Category: Non-disposable

Posts that may have some sort of permanent value, or that I consider to be the best of what I have posted here.

Post #1776: Gas versus electric mowing, Part 6: Why I’m not buying a battery-powered mower

Weird, eh?  I’m happy to rely on a (mostly) battery-powered car.  But I don’t want a battery-powered lawn mower. Even though I used a plug-in electric mower for years.

I swore off battery-driven power tools years ago.  So, for me, it’s not as if this is some new stance.

In this post, I explain why.  Why I’m not going for a battery-powered mower.  And why I no longer buy any power tools that run on batteries.

Let me emphasize that my decision isn’t due to ignorance.  If anything, it’s because I’ve had too much experience with big lithium-ion batteries.

A few things about lithium-ion batteries.

Practically speaking, your sole option for a walk-behind battery-powered mower is lithium-ion batteries.  There have been some riding lawn mowers powered by lead-acid batteries.  But I don’t think there’s anything on the market today not powered by lithium-ion batteries.

Point 1:  Maybe you can recycle them.

Almost no lithium-ion batteries are recycled in the U.S.

I’m acutely aware of this because a) I bought a 200-pound lithium-ion add-on battery pack for my wife’s Prius in 2008, and b) recycling of those big lithium-ion batteries has been just around the corner for the past 15 years.  I think my most recent post on that was Post #1715.

Still don’t believe that lithium-ion is rarely recycled? Here’s a handful of relatively recent references.

That last reference is particularly illuminating.  Read down to the part where the Federal government is still at the point of offering cash prizes for anybody who can figure out how to do it cost-effectively.  Its not merely that lithium-ion batteries aren’t recycled, it’s really that there’s not even one good, standardized, agreed-upon process for doing it, let alone doing it cost-effectively.

Post #1712 has the details, but the reason for the lack of recycling is obvious.  It costs money.  Reportedly, Tesla currently pays $4/pound to recycle is lithium-ion batteries.  Even with that, the cost of post-recycled lithium is higher than that of virgin lithium, making it an uneconomic source for production of new batteries.

Still, some stores — around here, notably Home Depot — have boxes where you can drop off old batteries weighing under 11 pounds.  That should cover most lawn tool batteries.

That’s free to you because Home Depot covers the cost of processing those via call2recycle.  This is an organization whose funding comes from battery- and battery-powered device manufacturers, or from organizations willing to pay to recycle those batteries.   For example, their board of directors has representatives from Panasonic, Sony, Energizer, and Duracell, among others, based on their 2021 annual report.

You can see examples of their retail pricing on this page.  It looks like they charge about $2.50 a pound to take boxes of mixed rechargeable batteries off your hands.  So Home Depot is paying on-order-of $12 to allow you to dispose of a 5-pound lithium-ion lawn mower battery.

What happens after that is a bit unclear to me.  For sure, the value of the materials recovered appears trivial.  Here’s their 2021 Annual Report, showing revenue sources.  Less than five percent of their revenues comes from the materials recovered from those batteries.

Source:  call2recycle 2021 annual report.

They do not break out their collection and recycling costs separately.  Combined, those account for the bulk of their costs.

At any rate, they are clearly at least paying to have those batteries disposed of properly.  What fraction of the materials actually ends up in new products — is actually recycled — is not possible to determine from their annual report.

Interestingly enough, when I look up their lithium-battery recycling partners, the only U.S. partner appears to be a 2021 startup.  Which again seems to emphasize just how iffy lithium battery recycling remains, at this time.

Fifteen years.  For fifteen years, I’ve been living with a 200 pound LiFePO battery pack.   And for fifteen years, large-scale lithium-ion battery recycling has been just around the corner.  Which is right where it is today.

Point 2:  Batteries trade lower fuel cost for higher capital consumption cost.

Which is a fancy way of saying, if you want to keep using the tool, you have to keep buying batteries.

We replaced the nickel-metal-hydride traction battery in my wife’s (now son’s) 2005 Prius somewhere around 178,000 miles.  Doing the math, the cost of that new battery ate up roughly half of the total lifetime savings in gasoline costs, from driving that efficient hybrid compared to a similarly-sized non-hybrid 2005 vehicle.

But it’s not just the dollar cost.  It takes quite a bit of energy to manufacture batteries, something that contributes to the multi-year “payback period” of a Prius relative to a non-hybrid automobile.  For the first couple of years that you drive a hybrid, from a carbon-footprint standpoint, all you are doing with your lower fuel use is paying back the higher energy cost of the vehicle’s manufacturing.

In particular, worst-case (made-in-China, meaning, made using coal-fired electricity), large-format lithium ion batteries result in the release of roughly 200 kilograms of C02 per KWH of battery capacity (calculated from this MIT reference, 16 metric tons per 80 KWH battery pack).

And so, creating a typical lawn-mower battery — 0.3 KW (72 volt, 4 amp-hour)  would result in (200 KG/KW x 0.3 KW * 2.2 lbs/KG = ) 132 pounds of C02 released into the atmosphere.

I use 2 gallons of gas a year to mow my lawn.  That generates about 40 pounds C02 per year.  The upshot is that even if my electricity were carbon-free, I’d spend the first three years of battery-powered lawn mowing merely paying back that initial 132-pounds-of-C02 debt, for the manufacture of that disposable battery.

That’s not a huge surprise, to those of us who have been using big battery-powered objects.  It was an estimated two year payback period for a 2005-era Prius, where the battery and motors didn’t really power the entire car.  So, a three-year payback period for a small tool that’s entirely battery-powered?  To me, based on my experience with the Prius, that seems entirely plausible.

As for the energy cost of the rest of it, I’ll just point to the high energy cost of smelting copper.  Electric motors require quite a bit of that, which is another reason hybrids require more manufacturing energy than non-hybrid cars.  Plausibly, depending on expected lifespan, there may be no manufacturing energy savings in the non-disposable portions of the devices.

For an extremely-long-lived battery, such as one used in a car, that payback period usually isn’t much of a consideration.  You’re saving a ton of fuel, and the battery will typically last well over a decade.  Overall, it’s a winner, even if you fully acknowledge the energy cost of producing the battery.

Here’s the kicker:  How long do those lawn-mower batteries last?  Every website I visit seems to give the same answer of three-to-five years.  So they might last long enough to pay back that initial carbon-footprint debt.

The upshot is that a lithium-ion powered lawn mower is a fine way to reduce local air pollution.  It may not be such a winner from the standpoint of reducing your carbon footprint.  And since global warming/carbon footprint is my main concern, I’m not hugely attracted to those devices from an environmental standpoint.

In addition, knowing what I now know about lithium-ion batteries, I’d bet on the lower end of that three-to-five-year range.  My wife’s new Prius — a Prius Prime — arguably contains a $12,000 lithium battery pack.  With no warranty to speak of.  So I got kind of serious about not trashing that.  And that’s when I learned the rules for lithium-ion batteries.  See Post #1703.

The rules, in brief:  Lithium-ion batteries don’t like heat.  They don’t like to be fast-charged.  They don’t like rapid rates of discharge, either.  And they really don’t like being worked from fully charged to fully dead.  They much prefer shallow charge-discharge cycles.

And yet, every manufacturer seems intent on using them in all the wrong ways, in mowers.  These will see highest use in the heat of summer, and typically be stored in a non-climate-controlled space.  Everybody seems to charge their lawn-mower batteries at a “1 C” rate of charge or higher — from dead to fully charged in one hour.  (Presumably, that’s to all ow you to swap batteries continuously and mow very large lawns.)  I’m pretty sure manufacturers allow the full capacity of the battery to be used, unlike cars that reserve the top and bottom 10 to 15 percent as a buffer against over– and under-charging.  (That’s why a 72-volt battery pack can be advertised as 80 volts, because once you’ve absolutely fully charged it, that’s what it’ll read, despite the fact that charging it to that degree is bad for battery life.)

Point 3:  If you love buying name-brand inkjet cartridges, you’ll enjoy purchasing batteries for your lawn mower.

Here, I’ll just refer to the highest-rated 21″ walk-behind battery powered mower on Amazon.  This is the Greenworks Pro 80V 21″ model, with 4.0 Ah battery.

On Amazon, the complete mower, with battery and charger, is $425.  But the replacement 4.0 Ah battery, by itself, costs almost $300.

In short, your cost of the replacement battery is 70% of the total cost of the functioning lawn mower.  And, as with power tools of all sort, manufacturers go way out of their way to make sure that only their batteries will fit their tools.

This, more than anything else, is why I swore off battery-powered shop tools.  It’s the monopoly-exploitation aspect of the battery replacement.  Once you’ve bought into a particular manufacturer’s line, they’ve got you.  And as far as I was ever able to tell, generic batteries manufactured to fit those tools are all completely dreadful.  So if you want a battery that works, for that name-brand tool, you pay that name-brand price.

Once I bought my third $45 battery pack, for my $60 drill, I did eventually figure out that a battery-powered drill is an expensive way to make holes in stuff.   That drill eventually got to the point where battery packs were no longer available.  (Which, if you own one long enough, will happen.)   At that point, it too became just another particle in our great national solid waste stream.  And was replaced by a corded drill.

Point 4:  Caginess about power.

This is more of an irritation than a point of substance.  But take any battery-powered lawn mower on the market, and try to find out the peak power of the electric motor, expressed either as kilowatts or as horsepower.  Nobody will tell you that basic information.

At some level, the average power output is just basic physics.  The mower above has a 72-volt, 4 amp-hour battery, and claims to be able to run for an hour on that.  That should be sufficient to cut my half-acre lawn.

But do the math.  How much energy is at your disposal, for that hour of mowing?  Well, 72 volts x 4 amps = ~300 watts of average instantaneous output.  Or, over the course of an hour, you have 0.3 KWH of power available to you, to accomplish your hour of mowing.  For sure, your peak power output will be much higher than that.  But if that battery is going to last an hour, it can’t put out more than an average of 300 watts, over that hour.

One horsepower is about 750 watts.  So the average available power output is less than half a horsepower, if you’re going to get your hour of mowing out of that battery.  Again, peak output will clearly be many multiples of that.  But that’s what you have, to get through your lawn, on average, over the course of an hour.

In my case, there are parts of the lawn, at times of the year, that nearly stall the Honda 3.3 KW gas engine that runs my mower.   I would love to know that some prospective battery-powered mower has a peak power output that meets or exceeds that 3.3 KW instantaneous power output.

But here, I bring up the last thing I know about lithium-ion batteries.  If that battery could, in fact, produce 3.3 KW of instantaneous power, it would be discharging at more than a “10 C” rate.  (That is, at that rate, the battery would be dead in less than one-tenth of an hour.)  Discharges at rates like that are unambiguously bad for battery life, for traditional cylindrical-design lithium-ion cells.  So even if it could match the peak power of my current mower, I’m not sure I’d want it to.

In other words, just as was true for my old corded Black-and-Decker, I’m pretty sure that the mower will get through my lawn.  But I’m also pretty sure that I’m going to have to “baby” it when the going gets really tough. 

But short of buying one and using it, there’s no way for me to tell, because manufacturers do not disclose peak power output of these mowers.  And so, how well will some battery-powered mower cut through stands of uber-thick Zoysia grass?

Instead of providing me with the concrete information that would allow me to judge that, manufactures require that I take a guess.  And when I see something like that, I assume it’s because their product would appear in an unfavorable light, if that information were disclosed.

Let me put it this way:  If those battery-powered lawn mowers had peak power that exceeded that of a typical gas mower, you can bet that manufacturers would crow about it.  So I think the absolute silence regarding peak power output tells me more-or-less all I need to know.

Point 5:  Summary

For the time being, I’ve decided to continue using a gas-powered lawn mower.  It’s a modern overhead-valve design, and (best guess, see prior post) mowing produces as much smog-forming pollution per hour as driving a mid-2010s-era sedan for an hour.  That’s clearly a downside, compared to battery-powered mowing, but not an extreme one.  For good measure, I’ve tossing my antiquated gas can in an effort to keep my gas-powered mowing as clean as possible.

My main environmental concern is global warming, and it’s not clear that a battery-powered mower offers much advantage there, compared to gas.  That’s due to the carbon-intensive nature of lithium-ion battery production and the relatively short expected lifetime of those batteries in fairly harsh use conditions.

Otherwise, not switching to battery-powered mowing is mostly a question of avoiding annoyances.  No mower maker will bother to tell me peak power.  So I suspect that will be lacking.  Each mower maker uses proprietary batteries.  So I expect to pay an outrageous amount for them.

And the whole lithium-ion battery-recycling thing is one big question mark.  Yes, you can drop your dead lawn mower batteries off at Home Depot, and Home Depot will cover the cost of getting them recycled, to some degree.  The degree to which the material in these batteries is actually re-used is far from clear.

So that’s it.  I saw a compelling reason and significant gains from switching car transportation to electricity.  There, at issue was a considerable amount of gasoline burned per year, batteries with an extremely long projected life-span, and some guarantee of responsible end-of-life recycling via Toyota.  Maybe. And the driving experience is better under electricity than with gas.  For mowing the lawn, by contrast, at issue is just two gallons of gas a year, there’s no clear benefit in terms of carbon footprint, and I’m betting that it’s harder to mow with a battery-powered mower than with a modern gas mower.

So this is one area where I’m not going to electrify the task.

Post #1775: Gas versus electric mowing, Part 5: Finally, a sensible estimate

To cut to the chase:  I use a 21″ push mower with a modern Honda overhead-valve engine.  Starting from EPA data on emissions for engines of that type, I calculated two simple rules of thumb, for the pollution generated by my lawn mowing.

If the standard of comparison is the typical car on the road — call it a mid-2010s full-sized sedan — then gas lawn mowers are 100 times dirtier than gas cars, per horsepower.  And an hour of mowing generates about as much pollution as an hour of driving.

That’s just the mower.  That doesn’t include emissions from your gas can, as outlined in the just-prior post.

Also see Post #1776, explaining why, despite this level of pollution, I’m not going to switch to an electric mower any time soon.  This, even though I drive an electric car (Post #1924, et seq.) Continue reading Post #1775: Gas versus electric mowing, Part 5: Finally, a sensible estimate

Post #1774: Gas vs. electric mowing, part 4: A correction on vapor recovery, and why you’re not supposed to top off your car’s gas tank.

 

In my just-prior post, I was about a decade out-of-date in my understanding of the gas vapor recovery systems installed on U.S. gas pumps.  I’m going to correct that here.

  1. Gasoline vapors are a major contributor to photochemical smog, and, in particular, to the creation of ground-level ozone.
  2. Once upon a time, the U.S. EPA required that gas pumps in some urban areas have vapor-recovery nozzles.  These were designed to collect the gasoline vapors that would otherwise just pour out of your car’s gas tank as you refilled it.
  3. By and large, these were only mandated in areas that could not meet federal air pollution standards for ground-level ozone.
  4. But by 2006, virtually all new cars and trucks were equipped with on-board vapor recovery systems.  They collected their own gasoline vapors during refueling, stored them, and burned them
  5. In 2012, the EPA dropped its requirement for vapor-recovery nozzles (reference).  At that point, so many cars had the new on-board systems that the vapor-recovery nozzles no longer offered sufficient benefit to justify their cost.
  6. Whether or not gas stations were required to keep up those vapor recovery systems was left up to the states.  For example, Virginia chose to decommission all those vapor recovery systems in 2017 (reference).

The upshot is that gas pumps in my area haven’t had those vapor-recovery nozzles for more than half a decade.  They still have some sort of rubber cup on the fuel nozzle, but I guess that’s just to prevent splashback or possibly to aid the car’s own on-board recovery system.

Some implications

With this, a lot of things now click into place.

Vehicle fuel tank filler necks now have an elastic seal in them.  I’m sure that older cars did not have those.  That seal is required on a modern car because the on-board vapor recovery system needs a tight seal against the gas nozzle.  That’s the only way to make sure that the gas vapors in the tank end up in the on-board charcoal canister.

The standard advice of “Don’t top off your tank” now has a new rationale.  In the ancient past, that was the advice because gas expands as it warms, and if you topped off your tank in summer, you’d end up spilling gas out the fuel filler as you drove down the road.  Now, that advice is there to protect your on-board vapor recovery system.  If you top off you tank, you can end up shoving liquid gasoline into your vapor recovery system, something it was not designed for.

My old two-gallon gas can produced four gallons of gasoline vapors before I even considered spills, venting, and the gasoline-permeability of the plastic.  Every time I filled that at the gas pump (since 2017), that displaced the two gallons of vapors, in the gas can, into the atmosphere.  And then, as I repeatedly filled the tank on the mower, that sums up to another two gallons of gasoline vapor displaced into the atmosphere.

How does that compare to gasoline vapor emissions from cars?

The EPA estimates that these on-board vapor recovery systems capture about 98% of gasoline vapors, at least according to this presentation.  The same source shows that the EPA estimates an average of 0.32 grams of gasoline spilled per gallon dispensed at a typical gas station.

The U.S. averages about 650 gallons of gasoline consumed per licensed driver.  Based on that, a year’s worth of fill-ups, for the typical licensed driver in the U.S., would generate:

  • 13 gallons of gas vapor spilled directly into the atmosphere (2% of that 650 gallons).
  • Another 12 gallons of gas vapor due to the average 208 grams of fuel spilled (0.32 g/ gallon).

In other words, the average driver with properly-functioning vapor recovery equipment and average diligence about spilling gasoline will generate about 25 gallons of gasoline vapors annually.

In that context, the 4+ gallons of gas vapor directly emitted by my old gas can seems quite material.  Particularly because my wife and I now exclusively drive her Prius Prime.  We seem to use on-order-of 40 gallons of gas a year, with the rest of our travel being electric.  From that 40 gallons, based on those EPA averages, we’d only be emitting about 1.5 gallons of gasoline vapor per year.  So that, in our household, the lawn mower and old gas can were responsible for far more gas vapor emissions than our car was.

That said, it’s worth noting that the lawn mower — even with the old gas can — is nowhere as bad as the average American passenger vehicle, in terms of venting gas vapor to the atmosphere as a result of refueling.  That’s not because the lawn equipment is clean — it’s not.  That because the average driver uses such a vast quantity of gasoline.  Even those small fractional losses during refueling add up to far more gasoline vapor than the lawn mower / old gas can emit in a season.

But that’s only for refueling-related gasoline vapor losses.  That does not include any gasoline vapor losses by the mower during operation.  For example, losses through the charcoal-filled gas cap, losses from the vented carb bowl after engine shutoff, and so on.  I still need to track those down.

The new gas can ought to eliminate half of those “displacement” gas vapor emissions.  The new can vents through the end of the pouring spout, so it’s “inhaling” the gas fumes out of the tank as it puts new gas into the tank.

The only gas vapor that will be directly emitted as a result of displacing vapor during refueling will be from refilling the gas can, at the local gas pump.  That, because our gas pumps no longer have vapor-recovery nozzles.  And apparently haven’t had them since 2017.

Post #1773: Gas vs. electric mowing, part 3: Why do all gas cans suck?

Source:  ACE Hardware.

I’m not the sort of person to buy something new, when the old one still works.  But my deep dive into lawn mowers and air pollution has convinced me to buy a new gas can, shown above.

There was nothing wrong with my current gas can.  In the sense that it worked exactly as it did when I bought it about three decades ago.

But technology that was fine three decades ago doesn’t really cut it in the modern world.

In this post, I’m going to explain why I took this momentous step. Continue reading Post #1773: Gas vs. electric mowing, part 3: Why do all gas cans suck?

G23-012: Luke 13:6-9, and the chainsaw of time.

Then he told this parable: “A man had a fig tree planted in his vineyard; and he came looking for fruit on it and found none. So he said to the gardener, ‘See here! For three years I have come looking for fruit on this fig tree, and still I find none. Cut it down! Why should it be wasting the soil?’ He replied, ‘Sir, let it alone for one more year, until I dig around it and put manure on it. If it bears fruit next year, well and good; but if not, you can cut it down.’ ”

— Luke 13:6–9, New Revised Standard Version, via Wikipedia.

Dödsträdgårdsskötsel

I’m not normally one for literal interpretation of the Bible.  But in this case, I’m going for it.

I have a fig tree that will not bear fruit.  I have now made up my mind to give it the final New Testament treatment, as above. After which, I shall cast it into the fire.  Once the wood has seasoned enough to burn well.

I’m not quite sure what prompted me to take action.  I’ve been putting in new raised beds.  After my Nth shovelful of dirt, I kind of woke up and realized that I had been looking at the same big, ugly fig bush for going on 15 years now.  Patiently waiting that one more year, for fruit that never appeared.  Year after year after year.

But once my eyes were opened, I could not help but notice the fig was just one of many lingering gardening failures that fill my yard.   The in-ground deer-feeding stations that were mistakenly labeled “blueberry bushes” when we bought them.  The 30′ tall fruit trees bought as dwarf varieties.  The landscaping that has to be hacked back twice a year so that the mail carrier can get to the front door.  The azaleas that overtop the windows.  And so on.

Nothing that, by itself, jumped out at me.  Nothing that couldn’t be ignored for yet another year.  Just the result of slow accretion over time.  A bush here, a tree there.  And as long as I could still walk around in the back yard, I let them be.

It finally dawned on me that the outside of my house was just like the inside.  It was full of stuff that I had accumulated over the years.  Stuff that no reasonable person would want, de novo.  Stuff that I kept only because, at some point, I bought it.

The fig tree that would not bear fruit made me see that it was time for some dödsträdgårdsskötsel.  A bit of Swedish death landscaping, to match the döstädning (Swedish death cleaning) I’ve been doing inside (Post #1667).

 

Never a dull moment

That’s when I decided to pull out my chain saw.  Because, hey, what could possibly go wrong when an old, out-of-shape Joe Homeowner with mobility issues decides to chain-saw down a bunch of trees.  In close proximity to buildings and fences.  Trailing a great big power cord.

In all seriousness, my wife forbade me to use my chain saw when she’s not around.  And rightly so.  She’s the designated dialer.  This, under the theory that it might be a challenge to type 9-1-1 with the stump of an arm, before I bleed out.

 

Much like the trees I’m going to cut down, this chainsaw is a leftover from an earlier time.  I bought it when I was much younger.  It’s not clear at this point that I should have kept it.  Arguably, it may now be an age-inappropriate power tool.   But unlike a geezer in a sports car, there’s no equivalent of the DMV to make me prove periodically that I’m still capable of using it.  Thus, the decision to put down that chain saw, once and for all, is supported by the slenderest of reeds, the common sense of the aging user.

But, my life is pretty dull.  My health insurance is paid up.  So what the heck.

To be clear, this is about as wimpy as chain saws got, back in the day.  It’s a Sears Craftsman 18″ plug-in electric chain saw.  That size being about as big as electric chainsaws can get, and still operate on a standard 120V household circuit.

That said, a wimpy chain saw is a like a low-powered shotgun shell.  Use it wrong, and there’s no question it’s going to hurt.  It’s only a question of how badly.

I recalled that the last time I used it, the blade seemed a bit dull. 

Which, by itself, sent me down a little philosophical trail, trying to recall how often I had used that chainsaw.  I definitely recalled cutting up some firewood at my current house.  Which led me to my wife’s grandmother, because I distinctly recall cutting up a bunch of firewood for her, a few years back.  And I was pretty sure I hadn’t sharpened or changed that chain in the intervening years.

Seemed like that might have been a few years ago, that I did that little favor for my wife’s grandmother.  So I checked with my wife. Her grandmother passed away 25 years ago, in 1997.

The upshot is that the chain is the original.  It was on the saw when I bought it about 30 years ago.  It was on it when I cut up that firewood for my wife’s grandmother.  When I cleared trees and brush from my last house.  When I cut up my own firewood.  And it just got duller and duller, so gradually that each time I used it, well, it worked about as well as the last time I used it.  And as long as it still worked, I wasn’t going to mess with it.

Anyway, I splurged for a new chain.  They still make them to fit, and a new one is about $12.

The upshot is that my 30-year-old electric chain saw cuts like it’s brand-new.  Took maybe two minutes to cut down that non-productive fig bush.

I retain all of my appendages.  So far. And I’m looking forward to taking down the rest of my landscaping mistakes when the rain lets up.

So, happy ending all around.

Any larger lesson?

I was going to try for some sort of larger life lesson here, but it’s not worth the effort.  The larger lessons are pretty obvious.  Age creeps up on you.  Getting rid of stuff is just part of life.

I guess the only one that surprised me is that a chainsaw with a new blade is a joy to use.  I spent years struggling with a dull blade on that saw.  And so I missed out on a lot of joy.  All for my unwillingness to spend $12 for a new blade. I now wonder how much of the rest of my life has been like that.  And whether its too late to change those long-ingrained habits of cheapness.

 

Post G23-010: No-dig potatoes, using leaf mulch

Today is St. Patrick’s day.

That’s the traditional day for planting potatoes, in this climate.

But my new raised beds aren’t ready yet.  And the old ones are a weedy mess.  Which I didn’t much feel like hoeing out of the way, this rainy St. Patrick’s day morning.

So I planted this year’s potatoes as no-dig (no-till) potatoes.  I placed them on top of an existing weedy garden bed, and buried them under half-a-foot of free leaf mulch.

Edit 7/23/2023:  Near-total failure.  See Post G23-041. Continue reading Post G23-010: No-dig potatoes, using leaf mulch

Post G23-009: New garden beds. Working harder, not smarter.

 

At the start of the pandemic, I recycled some political yard signs and bamboo into a set of raised garden beds (Post G05).   After three years of intensive use, a) those are now in disrepair, and b) I know a whole lot more about gardening.

My plan is to replace those beds with something better.  With St. Patrick’s day just one week away — the traditional day for planting potatoes — I can’t procrastinate much longer.   Time to finish pondering and start shoveling.

This post documents the final design.  The next post will show the construction.

Continue reading Post G23-009: New garden beds. Working harder, not smarter.

Post G23-008: Simple geometry of sun and shade, or, keep your gnomon pointing north.

 

This post is about making sure my new garden beds don’t end up in the shadow of my back porch, during the summer.  Based on the length of the shadows today, in late winter.  And, ultimately, based simply on the height of the porch roof.

To cut to the chase:  If you use Excel, and the NOAA sun-angle calculator, you can accurately predict the length of a shadow, for any date and time, anywhere on earth, via this formula:

Shadow length = obstruction height * cotangent (solar elevation angle in degrees * π / 180)

The π / 180 is there because Excel wants to see angles expressed in radians.  If you’re using a calculator that accepts angles in degrees, omit that.

 

Continue reading Post G23-008: Simple geometry of sun and shade, or, keep your gnomon pointing north.

Post #1716: COP out. Does it ever get cold enough, in Virginia, to make gas heat cheaper to run than a modern heat pump?

In Post #1706, I determined that, for heating my home here in Virginia, it was far cheaper to run my heat pumps than to run my natural gas furnace.  That’s based on costs of $1.70 per therm of natural gas, and $0.12 per kilowatt-hour (KWH) of electricity.  Like so: Continue reading Post #1716: COP out. Does it ever get cold enough, in Virginia, to make gas heat cheaper to run than a modern heat pump?