We use a milk/eggs/etc delivery service operated by a local farm, we’ve returned 100s of washed glass bottles without breaking any. They’re thick bottles designed for reuse, they’re not fragile. Despite that, the empties are a tiny fraction of the weight of a full plastic bottle. It seems like a pretty a clear, unmitigated win vs plastic with a local service.

> It seems like a pretty a clear, unmitigated win vs plastic

Did you use hot water to wash them?

Probably yes. Last time I did the math making them out of plastic saved energy vs heating water to wash glass (it was a close call, it depended on if you used a dishwasher vs sink washing).

So it might seem environmental friendly, but if you run the numbers it's not necessarily so.

Energy usage for creation is only one axis of "environmentally friendly", though. It's starting to seem like small bits of plastic permeating everything might not be ideal.

Did your calculations include things like the extraction and distillation of the petroleum?

Beyond the environmental impact, there's also just the stupid, wasted effort that goes into pointlessly recreating the same thing over and over when you don't have to. In this case, the bottle goes back on the return trip from delivering new milk, which had to happen anyway. The milk ends up being the only thing delivered, on net. It's just strikingly elegant in its lack of wasted effort and material. It's not clear if it's a net win, though, given the delivery part, unless there are others on the same street signed up for the same day.

If anyone's in the Bay Area and is interested in delivery sort of like this, which also tries to set up regular delivery routes to minimize the marginal impact of a customer, I recommend checking out Farmstead (https://www.farmsteadapp.com/). They provide a similar milk delivery service by picking up Straus milk bottles and refunding the deposit. They also solved my biggest issue with most of the delivery services by picking up their reusable bags and having minimal packaging inside, but COVID put a stop to the bag pickup, at least temporarily.

That’s honestly one of the most interesting parts of nuclear for me, along with large scale renewables (eg hydro): when you can break the energy = CO2 connection by using energy sources that don’t release extra CO2 per kWh, a lot of the math starts to change. Things that didn’t help before (washing glass bottles with water heated by natural gas) actually become a net benefit. Likewise making the glass in the first place.

People are cleaning the plastic with hot water to put it into the recycling. The only difference being that the glass actually gets used again and isn't dangerous to the environment and us as it breaks down. Plastic has turned into an unmitigated man made nature disaster.

Commercial glass washers can use very little energy; the rinse is done with a small amount of near boiling water which goes into the wash tank, where it's then used for washing.

Doesn't that depend on where the electricity for the hot water comes from?

I'm inclined to say "no", unless you're using a renewable energy source that would otherwise go unused. So excess locally produced power that can't be sold to the grid, essentially.

Power markets are very liquid, so I tend to favour calculating your personal footprint based on the average co2 output of the grid, not the particular energy production method you've chosen. This makes it clear that even if you're paying for wind power, it's still better not to waste electricity.

Some of that energy may become greener over time. There's also the final output of unrecyclable, possibly toxic (if heated in the sun) plastic vs glass which naturally degrades to ... sand?

Reusing washed glass bottles for perishables like milk can be a public health risk. It's hard to get the cleaning process to the point where when the stars align for that 1 out of 100,000 bottles it still gets sterilized.

Until I see statistics proving the opposite I don't believe that. Washing bottles hot enough to kill germs really is not hard and we used to reuse lots of glass bottles.

Getting glass hot enough to kill microbes isn't hard, but it does take a lot of energy. Microbes will attach to the glass and use that as a heat sink, so just hot water isn't enough, you have to use enough to heat the glass.

It's actually tremendously hard to do that on an industrial scale. We still get listeria outbreaks even with pasteurized milk and new bottles. Adding in a source of contaimination is going to make it that much harder.

The issue isn't getting bottles hot enough to kill germs. It's doing so in a way that doesn't aerosolize the bacteria and preventing all the other ways cross contaimination can occur.

If you pour a glass of milk at home, do you throw the glass away afterwards?

That's not the risk. The risk is introducing harmful bacteria into a bottle and then having it reproduce for some days before someone drinks it. Since you're not storing milk in the glass it's not an issue if it isn't completely sanitized.

All of that could be done sustainably if the energy we generated and used was sustainable. Electric trucks and trains, clean energy to run the cleaning facility, even the glass furnaces themselves can be run off electricity which is great if it is clean energy. And when it does break? You can throw it away without worry because it is completely inert and breaks down into sand. Throw all your glass into a specific area on a coast line and the waves will turn it into sand for free. Throw it in a hole as fill material and nobody will ever care because it doesn't pollute.

Contemporary glass bottles break easily. But historically bottles were much thicker and could be re-used dozens of times.

In Germany you can buy milk in glass bottles in some super markets and they don't brake easily.

And not only can they be reused, broken glass bottles can still be recycled.

Beer too IIRC - you can buy it by the crate and return the empties to get a meaningful deposit back.

Though most of the deposit for returning a beer crate is on the crate. The deposit for a regular beer bottle is 8cents - it used to be 15Pfennig, cut in half when the EUR was introduced. The problem is that you cannot easily raise the deposit value of a bottle and inflation has taken most of the value away.

Ah, I was there pre-Euro.

Glass is 100% recyclable infinite times with zero loss. If you shatter it, you can just melt it and reform it again.

Glass is also 100% pointless to recycle. The planet's crust is made of glass, it's not exactly a scarce resource, and old glass is environmentally harmless.

And in the real world it's virtually never recycled, instead its crushed and used as landfill cover (they cover the trash each night to keep down vermin).

It's easier, cheaper and less energy intensive than producing new glass. Literally billions of tons of glass are recycled each year.

Sand is starting to get scarce. https://www.businessinsider.com/global-sand-shortage-could-c...

I can't read the article, but in my understanding, sand for concrete is what might be scarce. Because it has to have particles with the right degree of sharp corners. (IIRC, the Saudis import this from Australia or something, because their wind-blown sand is too round.) But glass is much easier.

"they cover the trash each night to keep down vermin"

shudders

Do you think that energy is free? Do you think that heat comes from magic?

Don't we have an oversupply of renewable energy when the sun is shining and the wind is blowing, and nowhere to store it?

I'm not too knowledgeable on the process of glass manufacturing, but I know glass takes a pretty high temperature to melt. Mega operations needed for mass manufacture might be different, but smaller scale ones usually heat things up in furnaces burning at thousands of degrees.

Not too hard to get that heat by burning fuel, but through wind power? Not sure how it'll be done.

Not dismissing it. I just really don't know.

Wind to heat is easy: just run an electric [arc] furnace. This is how most commercial steel foundries heat iron. this is how Aluminum ore is smelted (the point is the electron exchange, molten metal is a welcome side effect).

The above is why aluminum is smelted in low energy cost areas. the above is why my company runs the foundry only for the night shift - the power company gives us a discount for using power at night when they need to keep the base load power plants running even though nobody is using power, which more than makes up for the extra pay we give to for working the night shift. (Now that wind is >50% of the electric mix in my state I wonder if the shifts are changing)

In fact most high temperature is generated from electric not fuel. If you burn something to get high temperatures the process is inefficient, turning the fuel into electricity and then the electricity into heat is more efficient (look up carnot efficiency)

Frickin' lasers, perhaps?

Sometimes and someplaces. Australia regularly has negative power prices due to rooftop solar.

Recycling glass takes a bit less energy than producing new glass (and a lot less CO2 is emitted during the process).

Wait till you learn how glass is made in the first place.

Any problem with steel bottles?

In India, they do use them often for delivering milk and it's very sturdy.

The problem in the US is that the seller has to use the method that results in them having the least liability in case something goes wrong.

If they choose to use steel or glass, and it doesn't get cleaned properly, and it ends up causing damage, then they might be liable for damages. Their liability insurance will deny coverage for damages because they knowingly used a method that had a higher probability of harm than using new plastic.

I'm sure there might be some way to ensure cleanliness of steel and glass, but it's probably cost prohibitive versus just using plastic, so it might cause the cost of the product to be too high to compete in the market.

sounds like just the case for government regulation allowing the free market to get out of a local optimum.

Any reason you can't just autoclave the glass for a bit?

Possibly? I guess I assumed there's some cost based reason that plastic is preferred over glass, even excluding for transportation costs due to lower weight and less cleanup costs in case of accidents and glass breaking.

It's probably a combination of all of these things, but the fact that no glass alternatives exist in the market in a similar price range as plastic options indicates there's an overall cost advantage for plastic.

That is more expensive due to energy requirements over simple washes, but if the energy used to do that is renewable then that isn't a big deal. I think the big problem with autoclaving the glass is the time required for heating up and cooling off as thermal shock will break glass. That said, breaking more glass isn't a big deal because it is an inert material. And the sorting and cleaning of glass should be easier and cheaper than ever thanks to better automation and robotics.

That will kill anything, but if I put a bit a poison in the bottle...

You can also recycle broken glass, creating new glass from melting glass prices costs less energie then creating glass from scratch.

Through there are limits for white glass this is much less the case for brown and green glass.