|
|
Post by leftieliberal on Jan 2, 2024 10:36:54 GMT
BBC News article on heat pumps. Will hotter heat pumps win over homeowners?Newer heat pumps are providing radiator temperatures similar to combi boilers, using R290 (propane) or R774 (carbon dioxide). One downside is that R290 systems cannot be located near to ground-floor windows or air bricks in case of leaks, because it is flammable (this seems to be a pretty major restriction to me). The downside is that the COP (coefficient of performance) is down at 3 for these higher temperatures. To get a COP close to 4 one still has to keep the flow temperature down to 45 C and use bigger radiators. The old trade-off is still there, but at least the new heat pumps use more environmentally-friendly gases. |
|
|
|
Post by leftieliberal on Feb 9, 2024 19:39:05 GMT
|
|
|
|
Post by leftieliberal on Feb 15, 2024 12:55:01 GMT
Data centres in Ireland use 18% of all electricity generated. An interesting long read in The Guardian. This is the ultimate example of baseload electricity demand as one cannot turn a data centre off. Note also that the IRIS undersea cable terminates at its Icelandic end close to where the current fissure eruptions are taking place.
|
|
|
|
Post by leftieliberal on Feb 16, 2024 11:31:30 GMT
|
|
|
|
Post by John Chanin on Feb 16, 2024 13:47:45 GMT
This simply requires telling Nimbys to fuck off. It's one of the few things that I expect the new Labour government to do differently from the Conservatives. |
|
|
|
Post by leftieliberal on Feb 16, 2024 17:23:54 GMT
This simply requires telling Nimbys to fuck off. It's one of the few things that I expect the new Labour government to do differently from the Conservatives. It's more than just that. As I have pointed out before on here there are supplier issues and National Grid is way behind in being able to connect new renewables. It's mainly a failure of the Tory Government over the last 14 years to fund investment in the grid. Nimbys are just an excuse. |
|
|
|
Post by johntel on Feb 23, 2024 16:51:51 GMT
|
|
|
|
Post by leftieliberal on Feb 23, 2024 18:44:34 GMT
Why just planting trees may not be a good ideaLooked at simplistically, tree-planting is often suggested as the best approach to countering global warming caused by higher levels of CO2 in the atmosphere. However when you drill down into the details, it is a bit more complicated than that. Our findings suggest that while forestation – the restoration and expansion of forests – can play a role in tackling climate change, its potential may be smaller than previously thought.
Forests emit large quantities of volatile organic compounds (VOCs), with these emissions increasing with rising temperatures. VOCs react chemically in the atmosphere, affecting the concentrations of methane and ozone, which are also greenhouse gases. We find the enhanced VOC emissions from greater forest cover and temperatures increase levels of methane and, typically, ozone. This reduces the amount of radiation escaping to space, further opposing the removal of carbon.
However, the reaction products of VOCs can contribute to aerosols, which reflect incoming solar radiation and help form clouds. Increases in these aerosols with rising VOC emissions from greater forest cover result in more radiation escaping to space.
We find the net effect of changes to albedo, ozone, methane and aerosol is to reduce the amount of radiation escaping to space, cancelling out part of the benefit of reducing atmospheric CO₂. In a future where climate mitigation is not a priority, up to 30% of the benefit is cancelled out, while in a Paris-compatible future, this drops to 15%.
|
|
|
|
Post by lens on Feb 25, 2024 0:25:05 GMT
Drill down a little deeper into the figures and the picture isn't as good as certain interests would like you to believe. Firstly - globally - the amounts being talked about are relatively small. They may be locally useful, but forget about any such being a global solution. Even more importantly, they are virtually never pure hydrogen. In many cases the hydrogen is a pretty small minority in a mix that is mainly methane. That may not matter as much if it is to be used to burn - though such will still give high carbon emissions due to all the methane - but forget about any idea of simply drilling for such and using it as a direct fuel for a fuel cell application. For such the hydrogen needs a high level of purity, which these deposits mainly just do not come close to. I'm afraid that all too often nowadays when you see the word "hydrogen" you should be on the alert for bull@#%t. Coming from a gas industry under challenge for genuine environmental reasons, but desperately trying to stay relevant and greenwash their industry. Huge amounts of hydrogen are used (with no alternative) in the chemical industry, with the hydrogen currently being made by reforming fossil fuel with consequent carbon emissions. The best scenario would be for such to be made increasingly in a green way. That's sensible in a way that trying to pretend it has a viable future in applications such as hydrogen cars just is not. |
|
|
|
Post by leftieliberal on May 8, 2024 13:52:04 GMT
|
|
|
|
Post by alec on May 9, 2024 18:33:22 GMT
DESNZ announced today the postponing (likely abandoning) of the 'hydrogen town' initiative. Hydrogen as a domestic heating source in the UK now looks to be the dead duck all sensible people knew it was a decade and a half ago. The independent expert they interviewed on the PM program kept highlighting the fact that hydrogen was never going to be the answer to that particular part of the energy landscape, and should instead have been focused on industrial uses and back up power generation alongside intermittent renewables. Not as domestic heating. His view (with which I completely concur) was that hydrogen was pushed by the gas and oil production & distribution sector, for obvious reasons of self interest, but in doing so they have caused years of delay in adopting the proven technologies that we will need.
|
|
|
|
Post by lens on May 12, 2024 12:08:48 GMT
......... kept highlighting the fact that hydrogen was never going to be the answer to that particular part of the energy landscape, and should instead have been focused on industrial uses and back up power generation alongside intermittent renewables. Not as domestic heating. His view (with which I completely concur) was that hydrogen was pushed by the gas and oil production & distribution sector, for obvious reasons of self interest,............... Nice to see common sense prevail! And I wholeheartedly agree with everything you say. alecYes to hydrogen for industrial use (it's already widely used - but derived from fossil fuels, and should increasingly be from green sources) but for power generation? By and large green energy starts with electricity, and to then go through lossy processes (electrolysis, compression and distribution) to distribute for pure heating just doesn't make sense. Why not simply use the electricity directly ..... as electricity!? An argument that has been put forward to counter is "ah!, what about the capital cost of heat pumps!?" Whilst they may be optimal in usage, then simple electric resistive heating is still more efficient than going the hydrogen route - a kWh generated means (nearly) a kWh of heat in the home. Go via hydrogen and for every kWh generated it's much less as heat in the home. Yes, all this is going to need a lot of upgrades to the electricity grid - but any move to hydrogen would likewise mean big upgrades to the gas grid and boilers. We've got used to a situation whereby electricity is largely generated from fossil fuels (with energy losses) so it's not surprising a kWh of chemical fuel costs less than a kWh of electricity, so consequently a unit of electricity cists more than a kWh of gas. People have been prepared to pay the extra for the versatility and convenience of electricity, (ever seen a gas powered television?) but we're now moving into a world where it's the opposite way round - the starting point is electricity from such as wind and solar, and if you want to make a chemical fuel such as hydrogen from it, then unit for unit it's electricity that will have the cost advantage. Of course, that's in a world free of price distortions and personally I think it's high time there was an increase in gas prices with a corresponding fall in electricity to help influence the market. |
|
|
|
Post by lens on May 13, 2024 23:51:18 GMT
|
|
|
|
Post by leftieliberal on May 22, 2024 18:51:47 GMT
Potentially zero-carbon cementScientists say they've found a way to recycle cement from demolished concrete buildings.It exploits the fact that you can reactivate used cement by exposing it to high temperatures again.
The chemistry is well-established, and it has been done at scale in cement kilns.
The breakthrough is to prove it can be done by piggybacking on the heat generated by another heavy industry – steel recycling.
When you recycle steel, you add chemicals that float on the surface of the molten metal to prevent it reacting with the air and creating impurities. This is known as slag.
The Cambridge team spotted the composition of used cement is almost exactly the same as the slag used in electric arc furnaces.I think they will still need to capture the carbon dioxide emitted when baking the cement.
|
|
|
|
Post by mercian on May 23, 2024 15:17:18 GMT
This is an interesting link: co2coalition.org/news/over-1600-scientists-sign-no-climate-emergency-declaration/As the link says, over 1600 scientists worldwide have signed this declaration including 2 Nobel Prize winners. Here's a short quote from one of them: “It has been promoted and extended by similarly misguided business marketing agents, politicians, journalists, government agencies, and environmentalists. In my opinion, there is no real climate crisis.” |
|
|
|
Post by leftieliberal on May 29, 2024 8:56:04 GMT
|
|
|
|
Post by leftieliberal on May 30, 2024 15:04:35 GMT
|
|
|
|
Post by leftieliberal on Jun 12, 2024 10:47:37 GMT
I found this on my LinkedIn feed, it's 14 years old, but reposted recently. As not everyone is on LinkedIn, I'll post it in full. It's a description of what our seas will become like if we don't get to net zero, because it is a result of a natural seep of carbon dioxide from volcanic ocean vents (bold text my emphasis).
Today I see the future. (Written 14 years ago).
I am sitting in the middle of Bismark sea off the coast of Papua New Guinea eating my breakfast. To my left is Charlie Veron, a preeminent scientist on extinction.
We are on our way to see ocean vents leaking pure carbon dioxide from the ocean floor - a reminder of the ring of fire, one of the most active volcanic areas of the world.
The future is here for us to see if we look. The oceans are acidifying at an alarming rate, and this will have profound impacts. By examining ocean vents and their surrounding coral, we can predict the future. The acidity around these vents mimics the future of all reefs if acidification continues. The ocean, where life began, is the canary in the coalmine for mass extinctions. Charlie’s work shows that the last four mass extinctions are linked to ocean changes. Examining ocean history reveals how mass extinctions and evolution occurred, providing clues about future evolution.
Charlie describes reefs covered in algae, molluscs unable to grow shells, monoculture coral reefs, and an increase in seagrass and jellyfish. He calls this area the “headwaters of biodiversity,” where life flows to other oceans, potentially regenerating extinct species globally.
This might sound like science fiction, but it is objective science. The concentration of carbon dioxide in the atmosphere is higher today than in the last million years. Oceans absorb much of this CO2, causing acidification, which has increased by 30% since the industrial revolution. Katharina Fabricius, a world expert on ocean acidification, is with us. She will show how CO2 bubbling through coral eats away at entire reefs. We will collect samples from these vents and compare them to nearby reefs without carbon bubbling out of the earth.
Previously, scientists tested samples in labs. Today, organisms will be tested in their habitat. Indigenous elders remember the vents bubbling when they were children, indicating coral has been exposed to CO2 for at least 70 years, allowing long-term hypothesis testing.
Branching coral grows faster but is more sensitive to environmental changes. Few coral species can handle increasing acidity. Porites coral, which can, will dominate, resulting in coral monoculture and the loss of other marine life.
Seagrass will thrive, looking like a golf course in the ocean. This story has winners and losers, with more losers than winners.
Looking 50 years ahead, if fossil fuel burning continues, many species will face extinction. A few sites will preserve coral diversity, but biodiversity will be vastly reduced. Humanity’s role is uncertain as we consume our children’s world at an alarming rate.
Scientists agree: once our atmosphere and oceans are acidified, reversal will take millennia.
We need to act now to stop it.
Ron Dembo, Milne Bay, Papua New Guinea, December 2, 2011
|
|
Mr Poppy
Member
Teaching assistant and now your elected PM
Posts: 3,774
|
Post by Mr Poppy on Jun 24, 2024 9:40:49 GMT
No I'm not back but just posting one of many pieces which are now highlighting the "Captain Obvious" of thinking loads of Solar is the way to go for Europe - a point I was making years ago. Also note the far larger than intra-day price swings that some people didn't think would obviously start to happen.
Europe’s solar power surge hits prices, exposing storage needswww.euractiv.com/section/energy-environment/news/europes-solar-power-surge-hits-prices-exposing-storage-needs/However, NO. "Increasing battery storage is (not) key". Very obviously battery storage is only financially viable when the batteries get lots of cycles but as "short-term" storage they quickly reach diminishing returns and will hit the same "Tragedy of the Commons" problem that solar is now hitting (ie some is good, too much gets to the "point, success is consuming its own offspring"). EG Electricity will end up -ve price in Summers but very expensive in Winter if we overdo the solar+batteries and neglect to invest in long-term storage (which includes hydrogen and related storable products). Of course if Europe was closer to the equator and didn't have cold Winters then solar+batteries could be a much greater component but Europe needs long-term storage solutions due to the high inter seasonal demand needs - which is an even greater issue with solar as that has the "opposite" peak in seasonal supply relative to our peak demand periods. It is great that the weather is so sunny though  |
|
|
|
Post by alec on Jun 24, 2024 10:03:53 GMT
Mr Poppy - it wasn't too long ago that the focus of over supply was excess wind power, which tends to be a winter occurrence. If this is now happening in summer also, due to excess PV, then that makes the rationale for battery investment better, due to the point you make about needing to achieve high numbers of cycles. As ever, the role of hydrogen in grid storage will come down to costs. We have quite a few cheaper seasonal storage options at present, but these are less fashionable amongst the big infrastructure companies looking to repurpose their assets, but I suspect we'll get to the point where hydrogen is allocated the roles it is best for and more cost effective options for grid balancing are adopted.
|
|
|
|
Post by leftieliberal on Jun 24, 2024 16:03:11 GMT
Mr Poppy - it wasn't too long ago that the focus of over supply was excess wind power, which tends to be a winter occurrence. If this is now happening in summer also, due to excess PV, then that makes the rationale for battery investment better, due to the point you make about needing to achieve high numbers of cycles. As ever, the role of hydrogen in grid storage will come down to costs. We have quite a few cheaper seasonal storage options at present, but these are less fashionable amongst the big infrastructure companies looking to repurpose their assets, but I suspect we'll get to the point where hydrogen is allocated the roles it is best for and more cost effective options for grid balancing are adopted. I've seen statements that there is a "sweet spot" for the ratio of wind- to solar-generated electricity at 80/20, but I haven't seen the calculations supporting it. Also a high number of cycles implies short-term storage. If your cycle is twelve months because you are generating electricity in the summer, storing it in the form of, say, hydrogen, and then consuming it to generate electricity in the winter, you only have one cycle per year so you are looking at a few tens of cycles over a human lifetime. The capital cost then becomes very important. In contrast, if you are looking at pumped-storage for grid balancing over periods of a few days, you may get of the order of a hundred cycles per year and the capital cost is much less important. My own inclination is to say solve the short-term storage problems first because then you can turn off fossil-fuel generating plants for days at a time, which is more efficient than keeping some on spinning reserve. |
|
c-a-r-f-r-e-w
Member
A step on the way toward the demise of the liberal elite? Or just a blip…
Posts: 6,700
|
Post by c-a-r-f-r-e-w on Jun 25, 2024 14:21:12 GMT
No I'm not back but just posting one of many pieces which are now highlighting the "Captain Obvious" of thinking loads of Solar is the way to go for Europe - a point I was making years ago. Also note the far larger than intra-day price swings that some people didn't think would obviously start to happen.
Europe’s solar power surge hits prices, exposing storage needswww.euractiv.com/section/energy-environment/news/europes-solar-power-surge-hits-prices-exposing-storage-needs/However, NO. "Increasing battery storage is (not) key". Very obviously battery storage is only financially viable when the batteries get lots of cycles but as "short-term" storage they quickly reach diminishing returns and will hit the same "Tragedy of the Commons" problem that solar is now hitting (ie some is good, too much gets to the "point, success is consuming its own offspring"). EG Electricity will end up -ve price in Summers but very expensive in Winter if we overdo the solar+batteries and neglect to invest in long-term storage (which includes hydrogen and related storable products). Of course if Europe was closer to the equator and didn't have cold Winters then solar+batteries could be a much greater component but Europe needs long-term storage solutions due to the high inter seasonal demand needs - which is an even greater issue with solar as that has the "opposite" peak in seasonal supply relative to our peak demand periods. It is great that the weather is so sunny though Hello again Trev.! Regarding solar, they say that we have wound up doing solar first in countries that aren’t as good for solar. If solar ramps up in places like Africa to which we might have more of those High voltage DC links, might that help in winter? Or is winter sun still not good enough to help us out, even somewhere like Africa? |
|
|
|
Post by alec on Jun 25, 2024 18:09:18 GMT
|
|
|
|
Post by lens on Jun 25, 2024 23:00:18 GMT
Mr Poppy - it wasn't too long ago that the focus of over supply was excess wind power, which tends to be a winter occurrence. If this is now happening in summer also, due to excess PV, then that makes the rationale for battery investment better, due to the point you make about needing to achieve high numbers of cycles. As ever, the role of hydrogen in grid storage will come down to costs. We have quite a few cheaper seasonal storage options at present, but these are less fashionable amongst the big infrastructure companies looking to repurpose their assets, but I suspect we'll get to the point where hydrogen is allocated the roles it is best for and more cost effective options for grid balancing are adopted. But the problem with hydrogen for grid storage comes down largely to efficiency. For every kWh generated as electricity, you lose a large chunk in making the hydrogen, then (for grid storage) at that scale you really need to burn the gas in a turbine rather than use a fuel cell - so another large loss. It can come to the point where it's simply cheaper to overbuild the renewable in the first place than spend the money on something as inefficient as production and storage via hydrogen. If you want the hydrogen for its own sake (eg in industry) it's a different matter, but as a means of "storing electricity" - in general, no. |
|
|
|
Post by lens on Jun 25, 2024 23:13:07 GMT
I tend to avoid "manufacturer announcements" in general, because too often they emphasise a few positives whilst brushing negatives under the keyboard. And nowhere can that be more true than "battery breakthroughs"!  That said, this may show how rapidly some matters are progressing - electrek.co/2024/06/25/catl-successfully-tests-electric-plane-1800-mile-model-nears/? albeit yes, there's still a long way to go. (I believe they are talking about something carrying around 20 passengers, so whilst we're not rivalling 737 territory yet, it still shows a lot of progress in a fairly short time.) |
|
|
|
Post by leftieliberal on Jun 28, 2024 9:03:08 GMT
Reported on the BBC today: Electric car battery charges in under five minutes in track testAn electric car battery developed by UK start-up Nyobolt has successfully charged from 10% to 80% in four minutes and 37 seconds in its first live demonstration.
It was achieved with a specially-built concept sports car on a test track in Bedford, and is part of industry-wide efforts to get electric vehicles (EVs) charging more quickly.
By comparison, an existing Tesla supercharger can charge a car battery to 80% in 15-20 minutes.Once one is getting down to charge times of a few minutes, charging an electric car becomes little different from putting petrol into a conventional car. |
|
|
|
Post by lens on Jun 30, 2024 22:29:53 GMT
I'd like to know a few more numbers before getting too excited! There are so many "revolutionary" battery announcements....... (And don't get me wrong, substantial progress is happening, but more a bit here, a bit there.)
First off is size of battery? I read this as a claim that they are achieving a high C rate, but without battery size it doesn't mean a lot in terms of putting in a lot of range quickly.
As a quick rule of thumb, an EV will do about 4 miles per kWh. So to restore a hundred mile of range in an hour will need a charger power average of 25kW. To do it in 5 minutes will need 300kW. So let's say we now want 400 mile of range added in 5 minutes. Straight off ( before even thinking about battery constraints) we would need an average charger power 1,200kW.
And think what that means. For starters, even at 1,000 volts, it means an average current of 1,200 amps (!) Are the necessary conductors actually feasible? What about managing the supply? How do you go about getting a grid power supply of that size? You can't just equate ultra fast charging possibilities with battery performance alone.
The comparison with Tesla is a bit disingenuous. Tesla have batteries which will give higher ranges, so the same power - same number of miles range added per minute - will give lower C numbers. And Tesla are building these for real, not a battery experiment, so are fully constrained by available supply and local battery storage with total cost.
This article hints at charging a relatively small battery at a high C rate. Fine, but the suggestion then is of 350kW charging over about 5 minutes from 10-80%. Which hints at a car with pretty low range?
|
|
|
|
Post by johntel on Jul 2, 2024 17:37:01 GMT
Bill Gates' latest investment looks interesting - www.utilitydive.com/news/terrapower-smr-advanced-nuclear-reactor-bill-gates/718722/"Alongside its 345-MW reactor, the facility will have a molten salt-based energy storage system that can achieve power output of 500 MW for more than five and a half hours. The storage system is unique among advanced nuclear reactor designs and “allows the plant to integrate seamlessly with renewable resources,” TerraPower said". |
|
Danny
Member
Posts: 10,355
|
Post by Danny on Jul 10, 2024 8:38:38 GMT
Plus the obvious, that if you plant the whole planet with trees then we starve to death. |
|
Danny
Member
Posts: 10,355
|
Post by Danny on Jul 10, 2024 8:47:32 GMT
We've got used to a situation whereby electricity is largely generated from fossil fuels (with energy losses) so it's not surprising a kWh of chemical fuel costs less than a kWh of electricity, so consequently a unit of electricity cists more than a kWh of gas. People have been prepared to pay the extra for the versatility and convenience of electricity, (ever seen a gas powered television?) but we're now moving into a world where it's the opposite way round - the starting point is electricity from such as wind and solar, and if you want to make a chemical fuel such as hydrogen from it, then unit for unit it's electricity that will have the cost advantage. The bit you are missing is energy storage. What to do when its dark and there is no wind, and if they ever get it together when this coincides with the lull in the tides. Hydrogen is a mechanism to store energy, and its big plus currently is we already have the infrastructure to store it and burn it to generate power. There is no consensus how to store huge amounts of power. Ideas yes, real world cost effective examples no. We are already wasting wind power and we will be wasting who knows, half the power being generated by the time we have enough to mostly fulfill average load. Thats essentially free electricity at peak renewables times. If its free, then the economics of turning it into hydrogen suddenly change. |
|
