Comments on: British Energy Demand, and Professor MacKay’s estimate of it: an explanation of the differences http://www.energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences Thinking about energy Mon, 21 Nov 2011 11:46:45 +0000 hourly 1 By: Robert http://www.energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences#comment-637 Robert Mon, 21 Nov 2011 11:46:45 +0000 http://www.energynumbers.info/?p=305#comment-637 Good piece Andrew. And please also see: Shock: "Food supply could blot out countryside, warns government scientist" > http://bit.ly/rrTZPe Good piece Andrew. And please also see:

Shock: “Food supply could blot out countryside, warns government scientist” > http://bit.ly/rrTZPe

]]> By: David MacKay’s ‘Sustainable Energy – Without The Hot Air’… Perhaps A Little Hot Air? | BlueRock http://www.energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences#comment-186 David MacKay’s ‘Sustainable Energy – Without The Hot Air’… Perhaps A Little Hot Air? | BlueRock Mon, 16 May 2011 19:58:53 +0000 http://www.energynumbers.info/?p=305#comment-186 [...] claims that the UK’s energy demand figure is 195 kWh/d – but the true demand figure is 82 kWh/d and can be readily reduced with efficiency measures and EVs. Therefore the UK can quite realistically be powered by 100% renewable energy – even using [...] […] claims that the UK’s energy demand figure is 195 kWh/d – but the true demand figure is 82 kWh/d and can be readily reduced with efficiency measures and EVs. Therefore the UK can quite realistically be powered by 100% renewable energy – even using […]

]]> By: admin http://www.energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences#comment-142 admin Mon, 04 Apr 2011 07:20:16 +0000 http://www.energynumbers.info/?p=305#comment-142 Hello Patrick, I seem to have failed to get the gist of the piece across to you, which is a shame. I'll try to phrase it differently. Let me know if this helps. The numbers in the first third of Professor MacKay's book all lead to the conclusion on page 103 that even if we used all of our renewable resource to its technical maximum, ignoring economic, social and environmental constraints, then it is not enough to meet our energy demand. And that (as he writes later in the book) this applies to Europe too - he writes: <i>"Europe, like Britain, cannot live off its own renewables"</i>. And yet the figures on 103 are wrong - we all agree on that - you, me, David, the official statistics. So any conclusion based on them must be in doubt. Indeed, there are plenty of reasons for doubt - because in addition to the inflated demand, the first third of the book also contains economic, social, and environmental constraints on supply, despite the statement to the contrary (I'll write a bit more about the supply side in a new article, later). So those are not about the physics of the thing at all - they're opinions. So, we have an inflated demand, and a set of political opinions on supply. That's not (in Professor MacKay's words) <i>"what the laws of physics say about the limits of sustainable energy"</i>. As it turns out, Britain's renewable resource is an order of magnitude higher than our energy demand. And so <b>Britain, (just like Europe and the whole world) can get 100% of its energy from renewable resources</b>. Now, as that's fundamentally different to Professor MacKay's conclusion, I think it's pretty important. Because it means that we have very real choices about the next 40 years. We can choose nuclear or CCS as transition technologies if we want - but we don't have to have either of them. They are only options, not necessities. Hello Patrick,

I seem to have failed to get the gist of the piece across to you, which is a shame. I’ll try to phrase it differently. Let me know if this helps.

The numbers in the first third of Professor MacKay’s book all lead to the conclusion on page 103 that even if we used all of our renewable resource to its technical maximum, ignoring economic, social and environmental constraints, then it is not enough to meet our energy demand. And that (as he writes later in the book) this applies to Europe too — he writes: “Europe, like Britain, cannot live off its own renewables”.

And yet the figures on 103 are wrong — we all agree on that — you, me, David, the official statistics. So any conclusion based on them must be in doubt.

Indeed, there are plenty of reasons for doubt — because in addition to the inflated demand, the first third of the book also contains economic, social, and environmental constraints on supply, despite the statement to the contrary (I’ll write a bit more about the supply side in a new article, later). So those are not about the physics of the thing at all — they’re opinions. So, we have an inflated demand, and a set of political opinions on supply. That’s not (in Professor MacKay’s words) “what the laws of physics say about the limits of sustainable energy”.

As it turns out, Britain’s renewable resource is an order of magnitude higher than our energy demand.

And so Britain, (just like Europe and the whole world) can get 100% of its energy from renewable resources.

Now, as that’s fundamentally different to Professor MacKay’s conclusion, I think it’s pretty important. Because it means that we have very real choices about the next 40 years. We can choose nuclear or CCS as transition technologies if we want — but we don’t have to have either of them. They are only options, not necessities.

]]> By: Patrick Stewart http://www.energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences#comment-141 Patrick Stewart Mon, 04 Apr 2011 03:34:36 +0000 http://www.energynumbers.info/?p=305#comment-141 To be fair, that comparison on page 103 is between his two ballpark figures based on back of an envelope estimates. His actual conclusions on what is and isn't possible are much later in the book (page 203 onwards), but as you seem to half-acknowledge above, on the following pages (104 and 107) he compares both of these estimates to official figures. He finds that he overestimated consumption by about 50% as compared to the same DTI figures you're using except from 2006 rather than 2008; mostly by including the energy used to make things that isn't expended in the UK. So pretty much your entire article is already in the book. He uses those corrected figures, with further reductions due to efficiency, in the rest of the book, including in his actual conclusions. What you haven't written about at all is that he also finds that his total renewable energy potential estimates were very optimistic, about 3-10 times higher than similar estimates by several other groups. I don't really know why I'm posting this, you're clearly already aware of it, it's in you graphs; I just can't understand how you can complain about Mackay inflating his figures while also being aware that they're lower than yours in his conclusions on pg 204. If you actually read the text on page 103 it clearly says "Now we will see if these estimates are correct", not "so here I have conclusively proved renewables are insufficient" To be fair, that comparison on page 103 is between his two ballpark figures based on back of an envelope estimates. His actual conclusions on what is and isn’t possible are much later in the book (page 203 onwards), but as you seem to half-acknowledge above, on the following pages (104 and 107) he compares both of these estimates to official figures. He finds that he overestimated consumption by about 50% as compared to the same DTI figures you’re using except from 2006 rather than 2008; mostly by including the energy used to make things that isn’t expended in the UK. So pretty much your entire article is already in the book. He uses those corrected figures, with further reductions due to efficiency, in the rest of the book, including in his actual conclusions.
What you haven’t written about at all is that he also finds that his total renewable energy potential estimates were very optimistic, about 3–10 times higher than similar estimates by several other groups.

I don’t really know why I’m posting this, you’re clearly already aware of it, it’s in you graphs; I just can’t understand how you can complain about Mackay inflating his figures while also being aware that they’re lower than yours in his conclusions on pg 204. If you actually read the text on page 103 it clearly says “Now we will see if these estimates are correct”, not “so here I have conclusively proved renewables are insufficient”

]]> By: Energy Numbers http://www.energynumbers.info/british-energy-demand-and-professor-mackays-estimate-of-it-an-explanation-of-the-differences#comment-34 Energy Numbers Tue, 29 Jun 2010 20:38:04 +0000 http://www.energynumbers.info/?p=305#comment-34 <span class="topsy_trackback_comment"><span class="topsy_twitter_username"><span class="topsy_trackback_content">New:: British Energy Demand, and Professor MacKay's estimate of it: an explanation of the differences http://j.mp/aqHvpQ</span></span> New:: British Energy Demand, and Professor MacKay’s estimate of it: an explanation of the differences http://j.mp/aqHvpQ

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