Tag Archives: David MacKay

What Should Be In SEWTHA 2.0?

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In case the six letter acronym (SLA for short) in our title for today means nothing to you it stands for “Sustainable Energy Without The Hot Air“, the title of a 2008 book by David MacKay, who amongst other things is Regius Professor of Engineering at the University of Cambridge. We first mentioned SEWTHA back in 2012, when Bill Gates praised it in an interview with the Wall Street Journal. I mention it again today because my attention was drawn by a bit of a barney (BoB for short) on Twitter between Prof. MacKay and Jeremy Leggett, who amongst other things is a founding director of solar PV company Solarcentury.

First of all here’s the BoB in question, including the V2G UK addendum!

 

In case you would like to listen to the edition of Evan Davies’ “The Bottom Line” on the topic of “Renewable Energy” under discussion, here it is:

http://bbc.in/1PIZD9G

Evan’s guests were Jeremy Leggett, Juliet Davenport of Good Energy and Paul Cowley, managing director of RWE Energy UK. Here are of few of my own “edited highlights”:

01:30 JD – One of the examples is Wyke Farm Cheeses. When they wash down the dairy every night and when they make the cheese, that they then anaerobically digest which creates a gas and they generate power. That’s one of our generators.

02:37 JL – A small cottage with bespoke solar tiles. these are different from the modules you use in solar farms or on a big installation on a commercial roof because they really are tiles. They go straight on the battens of the house. They generate electricity. They’re waterproof.

08:45 ED – I also wanted to talk about the physical constraints on whether you can get, in a country like ours, to 100% renewables. I’ve been very influenced by a particular book called SEWTHA by David MacKay.

09:30 JL – That book was published a good few years ago now. It’s out of date and I don’t think Dr. MacKay even believes that any more.

10:18 JD – We did some work, following David MacKay’s book actually, and used the work that he did. He went on to be the scientific advisor to DECC. He developed these pathways/models and we used them to look at how hard can you push the system to get it 100%. The UK has sufficient resource, whether it’s wind, whether it’s solar, to get to 100% on the current usage. [My emphasis!]

One of the things about climate change, it’s going to change the way we use power as well. So we saw last year energy usage in the domestic gas market dropped by 10%. 2014 one of the warmest years ever. You’ve also had the highest ever wind power production this winter. We’ve seen a lot of storms come through… So the parameters that David used in that book, I think we’re now looking for Hot Air 2.0.

11:30 ED – To give another example from the book, taking that it’s out of date, to get 50 kWh per day per person, and we’re currently using 125 kWh per day, to get 50 from offshore wind would mean filling a sea area twice the size of Wales. It would be expensive. It would be a very big deal.

One of things here, and it’s been much under-discussed in this area, is not only do we need to get our current electricity decarbonised, but we’re talking about decarbonising the transport industry to a large degree, and David MacKay’s good on this. You’ve got to almost double or triple your electricity generation, so not only do we have to replace the nuclear power and the coal that’s falling out of use over the next decade. You’ve got to replace that and add in plug-in cars. [My emphasis!]

12:59 JD – That’s what really exciting about right now. We’ve got a different problem on our hands. We’re going to have different technologies coming through, and we’re going to have to figure out how consumers use that. And actually the car storage part is really interesting because each car has a battery in it, and suddenly you’ve got a flexible power source that you can either use for transport or potentially use within people’s homes. And that piece of technology hasn’t really been thought through, about what that can really deliver [Juliet’s emphasis!]

13:45 PC – We see it in the press all the time. Wind turbines not running because the wind’s not blowing! The reality is that turbines generate around 85% of the time. They start generating at a very low wind speed… and then builds up to an optimum wind speed.

14:13 ED – We haven’t got yet a very efficient mechanism for storing electricity have we?

14:25 JL – Things are moving so fast. Let’s not forget, Apple is going to be mass producing electric vehicles four years from now. That is their stated intent. Each one of those is going to be a little power plant, and who knows how they’re all going to be hooked up to each other? It’s going to move so fast Evan, and I think this is the criticism that people like me have of, you know good guys like David MacKay with his book. They’re still flogging the idea of these vast centralised, humongously expensive centralised power plants, nuclear in particular, that take 10 years to construct.

The upshot of all this, apart from the BoB? More and more people are mentioning the concept of vehicle-to-grid technology in public pronouncements here in the UK. Andrea Leadsom at DECC assures us that she’s “as keen as mustard” on energy storage. That is of course nice to hear, but what do Physics & Chemistry have to tell us about the hard realities of distributed energy storage? And what about DECC & Ofgem too, with their assorted rules and regulations?

I might also have a minor quibble about Juliet’s “hasn’t really been thought through” remark. Some people have been thinking quite hard about V2H and V2G for quite some time!

Renewable Energy is the Work of Generations of Engineers?

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Fresh from bemoaning the lack of grid-scale energy storage to support all the large scale solar PV parks currently being proposed here in not so sunny South West England, the latest edition of the IEEE Spectrum magazine landed on my doormat this morning.  In all the circumstances it would have been very handy if it had arrived this time last week, since it contains all sorts of statistics and arguments derived therefrom that support my position on that locally contentious issue!

In an article entitled “A Skeptic Looks at Alternative Energy” Vaclav Smil, a distinguished professor in the department of environment and geography at the University of Manitoba, bemoans (amongst other things) solar PV subsidies here in Northern Europe:

In June 2004 the editor of an energy journal called to ask me to comment on a just-announced plan to build the world’s largest photovoltaic electric generating plant. Where would it be, I asked—Arizona? Spain? North Africa? No, it was to be spread among three locations in rural Bavaria, southeast of Nuremberg.

I said there must be some mistake. I grew up not far from that place, just across the border with the Czech Republic, and I will never forget those seemingly endless days of summer spent inside while it rained incessantly. Bavaria is like Seattle in the United States or Sichuan province in China. You don’t want to put a solar plant in Bavaria, but that is exactly where the Germans put it. It happened for the best reason there is in politics: money. Welcome to the world of new renewable energies, where the subsidies rule—and consumers pay.

After laying his cards on the table at the outset Vaclav then lays into a wide range of renewable energy subsidies, making only two exceptions:

Without these subsidies, renewable energy plants other than hydroelectric and geothermal ones can’t yet compete with conventional generators. There are several reasons, starting with relatively low capacity factors—the most electricity a plant can actually produce divided by what it would produce if it could be run full time. The capacity factor of a typical nuclear power plant is more than 90 percent; for a coal-fired generating plant it’s about 65 to 70 percent. A photovoltaic installation can get close to 20 percent—in sunny Spain—and a wind turbine, well placed on dry land, from 25 to 30 percent. Put it offshore and it may even reach 40 percent. To convert to either of the latter two technologies, you must also figure in the need to string entirely new transmission lines to places where sun and wind abound, as well as the need to manage a more variable system load, due to the intermittent nature of the power.

I couldn’t have put it better myself, and I couldn’t have fitted it all into 5 minutes last Monday  either. If you have any interest in learning how to discern the difference between Green Energy and GreenWash I heartily recommend you read the article in full. Several times if necessary, until Vaclav’s message makes sense to you. To summarise, here’s his closing remark:

It is impossible to displace [the world’s fossil-fuel-based energy system] in a decade or two—or five, for that matter. Replacing it with an equally extensive and reliable alternative based on renewable energy flows is a task that will require decades of expensive commitment. It is the work of generations of engineers.

As if all that wasn’t enough, here’s a 45 minute video in which Bill Gates presents his views on energy policy in general, and Vaclav Smil in particular:

Finally here’s David MacKay’s “brilliant book” that Bill refers to around 18 minutes into his presentation. Sustainable energy, without the hot air.