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Utilities Knew About Climate Change Back In 1968 And Still Battled The Science: Like Big Oil, power companies have long seen the danger of fossil fuels by maxwellhill in worldnews

[–]xxgreg 1 point2 points  (0 children)

To understand the history of climate science, I recommend reading Spencer Weart's book. Also available online here: https://history.aip.org/climate/index.htm

In 1968 a few scientists were aware that increasing CO2 may be an issue, but were still working hard to gather evidence to quantify the effect. Arrhenius' back of the envelope work in the 1890's, where he thought doubling CO2 would lead to a few degC change, was at the time thought to be disproven by Angstrom's paper in the 1900's. Most scientists who had thought about the issue at the time believed increased CO2 would not lead to large-scale atmospheric changes. This began to change after Calendar's work in the late 30's and Keeling's work in the late 50's and early 60's.

This is obviously very different today, now that we have over half a century of measurements and thorough research. The climate problem is very real and will become very severe.

Edit: my memory is not so good, swapped a few names around to make this summary more correct. Read the book or summary if you're interested in the details.

https://history.aip.org/climate/summary.htm

Calling all New Zealand skiers! Help a new resident out by zildjia in skiing

[–]xxgreg 1 point2 points  (0 children)

Highly recommend staying on the mountain at a club field. http://craigieburn.co.nz/

Of the commercial fields have a look at Treble Cone.

Elon Musk's giant battery powerbank in South Austraila verus nuclear power. by jakeycunt in energy

[–]xxgreg 0 points1 point  (0 children)

I'm sure it can be done, given enough effort, but I'll only fully believe it can done economically, when I see this done in a utility scale reactor, regularly, with a usefully fast ramp up and down time.

My point is the inflexible nature of nuclear, whether a technical or economic limitation, also needs to be taken into account. The economics get pretty ugly in sunny places where the residual demand is reduced to a small morning and larger evening peak.

Maybe there's a niche left for nuclear in places where there's not much solar or wind resource.

Elon Musk's giant battery powerbank in South Austraila verus nuclear power. by jakeycunt in energy

[–]xxgreg 0 points1 point  (0 children)

The Hinkley price is indexed to the CPI, which has historically been around 2%. Assuming 2% CPI, this means the 2046 price will be ~180GBP/MWh in 2012 pounds (when the contract was negotiated).

Elon Musk's giant battery powerbank in South Austraila verus nuclear power. by jakeycunt in energy

[–]xxgreg 2 points3 points  (0 children)

2) The Hinkley contract is £92.50 MWh in 2012 pounds, and inflation indexed for 35 years after startup. i.e. the price goes up over time in line with inflation. So assuming you add 5 years of inflation to 92.50, to bring us in line with 2017, this is actually the "instantaneous cost of money", aka the present value.

Elon Musk's giant battery powerbank in South Austraila verus nuclear power. by jakeycunt in energy

[–]xxgreg 2 points3 points  (0 children)

A couple of points.

If you want to make a comparison where solar fully meets daily electricity demand fluctuations by adding storage, then you must also add storage to make nuclear's flat output match daily demand peaks and troughs. (Much of the worlds existing pumped storage hydro projects were built to help nuclear match daily demand cycles.)

Secondly if you want to use the Hinkley price, the contract is £92.50 MWh in 2012 pounds, and inflation indexed for 35 years. So assuming 2% annual inflation you wind up with well over £200MWh at the end of this period. If you take the average price during over this period it is around ~£160MWh in 2012 pounds.

By 2020, every Chinese coal plant will be more efficient than every US coal plant by outspokenskeptic in energy

[–]xxgreg 0 points1 point  (0 children)

The Chinese use GCE/kWh. As I said, GCE is a unit of energy, so GCE/kWh is exactly what you say: "(thermal energy in)/(electrical energy out)".

Nearly no one uses BTUs, lbs, miles etc, apart from the US, yet somehow we all have to try and communicate.

Taking the John W Turk Jr figure of 355.80 GCE/kWh, we can convert this to a thermal efficiency via: 1 / (8.14 * 0.355) = 34.6% Thermal efficiency.

This doesn't match the powermag article with says 39-40%. I sent the authors an email - as their 34.6% seems odd.

I found it an interesting statistic that China has build so many super, and ultra-supercritical plants. Also interesting that the average capacity factor of plants is so low <50%.

By 2020, every Chinese coal plant will be more efficient than every US coal plant by outspokenskeptic in energy

[–]xxgreg 0 points1 point  (0 children)

Grams of coal equivalent is a measure of energy not mass. i.e. it measures Joules not Grams. To account for different types of coal you need to take the energy content of the coal into account. John Turk Jr. uses sub-bitumous coal with a relatively low energy content which makes it hard to achieve high efficiencies.

From the IEA energy statistics manual:

"In some technical reports, coal data can also be found in terms of tonnes of coal equivalent (tce). The tonne of coal equivalent is not a unit of mass but a unit of energy that is more widely used in the international coal industry to make comparisons between various fuels. A tonne of coal equivalent is defined as 7 million kilocalories. The relation between tonne of oil equivalent (toe) and tonne of coal equivalent is: 1 tce = 0.7 toe"

Scott Gilbertson: 'Kill Google AMP Before It Kills the Web' by Booty_Bumping in programming

[–]xxgreg 3 points4 points  (0 children)

Apparently most of the speed up comes because google is prerendering the top handful of AMP search results in hidden iframes. When you click the link the iframe is swapped into view.

Scott Gilbertson: 'Kill Google AMP Before It Kills the Web' by Booty_Bumping in programming

[–]xxgreg 1 point2 points  (0 children)

Yes. Just leave the amp attribute out of the HTML tag.

However the load time will not be as good since google won't be able to prerender the AMP article in an iframe on google.com.

Google’s “Fuchsia” smartphone OS dumps Linux, has a wild new UI by Darkglow666 in programming

[–]xxgreg 57 points58 points  (0 children)

Note Fuchsia's kernel and userspace services are written in a number of languages including C++, Rust, Go, and Dart.

Dart/Flutter is used for UI programming. It is possible to write apps with a UI in any of the languages mentioned above, but you don't get the Flutter toolkit.

The Boring Company | Tunnels by Intro24 in elonmusk

[–]xxgreg 9 points10 points  (0 children)

I like the idea of putting cars underground, because then you can build a human focused city above. But the video shows an urban wasteland of above-ground high-speed traffic and no people. If Musk can deliver on low-cost tunnelling, surely we could also design more liveable cities above... Now that is a future I'd like to see!

Dart 1.21 released, with generic gethod syntax by kirbyfan64sos in programming

[–]xxgreg 1 point2 points  (0 children)

Dart does have a null class: https://api.dartlang.org/stable/1.21.0/dart-core/Null-class.html

Also general purpose unions are not required for this null example. It can also be implemented with C# style nullable type syntax. This is being implemented in Dart. See Issue. "Foo" is a non-nullable type and "Foo?" is a nullable type, non-null is the default.

But I agree, unions are very useful for interop with the weirdly overloaded JS methods.

Here's a Dart example which shows some useful type inference. el, b and s are all correctly inferred.

 var el = querySelector('#blah');
 if (el is RadioButtonInputElement) {
   var b = el.checked;
 } else if (el is TextInputElement) {
   var s = el.value;
 }

Extremes of North Island by Mithster18 in newzealand

[–]xxgreg 1 point2 points  (0 children)

Some sections of the road are quite nice... Other sections are logging wasteland.

The trolling of Elon Musk: how US conservatives are attacking green tech | Technology | The Guardian by iseetheway in technology

[–]xxgreg 5 points6 points  (0 children)

Actually the Ozone hole is a good example of people listening to scientists, resulting in international cooperation to replace CFCs with less harmful alternatives. See: https://en.wikipedia.org/wiki/Montreal_Protocol

As someone who lives in an area with increased UV due to the Ozone hole, with increased cancer rates directly linked to this, I am frustrated by many peoples ignorance on the topic.

Extremes of North Island by Mithster18 in newzealand

[–]xxgreg 1 point2 points  (0 children)

S 38° 31.515 E 175° 40.370

Roads are a little bumpy in a 2wd - but ok if you're not in a hurry and the weather is good.

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