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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
by DontGiveTwoFlux 8y ago
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?
- tomp 8y agoA 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.
- acidburnNSA 8y agoI 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.
- bluGill 8y agoA 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.
- dashundchen 8y ago> 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_considerations https://en.wikipedia.org/wiki/Heat_pump#Performance_consider...
- zaroth 8y ago5 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/aou36rlxfzh.html http://www.fujitsugeneral.com/us/products/multi/2-3-4rooms/a...
- ip26 8y agoBetter 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)
- acidburnNSA 8y agoThere'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?
- ip26 8y agoI'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.
- Scoundreller 8y agoOr a home natural gas turbine that also runs your heat pump compressor. And condenses the steam for high efficiency.
- deleted 8y ago[deleted]
- acidburnNSA 8y ago30-50% 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.
- maxxxxx 8y agoOther than being super explosive would liquid hydrogen work for an airplane?
- nradov 8y agoEven 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.
- acidburnNSA 8y ago*Manufacturer using low-carbon energy. At the moment, biofuels are renewable but high-carbon and nuclear is low-carbon but not (considered) renewable.
- carbocation 8y agoI 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 https://en.wikipedia.org/wiki/Hydrogen-powered_aircraft
- swampthinker 8y agoBuilding 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.
- thatfrenchguy 8y agoIt’s because of AC too. In France buildings have to be more efficient else you die in the summer.
- Scoundreller 8y agoEuropeans also need to understand that A/C does not make you ill.
- thatfrenchguy 8y agoIt’s killing the planet and making you less aware of your surroundings though.
- beat 8y agoMost 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.
- swampthinker 8y agoSpeaking 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.
- Retric 8y agoFor 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.
- Tharkun 8y agoElectric 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.
- danans 8y agoThe 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.
- Scoundreller 8y agoOr 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.
- dv_dt 8y agoHeating buildings is where passive unsexy solutions like insulation will work very well.
- acidburnNSA 8y agoInsulation will not deeply decarbonize space heating worldwide. It can help, but you still need trillions of BTUs.
- Tharkun 8y agoA 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.
- philwelch 8y agoIf you don't count the energy expenditure of either replacing or renovating 99% of the world's housing, sure.
- dv_dt 8y agoIt'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.
- philwelch 8y agoThe 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.
- ZeroGravitas 8y agoI'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.
- bluGill 8y agoUnfortunately 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)
- ginko 8y ago>My understanding is that electric heating is not cost effective compared to carbon based fuels Pretty much everyone is heating electrically here in Norway.
- munk-a 8y agoGood 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_.
- twistiti 8y agoWould 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.
- swampthinker 8y agoI would recommend checking out the guidance and tips pages from the Building Science Corporation [0] [0]https://www.buildingscience.com/ https://www.buildingscience.com/
- matt2000 8y agoThe path to vehicle electrification might not be that long: https://about.bnef.com/electric-vehicle-outlook/ 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.