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In this situation, why would solar power alone account for ANY cost savings? They just replaced traditional garbage cans (that require no electricity/power at

In this situation, why would solar power alone account for ANY cost savings? They just replaced traditional garbage cans (that require no electricity/power at all) with compactors that run on solar power and send out an electronic message when they are full. It's not like the previous garbage cans ran off of electricity from the local power grid, or required gasoline or something to run, and now the new solar-powered units yield a cost savings because they are off-grid. They were just regular old trash cans that sat there and did nothing but hold trash, no electricity required.

schiffern 14y ago
The savings were because of new capabilities, not new efficiencies. Adding power (which they happened to use solar power) gave them new capabilities (compaction, signalling), which saved them almost a million bucks. Solar was still the enabling technology. Marginal energy cost comparison with grid electricity is irrelevant, since the cost structure is dominated by fixed costs. Can you imagine installing, reading, and maintaining an electric meter and utility interconnect for every single trash can?
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sophacles 14y ago
Wow, OK simple math lesson for you: I can reduce my per year cost by $X, but I need to spend $Y to install some technology to enable the savings. If $Y < $X * N (where N is the number of years that tech will last), then you are saving money. Now lets say the cost of putting in those trash cans is $Y1 with a wired connection. $Y1 includes tearing up the street to run power cables. That makes $Y1 not meet the inequality. No savings happen. But with solar powered trash cans, which cost $Y2 to install, and $Y2 meets the inequality, then the solar power is enabling the savings. That is the difference. In another post you already mention that you understand why the savings occur - fewer trips because of logistical planning from communications, plus fewer trips because compaction allows more trash per bin. This makes me wonder if you are just being disingenuous with your second paragraph. Or maybe you just don't understand that less time and fuel means less money spent. The fact that you and the GP are fixating on solar being off-grid to provide savings doesn't even make sense as the article doesn't claim that to be the case.
- smspence 14y ago
  lol, thanks for the math lesson. When I said "in this situation", I wasn't referring to your hypothetical situation where the alternative is to tear up sidewalk and run new power lines to the trash cans. I was talking about the article, which had nothing to do with that. Maybe I misunderstood what the parent commenter was asking when they were asking about cost savings coming from solar power. Doesn't matter, moving on.
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schiffern 14y ago

The savings were because of new capabilities, not new efficiencies. Adding power (which they happened to use solar power) gave them new capabilities (compaction, signalling), which saved them almost a million bucks. Solar was still the enabling technology. Marginal energy cost comparison with grid electricity is irrelevant, since the cost structure is dominated by fixed costs. Can you imagine installing, reading, and maintaining an electric meter and utility interconnect for every single trash can?

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sophacles 14y ago

Wow, OK simple math lesson for you: I can reduce my per year cost by $X, but I need to spend $Y to install some technology to enable the savings. If $Y < $X * N (where N is the number of years that tech will last), then you are saving money. Now lets say the cost of putting in those trash cans is $Y1 with a wired connection. $Y1 includes tearing up the street to run power cables. That makes $Y1 not meet the inequality. No savings happen. But with solar powered trash cans, which cost $Y2 to install, and $Y2 meets the inequality, then the solar power is enabling the savings. That is the difference. In another post you already mention that you understand why the savings occur - fewer trips because of logistical planning from communications, plus fewer trips because compaction allows more trash per bin. This makes me wonder if you are just being disingenuous with your second paragraph. Or maybe you just don't understand that less time and fuel means less money spent. The fact that you and the GP are fixating on solar being off-grid to provide savings doesn't even make sense as the article doesn't claim that to be the case.

smspence 14y ago
lol, thanks for the math lesson. When I said "in this situation", I wasn't referring to your hypothetical situation where the alternative is to tear up sidewalk and run new power lines to the trash cans. I was talking about the article, which had nothing to do with that. Maybe I misunderstood what the parent commenter was asking when they were asking about cost savings coming from solar power. Doesn't matter, moving on.
- deleted 14y ago
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