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I have quite a bit of surplus power most of the year (on the order of 10-15kWh/day). If I use it, great, if not... it just doesn't get pulled out of the panels. The office is standalone (and way more trouble than it's worth to grid tie)

I know you said grid-tie isn't worth the trouble, but until the USA moves to more renewable energy for power production, that might yield the best carbon reduction, depending on how much you could otherwise sequester per KWh.

The national average CO2 emissions for power production is 947.2 lbs CO2 per megawatt-hour [1] (or 0.947 lbs/KWh).

So unless you can sequester 10-15lbs or more of CO2 a day, then you may be better off sending your excess power to the grid if your goal is carbon reduction.

Though I'm not sure how to account for the actual CO2 reduction - is the national average fair? Should you use the average per state since states vary widely in their renewable energy status? Is there some other way to determine how much CO2 you've offset?

[1] https://www.epa.gov/energy/greenhouse-gases-equivalencies-ca...

I guarantee my office is radically more trouble than it's worth to grid tie. I'd have to put a second meter in, or lose net metering on my house, I'd have to trench across an awful lot of quite hostile ground (literal rock outcroppings between "where my office is" and "where the grid tie would be"), upgrade my house's electrical panel, and pretty much entirely redo my office power system from the ground up, get a permit for my office (it's under the size minimum, but with hard wired power it would need a permit), rebuild my panel mounts, and an awful lot of other stuff.

It would easily run me $10k to do all this, before I was able to cross tie a single kWh. And, in the bargain, I'd lose the standalone power system that is my office, because getting battery backed stuff approved out here is basically impossible. I tried for the house system, and after 18 months of fighting red tape that exists to fund the red tape, I gave up and built a grid tie system without a backup.

I get that it sounds easy, but it would cost more to interconnect it than the standalone system cost in the first place, drop me out of a very sweet 25 year net metering grandfathering, and leave me with a far less capable property in the deal. Sorry, just not interested in that.

Put an electric car charger on the side of your shed?

When I redo the wiring in my shed, that's one of the things I plan on doing - more exterior outlets. Right now, I don't have an easy way to plug the Volt in down there, but on days when it's used early and has the full day to recover, I probably could. The main limit is that I only have a 2kW single phase (120V) inverter down there, so I can't really charge at a full 2kW, and I can't charge hard while also running my air conditioner. I can spare 500-800W, no problem, but beyond that, it starts to be harder. I've got a bigger inverter on a trailer I can parallel in, though, and that might work - run 900W out of my office into the aux charger on that, with another 900W coming in from solar, and then charge the car at 3.3kW, buffering off the battery pack. I need to play with it a bit more this winter, but having some good outdoor outlets on my office will make things easier.

Sounds like attacking the bureaucracy around solar power regulation is a great place to start.

I get it. I have a solar system too and there's no way in hell I'm updating it.

Given how much you are curtailing it could be the case that your system is worse off with respect to carbon than if you just used grid electricity. We'd have to do the math but there are large embodied emissions in your pv panels and battery, your curtailing means you are making up for those more slowly.

Oh, I'm almost certain it is. But, given that, the more energy I can make and utilize with it, the lower the effective carbon per kWh is. It's also, of value to me, a totally standalone power system, and a good R&D system for me to experiment with, because I can do things without bothering the house system. If I screw up and black out my office, well... I've blacked out my office.

However, my system is also rather a good bit more reliable than the grid power on the house, which is nice for remote work.

Advocate for more efficient land use requiring less transportation, heating, and cooling.

Advocate for increased carbon taxes, extraction duties, and limits on new uses and loads.

Encourage wetlands and forest preservation and expansion. Wetlands, by unit area are the most productive carbon sequestering ecosystems on Earth.

Grow plants. Compost.

Reduce your own carbon footprint. Reduce meat consumption, use of manufactured goods (most especially with high embedded energy content), and energy useage. Reduce, reuse, and recycle, in that order.

> Is there any work on smaller scale, "home" or "neighborhood" carbon capture technologies that could work with some extra energy laying around?

Gardening.

If you garden without fertilizers, and compost garden waste, then you are capturing carbon in the soil. If you use a composting toilet too, you capture even more.

If you compost only the garden waste, and only( spread that compost on your garden, then the amount of stored carbon won't increase much, because a lot of what goes into your compost must have come from the soil. But if you also compost food-waste, and if you add soil-conditioners such as farmyard manure, then the amount of stored carbon will increase steadily.

But as has been noted up-comment, the easiest, cheapest way to get carbon into the ground is to not dig it up in the first place.

It's not a great idea, but you can pump air into lime water and it'll turn into calcium carbonate. Basaltic rock will also form calcium carbonate when CO2 infused water is passed through it.

I'm not sure these work at such small scales, but it could at least give you a starting point and a project. If you start a blog about these experiments I'd love to follow. Hard to know if your operating emissions would be offset by your sequestration. If anyone has better ideas I'd also like to know.

There could also be a monetary reason to do carbon capture at home. There can be a lot of CO2 buildup in homes and offices with poor ventilation (read: most).

If I do any experimentation, it would be over at my normal blog. My operating emissions, if powered by my office, are zero incremental emissions - the system is overpaneled and there's no cost for extra production within the bounds of what it can do.

I don't know if there's any sane way to do this on a small scale and without concentrated CO2, but the first thing that comes to mind is to make synthetic methane using a Sabatier process. I think the way this works is you create hydrogen through electrolysis of water, and then react it CO2 to make methane.

Methane is a worse greenhouse gas than CO2, but if you burn it as fuel it's a carbon-neutral energy source.

Alternatively, you could use electrolysis to make hydrogen, but hydrogen is harder to store.

(I'm not a chemist, so I have no idea if this could work. And it probably wouldn't be very practical even if it did.)

I do like your idea of experimenting with a rock crusher. The article mentions that finding the least-energy means of crushing rocks to the appropriate size is something of an open problem.

What purpose would the methane serve?

Assuming it's possible to use this process on a home scale with a decent solar grid and energy storage, it seems to me that you would be sequestering the carbon only very temporarily. Wouldn't the electrical energy used to produce the methane heat your home more efficiently (assuming you have an electric heating system) as you would be inviting energy losses through the Sabatier process?

Seems you would need to produce industrial levels of methane and distribute it (which would almost certainly be carbon expensive in it's own right) as substitute for naturally occuring methane being extracted from deposits.

It's a cool idea though. If there were a process to produce solid carbon, this would be much more promising (disclaimer: definitely not a chemist).

The general idea is you can make methane that's equivalent to the methane that comes out of the ground, but in a carbon neutral way. So it's a benefit if you can give it someone who was going to burn methane anyways, like to run their natural gas furnace.

That's not as satisfying as just plain sequestering the carbon somehow. I mean, it would almost certainly be better to just run an extension cord to a neighbors house and let them run an electric space heater or heat pump off of the excess electricity.

Maybe methane could be used as an ingredient to make something else that's possible to store or bury long term, like some kind of plastic or liquid? (Most of what I know about the processing of hydrocarbons is probably wildly inaccurate because I learned it from Factorio.)

Time-shifting. If you have a good way of storing it you could generate methane during the months when you have surplus solar power and use it in winter after you've depleted your batteries and the sun is not bright enough.

Probably (over) insulating the house is the most efficient way of minimizing energy loss. But then does an over-insulated house get overly warm in summer or easier to cool?

The air-sourced methane could be used for things that are hard to electrify/de-carbonify, and could reduce the use of ground based sources.

I'm wondering at what level of carbon tax it makes more sense to extract the carbon from the air to turn it into plastic than to use ground-based oil.

I know nothing about the practicalities, but could you run grow lights and head pads to raise seedlings and hydroponic food and then donate to the neighbourhood? Meagre, but might save on some tiny transport cost somewhere.

> Is there any work on smaller scale, "home" or "neighborhood" carbon capture technologies that could work with some extra energy laying around?

Trees? They make efficient use of solar energy to capture carbon and have a lot of other benefits:

https://www.cnu.org/publicsquare/2020/08/31/powerful-virtuou...

If I could grow the things... I struggle to get them watered properly.

Practically, though, I'm out in some fairly high desert, and I have to pump water for irrigation out of a deep well. I can certainly do it, but I'm looking for something of a bit more "geologic scale" sequestration, if it's possible.

You might consider hydroponics (ie consumer Aerogarden) as the water requirements are approximately 90% less. It does the "watering" for you.

I'm actually planning to get a backhoe for a couple years to build a large basalt greenhouse, then do aquaponics - combine growing fish and plants in something that removes most of the downsides of aquaculture and hydroponics. Done properly, it's a synthetic pond ecosystem that doesn't require flushing the water ever.

Looks like you're somewhere east of where I live in Oregon. Do Junipers grow there with maybe a little bit of water?

FYI, it takes 7-8 trees just to offset a single person's breathing if this math is right.

https://www.sciencefocus.com/planet-earth/how-many-trees-doe...

The maths may be right but the thought is wrong since it takes zero trees to offset the whole world's population of air-breathing organisms as all the CO₂ they produce started out as... CO₂. This is taken up by algae and plants, which are eaten by organisms which are eaten themselves until the target organism is reached, which will use the energy gained from consuming the previous hop in the carbon chain, breathing out CO₂ upon which the circle is complete.

Had humans consumed fossilised carbon the thought would still be wrong since trees only store the carbon temporarily, eventually it is released as CO₂ when the tree burns up or rots away.

This leaves aside the whole discussion on whether there is any need to offset CO₂ from non-fossil sources - which there is not as far as I can see.

That's ok, I've planted 920,000.

It's not how many you've planted, it's how many are still alive at age 20.

They all had good quality and trees make pine cones.

Those calculations are for oxygen required to breathe, not carbon dioxide exhaled by people. The cycle for biologically produced and consumed CO2 tends to be carbon neutral.

As far as I'm aware, the issue isn't with CO2 produced by cellular respiration, the issue is the burning of fuels dug up from the ground and the destruction of natural carbon sinks.

Trees are a temporary carbon store, but the issue is that they eventually die and rot, and then that carbon gets released right back into the atmosphere. A permanent solution would be to grow trees, chop them down, and then bury them.

Alternately, let new trees grow to take the place of trees that die.

This is yet another stock/flow issue, where the sequestered carbon is a function of the stock of living trees, which itself grows with the delta of trees added - trees removed. You don't need to manually manage the lifecycle of each individual plant, just focus on the increasing the living stock, or rather, letting the living stock increase all on its own in response to more carbon in the air. So this is about land zoning and habitat protection, not building little coffins for individual trees. Let forests grow and protect their habitat, they will grow all on their own if allowed to.

FYI we've added 60 million hectares of forests since 2000. That process can be even expanded.

Yes, this is true. If you can create a stable forest then that becomes a carbon sink for the lifetime of the forest. It is still hard to see how this is going to make a big difference. The biomass of the Amazon rainforest is ~120 gigatons. Annual CO2 emissions are right now around 30-36 gigatons. Growing a new forest the size of the Amazon would make up for about four years of emissions.

Of course that doesn't mean that reforestation isn't valuable. It certainly is. But even enormous growth of forest wouldn't make a big dent in atmospheric CO2 levels. The carbon came from underground and almost all of it will have to return underground to get CO2 levels down.

Those are valid points. But you don't need to add the square footage of the Amazon, what also happens is that forests become more dense per square foot. But not only forests, grassland sequesters about 343 gigatons and that rate has been growing at half a gigaton/year as the grassland gets taller/denser due to increasing carbon in the air. Biomass in topsoil itself sequestors twice as much carbon as biomass in trees, but this covers only 3% of the earth's surface. This paper has a nice overview[1]

[1] https://innovate-eco.com/storing-carbon-in-plants-and-trees-...

Mature forests are carbon neutral because new growth will take the place of growth that dies and decays.

Bacterial rot is not the only thing that trees can turn into: their carbon can enrich the soil and be consumed by insects, fungus, lichens etc that goes onto feed higher species on the food chain. On top of that, rotting trees is fantastic habitat for animals, which are also made of carbon.

“the issue is that they eventually die and rot, and then that carbon gets released right back into the atmosphere”

You make it sound like a rapid process. Univ of Arizona did a study that showed CO2 emissions of dead trees was lower than living ones due to the rotting process being very slow compared to a living trees normal respiration cycle

Well the timescale of climate change is on the order of a few decades to a century. The decomposition process is somewhat slow by human standards, but it's still fast compared to a century. In order to effectively remove CO2 from the atmosphere to prevent climate change, it needs to be removed on timescales longer than a century.

decomposition doesn’t evaporate the tree into the air, it can build the soil and become habitat for larger animals (which also count as biomass)

Grow trees, chop them down, and build houses. We still have a housing shortage.

So long as lifespan is on the order of 100 -- 1,000 years, the net gain is all but certainly worthwhile.

I still favour wetlands over trees as a first priority.

You can cut them down regularly and turn the wood to biochar and bury it. That is fairly stable in the soil. If you just bury them normally they'll decompose back to carbon dioxide much faster.

It is something that have to be done anyway, as the other benefits matter too. But how it is done could be the difference between a solution and a far worse problem.

Global warming is already pushing toward more frequent forest fires, or droughts in vast regions that if they have trees will end burning up as well.

Intensive tree planting in relatively small areas probably is a bad idea, or will have a big maintenance cost to try to avoid that risk.

But, in any case, it is the low hanging fruit of carbon capture. I just hope that it is done in the right way.

While I believe this comment is well intended, I don't believe it addresses the parent's question. The extra resource they have is electrical power, not land. They are asking if there is a way to turn electrical power into carbon capture.

I also want to say that the planting trees method is a bit more nuanced than everyone makes it out to be. But don't trust me, let's ask someone who knows better: Forrest Fleischman[0][1]. I'm not saying "don't plant trees" (do) but that this is often everyone's go to response to CCS and it is a bit naive (as explained in the threads).

[0] https://twitter.com/ForrestFleisch1/status/13062214459331297...

[1] https://twitter.com/ForrestFleisch1/status/14440088233506037...

Also interesting that grassland can in some cases like California be better co2 sinks than trees. https://www.earth.com/news/trees-grass-carbon-sink/

If only there’s a market network for quick-swappable rechargeable battery packs for electric cars.

Here’s how it would work: you pass by a convenience store or gas station on your way home or to work, pick up some depleted battery packs, you get home and recharge those battery packs with your excess solar power, then bring the recharged battery packs back to convenience store or gas station for a bit of money. That way you don’t need to grid tie your solar installation. :P

A grid (even if local) is far more efficient. Moving things takes a lot of energy. It would be more efficient to just put those batteries in the grid, since everyone will be generating surplus at the same time, and it would never be unutilized while disconnected.

So, your answer to global warming is to move already-generated electricity via truck, instead of wires?

There are such picker/chargers for the electric scooters available in many cities.

Is it safe to just leave the panels in the sun without letting them convert sun energy into electricity?

If connecting into the grid isn't possible you could maybe attempt to charge batteries that you then take home and use there. Would require some calculations to check if it's worth it though... Would maybe be best if it were an electric car that can feed back into the grid.

Or run a desalination plant ;D

> The office is standalone (and way more trouble than it's worth to grid tie), so when the battery bank is full, there's nowhere to stick extra energy.

I don’t know the details of your site/situation, but I suspect any alternatives to grid-tying your system will turn out to be a lot less efficient than whatever (mostly one-time) trenching, cabling, and paperwork would be required.

I have a mind-blowing idea. Don't have children...?

Birth rate decrease -> demand decrease -> CO2 decrease

If we have the same birth rate as Korea or Japan, the population would drop more than 20% in 50 years according to the population prediction in these two countries. This means lots of demand would not need anymore, and might be the best practice which could be done by individual.

We don't have to reduce carbon emissions by 20% in 50 years, we have to reduce them by >100% in less than thirty years. Reducing birth rates is both, much too slow, and not sufficient (unless you propose reducing population to 0).

At least, workable and easy.

Is there any solution could really reduce around 20%? (Not to mention more than 20% and not to transfer the emission to other countries)

Sure, replace fossil fuels for electricity generation with renewables and/or nuclear. Replace fossil fuels in cars with batteries. Replace fossil fuels for heating with electricity.

Each of those saves on the order of 20% of emissions and could be done in less than a decade if we put maximum effort into it.

I really doubt convincing a sufficient number of people to not have children is easier than any one of those measures. Just imagine the political backslash if the government suggested not to have kids for the climate. It's a lot easier to convince people to stop eating meat for the climate and even that is essentially impossible.

Uh... I replied to OP which is for individual.

In the scale of country, East Asia did quite well without any policies (exclude China, they have a special policy on it). Just keep raising the price of estate, and then birth rate would drop and never come back.

For the part of energy, according to the EPA report[1], the emissions by electricity and heat are around 25% in total. If we want to reduce 20% in total, we need to close 80% of fossil plants. For me, it is nearly impossible. There are some countries may not have the land or safe area to place nuclear/renewable plants. (e.g. Singapore...) I know there is a plan for Singapore to buy the clean solar energy from Australia, but it only covers 1/5 of the consumption. Also, there must be security issues for transferring power between countries.

[1] https://www.epa.gov/ghgemissions/global-greenhouse-gas-emiss...

Global numbers are not representative of industrialized countries. E.g. in the US electricity is about 25% of GHG emissions. Many individuals too can choose to use an electric car (or even no car at all), to install solar panels (or at least pay for greenwashed electricity), and improve insulation and switch to electricity for heating (if they own a house).

There's also a Singaporean project in Batam Indonesia for a solar power plant (it's only 50km away from Singapore).

https://www.sunseap.com/SG/newsroom/2021/sunseap-signs-MOU-w...

"Workable" is arguable, "easy" is a bit of a stretch.(assuming you're not trolling.)

I suspect most westerners are not going to be thrilled when receiving the government email about their mandatory sterilization.

Usually the idea floats in circles of people convinced we'll reduce the birth rate of "other" people (wink wink dog whistle yeah they're thinking of Africans)

Get replaced by people who don't have such unfit qualms, great idea!

You can utilize the excess electricity to gasify waste woody biomass from tree trimming, etc; store the syngas that is produced for heat production during the winter, and bury the biochar (carbon) that is left over build soil health and recapture carbon.

It's probably not worth the resources to do something like this at such a small scale.

It will just never be as efficient as an industrial scale operation.

I'm sure it won't be as efficient as a large operation, but neither can I get my surplus power to an industrial operation. And I'd happily follow the power supplies - run equipment during the day, when it's clear, not run it at night, etc. I'm already used to using energy based on what's available, this would just be something additional to add into the blend.

I've got an awful lot of basalt laying around, though...

Mine crypto and donate the money. Minimally you reduce the incentive for others to use electricity to mine more.

I'm not sure if that holds - wouldn't additional work on the network encourage others to then add more capacity to recapture their share?

I've looked into it briefly, and came to the conclusion that the BOINC stuff (it used to be F@H but I gave that GPU to a friend for some CAD work) was more useful than crypto mining, because I simply couldn't mine enough to matter out here - a dollar or less a day sort of thing, with my annual power profile.