5 ms·

Prof Mackay's talk pretty much says that in order to use renewable energy the whole UK would have to be covered in electricity generating equipment. However, 1

by phaemon 12y ago

Prof Mackay's talk pretty much says that in order to use renewable energy the whole UK would have to be covered in electricity generating equipment. However, 15% of UK energy is generated from renewables (excluding nuclear), which would mean that currently one seventh of the landmass of the UK was covered in wind turbines etc. Which it isn't. You'd be able to tell. So, one of us has made a mistake with our calculations somewhere.

mschuster91 12y ago
> However, 15% of UK energy is generated from renewables (excluding nuclear), which would mean that currently one seventh of the landmass of the UK was covered in wind turbines etc. Which it isn't. Most likely brought in from other countries, and the wind parks in the North Sea. Many local utilities in Germany hold stakes e.g. in a Norwegian (iirc) dam project, so they recieve a given amount of electricity output. This increases Germany's renewable-source amount even if the energy itself isn't produced in Germany.
- phaemon 12y ago
  Nope, Scotland over produces and sells to England, but that's still UK, at least for another month ;-) Offshore wind was included in the impossible. There's something off in his figures. Perhaps wind turbines have become more efficient since he first made his calculations?
  - cmdkeen 12y ago
    It may also be diminishing returns, not all land is equal for wind turbine placement. If all the "good" spots can't generate enough for the UK's needs you might need to start using less suitable locations.
    - TheOtherHobbes 12y ago
      By far the most efficient wind turbine placements are offshore. We have plenty of coast, and so far very little of it has offshore wind farms. We also have a good few estuaries that could create electricity relatively easily - using known and proven technology, which fusion certainly isn't. Bottom line is these figures are either incompetent or disingenuous. I'm old enough to remember fusion being touted as the Next Big Thing for literally all of my life. Commercial containment fusion seems no closer now than it did fifty years ago. There are alternatives, but they're highly speculative. Dropping YC cash on them makes sense as a long shot, but the science doesn't suggest it's wise to expect them to make good.
reitzensteinm 12y ago
To start with, you're talking about electricity generation, where he is talking about total energy requirements. So your 15% figure doesn't include the energy consumption of cars, aeroplanes, many types of heating etc. I believe he also includes the embodied energy of imports (this was in his book), where if goods are manufactured overseas and imported, it may make sense to count the energy used to manufacture them, depending on what you're measuring exactly. For example, there's little difference between importing aluminium, or importing energy and bauxite and smelting it yourself. Also, area use will not increase linearly with the addition of many renewables, because in many cases the best sites are taken first. Hydro can generate a lot of energy around the clock, but you quickly run out of the best locations. Wind strength varies across the country. In a small country like the UK, solar isn't going to vary much by latitude, and you can probably build it out all over the country. But time shifting of demand isn't always possible, so even if the panels were free, using them to push from (say) 50% of energy from renewables to 100% is going to involve some kind of storage system, which is either going to be very expensive (probably exceeding GDP) and unproven (eg hydrogen fuel cells, lithium ion batteries), or require a ton of space and specific terrain, like pumped water. So that's going to cost a lot of space. Lastly, electricity isn't always the desired final form. If you're powering jet planes, you're going to need some type of biofuel, which is very inefficient per unit area. If and when hydrogen planes are developed, this will stop being an issue (electric cars have already proven their viability). I highly recommend his book. It's a brilliant read, he nicely boils down the issues, and is thoroughly committed to stopping global warming - it's not some doom and gloom oil industry sponsored thing. But he doesn't have his head in the sand about how hard a switch to renewables is going to be, unlike (unfortunately) a ton of the green movement seems to.
- Retric 12y ago
  If your talking total energy then you need to include food and farms already take a lot of land. So, while close it's vary misleading as going 100% renewable would take less new land than he is suggesting. Add to that you can mix wind farms and regular farms at the cost of less than 1% of the farm land. Not to mention off shore wind farms. Which further reduces the land requirements well below his calculations. Also, Hydro is vary efficient built in storage using it 24/7 is vary wasteful. Wind is 24/7, and solar aligns with peak demand fairly well. Anyway, rather than storage your better off with extra wind capacity that's often wasted, with solar to meet your daily peak and hydro to fill in the gaps. PS: Adding a few peaking power plants is still a good idea, going 80% renewable is a much more reasonable goal until most of the world is at that point. It's silly to chase a few extra % when china is using so much coal power.
michaelt 12y ago
According to [1] in 2012 for the UK renewables provided 11.3% of electricity demand and 3.94% of total energy demand. It's an important distinction, because petrol natural gas and jet fuel aren't renewable. MacKay is the author of a book - "Sustainable Energy without the hot air" - which lays out all his calculations and the rationales behind the inputs. And it's available online [2]. So if you want to audit his calculations, have at it! [1] https://en.wikipedia.org/w/index.php?title=Renewable_energy_in_the_United_Kingdom&oldid=618671164 https://en.wikipedia.org/w/index.php?title=Renewable_energy_... [2] http://www.withouthotair.com/ http://www.withouthotair.com/
- phaemon 12y ago
  I've looked at the book, there's when I checked his figures and they seemed to disagree with reality. So, electricity is about 1/3 of total energy. The 15% figure is the latest one for the last quarter of 2013[1] (PDF, see page 13). That means that (according to Prof Mackay) 5% of the UK is covered in renewable electricity generation. No, it's still not. [1]https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/255182/UK_Renewable_Energy_Roadmap_-_5_November_-_FINAL_DOCUMENT_FOR_PUBLICATIO___.pdf https://www.gov.uk/government/uploads/system/uploads/attachm...

by phaemon 12y ago

mschuster91 12y ago

> However, 15% of UK energy is generated from renewables (excluding nuclear), which would mean that currently one seventh of the landmass of the UK was covered in wind turbines etc. Which it isn't. Most likely brought in from other countries, and the wind parks in the North Sea. Many local utilities in Germany hold stakes e.g. in a Norwegian (iirc) dam project, so they recieve a given amount of electricity output. This increases Germany's renewable-source amount even if the energy itself isn't produced in Germany.

phaemon 12y ago
Nope, Scotland over produces and sells to England, but that's still UK, at least for another month ;-) Offshore wind was included in the impossible. There's something off in his figures. Perhaps wind turbines have become more efficient since he first made his calculations?
- cmdkeen 12y ago
  It may also be diminishing returns, not all land is equal for wind turbine placement. If all the "good" spots can't generate enough for the UK's needs you might need to start using less suitable locations.
  - TheOtherHobbes 12y ago
    By far the most efficient wind turbine placements are offshore. We have plenty of coast, and so far very little of it has offshore wind farms. We also have a good few estuaries that could create electricity relatively easily - using known and proven technology, which fusion certainly isn't. Bottom line is these figures are either incompetent or disingenuous. I'm old enough to remember fusion being touted as the Next Big Thing for literally all of my life. Commercial containment fusion seems no closer now than it did fifty years ago. There are alternatives, but they're highly speculative. Dropping YC cash on them makes sense as a long shot, but the science doesn't suggest it's wise to expect them to make good.

reitzensteinm 12y ago

To start with, you're talking about electricity generation, where he is talking about total energy requirements. So your 15% figure doesn't include the energy consumption of cars, aeroplanes, many types of heating etc. I believe he also includes the embodied energy of imports (this was in his book), where if goods are manufactured overseas and imported, it may make sense to count the energy used to manufacture them, depending on what you're measuring exactly. For example, there's little difference between importing aluminium, or importing energy and bauxite and smelting it yourself. Also, area use will not increase linearly with the addition of many renewables, because in many cases the best sites are taken first. Hydro can generate a lot of energy around the clock, but you quickly run out of the best locations. Wind strength varies across the country. In a small country like the UK, solar isn't going to vary much by latitude, and you can probably build it out all over the country. But time shifting of demand isn't always possible, so even if the panels were free, using them to push from (say) 50% of energy from renewables to 100% is going to involve some kind of storage system, which is either going to be very expensive (probably exceeding GDP) and unproven (eg hydrogen fuel cells, lithium ion batteries), or require a ton of space and specific terrain, like pumped water. So that's going to cost a lot of space. Lastly, electricity isn't always the desired final form. If you're powering jet planes, you're going to need some type of biofuel, which is very inefficient per unit area. If and when hydrogen planes are developed, this will stop being an issue (electric cars have already proven their viability). I highly recommend his book. It's a brilliant read, he nicely boils down the issues, and is thoroughly committed to stopping global warming - it's not some doom and gloom oil industry sponsored thing. But he doesn't have his head in the sand about how hard a switch to renewables is going to be, unlike (unfortunately) a ton of the green movement seems to.

Retric 12y ago
If your talking total energy then you need to include food and farms already take a lot of land. So, while close it's vary misleading as going 100% renewable would take less new land than he is suggesting. Add to that you can mix wind farms and regular farms at the cost of less than 1% of the farm land. Not to mention off shore wind farms. Which further reduces the land requirements well below his calculations. Also, Hydro is vary efficient built in storage using it 24/7 is vary wasteful. Wind is 24/7, and solar aligns with peak demand fairly well. Anyway, rather than storage your better off with extra wind capacity that's often wasted, with solar to meet your daily peak and hydro to fill in the gaps. PS: Adding a few peaking power plants is still a good idea, going 80% renewable is a much more reasonable goal until most of the world is at that point. It's silly to chase a few extra % when china is using so much coal power.

michaelt 12y ago

According to [1] in 2012 for the UK renewables provided 11.3% of electricity demand and 3.94% of total energy demand. It's an important distinction, because petrol natural gas and jet fuel aren't renewable. MacKay is the author of a book - "Sustainable Energy without the hot air" - which lays out all his calculations and the rationales behind the inputs. And it's available online [2]. So if you want to audit his calculations, have at it! [1] https://en.wikipedia.org/w/index.php?title=Renewable_energy_in_the_United_Kingdom&oldid=618671164 https://en.wikipedia.org/w/index.php?title=Renewable_energy_... [2] http://www.withouthotair.com/ http://www.withouthotair.com/

phaemon 12y ago
I've looked at the book, there's when I checked his figures and they seemed to disagree with reality. So, electricity is about 1/3 of total energy. The 15% figure is the latest one for the last quarter of 2013[1] (PDF, see page 13). That means that (according to Prof Mackay) 5% of the UK is covered in renewable electricity generation. No, it's still not. [1]https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/255182/UK_Renewable_Energy_Roadmap_-_5_November_-_FINAL_DOCUMENT_FOR_PUBLICATIO___.pdf https://www.gov.uk/government/uploads/system/uploads/attachm...