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Comment by acidburnNSA | Hacker News Reader

These trends are excellent and impressive.

> But these problems are distant. Renewables will start to encounter them in earnest when solar makes up >20-30% of electricity and when wind makes up >40-50% of electricity. Today, worldwide, solar is only 2% and wind is only perhaps 6% of global electricity. Cheap multi-hour storage will arrive before that (indeed, in the next few years), lowering the price of using solar to meet the evening peak, and of dealing with intermittency on the order of minutes to several hours. Only seasonal storage (and perhaps the political challenges of long-range transmission) seem to be truly difficult problems. And we have time before they begin to impair the growth of renewables.

This is where things get hard. Besides electricity, we also have to clean up all transportation, industrial, and space heating. This isn't so distant in an energy systems perspective. This is where having things like nuclear power plants with district heating will likely be important.

Until then, it's great to see wind and solar performing so excellently.

I still can't believe San Bernardino county already NIMBY-banned more large solar installations in the California deserts.

View on HN

With electricity going towards renewables, it seems clear that the best strategy will be to get the other major uses of energy on electricity as well.

Vehicles have a clear (if long) path to electrification. But what about heating buildings? My understanding is that electric heating is not cost effective compared to carbon based fuels. Lower costs driven by renewables can help here, but will it be enough? Are there alternatives being developed to tackle this major energy use?

A lot can be done just by upgrading technology, regardless of the energy source. For example, heat pumps achieve more than 100% (!) efficiency (i.e. by exchanging heat between outdoors and inside of the building, you can heat it up more than you could by just converting the spent energy straight into heat). I imagine similar can be achieved with better insulation.

I don't think that's quite the right energy balance for heat pumps ;)

You can upgrade equipment but that's not even remotely a solution to decarbonize at the rates we apparently need. There are lots of quadrillion BTUs that need to be decarbonized, and upgrades alone won't get us there. We need clean energy sources to ramp up and replace natural gas, oil, and coal.

A modern furnace is only expected to last 20 years or so. Upgrading equipment is a solution is the upgrade isn't too expensive. I've looked into geothermo heat pumps a few times in the past, and they never worked out because of cost. I'm thinking seriously about replacing my current (working) furnace with a heat pump though just because I want some zoning that the natural gas furnace cannot do.

> I don't think that's quite the right energy balance for heat pumps ;)

It's exactly right. A good heat pump will have a coefficient of performance (COP) of 5, which means for every watt of electricity put in, 5 watts of heat is moved from outside to inside - effectively an efficiency of 500%. While resistance electric heat and fossil fuel can never give more heat than the energy put in.

https://en.wikipedia.org/wiki/Heat_pump#Performance_consider...

5 is highly optimistic. Real world average efficiency is closer to 2.5 (lower in colder climates) because there are a lot of variables you have to get exactly right to hit that 5 COP, and they very rarely line up.

Source: I have a Fujitsu 36K BTU cold climate 4-zone system installed two years ago to replace electric baseboard heat. [1]

[1] - http://www.fujitsugeneral.com/us/products/multi/2-3-4rooms/a...

Better building codes for insulation & air sealing, and air source heat pumps, which can provide 5kW of heat for 1kW of electricity depending on the weather & unit.

As far as I hear the operating performance is mostly there with the heat pumps, now they just need to bring down the unit cost (and do a little more work on performance in very cold weather)

There's still the problem of powering the heat pumps with clean energy in winter. It has to come from somewhere. These polar vortices aren't getting any milder. This is a massive slice of the energy pie that requires discipline and planning to decarbonized. I worry because I perceive complacency due to cheap natural gas and I fear we won't come close to decarbonizing enough unless we're serious and quantitative. How many new kW of heat pumps would it take to heat the US Midwest through a winter?

I'm not close enough to the problem to identify the solution with authority, but there are many options. Most significantly to me, long distance transmission lines will hopefully allow sunny Arizona to sell power to wintery Minnesota. But I do agree about the pitfalls of complacency.

The beautiful thing about electrification is its source agnosticism. You can put in heat pumps today, power them off natural gas turbines for now, and switch out to something better in the future at will. As long as your heat pumps can achieve COP of ~2 or better for most of the winter, they should have comparable overall efficiency if we assume the electricity from the natural gas plant is in total about 50% efficient.

Or a home natural gas turbine that also runs your heat pump compressor. And condenses the steam for high efficiency.

Over here heat pumps are quite popular (both ground source and air). Problem is people size them so they can get through most of the winter, but for cold spells they're not enough and you need supplemental resistive heating.

Sure, cost optimal for the individual consumer, but for the entire grid?

Depends where you are: in a lot of places, it only gets cold when a weather system moves in, which means lots of wind power available.

The backup power could be propane, but electric-resistive is still cheaper.

The other issue is that air source heat pumps should really create blocks of ice from municipal water and then dump them in the yard, instead of trying to squeeze heat out of cold air.

Where I live, cold spells unfortunately tend to coincide with very low winds.

And yeah, adding a supplemental resistive heater to a heat pump is certainly a lot cheaper than adding a separate combustion based backup heating source.

For some reason, we don't really use propane over here, except for running grills in the summer, or for boat stoves etc. Fossil fuel heating for houses tends to be fuel oil, though that is on the way out.

30-50% of electricity is going to renewables, and how. Above that, intermittency and storage is significantly challenging.

Don't forget jets. Jets are mega-emitters and have very few electrification options because lithium-ion has about a 50th the energy per mass as jet fuel.

For heating, cheap, fracked natural gas is dominating in the US, with a battle cry of "better than coal"! Unfortunately it's still extremely high carbon. They do amazing PR though.

China is building a few supercheap swimming pool TRIGA nuclear reactors specifically for district heating in northern regions for winter, where coal is the only alternative. This is wild, but makes sense. They aren't usually used commercially because the temperatures are too low for conversion to electricity. But for straight heat it makes plenty of sense.

Also heat pumps can help but won't get you there alone.

Other than being super explosive would liquid hydrogen work for an airplane?

Even if the safety issues could be resolved, the cooling requirements and high volume make liquid hydrogen impractical for commercial aviation.

The most likely carbon neutral solutions for aviation fuel are either algae produced bio fuels, or synthetic hydrocarbons manufactured using renewable energy.

*Manufacturer using low-carbon energy.

At the moment, biofuels are renewable but high-carbon and nuclear is low-carbon but not (considered) renewable.

I know nothing about the topic, but there seems to be a nice Wikipedia article that your question prompted me to find: https://en.wikipedia.org/wiki/Hydrogen-powered_aircraft

I'm suddenly imagining a hydrogen balloon-plane at take off that uses up the hydrogen in the balloon as it flies, until the balloon has been fully reeled back into the plane and it lands on a runway like a normal plane, with reserve hydrogen in its wing-tanks.

If you time it right, it just slowly drifts to the ground and lands vertically with a slight jolt.

Depends on your definition of aeroplane: https://en.wikipedia.org/wiki/Skylon_%28spacecraft%29#SABRE_...

Regarding aviation: worldwide and in the EU, transportation accounts for about 25% of energy consumption [1].

Aviation accounts for 10-13% of transportation [2]. (global data looks similar, although I don't have a link at hand)

So while 2.5% is not nothing, it is only a small fraction of energy consumption and could remain Kerosene based in the medium term.

Also, a lot of flights could theoretically be shifted to high speed rail.

[1] https://en.wikipedia.org/wiki/World_energy_consumption#By_se...

[2] (2016) https://www.eea.europa.eu/data-and-maps/indicators/transport...

If we can use electricity to turn atmospheric CO2 back into jet fuel it could still be net zero emissions. At that point the planes are just using hydrocarbons as a means of dense energy storage.

Technologically-speaking, been done; the economics aren’t quite there yet, but there are some promising noncarbonization paths that potentially could scale to price-parity, depending on global fuel costs.

Going into the future, I think the assumption that one needs to hit exact parity with existing fossil fuels at their current price point will be re-examined. The economic comparison should be conventional extraction fossil fuels + externality costs vs cost of a scaled carbon neutral jet fuel production.

One could already see maybe small scale operations capturing niches - maybe if a corporation that operates a private jet wants to further a reduction in their carbon footprint.

Completely agree that the best and most market-friendly path is to take socialized CO2 costs and apply them to point-of-emission prices — though I doubt entrenched interests of the iron triangle variety will allow that to happen. Nonetheless, if we assume Johnson and Hope (2012)’s range of $55-$266 social cost per ton of CO2, even current capture-and-sequester methods look price-competitive, which is encouraging!

Politically, I wonder if the best solution is the approach the other end of the development cycle, with dynamically scaling investment incentives that expand your "credit limit" to lend more if your projects successfully reduce carbon, but overall scale back as total carbon emissions reduce. Sort of a Green New Deal Fannie Mae type entity. Add in incentives to retire stranded fossil fuel centric assets like fracking rights, etc. This creates a psychologically different environment, more like a Fear of Missing Out on the development rush instead of a Fear of getting a Big Stick regulation.

Sounds like an approach that would coexist nicely alongside technology funding efforts! ARPA-E and EERE have done some great work in that regard; thankfully and a bit surprisingly Congress has so far declined to defund them, despite the Trump administration’s consistent efforts to shut them down, so hopefully they’ll continue to support innovative and incremental advances. Adding carbon incentives to a tax-and-rebate scenario (should we ever get to that) would seem prudent.

I not intimately familiar with ARPA-E and EERE funding programs, but if the follow the common model of selection of funding to a expert tech evaluators, they are a bit different from what I was musing about. They aren't bad, just far too constrained for what we need.

Instead, I'm for transferring funding decisions under the program to a much more open set of actors to originate investment loans (much like mortgage brokers). The investment performances are evaluated on their successes/feasibility, the loans purchased from their originators with high feasibility (i.e. we're scaling known limits), as well as opening up higher origination limits (if they prove out better carbon negative/netural tech). It's more of a financial tooling solution than a tech centered solution. This increases the possibility of failures, but provides a regulated scale out needed with a optimization criteria to keep scaling along successful lines with more organizations rewarded who make successful carbon investments. Experts like ARPA-E could definitely be involved in assessment, but the scale would be completely different then what has gone on before.

The economics are extremely attractive if you have an abundance of electricity production at unpredictable times with build electricity rates tending negative occasionally. Turn that excess electricity into kerosene for jets and ocean travel and turn a profit!

This is discussed in this headline article on carbon capture developments on the BBC today. https://www.bbc.com/news/science-environment-47638586

Check out carbon engineering[1]. They are using direct air capture and hydrogen to create synthetic fuels using a fischer-tropsch like process.

https://www.carbonengineering.com/

Could we power airplanes with ethanol? I've heard that we couldn't realistically grown enough corn/canes to produce ethanol for all cars, but if cars are electric, could we potentially produce enough ethanol for airplanes?

If we can't make enough ethanol for all air travel, I'm still optimistic. It's likely that battery densities will become good enough for us to have electrically powered regional jets within the next decade. Then only long flights would need liquid fuels. As a last option, we could also switch to high-speed trains for continental travel.

Piston-engined aircraft, which are basically just light general aviation aircraft, can and have used ethanol.

Most commercial aircraft use jet engines. Other biofuels that are chemically closer to kerosene can be used in most existing jet engines in blends; use of 100% biofuels for hasn't been extensively tested-- but it has been tested![0] This is also the highest-hanging fruit and I wouldn't worry about it in 2019.

[0]https://www.navy.mil/submit/display.asp?story_id=96702

Turbine engines in theory can run on almost any flammable liquid. However in practice they would need substantial re-engineering. Also ethanol is less energy-dense than kerosene/jet fuel.

Have high-power turbocharged piston engines been run on ethanol in service? I’m not aware of any. GA piston fleet has the common property where 20% of the fleet burns 70+% of the fuel as they are working airplanes. (Think CapeAir and similar in passenger service.) Those highly stressed turbocharged engines have lower detonation margins, currently requiring tetraethyl lead additive to meet worst case detonation margins.

The US DOD has a project which qualifies what is essentially biodiesel (bio-derived JP8) for use in jet aircraft.

There's not a lot of work to do, just the details of making a mil-spec standard and then doing the testing in each engine type. In other words, everyday blocking and tackling not scientific breakthroughs.

A lot of companies are working on electric planes for short haul flights:

https://techcrunch.com/2018/07/08/the-electric-aircraft-is-t...

And what fraction of aviation emissions are short haul? My hunch is not much. Factor of 50x in energy density really matters in the air.

It’s closer to 19x when you consider engine efficiency. Heat is not that useful on it’s own.

Considering jets already do 9,500 mile flights a 500 mile range seems viable. But, if you start talking significant amounts of electric aircraft, very short landings for battery swapping are also possible. That's not going to get you to Hawaii, but it's still faster than taking a high speed train.

PS: You can also push these numbers as electricity is much cheaper than jet fuel. Electric engines also weigh less than batters which allows for a higher mass fraction for fuel. Shorter flights also have lower penalties for going slower. So, an optimized electric aircraft could probably make 800 miles with similar costs to current jets without any major breakthroughs.

Yes, and it could be viable for short flights with mountains between, where it's hard to build high speed rail, like flights LA<->Las Vegas.

Ops: Electric engines also weigh less than jet engines which allows for a higher mass fraction for batteries.

Really? I thought turbines were really excellent in terms of power to weight?

Currently you can get 10kw/kg turbines and 10kw/kg electric motors so they are close.

However, the turbines require more infrastructure around the turbine. Put another way, simply comparing fuel vs batteries ignores the weight of fuel tanks, fuel pumps, etc. We care about the system not just individual components. That said, the fact that burned fuel reduces aircraft weight is a huge advantage over batteries.

Building science has been stonewalled and ignored by regulators who work closely with property developers. The efficiency of US buildings/homes is abysmal, and because energy is relatively cheap, there is little economic pressure to invest in efficiency upgrades.

It’s because of AC too. In France buildings have to be more efficient else you die in the summer.

Europeans also need to understand that A/C does not make you ill.

It’s killing the planet and making you less aware of your surroundings though.

Most buildings aren't new. They're old. My house is over 100 years old, and it could still be standing in another 100 years. The neighborhood is mostly these old houses, and lots of the people living here are retirees or young couples who simply don't have the money to do massive renovations on their homes. And frankly, there's an upper limit to the energy efficiency of a drafty old bungalow.

Speaking as someone who spent a good part of my life renovating homes, I can tell you that there is not much of an "upper limit" to the energy efficiency of an older home. If you're already planning on renovating a home, there is an incremental $25-$50k energy efficiency improvements that you can make to turn the house into a nearly net-zero energy home.

The issue is that the young couple who do renovate their home have a far better ROI on updating the kitchen + bathroom than the efficiency of the house.

As half of a young couple that's at the cusp of starting a remodel (focusing as you point out on bathrooms and the kitchen), I'd be very interested in your thoughts on what's possible in terms of efficiency.

We're replacing the insulation in the attic and getting mini-split based cooling/heating. We also replaced the windows and briefly considered blown-in insulation for the walls, but weren't convinced that it would be worthwhile.

Sure! Email is in my profile. Happy to nerd out over building efficiency and help out.

For home heating, heap pumps are generally cost competitive with carbon based fuels in temperate climates. They become less efficient as the temperature drops until they are equivalent to resistance electric heating. However, they can be extended via ground source heating at reasonable cost.

Turning sunlight to heat directly is both cheap and efficient. Most often seen in greenhouses and solar pool heaters, but similar tech works on homes and hot water just fine. This does require sunlight so while it can work as far north as Maine it falls off in the Artic. Luckily a relatively small chunk of the global population lives that far north.

Electric heat pumps + insulating to PassivHaus standards is very much competitive with carbon based fuels in colder climates. The operating cost is very low. But the up front investment can be steep.

The insanity is that tons of houses have central air conditioning systems installed without a thought, and those are just heat pumps that can only be run one direction, for cooling.

The problem is that heat pump based heaters and cooling devices are still produced, marketed, and priced for the green and well off crowd, not the general public.

In the general public has no concept that the same technology they use for cooling could be used to heat their homes.

So far the manufacturers of heat pumps seem content with their well-off niche, and don't seem interested in scaling production so that the technology is available to regular folks.

Perhaps the margins on heat pumps aren't as good and they don't want to cannibalize their existing businesses selling natural gas powered heating systems, which they probably manufacture for a song (recall how Carrier ended up moving their home furnace production to Mexico anyway despite the political show that was made of them supposedly staying in Indiana)

In other parts of the world many split heat pump systems are much cheaper.

Or an air conditioner along with a separate pool heater.

Or a fridge/freezer that dumps out heat indoors during A/C season, and/or a hot water heater that isn’t combined with the refrigeration system.

A single heat pump could run it all: fridge, freezer, pool, HVAC and hot water. Maybe even a pre-heat element on a stove top.

>Maybe even a pre-heat element on a stove top.

Going a little far there. The preheat loop would have to survive regular heating element temperatures, and most common refrigerants decompose above 500C.

More like a keep-warm element on the stove top. Maybe it’s too close to the heating elements. Dunno. Would probably be fine for an inductive range.

Stovetop elements get over 900* F? That doesn’t seem intuitively right to me.

Both electric and infrared stovetops can get hot enough to glow red, which means they have to be at least 550C: https://en.wikipedia.org/wiki/Red_heat

The problem is that heat pump based heaters and cooling devices are still produced, marketed, and priced for the green and well off crowd, not the general public.

When I was growing up I lived in a suburban American house that was built in 1982 and had a heat pump. It was a middle class suburb and none of the adults were environmental activists. Every house in the neighborhood had a heat pump. I thought this was totally normal.

With hindsight, I see that there was significantly more American concern about energy efficiency in the late 1970s and early 1980s than in the early 1990s, probably due to resumption of relatively low oil prices in the mid 1980s. It's sad that the attention to efficiency did not continue after the immediate crisis had passed.

The concern for energy efficiency died in the mid 1980s because there were a lot of badly done improvements. Many houses were insulated better - with a foam that had hazardous off gas problems. New homes were often insulated well and rotted away because the insulation trapped moisture. Heat pumps sounded good, but were useless on the cold days and so people paid huge power bills in January for electric heat.

None of the above problems are inherent in energy efficiency, but they did give the whole field a bad name.

In the UK, electric heating also got a reputation for not really having working temperature control. Because it was expensive to heat using day-rate electricity, most UK homes with electric heating have some kind of heat-storage system that charges at night at the "Economy 7" rate. The apartment I lived in (built 1984) heated up something like 100 lbs (60 kg) of ceramic blocks, for example. You could sort-of regulate how fast this heat dissipated during the day by opening and closing a vent, but in practice the biggest usable knob was choosing how much to charge overnight. That meant you had to predict before going to bed how much heat you'd want the next day! One strategy is to go very warm and then open your windows to cool back down if you overshot. Another strategy is to somewhat under-heat and then have a portable electric space heater to add extra heat in your immediate vicinity (though this is a common source of fires).

> PassivHaus standards

The PassivHaus stuff is a really good example of the derangement you get when people try to optimize for only one metric. PassivHaus's are expensive, mandate the use of petroleum based insulation (you're living in a plastic burger box), prone to water intrusion mold and sick building syndrome and the supposed efficiency gains disappear when you open a window.

Telling is the PassivHaus nutters response to builders wanting to use solar panels to build houses with low external energy needs. AKA why spend $100k on insulation when you can put a $20k worth of solar on the roof and a ground sourced heat pump. PassivHaus response is to get regulators to ban that option.

Even a cursory investigation or education of passivhaus concepts would show this to be nonsense.

Passivhaus is not focused on one metric. To achieve passivhaus there are many metrics measured. Energy use, overheating, air quality, thermal bridging... The list goes on. I'm not sure what one metric you're referring to.

Passivhaus does not mandate plastic based insulation. Many are built with cellulose, wood fibre,straw bales...

They are not in any way more prone to water intrusion any more than any other building.

They are far less likely to suffer sick building syndrome because ventilation standards are far higher than for 'normal' houses.

You can open the windows if you want. Sure, if you do it in -10 temperatures you lose some heat.

Passivhaus 'nutters' are generally apathetic about PV. You don't need PV ; simplicity is part of the point. The marginal cost on insulation is generally pretty low. The difficult but it's getting builders diligent enough for the challenge.

Hope that helps to encourage you to continue researching the subject.

> Passivhaus does not mandate plastic based insulation... wood fibre,straw bales...

So, I presume that in the case of a fire, they go up like a match?

i think you're confusing a haystack with a compressed straw bale - IIRC the fire resistance of a compressed straw bale is excellent. it singes on the outside but it's v difficult to burn through.

Plus, regs in your locale should cover this, but always good to DYOR.

There's a lot of greenwashing in the insulation business. Rockwool uses coal to melt stone, binds the fibers with formaldehyde, and puts the coal ash waste in the final product. That's not something I want deteriorating in my walls.

It's amazing to me that aerogel windows/skylights/multi-panes haven't gotten more attention in this arena. What if your window was as good an insulator as your wall? What if it was better? What if you could have translucent skylights heat the house without losing any (effectively) heat through them?

What happens if you like having the windows open?

Where is your sacred R value now?

When you open a window, do you open every single window in your house? If not, the greenhouse effect keeps working through the others.

> PassivHaus response is to get regulators to ban that option

Can you clarify what specifically this refers to - i.e. a particular law or regulation?

I really don't like the idea of PassivHaus. I don't want to live in a hermetically sealed pod. I like a house with a very high rate of fresh air exchange with the outdoors. There are so many sources of odor in a house that need to be cleared out, not to mention CO2.

Yeah, you could have some sophisticated ventilation with a heat exchanger but that's one more piece of equipment to maintain and if it fails without you noticing it then the air quality could decline very rapidly.

The current recommendation here is to air out for 5-10 minutes, 3 times a day. Not just one window open, but full airing out with as many open windows and doors as possible.

It's a good habit to get into, no matter how old and drafty or new and tightly sealed your house is.

These objections make sense, and in the right climate open windows will meet most of your comfort needs. In other climates controlling the movement of air is the only way to control the energy needed to heat and cool.

I think you misunderstand PassivHaus. Ventilation and air quality are a big part of it. If there are smells or high CO2 levels, it's not up to the standard.

Heating buildings is where passive unsexy solutions like insulation will work very well.

Insulation will not deeply decarbonize space heating worldwide. It can help, but you still need trillions of BTUs.

A house insulated to PassivHaus standards will drastically reduce the carbon footprint of space heating. Reducing your energy needs by 90% makes the origin of said energy largely irrelevant.

If you don't count the energy expenditure of either replacing or renovating 99% of the world's housing, sure.

It's a given that all of our renewable infrastructure will have to be bootstrapped via our current system of non-renewable sources. So the fact that more efficient housing may do so too is not disqualifying.

The question is how much bootstrapping you need. Synthesizing liquid fuel from atmospheric gases and ocean water, for instance, requires only the bootstrapping necessary to build those facilities. Electrifying automobiles requires replacing all of the automobiles. Upgrading all housing to PassivHaus standards requires approximately enough construction to house over 7 billion people in new homes. Maybe half of that if you exclude people who don't already heat their homes, as well as the approximately tens-to-hundreds of thousands of Scandinavians whose homes already meet these standards.

I think you are suffering a little bit from analysis paralysis. I don't think anyone has a good answer on how much bootstrapping is needed. Even if we had a good estimate in mind, it's going to be wrong at some point. Even if we have a bad or no estimate, it is neccessary to move forward with an optimization method of following the derivative on actions that reduce carbon. It's not a closed form world, following promising trends is the best way to collect more information. And the world is a big place, we can trace multiple paths forward in parallel and continue to reduce carbon, as well as collect data to find more optimal paths.

I agree with that approach in principle. I don't think "let's immediately replace everyone's housing" is a good instance of that approach being followed rigorously.

I apologize if I've read too much into your comments, but I think you're the one making estimates replacing everyone's housing? It's certainly not something I'm suggesting.

I was replying to Tharkun's comment that upgrading housing to PassivHaus standards could "solve" the problem of generating energy for heating. It does no such thing unless you actually upgrade the housing, and there's a lot of housing in the world.

Depending on where you are and what your house is like, it could be feasible and financially viable to retrofit your house.

In other places (Japan comes to mind), houses have a relatively short shelf-life. Making passive the default could have a big impact there.

And in many urbanized areas, there is a housing shortage. This can lead to ridiculous price increases, or to a housing boom. Again, building new developments to passive standards could make a big dent.

I would love a magic wand to make every house passive, but I'm sadly aware that it's unlikely to happen. In many cases, the economics make sense.

I'm not sure the path to electric vehicles is that long. It follows the same pattern as the article.

Roughly now buying an EV makes financial sense due to incentives. In a couple of years it'll have a lower TCO even without incentives, then it'll be cheaper up front with continued savings, then it'll be cheaper to ditch an otherwise working ICE as even taking a loss on its resale will be better than continuing to pay more for fuel and maintenance.

And at each step the increase in manufacturing level drives prices down further.

Fairly certain similar applies to hearing too, some countries are already mandating that new houses are not connected to the gas grid for example.

Unfortunately for EV, they make the least sense for those who drive the most. When you drive 3 miles a day even a 12 mpg gas guzzler doesn't cost much (why they don't bike is a good question, but off topic). When you drive 600 miles a day EVs would make the most sense - but they don't recharge fast enough (fast recharge is not only longer than adding fuel, it also damages the battery and so isn't a normal solution)

Who drives 10 hours a day on a regular basis?

A fair number of couriers, and delivery drivers. Over the road truckers as well, but even cars there are a lot of people who make a living delivering original documents where a copy is not legally valid.

>My understanding is that electric heating is not cost effective compared to carbon based fuels

Pretty much everyone is heating electrically here in Norway.

Good architectural design can also help a bunch here, having the majority of natural light sources on the southern wall (for us northern hemispherers) can drastically shift the heating profile of a building, especially when coupled with good insulation.

The bigger issue is that many buildings are built to be heat traps that necessitates active cooling in the summer, this is where architecture has long-known solutions but ones that haven't been well incorporated into modern styles, setting up buildings for consistent controlled cross breezes can, again, make a huge difference. A lot of actually traditional spanish architecture is a good reference for this since spain gets _hot_.

Would you have specific architecture ressources/techniques to avoid heat traps?

My experience in Spain is that comes winter time, flats are so poorly insulated that it is like you are heating a house windows opened.

I would recommend checking out the guidance and tips pages from the Building Science Corporation [0]

[0]https://www.buildingscience.com/

The path to vehicle electrification might not be that long: https://about.bnef.com/electric-vehicle-outlook/

Also, it's worth making the distinction between vehicles and vehicle miles travelled. We might not replace all the cars right away, but the majority of the miles travelled might convert pretty quickly if they're done via TCO sensitive fleet vehicles (Uber, Lyft, etc) and/or 2nd car commuter vehicles.

>and space heating //

Perhaps we can skip this and use wearables for "personal climate control" to some extent?

We manage a daytime domestic temperature range in the UK of about 20degC (14-34degC) just by changing clothes. Though if I'm sitting using a computer in 14degC then I'll stick a hot-water bottle up my jumper; and a paddling pool nearby is handy in 30+degC.

Better insulation/architecture can negate the need for Winter heating/Summer cooling in some regions.

In some regions, sure!

But in places like the US Midwest and northeast, no. We need massive and I mean massive conversions to clean energy that aren't even on the radar yet for heating. Natural gas does not count as clean in a carbon constrained world. It's -20C out there for many days in a row.

Not to mention heating greenhouses, hospitals, commercial spaces, etc.

Plus, convincing everyone to bundle up may be harder than switching to clean carbon free energy like nukes or wind+mega-storage

I did something like this when I got an electric mattress pad.

I don't know if it's absolutely necessary to completely zero our carbon emissions. We're going to need to do some sequestration and other countermeasures anyway to lower the current CO2 levels to a safe level, and it may very well end up more cost-effective to continue using those countermeasures than to try to invent an electric jet engine.

If we manage to make that jet fuel from anything else but fossil energy that should do. The only issue is that the CO2 emission up there has so much more impact, but I think we should be able to manage if we have the rest under control.

I'll feel more confident when we have large scale sequestration methods that are beyond the drawing board. I loosely agree with your conclusion, but until we KNOW the numbers, it seems worth it to shoot for as close to zero emissions as we can get while figuring out the sequestration options.

The closest I've heard of is some seabed oilfield sequestering from Nordic countries, IIRC, but that has some built in limitations.

Are you aware of sequestering efforts I've missed?

There's new research that suggests that there are soil-based sequestration methods that work far faster than the well-studied approach of growing forests:

https://www.nature.com/articles/s41467-019-08636-w

We should invest the R&D effort into as many places as we can. I just have a hunch that "electrifying everything" isn't going to win out over, say, "use electricity to synthesize energy-dense liquid fuels", which can even be generalized to the sequestration strategy of "use electricity to synthesize liquid fuels and then store them in underground salt caverns like the Strategic Petroleum Reserve".

Though I have no idea if we can make enough salt caverns, at least it would be a fixed amount of salt caverns, since you could establish a closed-loop supply of liquid fuel this way that was long-run carbon-neutral.

No argument here - I'm just saying we shouldn't lay off the emission reductions BEFORE we have any technological answers. Likewise, we should research such options rather than assuming someone will.

I think we're in full agreement. It appears that we've figured out how to electrify automobiles already, for instance. That's a good thing.

It's just that some emission reductions are also open technological questions, and sometimes they're more or less open than the questions around sequestration, so hard-and-fast rules are hard to come by. Is it easier to sequester the emissions from space rockets than it is to build a Lofstrom loop? Is it easier to synthesize jet fuel from the atmosphere than to electrify jets? Where should R&D resources be optimally allocated, especially if we're taking a risk that certain approaches won't work out?

Seasonal storage is a pretty huge issue which means some baseline capacity will most likely be kept, though not nearly at the same scale as today. Keep in mind that sometimes it's overcast/dark and the wind doesn't blow, and that this can occur for extended periods of time over large geographical areas. Demand response can help even then, by shutting down some energy-intensive industry - but you still need to provide a baseline supply for more critical stuff.

Seriously. I plotted these data in Dec. 2017 of the entire Pacific Northwest's wind resources drop to zero for ten full days. Not overly uncommon.

https://partofthething.com/thoughts/wp-content/uploads/decem...

I think that recently built gas-fired plants are going to be around for a long time. But like marginal coal plants today, they may shut down for entire seasons and only go to standby-active during high demand seasons. It's possible to reduce emissions a lot without entirely retiring combustion plants if the plants don't burn any fuel for 8 or 9 months out of the year.

That kind of duty cycle changes the economics of those plants drastically. The capital efficiency becomes much lower - basically turbines are very mature, efficient, but high capital. Then to only operate them 25-30% of the time seasonally, they lose even more economic efficiency. But, if that seasonal load becomes the operating demand, then certain kinds of other technologies like flow batteries become more attractive to the degree they can decouple the power regeneration equipment costs from the capacity of storage. i.e. if you only need to size the power generation equipment to the fairly small instantaneous demand, but have to some degree a separate capacity storage cost for the next added unit of run time.

I agree that lower duty cycles increase the per-MWh generation costs; I just think that there's going to be room for recently built plants to operate even with those higher costs.

The sunk costs of already-built plants don't affect whether they will operate going forward. It's even possible that plants would be mothballed for some years and then revived when the economics support at least part-time operation, as I expect to happen with the currently idled Irsching units in Germany.

New combined cycle gas plants are not terribly capital-intensive. Overnight capital cost is about $1/watt:

https://atb.nrel.gov/electricity/2017/index.html?t=cg

Since they can also be built quickly, overnight capital costs are relatively representative of true capital costs for gas plants.

I wish that the LCOE chart in the link above had included a scenario for "Gas combined cycle - low capacity factor" in the LCOE chart, because I think that's going to be how a fair number of plants end up operating: high CF in the peak demand season, but low annualized CF.

For new builds, I think we're beginning to see accelerating encroachment of renewable + storage on the low capacity factor natural gas plants. For short timeframes it looks like the existing cost reduction curves for PV, wind, and Lithium storage seem likely to grow to completely knock out the competition for hours to days level of intermittent supply.

https://www.greentechmedia.com/articles/read/record-low-sola...

For longer time periods, and comparisons vs existing plants, I agree that the economic changeover point will be less clear except that turbine tech is basically on the matured portion of a manufacturing S-curve, while PV, wind, storage are riding the downslope.

Maybe biomass could help. Already now we put apples etc into cold storage to get them out duringtimes where there are no apples growing on the trees. Same could be done for biomass. Put into the fridge and gotten out when we need it. Of course, cooling down the biomass does require energy, not sure whether it requires little enough.

Don’t forget steel and concrete! Every pound of concrete releases 1 pound of CO2

I think you mean cement. Cement is only 10-15% of concrete. The rest is water and rock/sand.

Yes, I do.

Half of that is from the chemical transformation of limestone to quicklime, and half of it is from the fuel energy currently used to drive the transformation:

https://blogs.ei.columbia.edu/2012/05/09/emissions-from-the-...

So if carbon-neutral fuels or clean electricity were substituted in the calcination process, the CO2 burden would be reduced by half without any additional downstream changes.

> Only seasonal storage (and perhaps the political challenges of long-range transmission) seem to be truly difficult problems.

Seasonal storage of heat is not that difficult a problem, given that you have large enough need of low enough temperature heat. Which at least district heating offers. And converging electricity to heat is not exactly expensive or difficult...

Can you elaborate? How many TW-hours of energy storage are you talking about being not difficult? Imagine for example the US Midwest and northeast from October through May.

Wikipedia has a decent article:

https://en.wikipedia.org/wiki/Seasonal_thermal_energy_storag...

At least this one seems to be commercially viable:

https://www.solarthermalworld.org/content/denmark-52500-m2-a...

And here seem to be some numbers:

https://www.gsenergy.eu/central-solar-heating/

To me these numbers are a bit confusing, though, it seems like they are production and not storage numbers.

Anyway, heat storage capacity goes on third power of the size of the storage size while heat losses go only on second power. So after some point the heat losses are small enough. And as an order of magnitude, storage of tens of GWh seems to be in the commercially viable range. Today, that is.

I would bet it is 100% about property values. If yourview has the disruptive harmony of hypnotically rotating windmills or solar panels lazily soaking up the sun embodying a rebellion and rejection of the economy you exploited to make your money, well, what rich people would want to buy your view that has such a noxious interjection into your narcissistic self-contained idyll?

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