Posts by Moz
Last ←Newer Page 1 2 3 4 5 Older→ First
-
So how can biomethane and fossil methane be considered to have the same GWP100?
Maybe consider a process view rather than a static view. For any given interval we have some methane being released, and some breaking down, but there's a net amount of methane in the atmosphere. Sure, that exact methane isn't there 50 years later, but the processes that produce and consume it are still running. That 10ppb of methane works the same whether it's from Cretaceous plants, kiwi plants or political ruminations.
As a GHG methane has the huge advantage that it's a short-term gas, so if we stop excreting it it'll be gone in a mere 20 to 100 election cycles. Which may be your confusion?
Alternatively, any given methane molecule will "live" in the atmosphere for, say, two half-lives or about five election cycles. During that time it will trap X joules of otherwise radiated heat.
The obvious solution, as always, is SPACE LASERS! Punch that unwanted thermal energy straight up and off the planet using lasers pointed into space. I am only slightly kidding here, as that approach at least has the advantage that it's permanent (barring aliens with space mirrors). Sequestration has the problem that it has to be permanent in the "diamonds are forever" sense, not the "no nuclear ships" sense.
-
Southerly: A Tale of Two Iceblocks: Part…, in reply to David Haywood,
I'm currently reading Anne of Avonlea to my daughter.
:) I was singing "there was an only lady who swallowed a fly" to entertain my sister in law yesterday. She loved it. Also, she's 25 years old. But apparently hadn't heard the story before
-
David, I agree with you in general and in more than 90% of the detail. I'm aware that I'm picking at the corners of an argument I wholeheartedly agree with, so I hope that's coming through.
I'm not convinced that your side notes and implicit "wood as a construction material is energy use" really convey even to me that you intend cutting down that tree in my front yard to incur an energy use tax for the embodied energy in the timber, let alone for the methane release as the waste breaks down.
I don’t even understand how biomethane from cattle can be considered to have the same effect as fossil methane ... since biomethane doesn’t leave net residual carbon dioxide after the methane breaks down
This week, this year, this decade, methane is methane regardless of where it comes from. Half life in the atmosphere is between two and five electoral cycles, so as far as the political system is concerned it's permanent once released.
I love the naive optimism inherent in ignoring the next 50 years in favour of the long-term effects, while we're still trying to understand where the tipping points are and how dramatic they are. Especially since we are in a catch-up year right now, where the suppression of warming due to ocean surface water movements is reversed and we've seen half a degree of warming this year alone. That kind of sudden change makes me very wary of "in the long term", especially when you're calling 50 years short term.
But even so, long-term we're looking at 10-50 metres of sea level rise and that is worth thinking about. All this "1-2 metre" stuff has the little caveat (not counting 70% of the fresh water in the world - the Antarctic and Greenland ice caps). But when engineers say "long term we need to rebuild our cities above the 10m mark" politicians get flighty.
-
It's worth noting that you have also focussed entirely on energy, so you're ignoring the flatulent bovine in the room.
It's at least conceptually possible to include methane waste/leaks/dumping from fossil energy mining as part of the "energy cost", but it's very easy when looking at energy to overlook GHG emissions from other sources. Deforestation and other land degradation, farming especially ruminants, clathrate destruction, refrigerant gas releases, etc, are all significant problems that should be included.
Note that Russia is basically fucked the day we count methane from permafrost and clathrates, as their whole economy is not big enough to buy the offsets required to adjust for that. Even if you just count the warming from the Siberian fires they're in trouble (which also introduces another twist, the cost of soot deposits decreasing albedo).
-
Southerly: A Tale of Two Iceblocks: Part…, in reply to Brent Jackson,
Lost my reply, FFS.
was shown a convincing graph of the efficiency based on angle
Was that the misleading raw output one or the seasonal output graph that actually matters? Until you can save the excess hot water from summer to use in the winter, it doesn't matter how much excess you have in summer.
This graph is probably what you were shown, and it's a class case of "technically correct but irrelevant and misleading". For PV it works because most people have a year-round surplus from their PV during weekdays, and don't store their PV output. So all they care about is maximising their annual output.
With hot water that is very rarely true. Most systems have storage, and the cost of extra collectors is low compared to the overall system cost so it makes sense for most people to over-collect. That means the desirable system characteristic is to maximise output in the winter trough in order to reduce the need for boost heating.
Especially for people who are switching from off peak resistive systems to on-peak boost (as in Australia and very probably NZ) because the boost cuts in in the evening when it's clear the solar has not got the water hot enough. A poorly set up system can end up increasing energy costs because while you're buying less total electricity, the electricity you do buy costs a lot more.
This blog post amusingly manages to both quote the correct text, then immediately summarise it but get it backwards. The bold text is wrong :) Full pdf (2 pages) and http://solarpaneltilt.com/ has better graphs of how tilt affects seasonal output.
-
Southerly: A Tale of Two Iceblocks: Part…, in reply to David Haywood,
composting lavatory
We have one in the shed, packed away, because I never really solved the vinegar fly problem to my partner's satisfaction, and with six people we really do need the second toilet working all the time. The "toilet room" is big enough to fit the composting toilet in front of the water-waster, but having it there makes the water one unusable. I really want to put squat rails on it, too, but have not yet got round to that. Maybe I should do that today rather than sitting on the interwebs.
I've often had to strip them at the door, wipe off the worst of the mud, and then carry them into the shower.
You're too kind. My mum used to hose us off on the lawn, then make us strip and go through the bootwash barefoot before we were allowed in to shower. We quickly learned that cold, windy days were a time for caution around mud.
But the difference between six adults who all understand that we have 300 litres of hot water each day, the end, and two children who like to play with dirty things is huge. We also live in Sydney, where heating is basically optional and cooling is becoming less so. So a lot of our "efficiency" comes from living in a mild climate.
-
Southerly: A Tale of Two Iceblocks: Part…, in reply to Alfie,
Solar City
Over here that name is one used by a succession of phoenixing solar scammers, IIRC. www.whirlpool.net.au is a geek forum with a useful green sub-board for that stuff.
Over here they just charge you if you want tilt rails, and most companies will do it if you ask. With the granny flat I was torn between an off-centre roof peak to get the north face to 50 degrees, and a single-piece roof with more panels at about 10 or 15 degrees. The cost difference meant it was cheaper to go one-piece, but the winter performance was noticeably worse. Still arguing with the architect (my partner) while the granny flat is on hold - we're probably moving instead.
-
Cracked mention NZ in a recent "5 Horrifying Laws It Took WAY Too Long To Fix" article saying that until 2005 women couldn't even be charged with sexual abuse of a minor because the law only recognised male perpetrators, citing an SMH article on the issue. Which is another legal problem.
I note that the Munster for Edumakaysian is once again trying to put at risk girls into a co-ed residential school, because closing Salisbury School will save money. No possibility of sexual abuse is being acknowledged by the munster.
Also, I keep coming back to this quote in the original article:"That never happened. I don't remember that."
Some quite important events in my childhood have received that response from people involved. It's not just sexual abuse that people don't remember, it's part of the human-memory editing process to remove (some) things you don't want to remember. While some of the contested stuff I have evidence for, other things are just my opinion against an adults, and a good dose of denial/gaslighting deals with that as far as most people are concerned. Any later memory lapse is evidence of "he makes things up", and after a while people stop listening.
-
Batteries are still not ready for mass market, that's for sure. But realistically, because they need care and feeding bigger ones with full-time staff are likely to be better. Same was as I have a driver take me to work when I don't ride - the days when even the biggest egos have their own train and drive it themselves are long gone.
There's a subdivision in Perth with their own communal battery, and a local cohousing group have one budgeted but they're still selling off round three of the empty plots and getting ready to build the first new houses, so it'll be a while before that goes in.
Meanwhile, I'm in inner-city Sydney wondering why my internet connection is so awful today. Ditto the different provider cellphone internet. First world problems... but it does remind me why I want to be grid-agnostic for electricity.
-
Gizmodo Oz has a review of the Tesla Powerwall with a headline David might like "can save you money, but only in very specific circumstances". They also go into opportunity cost/time value of money at the end, which is nice.
Some Oz solar thermal hot water systems used to dump the whole tank if the water got too hot. Usually late in the day, when there wasn't time to reheat. I believe due to the overheat valve being purely mechanical, and the reset time was long enough for empty all or most of the tank. These days that doesn't happen, but the heat pipe ones do need to be Oz-rated as some problems have been found with systems that fail if the collector gets much over 100 degrees... so they need active cooling on hot days. Not sure how they get round that.
Using the excess heat inside the house is difficult, as you're most likely to have it on hot days, when you probably don't want extra heat in the house. But solar-hydronic systems are used here, where a solar-thermal HWS heats pipes in the floor or radiators.