[HN Gopher] Oakland's new school buses reduce pollution and doub...
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Oakland's new school buses reduce pollution and double as giant
batteries
Author : rntn
Score : 42 points
Date : 2024-09-04 20:58 UTC (2 hours ago)
(HTM) web link (grist.org)
(TXT) w3m dump (grist.org)
| dmoy wrote:
| > 1300 students
|
| So for a big city like Oakland... this is what, 5% or less of the
| student body? Most kids just take city buses or walk or drive or
| whatever, yea?
| jerlam wrote:
| > Oakland Unified only provides bus services for its special-
| need students
|
| California has the lowest percentage of students taking the bus
| of all US states, thanks to Prop 13:
|
| https://www.kqed.org/news/11980715/11980715-revision-v1
| zdragnar wrote:
| Reading the article, it's clear the reason is the state froze
| the budget in 1982 and left it that way for 40 years. As with
| everything else in California, they could have done something
| about it, and didn't.
| kelnos wrote:
| I'm sure the reason they froze the budget, though, is
| because they couldn't fund it further. Whether or not the
| lack of growth in funding is due to Prop 13 is not
| something I care to figure out or verify, but it sounds
| plausible.
| jeffbee wrote:
| OUSD contracts with the local bus agency, AC Transit, to run
| special lines for schools.
| grecy wrote:
| > _this is what, 5% or less of the student body?_
|
| The goal is improvement, not perfection.
|
| We have to start somewhere, and this is a very good start.
| throwaway742 wrote:
| >All the while, fiercer heat waves will require more energy-
| hungry air conditioning to keep people healthy. (Though ideally,
| everyone would get a heat pump instead.)
|
| Isn't an AC already a heat pump?
| maxerickson wrote:
| Yes, but in the consumer space heat pump typically implies that
| it can heat and cool.
|
| In principle they should be about the same as far as
| efficiency, but it can be that heat pumps are typically
| constructed better or whatever.
| Diederich wrote:
| I think this author is effectively saying that the devices that
| are widely known as 'heat pumps' tend to be more efficient than
| devices that are widely known as 'air conditioners'.
| MostlyStable wrote:
| Became skeptical of the overall article at this line:
|
| >All the while, fiercer heat waves will require more energy-
| hungry air conditioning to keep people healthy. (Though ideally,
| everyone would get a heat pump instead.)
|
| Heat pumps and air conditioners are identical, with the sole
| difference being that the heat pump can _also_ function as a
| heater/furnace. Heat pumps are not more efficient than AC for
| cooling. If the concern is increasing heat waves and increasing
| need for cooling in the summer (as described), heat pumps provide
| no advantage.
|
| This is an _extremely_ basic technical point. Combined with the
| overall tone of the article, this reads like a PR fluff piece
| about the company providing the vehicles.
|
| -edit in response to numerous comments- Yes, heat pumps are good
| (I have one in my home), and, as a repalcement for _total_ HVAC
| systems, can provide a pretty significant efficiency bump, and
| reduce emissions...but for the _specific_ case of increased
| cooling needs, they will not make _that problem_ more efficient
| or reduce emissions.
|
| In other words, the fact that heat waves are increasing and we
| need more cooling has zero impact on the efficiency ganes/carbon
| savings of heat pumps, which are entirely from replacing
| _heating_ systems. And if the writer had understood this point,
| then an extremely minor change to the sentence would have
| conveyed the point. Although honestly, it's so orthogonal to the
| overall thrust of the article that it would have been better
| omitted entirely, in my opinion.
| tantalor wrote:
| Author might be forgiven, considering the quality of available
| information online:
|
| > Heat pumps offer an energy-efficient alternative to furnaces
| and air conditioners
|
| > Because they transfer heat rather than generate heat, heat
| pumps can efficiently provide comfortable temperatures
|
| https://www.energy.gov/energysaver/heat-pump-systems
|
| > heat pumps tend to be more energy efficient than an AC
|
| https://bkvenergy.com/blog/heat-pump-vs-central-air/
|
| Of course those sites don't cite a source. It's probably AI
| generated. Apparently this is a widespread confusion.
|
| My guess is they are comparing heat pump for both heating and
| cooling to conventional furnace/AC system, not just "for
| cooling" only.
| CorrectHorseBat wrote:
| Ground-water heat pumps can passively cool making them more
| efficient than traditional AC
| sidewndr46 wrote:
| I can't say I agree with this author, but this problem goes
| back many years: https://www.treehugger.com/why-are-there-so-
| many-fist-pumps-...
|
| People seem to think heatpumps are some mystical woo-woo new-
| wave energy healing device or something like that. It's an
| air conditioner. That's it.
| greenthrow wrote:
| In the abstract you are correct but in practical application,
| products sold as air conditioners and products sold as heat
| pumps are designed and sized very differently, resulting in
| different consumption/efficiency for the same home.
| lotsofpulp wrote:
| I imagine every heat pump can cool a house, even though every
| "air conditioner" cannot.
|
| If you have a gas furnace to heat the house, then it might
| not make sense to pay extra for a heat pump that works in
| both directions (to heat and cool a house). So you would just
| buy a heat pump that works in one direction to cool the
| house, aka an air conditioner.
|
| But if you buy a heat pump to heat the house, you might as
| well have the unit be capable of running in reverse to also
| cool the house (since you have no other way to cool the
| house).
| __MatrixMan__ wrote:
| Have you ever tried contacting an HVAC company and asking them
| to convert your AC to a heat pump so that you can use it to
| heat your house in the winter? I did, they told me that it was
| a nice idea in theory, but that it was the kind of work that
| nobody did unless they were teaching a class or something. The
| way to go is to just tear out my AC and have a heat pump
| installed. Nevermind that an AC is technically a heat pump.
|
| So in practice, they're quite different.
|
| > heat pumps provide no advantage
|
| If you're worried about carbon emissions, heat pumps provide an
| advantage over AC / fuel-burning furnace combo's. I assume this
| is what the article was talking about.
| kelnos wrote:
| > _Have you ever tried contacting an HVAC company and asking
| them to convert your AC to a heat pump so that you can use it
| to heat your house in the winter?_
|
| Of course not, that's like asking your car mechanic to
| convert your ICE car to an EV.
|
| While the principle of operation in a heat pump and AC unit
| is exactly the same, an AC-only unit is missing hardware to
| be able to be used to provide heat, and it's not just a
| matter of replacing a part or adding an optional feature. It
| would require major surgery.
| arijun wrote:
| Their point still stands, which is that a heat pump provides
| no advantage in the summer, so the article was wrong in
| indicating that it did. But yes, not all ACs can be run as a
| heat pump.
| brnt wrote:
| I don't know where you get your ACs, but any I've seen
| installed this side of the turn of the century has a heating
| setting.
|
| I use the AC unit (air to air heatpumps) in my attic mostly
| for heating in Winter and it works fine. The big downside is
| noise, (air to water) heatpumps let you move the noisy bit to
| another space which increases comfort.
| thinkcontext wrote:
| They don't claim heat pumps are more efficient than plain AC at
| cooling. Their parenthetical remark about people should ideally
| get heat pumps, links to an article about why people should get
| heat pumps. And why? Because they can have lower ghg emissions
| than natural gas furnaces and resistance heating through
| efficiency and the ability to use renewable electricity.
|
| Seems pretty clear they understand heat pumps.
| kelnos wrote:
| I like the idea of the buses providing power back to the grid
| when they're not being used in the late afternoon, but the
| article's author seems to think that even privately-owned
| passenger cars should be participating in this as well.
|
| I'm not sure how practical that would be, though. For school
| buses it's easy, because you know exactly the range of times
| during the day, every (week)day, when they're going to be out on
| the road. Late afternoon/evening use as a grid source is perfect,
| because they've already brought all the kids home, and won't be
| needed until the next morning, and there's plenty of time to
| charge them back up after they've sent energy to the grid.
|
| But for my own private vehicle, I don't use it on a schedule.
| Well, sure, there's some scheduled use, but there's also random
| unplanned use, or even just random planned use that might not
| conform to when the grid wants to pull from my battery. If I'm
| leaving at 6pm to start a 3-hour drive to visit out-of-area
| family for a few days, for example, I certainly don't want the
| grid pulling from it, say, from 3pm to 6pm.
|
| And on top of that is battery wear and tear. I would assume that,
| all else being equal, a car participating in a vehicle-to-grid
| program will need its batteries replaced sooner (maybe much
| sooner) than a car that isn't. And given how utilities seem to
| want to pay less and less for power that residential solar sends
| back to the grid, I can't imagine any paltry sum they pay for
| vehicle-to-grid use would offset the very real costs to the car's
| owner.
| rahimnathwani wrote:
| > And given how utilities seem to want to pay less and less for
| power that residential solar sends back to the grid, I can't
| imagine any paltry sum they pay for vehicle-to-grid use would
| offset the very real costs to the car's owner.
|
| But maybe it would be different during peak usage hours (when
| solar is unavailable).
| bryanlarsen wrote:
| All those same concerns apply to the existing Tesla virtual
| power plant's (VPP) in California and Texas. People buy Tesla
| power-walls to have emergency power that would be useless if
| their battery has been emptied by the VPP. And those PowerWalls
| are more expensive per kWh than a car is.
|
| The solution for the first is a simple power limit, typically
| 50%. So the VPP never drains the battery below 50%, leaving a
| nice margin for emergencies.
|
| The solution for the second is pricing: the VPP typically pays
| 50 cents per kWh, in return for about 0.1 cents/kWh of wear and
| tear on the battery.
| dheera wrote:
| Meanwhile, in Oakland, people are getting shot and killed every
| couple of days. Priorities?
| vsuperpower2021 wrote:
| Sorry, we can't improve school buses because Oakland is a
| shithole. Sorry, no space travel, Oakland is a shithole. No one
| is allowed to do anything good until Oakland looks like
| wakanda.
| dheera wrote:
| I mean, at least we could lock up bad people in droves in one
| of those buses if there aren't enough jails? Set its
| destination to some ghost town in Nevada and let them duke it
| out there.
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(page generated 2024-09-04 23:00 UTC)