Scrutable

AMS wrote: ↑

Tue Jul 28, 2020 3:56 pm

I was reading earlier today about electric combi boilers as replacement for gas. Anyone know if they're any good? It did say that gas is cheaper than leccy for heating per kW, but that this is partially offset by electric boilers being more efficient - close to 100% in fact, as for this application, energy lost as heat is kind of the point.
Presumably gas is much worse for efficiency because of heat carried away in the flue gases.

So when our current elderly boiler dies, are they worth it? (My view of electric water heaters is tarnished by those units you used to get on the hot water tap in places like village halls or pub toilets, which uniformly do nothing to the water temperature.)

Condensing Gas boilers are now about 90% efficient or so we're told.

Gfamily wrote: ↑

Tue Jul 28, 2020 4:09 pm

AMS wrote: ↑

Tue Jul 28, 2020 3:56 pm

I was reading earlier today about electric combi boilers as replacement for gas. Anyone know if they're any good? It did say that gas is cheaper than leccy for heating per kW, but that this is partially offset by electric boilers being more efficient - close to 100% in fact, as for this application, energy lost as heat is kind of the point.
Presumably gas is much worse for efficiency because of heat carried away in the flue gases.

So when our current elderly boiler dies, are they worth it? (My view of electric water heaters is tarnished by those units you used to get on the hot water tap in places like village halls or pub toilets, which uniformly do nothing to the water temperature.)

Condensing Gas boilers are now about 90% efficient or so we're told.

95% plus.

But the significantly more efficient option is a heat pump system. Those have efficiencies* approaching 300-400% in the UK environment, and thus about the same price to run as gas.

*Coefficient of performance

AMS wrote: ↑

Tue Jul 28, 2020 3:56 pm

I was reading earlier today about electric combi boilers as replacement for gas. Anyone know if they're any good? It did say that gas is cheaper than leccy for heating per kW, but that this is partially offset by electric boilers being more efficient - close to 100% in fact, as for this application, energy lost as heat is kind of the point.
Presumably gas is much worse for efficiency because of heat carried away in the flue gases.

So when our current elderly boiler dies, are they worth it? (My view of electric water heaters is tarnished by those units you used to get on the hot water tap in places like village halls or pub toilets, which uniformly do nothing to the water temperature.)

Fully charged did an episode on a hot water tank a couple of years ago and say that they’re going to do much more on domestic heat soon.

https://fullycharged.show/episodes/mixe ... ater-tank/

AMS wrote: ↑

Tue Jul 28, 2020 3:56 pm

I was reading earlier today about electric combi boilers as replacement for gas. Anyone know if they're any good? It did say that gas is cheaper than leccy for heating per kW, but that this is partially offset by electric boilers being more efficient - close to 100% in fact, as for this application, energy lost as heat is kind of the point.
Presumably gas is much worse for efficiency because of heat carried away in the flue gases.

So when our current elderly boiler dies, are they worth it? (My view of electric water heaters is tarnished by those units you used to get on the hot water tap in places like village halls or pub toilets, which uniformly do nothing to the water temperature.)

One issue with electric combi boilers (at least when I last looked into them) was their time to reach temperature. Gas combi boilers start hitting the desired water outlet temperature almost immediately; basically once the water that was just about to enter the boiler reaches the outlet it should be at temperature, because flame heat is instantaneous. Electric combi boilers have to heat the element up to temperature before the water outlet temperature hits the target. This leads to more under-heated water flowing through the system and, ultimately, straight down the plughole until the hot water reaches the tap. Electric combi boilers may have improved element reaction time in the last few years, but they cannot compete with gas for reaction time.

Gas combi boilers can struggle with low load, though; if you want hot water at a small but continuous amount, you can end up with the combi boiler cycling on and off and varying the water temperature - electric combi boilers handle this far better (at least if their control system is good enough - I've seen some where the control system was based on the gas version so was the worst of both worlds!)

This may be a silly question, but why don’t we use microwaves to heat water?

Grumble wrote: ↑

Thu Jul 30, 2020 6:31 am

This may be a silly question, but why don’t we use microwaves to heat water?

Some answers from reddit:
https://www.reddit.com/r/askscience/com ... the_water/

At my lab we heat water quickly by having a spiral tube wrapped around an element. Terrible for static water but great for flowing water. You may run the risk of local boiling if there’s a lot of heat in the body when flow turns off, but it should be possible to design something like that. I may resort to drawing a system in Paint.

shpalman wrote: ↑

Thu Jul 30, 2020 6:36 am

Grumble wrote: ↑

Thu Jul 30, 2020 6:31 am

This may be a silly question, but why don’t we use microwaves to heat water?

Some answers from reddit:
https://www.reddit.com/r/askscience/com ... the_water/

Ta, I knew I couldn’t be the first to think of that while having a shower!

I don’t think we’ve had this one, old news now but still awesome, superconducting wind turbine!
https://phys.org/news/2019-11-supercond ... ccess.html

BP has read the writing on the wall and has pledged to cut oil production 50% by 2030 as well as the emissions generated to make their stuff. Zero carbon by 2050 (with a minor weasel in that last one).

They also significantly reduced their dividends, partly as a response to the COVID downturn and partly to fund renewables. They plan on increasing investment in “low carbon energy” from $500 million to around $5 billion per year by 2030. Their share price has increased on this news.

bjn wrote: ↑

Wed Aug 05, 2020 6:09 pm

BP has read the writing on the wall and has pledged to cut oil production 50% by 2030 as well as the emissions generated to make their stuff. Zero carbon by 2050 (with a minor weasel in that last one).

They also significantly reduced their dividends, partly as a response to the COVID downturn and partly to fund renewables. They plan on increasing investment in “low carbon energy” from $500 million to around $5 billion per year by 2030. Their share price has increased on this news.

Good, BP have been reasonably fairly accused of green washing before but this looks more substantive.

Excellent news, thanks bjn!

Latest coal-free run ended after 55 days, because of low winds, and hot weather meaning gas-fired stations generate less.

Sciolus wrote: ↑

Thu Aug 13, 2020 6:40 pm

Latest coal-free run ended after 55 days, because of low winds, and hot weather meaning gas-fired stations generate less.

Yes, that does highlight the need for large amounts of stored power that we can call on when required. We’ve essentially had a few days of next to no wind production and building more capacity of generation isn’t going to solve that. Orange is gas in these graphs.

The world's biggest mining company is dropping thermal coal as it's no longer profitable enough:
https://www.thetimes.co.uk/edition/busi ... -p32tg00p0

The world’s biggest mining group has announced plans to exit production of polluting thermal coal, as it reported a 4 per cent fall in underlying net profits to $9.1 billion.

BHP said that significantly lower prices for thermal and coking coal and for oil as a result of the coronavirus pandemic had offset higher prices and profits from its biggest commodity, iron ore. Its profits were lower than analysts had expected.

Mike Henry, BHP’s chief executive, warned that it expected most major economies except China to “contract heavily in 2020”. However, BHP sees the world economy “rebounding solidly” during 2021.

Gov. John Bel Edwards commits to 25-28% emissions cut by 2025, 'net zero' in Louisiana by 2050

Louisiana will strive to reach a “net zero” level of greenhouse gas emissions by 2050 to play its part in a worldwide effort to limit the effects of global warming that threaten the state’s coast and its residents and businesses, Gov. John Bel Edwards said Wednesday before signing two executive orders that will guide the state’s efforts to both reduce emissions and deal with the effects of warming.

“In many ways, Louisiana is the poster child for climate risk. We are the canary in the coal mine,” Edwards said in explaining his plan , delivered during a meeting of the state Coastal Protection And Restoration Authority. “Beginning today, we want to be the gold standard for climate solutions.”

It's good to see targets for 2025: there are too many electoral cycles between now and 2050 for those promises to mean much on their own. Edwards got re-elected last year so he's holding the hot potato. And we really need drastic action before then anyway to stop runaway Arctic melting and massive loss of corals.

I was also heartened to see measures that will also benefit biodiversity:

The state hopes to rely on its own coastal restoration efforts -- rebuilding wetlands that can remove carbon from the air and permanently store it in soils -- and on creating financial incentives for the oil and gas industry to develop their own played-out oil and gas fields deep underground to permanently store carbon emissions captured from their own operations, and possibly from the state's petrochemical facilities.

Based on 2015-16 U.S. Department of Energy estimates, Louisiana is fifth among states in both total carbon emissions and emissions per-capita.

Louisiana does also subsidise its oil and gas corporations with tax breaks, which is totally stupid, but I don't know if that's under the governor's control. He has passed another executive order to force subsidised operations to retain jobs, so presumably he could go further. That money would be much better spent retraining those workers and/or providing jobs in a different sector. Presumably the CCS plans for old fossil wells would help for a bit.

And then there was one.

We mine about 2m tonnes a year and import about 6m tonnes a year, mostly from Russia. There’s talk about opening one more in Cumbria and Hartington are eke out the last few specks.

Barely seems worth the effort even disregarding the climate damage.

What with it being a bit breezy this evening, the UK is currently running on 12.5 GW of wind generation, just shy of 49% of demand.

This is very cool - a growing number of lawsuits against fossil fuel companies for lying about climate change for 50 years, causing irrevocable damage to communities.

‘At the Forefront of Climate Change,’ Hoboken, New Jersey, Seeks Damages From ExxonMobil

Hoboken is the 20th municipality, state or private organization to sue the fossil fuel industry over climate change since 2017. Other plaintiffs include Baltimore, Oakland and San Francisco; numerous counties in California, Colorado, Hawaii, Maryland, New York and Washington; and the states of Massachusetts, Rhode Island and Minnesota.

The number of high tide flood days has already more than doubled since 2000, the lawsuit said, while climate change also threatens the city with more frequent and severe flooding from storm surge during coastal storms.

Other defendants named in the lawsuit include BP, Chevron, ConocoPhillips, Shell and the American Petroleum Institute, an oil and gas trade association.

"The climate harms masked by defendants' half-century of deception have now slammed into the shores of Hoboken," the lawsuit said.

They do not raise claims against Republican propagandists. Forbidden by First Amendment?

bmforre wrote: ↑

Thu Sep 03, 2020 2:41 pm

They do not raise claims against Republican propagandists. Forbidden by First Amendment?

Disclaimer: I'm not a lawyer and I'm not even that familiar with the details of the case.

However, it's a matter of record that Esso in particular have known that combusting fossil fuels causes climate change since the 1970s but have funded disinformation campaigns. The Republicans could just have believed them (and I'm sure in some cases that's what happened), and thought they were spreading accurate information, whereas the corporations were deliberately and provably mendacious.

bmforre wrote: ↑

Thu Sep 03, 2020 2:41 pm

They do not raise claims against Republican propagandists. Forbidden by First Amendment?

Quite possibly, at least for elected officials. Just today an appeals court has confirmed the ruling that Elizabeth Warren's tweets about a racist kid who got famous are protected against defamation lawsuits by Sovereign Immunity, meaning that the liability moves to the United States instead.

dyqik wrote: ↑

Thu Sep 03, 2020 5:35 pm

bmforre wrote: ↑

Thu Sep 03, 2020 2:41 pm

They do not raise claims against Republican propagandists. Forbidden by First Amendment?

Quite possibly, at least for elected officials. Just today an appeals court has confirmed the ruling that Elizabeth Warren's tweets about a racist kid who got famous are protected against defamation lawsuits by Sovereign Immunity, meaning that the liability moves to the United States instead.

I don't know this case. What's it about?

CF

Cardinal Fang wrote: ↑

Fri Sep 04, 2020 11:50 am

dyqik wrote: ↑

Thu Sep 03, 2020 5:35 pm

bmforre wrote: ↑

Thu Sep 03, 2020 2:41 pm

They do not raise claims against Republican propagandists. Forbidden by First Amendment?

Quite possibly, at least for elected officials. Just today an appeals court has confirmed the ruling that Elizabeth Warren's tweets about a racist kid who got famous are protected against defamation lawsuits by Sovereign Immunity, meaning that the liability moves to the United States instead.

I don't know this case. What's it about?

CF

Just some young conservative grifter trying to sue Warren for calling him racist after he said a bunch of racist things on TV. And then got to speak at the GOP convention.

dyqik wrote: ↑

Fri Sep 04, 2020 12:26 pm

Cardinal Fang wrote: ↑

Fri Sep 04, 2020 11:50 am

dyqik wrote: ↑

Thu Sep 03, 2020 5:35 pm

Quite possibly, at least for elected officials. Just today an appeals court has confirmed the ruling that Elizabeth Warren's tweets about a racist kid who got famous are protected against defamation lawsuits by Sovereign Immunity, meaning that the liability moves to the United States instead.

I don't know this case. What's it about?

CF

Just some young conservative grifter trying to sue Warren for calling him racist after he said a bunch of racist things on TV. And then got to speak at the GOP convention.

Ah yes, that currently-popular one-way Freedom of Speech definition which goes "I have the freedom to say what I want but you don't have the freedom to criticise it or hold me accountable for what I say".