4 ms·

The US uses 4 trillion kWh per year. Assuming 3MW wind turbines at 30% capacity factor, you'll need around 3.5 billion wind turbines. They take around 23 millio

by ppf 7y ago

The US uses 4 trillion kWh per year. Assuming 3MW wind turbines at 30% capacity factor, you'll need around 3.5 billion wind turbines. They take around 23 million kWh to manufacture (each), so you'll need to find the energy for that. However, that's not really enough, as the entire economy needs to be carbon-neutral. Electricity usage accounts for about 40% of the total US energy usage, so you'll actually need to multiply everything by 2.5. Seriously, I understand the "we only have 10 years to do anything" line, but the math is so far from adding up, it completely defeats the point. The only realistic way to achieve the 10 year goal is to radically cut energy usage.

philipkglass 7y ago
A 3 MW wind turbine producing at 30% capacity factor generates 3000 * 0.3 * 24 * 365 = 7,884,000 kWh per year. 4 trillion kWh annually would require (4 * 10^12) / 7884000 = 507,357 turbines Not 3.5 billion.
- ppf 7y ago
  Fair point - I did the calc all at once and screwed up my parentheses. My point still stands. How realistic is it to manufacture 500,000 x2.5 = 1.25 million wind turbines, needing 27 trillion kWh to do so, in 10 years?
  - philipkglass 7y ago
    That's not going to happen. Nor are thousands of nuclear reactors going to be built in 10 years. Nor is the US going to cut its primary energy use by 60% in 10 years. Nor is the combination of all-of-the-above going to make the US carbon neutral in 10 years. Nor should we give up on continued incremental progress after another 10 years have passed without fully solving the problem. It's always possible to make climate change even worse by burning more fossil fuels. Regardless of whatever dangerous threshold of emissions has passed in 10 years, it doesn't make sense to resign ourselves to burning the rest of the fossil fuels. I'm afraid that the hardline "we need to have solved this emissions problem in 1X years" rhetoric is counterproductive. It asks too much and will prompt fatalism and/or cynicism when the deadline has passed, there are still billions of living people who need to make decisions affecting the future, and the problem still isn't "done with."
    - layoric 7y ago
      > I'm afraid that the hardline "we need to have solved this emissions problem in 1X years" rhetoric is counterproductive. It asks too much and will prompt fatalism and/or cynicism when the deadline has passed This is a risk yes, media have a big part to play here to try and build on positive inertia. A good example of the opposite of this is Australia in ~2005 vs ~2015 we went from enough political will to create a carbon tax (that was hugely successful is dropping our emissions in a short period of time) to removing it and likely never going back. IMO this was largely due to medias constant fighting in this direction (to serve those who were lobbying hard in this direction). The hardline approach does seem to have wakened a larger group of people to speak out and support trying to reduce how much worse the climate crisis will get in the coming decades. That combined with more frequent and intense natural disasters might just keep things moving. However, I've learnt never to be surprised by our collective short term memory when counter narratives are constantly bombarding us through media channels.
      - philipkglass 7y ago
        I agree with you. I support people doing the right thing even for mistaken reasons. That's why I don't normally criticize comments saying that we need to solve the problem in <some arbitrary number of years> even though I believe that "deadline" approach is technically incorrect. I don't look forward to the backlash after these various deadlines pass in the 2030s though. Fortunately, there is also a longer term trend of battery storage costs and renewable generation costs continuing to fall. It may be short term reactions to wildfires that guide Australian energy investment in the next couple of years, but it will be the technological improvements that keep low-carbon options on top in the next couple of decades.
    - ppf 7y ago
      The headlines absolutely do not help. They turn off people like me, who care deeply about sustainability, let alone your average reader. Nor do those promoting complex/high-tech solutions, or ideas like "you do your part if you buy an EV". The simple fact is - a sustainable, CO2 neutral civilization essentially only has the energy available daily from the sun to sustain itself (unless you include nuclear). This is orders of magnitudes less than our current energy usage. Unless you want another stone age, a compromise is necessary.

by ppf 7y ago

philipkglass 7y ago

A 3 MW wind turbine producing at 30% capacity factor generates 3000 * 0.3 * 24 * 365 = 7,884,000 kWh per year. 4 trillion kWh annually would require (4 * 10^12) / 7884000 = 507,357 turbines Not 3.5 billion.

ppf 7y ago
Fair point - I did the calc all at once and screwed up my parentheses. My point still stands. How realistic is it to manufacture 500,000 x2.5 = 1.25 million wind turbines, needing 27 trillion kWh to do so, in 10 years?
- philipkglass 7y ago
  That's not going to happen. Nor are thousands of nuclear reactors going to be built in 10 years. Nor is the US going to cut its primary energy use by 60% in 10 years. Nor is the combination of all-of-the-above going to make the US carbon neutral in 10 years. Nor should we give up on continued incremental progress after another 10 years have passed without fully solving the problem. It's always possible to make climate change even worse by burning more fossil fuels. Regardless of whatever dangerous threshold of emissions has passed in 10 years, it doesn't make sense to resign ourselves to burning the rest of the fossil fuels. I'm afraid that the hardline "we need to have solved this emissions problem in 1X years" rhetoric is counterproductive. It asks too much and will prompt fatalism and/or cynicism when the deadline has passed, there are still billions of living people who need to make decisions affecting the future, and the problem still isn't "done with."
  - layoric 7y ago
    > I'm afraid that the hardline "we need to have solved this emissions problem in 1X years" rhetoric is counterproductive. It asks too much and will prompt fatalism and/or cynicism when the deadline has passed This is a risk yes, media have a big part to play here to try and build on positive inertia. A good example of the opposite of this is Australia in ~2005 vs ~2015 we went from enough political will to create a carbon tax (that was hugely successful is dropping our emissions in a short period of time) to removing it and likely never going back. IMO this was largely due to medias constant fighting in this direction (to serve those who were lobbying hard in this direction). The hardline approach does seem to have wakened a larger group of people to speak out and support trying to reduce how much worse the climate crisis will get in the coming decades. That combined with more frequent and intense natural disasters might just keep things moving. However, I've learnt never to be surprised by our collective short term memory when counter narratives are constantly bombarding us through media channels.
    - philipkglass 7y ago
      I agree with you. I support people doing the right thing even for mistaken reasons. That's why I don't normally criticize comments saying that we need to solve the problem in <some arbitrary number of years> even though I believe that "deadline" approach is technically incorrect. I don't look forward to the backlash after these various deadlines pass in the 2030s though. Fortunately, there is also a longer term trend of battery storage costs and renewable generation costs continuing to fall. It may be short term reactions to wildfires that guide Australian energy investment in the next couple of years, but it will be the technological improvements that keep low-carbon options on top in the next couple of decades.
  - ppf 7y ago
    The headlines absolutely do not help. They turn off people like me, who care deeply about sustainability, let alone your average reader. Nor do those promoting complex/high-tech solutions, or ideas like "you do your part if you buy an EV". The simple fact is - a sustainable, CO2 neutral civilization essentially only has the energy available daily from the sun to sustain itself (unless you include nuclear). This is orders of magnitudes less than our current energy usage. Unless you want another stone age, a compromise is necessary.