STUDY: 40% grid energy reduction for NetZero by 2050

rr6013

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A Zero Emissions US ArsTechnica article determines that a future exists without increasing CO2. Its more complicated with energy mixes by region but I have a takeaway General question.

Here’s article TXT:

In many areas of the United States, installing a wind or solar farm is now cheaper than simply buying fuel for an existing fossil fuel-based generator. And that's dramatically changingthe electricity market in the US and requiring a lot of people to update prior predictions. That's motivated a group of researchers to take a new look at the costs and challenges of getting the entire US to carbon neutrality.

By building a model of the energy market for the entire US, the researchers explored what it will take to get the country to the point where its energy use had no net emissions in 2050—and they even looked at a scenario where emissions are negative. They found that, as you'd expect, the costs drop dramatically—to less than 1 percent of the GDP, even before counting the costs avoided by preventing the worst impacts of climate change. And, as an added bonus, we would pay less for our power.

But the modeling also suggests that this end result will have some rather unusual features; we'll need carbon capture, but it won't be attached to power plants, for one example.

Model all the things
Decent models of the future energy economy are complex. They typically involve breaking the grid down by region and simulating typical demand by using historic data, often scaled to represent increased demand. They'll then try to meet that demand using different energy sources, subject to a set of applied constraints. So, in this case, one of the constraints would obviously be limiting carbon emissions. The model then iterates over possible ways of meeting both the demand and constraints in the most economical way possible, identifying an optimal solution.

In this case, the researchers set up a series of eight scenarios which applied different constraints. These include things like continuing current trends into the future, a scenario where fossil fuel prices are low, and one that simply identifies the cheapest carbon-neutral pathway. Other variations include an all-renewable grid and high levels of efficiency technology, another where the land given over to energy production is constrained, and one where the United States manages to reach negative net emissions.

The US uses fossil fuels for a lot of things beyond electrical generation, and shifting these to emissions-free options are also part of the model. These include things like switching vehicles and heating to electrical options and altering industrial processes where possible. Carbon capture is deployed as needed to reach emissions goals.

One of the things that's immediately apparent from running the business-as-usual model is how much already changes thanks to the price drops in wind and solar. In this scenario, carbon emissions will drop by 22 percent, largely due to the displacement of coal use. It's worthwhile knowing, as any proposals for a target in that area can be dismissed as irrelevant. Another thing that is clear is that decarbonizing the energy system doesn't mean the US will eliminate greenhouse gas emissions. The noncarbon greenhouse gasses will still provide the equivalent of 500 metric megatons of carbon dioxide.

Efficiency and beyond
One of the things the research has made clear is that efficiency will be absolutely necessary for reaching emissions targets. By 2050, rising population and GDP should boost energy demand in the absence of efficiency. But, to get to carbon neutrality, we'll have to keep energy use roughly equal to our present levels. Some efficiency will occur simply because electrical vehicles and heating systems are inherently more efficient. But it's clear that we'll need quite a bit beyond that, since the research team estimates that per-capita energy use has to decline by about 40 percent in the next 30 years to reach carbon neutrality.

While energy use may stay level, the increased electrification of homes and vehicles will mean that we'll need significant increases in generating capacity. The typical scenario would involve about 3.2 terawatts of new capacity, almost all of it in the form of wind and solar power.

The good news is that doing this is relatively cheap. The researchers estimate that the net cost of the transformation will be a total of $145 billion by 2050, which works out to be less than a half-percent of the GDP that year. That figure does include the increased savings from electrical heating and vehicles, which offset some of their costs. But it doesn't include the reduced costs from climate change or lower health care spending due to reduced fossil fuel use. These savings will be substantial, and they will almost certainly go well beyond offsetting the cost.

Due to the reduced cost of renewable generation, the authors project that we'll spend less for electricity overall, as well.

The most expensive scenarios raise the cost to about 1 percent of the 2050 GDP. Notably, going to net negative emissions is not the most expensive; instead, limiting land use cuts down on the amount of renewable energy that could be deployed, raising costs.

Part of the reason it is so cheap is because reaching the goal doesn't require replacing viable hardware. Everything that needs to be taken out of service, from coal-fired generators to gas hot-water heaters, have finite lifetimes. The researchers calculate that simply replacing everything with renewables or high-efficiency electric versions will manage the transition in sufficient time.

Not what you might expect
Many takes on a carbon-neutral grid assume periods of low solar and wind production will be smoothed over with gas generators using carbon capture and storage. But this analysis suggests that any remaining gas plants simply won't run often enough to provide an economic justification for the carbon-capture hardware. Similar things are true with batteries; the periods when demand outstrips capacity are expected to be so rare that it doesn't make economic sense to build that many batteries to cover them.

Instead, gas plants will simply dump their carbon emissions into the sky. This ends up being carbon neutral because we'll still need some liquid fuels for things like air travel, and we'll make these with carbon pulled back out of the atmosphere, combined with hydrogen produced from water during periods of excess renewable supply. The researchers estimate that we'd require 3,500 terawatts just to make enough hydrogen—roughly the same amount of electricity we make currently.

“Until recently, it was unclear whether variable renewable energy, nuclear, or fossil fuel with carbon capture and storage would become the main form of generation in a decarbonized electricity system... The cost decline of variable renewable energy over the last few years, however, has definitively changed the situation.”
The scenarios with additional constraints produce some odd results as well. The only scenario in which nuclear power makes economic sense is the one in which land use is limited. This also drives more wind offshore and relies on fossil fuel plants with carbon capture. Not surprisingly, this turns out to be the most expensive situation the researchers looked at. Carbon capture, along with enhanced biomass use for power, also featurs prominently in a scenario where the shift to electric vehicles and appliances is delayed.

Going entirely renewable actually forces much higher levels of carbon capture to ensure that fuel needs could be met without any fossil fuels. And going net negative involves a variety of carbon capture and biofuels, with substantial land use as a result of the latter.

Everything has changed
To an extent, the researchers themselves seem somewhat surprised by how much has changed in the last few years. "The net cost of deep decarbonization, even to meet a 1°C/350 ppm trajectory," they write, "is substantially lower than estimates for less ambitious 80 percent by 2050 scenarios a few years ago." It also provides clarity to what has been an uncertain future. "Until recently, it was unclear whether variable renewable energy, nuclear, or fossil fuel with carbon capture and storage would become the main form of generation in a decarbonized electricity system," they note. "The cost decline of variable renewable energy over the last few years, however, has definitively changed the situation."

Now, even if we go for deep decarbonization, we'll be investing in the future. It will cost money to get there, but we'll have lower future energy costs if we pay the price upfront—as well as improved health and a more stable climate.

There are, however, significant hurdles to getting there beyond simple economics. The emission-free future will involve us installing roughly 160GW of wind and solar per year in less than two decades; 2021 will see us installing only 15GW. And the switch to electric vehicles and appliances has to start now—anything that breaks should be replaced with an electric version, which does not seem to be happening.

But if this analysis holds up, there are good reasons to think it's worth getting started.

AGU Advances, 2021. DOI: 10.1029/2020AV000284 (About DOIs).

GENERAL QUESTION

Why is it not affordable to off-grid Residential? This question has embedded within alternatives such as: DC -> X (Home, lighting, Vehicle and Powerwalls), Solar H2O and any other non-grid energy mix that mortals can buy. Does off-grid Residential approach 40%?





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ldjessee

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It is interesting that they assume air travel will still be as prevalent as it was and that it will require liquid carbon emitting fuel.
If the pandemic, not just from restrictions on air travel, but people just wanting to travel less, did not get people to think about less air travel, the rising cost of fueling such might.
I am not sure how this plan could be accomplished without a carbon tax. Make the emissions cost and inventors will find an alternative once it becomes an economic priority.
I think the failed attempt and boyant air craft (new blimps, dirigibles, etc) that failed in the 90s might be more economically and socially acceptable once fuel burning turbines are cost prohibitive to all but a very small percent.
And these designs, with current technology, could be all electric, with solar panels on the top and sides, spacious room (compared to passenger jets), and relaxed travel.
I also think that if you put energy generation near usage, then there will be less line loss, also increasing the efficiency of the grid in general.
Also, doing energy intensive industrial work when energy is cheap or over produced (such as when the wind is blowing and the sun is shining), like aluminum smelting, would also increase efficiency.
I would support mandates that all governmental buildings must have panels if it will be paid off in the expected life time. This would even allow such systems in more northern climates where such panels could not meet the daytime demand, but could help offset use and because it was generated where it was to be used, then there would be no line loss (nor need to store it, so no loss in efficiency in storing it in batteries). I do expect batteries, especially for larger buildings and campuses, to use the flow batteries, as energy generated on weekends and holidays could help offset usage during normal work hours.
Where solar is more available, than say Germany, maybe all new buildings should have some solar on it, to help offset power use. And if carbon emissions were taxed, then this would have a financial incentive.
I also think that a lot of work has been done on off-shore wind and large cities, like New York, LA, and SF, would really put pushing for this kind of energy generation... maybe again carbon tax would make it more feasible.
And why, as a parking lot or parking garage owner, they do not cover their facility in panels (again, if solar availability is decent) I do not understand.
Sure, Alaska might have issues with a big solar push, but almost all of the contiguous US has decent solar availability...
And not that I am saying the above is not a good start, but it seems to not take advantage of less obvious efficiency gains and changes to how energy is used and when it is used.
 

ajdelange

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GENERAL QUESTION

Why is it not affordable to off-grid Residential?
It is not 100% clear to me what "it" is (call me Bill Clinton) but I assume "it" is carbon neutral electricity. I'd say that the 3 main reasons it's not affordable now are storage, storage and storage. if you do a few calculations on what a carbon neutral grid isolated system would look like (I've done this as I am builing a garage/work shop for the electric cars that will not be connected to the utility) you quickly find that even with modest electrical demand, you need quite a bit of battery to cover nights, a few days of clouds and periods of unusually cold weather. Even so you will have to have a backup generator if you want to make it through cloudy periods seamlessly.

Now the generator is not carbon neutral. Yet. The way we store energy traditionally is to let nature do it: 6CO2 + 6H20 + hv --> C6H12O6 + 6O2 and the way we consume the stored energy (hv represents the energy in photons from the sun) is the exact reverse: C6H12O6 + 3O2 --> 6CO2 + 6H20 + Energy. This is carbon neutral as long as the hydrocarbon burned is sourced from something, for example, you grew and then regrow. The problem with fossile fuels is that we are burning hydrocarbon at a rate that puts CO2 into the air faster than we are taking it out. And of course it takes a while to grow a plant etc.

The more general reaction H20 + CO2 + Energy ---> Hydrocarbon can be much accelerated using catalysts and modern technology allows this with, if you do it right, gives you hydrocarbons in a form that can be put into a generator or car or airplane. There are companies exploring these blue-diesels or e-diesels as they seem to be called. Burning them is carbon neutral.

This tech isn't quite there yet (and may never mature). I don't know where to send you to buy a backup generator nor fuel to fill its tank. I mention this first because I think there is a possibility that such a generator may be available to the off grid guy at some time in the forseeable future.

In case it isn't clear the energy source for the blue diesel synthesis would be the sun. Another way to use solar energy in a carbon neutral fashion is to use it to hydrolyze water producing hydrogen which can then run a fuel cell. This technology isn't mature enough for the residential market. It's too expensive partly because it is inefficient.
 

TheLastStarfighter

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In my area, the power company offers 1:1 net metering, so it's pretty easy to go net-0 with solar. I plan to do that as soon as I can, hopefully within 2 years. But that means producing more solar in the summer than I need, and consuming grid power in the winter. Going off-grid would mean a whole lot of battery power, and drive the cost through the roof. My home is a converted industrial building with 5 rental units in addition to our loft. I can probably get it on solar for around 50k - absolutely worth it - but I'd probably need 6-8 powerwalls to go off-grid. More than doubling the price simply to give the finger to the power company seems pointless.
 

ajdelange

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In my area, the power company offers 1:1 net metering, so it's pretty easy to go net-0 with solar. I plan to do that as soon as I can, hopefully within 2 years. But that means producing more solar in the summer than I need, and consuming grid power in the winter. Going off-grid would mean a whole lot of battery power, and drive the cost through the roof. My home is a converted industrial building with 5 rental units in addition to our loft. I can probably get it on solar for around 50k - absolutely worth it - but I'd probably need 6-8 powerwalls to go off-grid.
With 6 residential units you will need more than that. My solar winter production covers 20% of my electric bill (house is heated with geotermal) whereas in the summer it covers all my electric needs (A/C by the same Geo system).

More than doubling the price simply to give the finger to the power company seems pointless.
Yes, it does but I'm doing it anyway because the building is really my solar laboratory rather than a means to give the utility the finger (though I must admit a wee tingle of pleasure when thinking of that aspect of it).
 
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rr6013

rr6013

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It is not 100% clear to me what "it" is (call me Bill Clinton) but I assume "it" is carbon neutral electricity. I'd say that the 3 main reasons it's not affordable now are storage, storage and storage. if you do a few calculations on what a carbon neutral grid isolated system would look like (I've done this as I am builing a garage/work shop for the electric cars that will not be connected to the utility) you quickly find that even with modest electrical demand, you need quite a bit of battery to cover nights, a few days of clouds and periods of unusually cold weather. Even so you will have to have a backup generator if you want to make it through cloudy periods seamlessly.

Now the generator is not carbon neutral. Yet. The way we store energy traditionally is to let nature do it: 6CO2 + 6H20 + hv --> C6H12O6 + 6O2 and the way we consume the stored energy (hv represents the energy in photons from the sun) is the exact reverse: C6H12O6 + 3O2 --> 6CO2 + 6H20 + Energy. This is carbon neutral as long as the hydrocarbon burned is sourced from something, for example, you grew and then regrow. The problem with fossile fuels is that we are burning hydrocarbon at a rate that puts CO2 into the air faster than we are taking it out. And of course it takes a while to grow a plant etc.

The more general reaction H20 + CO2 + Energy ---> Hydrocarbon can be much accelerated using catalysts and modern technology allows this with, if you do it right, gives you hydrocarbons in a form that can be put into a generator or car or airplane. There are companies exploring these blue-diesels or e-diesels as they seem to be called. Burning them is carbon neutral.

This tech isn't quite there yet (and may never mature). I don't know where to send you to buy a backup generator nor fuel to fill its tank. I mention this first because I think there is a possibility that such a generator may be available to the off grid guy at some time in the forseeable future.

In case it isn't clear the energy source for the blue diesel synthesis would be the sun. Another way to use solar energy in a carbon neutral fashion is to use it to hydrolyze water producing hydrogen which can then run a fuel cell. This technology isn't mature enough for the residential market. It's too expensive partly because it is inefficient.
Thank you!

Converting a handheld torch from halogen to LED – that stretched battery life for me. Suddenly the idea of taking household lighting from AC to DC solar started to cross a threshold mere mortals might use to get off the grid-teat. As in contribute in a measurable % toward that 40% reduction figure stated in the study.

LED lighting scaled worldwide powered by rooftop solar seemed like one “doable” lightbulb contibution that works even in the Great White North excepting sweeping snow off panels.

But DC LED is neither affordable just for lighting load nor is it scalable to convert DC-AC; neither as a store for VAC. Yet. The economies haven’t been reached by technology nor scale. Excepting the odd edge case for grid-tied storage as in AUS’s system for its grid stabilization.

Surprising that geothermal works for heat pump cooling during summer. So there’s one step forward in defined locales as a corner case solution.

No comments yet on the idea of Tri CT owners 160kW battery packs down there in the garage, yet. Other than grid-tied charging off hours to save $, the U.S. grid is not 1:1 for solar panels. A few granddaddy rates might be out there but utilities quickly shut that door.

TSLA, is that a path to getting off the grid-teat?. Cybertruck owners are under utilized assets. In the big scheme of max resource utilization (Li,Ni,Cobalt etc...) those resources aren’t utilized in a way to help further toward that 40% reduction needed. Wonder. What %age a Tri CT does contribute sustainably. Certainly tailpipes can be counted, added up to CO2 saved for every CT. But man CT sucks big electrons through the process of fueling, er charging 180kW.

We need a creative type to draw a picture to get our heads around Tri CT puzzle piece to a 40% reduction worldview. Math wiz’s can calc the 1000’s of CT bar graph contribution to that 40%. The sear sucker suit feeling of going in the right direction with CT is that still going to be warm? Buying into a Tesla sandbox is that more attractive for solar, battery or powerwall and the synergy in future proofing toward a less CO2 planet for posterity?

Well… so not yet?
 

ajdelange

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Converting a handheld torch from halogen to LED – that stretched battery life for me. Suddenly the idea of taking household lighting from AC to DC solar started to cross a threshold mere mortals might use to get off the grid-teat. As in contribute in a measurable % toward that 40% reduction figure stated in the study.
The question of AC vs DC doesn't mean what it used to. Rather than get into any of the details I just mention that my house has solar panels (DC) but that the output from them is 120V AC. This is distributed to LED lights throughout my house. The little chips that actually glow are DC devices but the "bulbs" they reside in screw into 120 VAC outlets - just as a tungsten or fluorescent bulb does. Suffice it to say that the process of conversion of DC at one voltag to DC at another voltag or AC at a third voltage can be done with very high efficiency.

LED lighting scaled worldwide powered by rooftop solar seemed like one “doable” lightbulb contibution that works even in the Great White North excepting sweeping snow off panels.
A LED "bulb" that draws 10 W produces more light than fluorescent or tungsten lamps drawing several times 10 W so yes, you can save quite a bit on your electric bills by replacing all your old bulbs with LEDs. They are much more expensive but they last much longer.

But DC LED is neither affordable just for lighting load nor is it scalable to convert DC-AC;
Not sure what you mean here. Perhaps on a boat or airplane a designer might use DC LEDs but in a residence he'll use AC. In a solar system the conversion to AC is done at the panel. Add, a panel, add a converter. The conversion back to DC is done in the bulb. Add a bulb; add a converter. Can't get much more scalable than that. There are still systems being sold in which a single inverter serves a string of panels. The advantages of the micro inverters are many but the block approach is somewhat cheaper and, under the right circumstances, feasible.

.. neither as a store for VAC. Yet. The economies haven’t been reached by technology nor scale. Excepting the odd edge case for grid-tied storage as in AUS’s system for its grid stabilization.
In the previous post I tried to make it clear that the fly in the ointment with solar is that the sun doesn't shine at night (when the LED lights are on) nor very much in the day in the winter. You have to have a battery - quite a big one in fact and that's what makes even a reasonably sized off grid solar system impractically expensive. With grid tied systems you can use the utility as your battery but you are storing "virtual energy" in it, not real energy as you do in a system with PowerWalls or other batteries,


Surprising that geothermal works for heat pump cooling during summer.
Not really, In an A/A heat pump you have to pump heat from your 75 °F house uphill to outside ambient air at 90 - 95 °F. With the geo system you don't have to pump at all as the heat would naturally flow from the 75 ° house downhill to the 55 °F ground water. Thermodynamically, the system should produce some energy. Practically, though, it in fact uses some. I does pump. But it's more efficient than an A/A.


So there’s one step forward in defined locales as a corner case solution.
Geo systems work pretty much anywhere that ground water is present. The problem with them is that they are complicated and expensive.

No comments yet on the idea of Tri CT owners 160kW battery packs down there in the garage, yet.
The Tri's battery pack will probably have a discharge capacity of closer to 200 kW. As such it has the storage capacity of 13 PowerWalls. Were it to be available to a Solar system then the biggest problem with solar systems would be solved. Or would they. The diurnal charge/discharge cycle implied by a solar system will deduct from the battery's life. The CT can't run the house at night if someone is out with it. Etc.




Well… so not yet?
That's really the bottom line.
 

Crissa

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We're converting much of our lighting to LED strips, which means it's DC low voltage already. As long as I'm not trying to convert the voltage (which I am, most are 5v but some are 12v) it's easier to keep the backup lighting as DC.

-Crissa
 

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