Slashdot is powered by your submissions, so send in your scoop

 



Forgot your password?
typodupeerror

Comment Re:Interesting how little storage is needed (Score 1) 160

Actually, it's not impossible at all. The UK grid needs about 3 times the amount of wind and much more solar and 2 terawatts of underground hydrogen storage.

There's enough salt caverns around the UK that can give it that storage, and the hydrogen can be manufactured via electrolysis when the wind and solar is producing too much. It's not very efficient, but renewables are cheap.

It CAN be done.

Comment Re:Not supported by subsidy (Score 1) 160

FYI as of 2021 the UK had 1.3 GW(h) of battery storage on the grid:

https://www.solarpowerportal.c...

I'm not sure what the total storage is now, it's going to be over 1.5 GW(h) with this installation, and probably a lot more. Note that large batteries aren't needed, it's the total battery storage that's important.

The UK grid operator was particularly keen on getting batteries on it, because the HVDC interconnectors to the continent have been unreliable, and they tend to suddenly break with no warning. That has meant that the grid needs to have a couple of gigawatt of spinning reserve instead, particularly spinning overnight, but with enough batteries they can shut most of that down into hot standby.

The last outage the grid had, due to a lightning strike, they didn't quite have enough battery, and that meant they had to do load shedding and that caused chaos. They should have enough battery now to keep it up long enough if there's a repeat to get backup power running and avoid any load shedding.

The other thing these batteries can do is help smooth out the production curve. If we had enough batteries to smooth out the evening power demand, the CCGT gas turbines would be much more efficient. When they first start up they use about twice as much fuel per kWh until the second cycle kicks in. If they start up less, costs should go down. But we'd need a lot more batteries to make that work.

Comment Re: Canada vs. Texas (Score 1) 275

No, there is apparently still one AC tie switch in Dayton, Texas that has been used only once in its history (after Hurricane Ike).

You're right, they do have to synchronize before they connect, but it's not usually a monumental task.

Amusingly the UK national grid was first connected up by technicians playing around in the night without any permission, they just synched up the regional grids that there were at the time and closed the switches- just to see what would happen, as you do! Worked fine, and the following year it was done permanently.

Comment Re:Canada vs. Texas (Score 1) 275

I think it was more that he was blatantly lying about it, not that it was renewables per se.

That, and the plain fact that the failures were very avoidable, that similar conditions had happened before both in Texas and elsewhere, and that the recommendations were simply not followed, meant that it was never going to look good for them.

Medicine

Can You Get Covid-19 Again? It's Very Unlikely, Experts Say 55

An anonymous reader shares a report: The anecdotes are alarming. A woman in Los Angeles seemed to recover from Covid-19, but weeks later took a turn for the worse and tested positive again. A New Jersey doctor claimed several patients healed from one bout only to become reinfected with the coronavirus. And another doctor said a second round of illness was a reality for some people, and was much more severe. These recent accounts tap into people's deepest anxieties that they are destined to succumb to Covid-19 over and over, feeling progressively sicker, and will never emerge from this nightmarish pandemic. And these stories fuel fears that we won't be able to reach herd immunity -- the ultimate destination where the virus can no longer find enough victims to pose a deadly threat.

But the anecdotes are just that -- stories without evidence of reinfections, according to nearly a dozen experts who study viruses. "I haven't heard of a case where it's been truly unambiguously demonstrated," said Marc Lipsitch, an epidemiologist at the Harvard T.H. Chan School of Public Health. Other experts were even more reassuring. While little is definitively known about the coronavirus, just seven months into the pandemic, the new virus is behaving like most others, they said, lending credence to the belief that herd immunity can be achieved with a vaccine. It may be possible for the coronavirus to strike the same person twice, but it's highly unlikely that it would do so in such a short window or to make people sicker the second time, they said. What's more likely is that some people have a drawn-out course of infection, with the virus taking a slow toll weeks to months after their initial exposure. People infected with the coronavirus typically produce immune molecules called antibodies. Several teams have recently reported that the levels of these antibodies decline in two to three months, causing some consternation. But a drop in antibodies is perfectly normal after an acute infection subsides, said Dr. Michael Mina, an immunologist at Harvard University.

Comment Re:Makes sense they'd be against it (Score 1) 287

I live near multiple wind turbines, and those are virtually never real problems. Unless you're VERY close to a wind turbine you can't hear it, and shutting down wind turbines to avoid the shadow sweeping across residential areas- something that will normally only happen at very limited times of day and only then at certain times of the year, are very real things that are done and cause very little loss of income for the owners of the turbine. On the contrary people generally LIKE wind turbines near them once they're actually up.

Comment Re:Natural gas is outpacing coal, with a bit of wi (Score 1) 276

> Now, how is Texas going to replace the natural gas, when the wind is not available 2/3 of the time?

That's not true, wind is always producing. Using the standard models there's zero chance of zero output. You're confusing capacity factor with availability. About a quarter to a third of the maximum wind power is available 95% of the time.

Comment Re:Hey folks. (Score 1) 240

> You seem to be conflating generation with consumption. Denmark is consuming large amounts of imported nuclear, hydro and gas-fired power.

But all of Denmark's wind power production is consumed. Your claim was that less than half of it is. Your claim is false.

> Anyone can generate more PV electricity than they consume, if they can sell to the grid and buy back.

Virtually all of grid-connected PV potential production is consumed worldwide right now. Not less than half.

> Until too many people try to do that.

There is nowhere in the world where they throw away half of their renewable grid connected electricity, and it's difficult to see how that could ever happen.

Slashdot Top Deals

They laughed at Einstein. They laughed at the Wright Brothers. But they also laughed at Bozo the Clown. -- Carl Sagan

Working...