received from Shellenberger and Nordhaus:

  We are pleased to inform you that you have been awarded the 2016 Breakthrough Paradigm Award. This annual prize honors those whose work has made a major contribution to realizing a future where all the world’s inhabitants can enjoy secure, free, prosperous, and fulfilling lives on an ecologically vibrant planet.
You were chosen in recognition of your path-breaking scholarship and public service on clean energy, energy systems, and innovation. Your influential text Sustainable Energy – without the hot air continues to be an invaluable resource to the popular and policy conversations on climate change. Your commitment to accessibility, both at the sentence level and in your efforts to make your books available for free, distinguishes you among many scholars and academics working today.
We are especially pleased to honor your five years of public service at the UK Department of Energy and Climate Change, and your work steering Britain toward one of the most ambitious and pragmatic climate policy trajectories in the world.
Your work has had a significant influence on our thinking about energy technologies and transitions, including on how we train our junior fellows to understand the cost, impact, and scale of energy transitions. Your work has made the global energy conversation less dogmatic and moved the world closer to more rational and effective action.
We hope the prize helps expand the valence of your work, introducing new scholars both young and old to Sustainable Energy – without the hot air. Of all the “Great Transformations” achieved by societies, energy transformations are perhaps the greatest and most central. You understand these transformations better than almost anyone living, and your writings will no doubt be read far and wide in the decades to come.
We offer our congratulations and deepest thanks for your inspiring work, and we look forward to meeting you soon.
Michael Shellenberger and Ted Nordhaus

Sunday, August 30, 2015

Some SEWTHA updates (video, html, and hype)

Three pieces of news...

1: Updated SEWTHA video

There is a new release of my 2010 "Sustainable Energy - without the hot air" lecture at Caltech which includes close-captioning. Thank you, CMU, for providing the cc!
Original version: Sustainable Energy - without the hot air - David MacKay lectures at Caltech, April 2010
NEW: on YOUTUBE with close-captioning kindly provided by CMU's Equal Opportunity Services
Caltech DJCM

2: Improving the HTML for viewing on small devices

I have made a New Contents Page for Sustainable Energy - without the hot air - which is intended for viewing on thin, small displays. This contents page enables quick navigation to any page in the book. I recommend bookmarking it as the best quick way into the HTML book, especially on a smart-phone.
More enhancements to the HTML version of the book may be on the way soon.
For twitter users, I've added a "tweet" button to the top of every HTML page.

3: Solar and Batteries

Lots of people have asked me whether recent hype and hoopla about solar panels and batteries overthrows what I wrote in my book in 2008. I am preparing a detailed update. Watch this space! The theme of my update will be the existence of a phenomenon called winter, which many of the solar-hyponauts seem to ignore. Here is a teaser trailer showing the winter and summer 3-month-average insolation in 50 US states.
winter and summer 3-month-average insolation in 50 US states

Monday, August 3, 2015

Offshore wind farm load factors

I heard that recently-built UK offshore wind farms have higher load factors than old wind farms. I thought it would be interesting to plot the raw data, which is available from the helpful REF website. (The load factor is the ratio of the average output of the wind farm to the maximum possible output, and it is usually expressed as a percentage.) The graph below shows the rolling load factor of the 27 offshore wind farms in the UK, versus their accreditation dates. The size of each point is proportional to the capacity of the wind farm. One of the newest wind farms has a very low rolling load factor - this is Gwynt y Mor, the bottom right point on the graph; Gwynt y Mor is the second biggest offshore wind farm in the world. Presumably this poor load factor is a temporary glitch associated with the commissioning of the wind farm. If we ignore that point as an outlier, and simply compare the average rolling load factors for accreditation dates before and after June 30th 2010, it looks as if the average load factor may have increased from about 33.9% (± 2%) to about 37.4% (± 1%).
Of course, a proper analysis should account for ageing effects and variations in the weather, both of which have been carefully studied by Staffell and Green. They found that "Wind turbines ... lose 1.6 ± 0.2% of their output per year" (which implies, for a load factor of 35%, a reduction in load factor of 0.56% per year - a trend that I have shown by the green straight line in the next graph).

So, has there been a technological improvement in offshore wind turbines that has boosted load factors? Having been involved in innovation support while I worked at DECC, my prior expectation was that the answer to this question could easily be "yes". But actually it looks like it is possible to account for the apparent trend in the data by a simple "ageing" hypothesis: perhaps the newer wind farms are better just because they have aged less?

Tuesday, January 20, 2015

Underfloor insulation - thinking about the business case

Having had a go at the walls, the windows, the roof, and air-tightness, I've decided to get the last physical improvement done to our house - the floor.

(image kindly supplied by

The area of wooden suspended floor is about 35 square metres. According to page 290 of my book, the U-value of the floor is 0.7 W/m2/K, so the floor has a leakiness of about 25 W/K, which assuming an average temperature difference of 6 degrees, implies a conductive heat loss of 147 W (3.5 kWh/day). (The floor may also contribute some of the ventilation-leakiness of the house, but I'll neglect that.) The floor doesn't just lose heat, it also feels cold, and thus (a) affects quality of life, and (b) perhaps causes us to turn up the thermostat sometimes to improve our feeling of warmth. If we manage to keep the whole house (leakiness 240 W/K) on average 1 degree cooler thanks to improved floor insulation, then that would be an extra 240 W of saving (6 kWh/day).
I didn't do an economic calculation before deciding to get the underfloor insulation. It just feels like the right thing to do, and Retrovive was recommended by someone from Max Fordham, whose judgement I respect highly. Anyway, let's work out a pay-back time. The anticipated new U-value is about 0.25 W/m2/K. It looks like the work will cost about £2900 including VAT (including insulating central heating pipes that run under the floor) (for comparison we are perfectly happy to put down new carpets over a smaller area for a cost of £1150). If the insulation eliminates two thirds of the floor's conductive heat loss (i.e., about 2.2 kWh/day) and delivers say one quarter of the notional 6 kWh/day saving guessed above (if we managed to turn the thermostat down a bit), the total saving might be 3.7 kWh/day. With gas costing 5.2p per kWh, that's 20p per day, or £70 per year. So the payback time might be about 41 years.
If I went to the high end of all my estimates, I might imagine a saving of 9.5 kWh/day on average, in which case the payback would be about £180 per year and the payback time would be 16 years.
I am expecting that the main value of this work will be the improved feeling of comfort. People are happy to pay £36,000 per year to rent a family home [That's what we paid to rent a flat in London, at least]. If the home's main room feels really cosy, how much extra would we be willing to pay? I could imagine 5% or 10%. On those grounds, the comfort of cosiness is worth £1800 to £3600 per year. So the payback time, taking into account this benefit, is just one or two years.
I will post again when the work is done! (April 2015)