6 ms·

Neat idea, neat solution, but the problem with articles like this is that it leaves out the other half of the equation - what was the marginal capital cost? Ie,

Neat idea, neat solution, but the problem with articles like this is that it leaves out the other half of the equation - what was the marginal capital cost? Ie, if they cost $100M (for hyperbole's sake, which clearly they did not), saving $900K a year is a pretty awful return on capital.

opendomain 14y ago
I completely agree. I would LOVE for some green solution to our energy problems, but everyone seems to forget the initial cost. as far as I know, there are NO energy technology that returns on investment less than 10 years. This includes 'hybrid' cars.
dangrossman 14y ago
The city spent $2.2M for the compactors, including installation and a service warranty. The estimated cost savings from the spend was $13M over 10 years; if they saved $900,000 in the first year that looks like a reasonable estimate.
- crapshoot101 14y ago
  Thanks Dan - didn't see that in the article, but if that's really the return on capital, its a significant one. I'd poke a little bit more as to what the real opportunity cost was here (ie, did you absolutely need to spend the $2.2M to get the fuel savings, or could a more efficient system of checking them with cheap transmitting devices work), but that's context that should have been in the main article.
- makomk 14y ago
  Assuming they last the predicted 10 years. Someone else linked http://www.philadelphiacontroller.org/publications/other%20reports/BigBellyReport_7-12-10.pdf http://www.philadelphiacontroller.org/publications/other%20r... which says: "Issue: Contract compactor specifications on expected life of product vague and not supported by data. "The contract included compactor specifications that included an expected life of 10 years. When questioned about data or research to support this expected life, the BigBelly Solar CEO stated the life expectancy was an estimate based on the type of products and materials used in the compactors. He further stated that the compactor had a life expectancy that was estimated similar to an automobile; in that some repairs and parts may need to be made during the normal life cycle, but full replacement may not need to be made for theyears. When asked if there was any testing data to support the 10 year life expectancy, he indicated that he was not aware of any specific data."
ams6110 14y ago
Our city has these. The price I recall they paid was $4K per unit. I think they are using some really twisted math on these claims. A simple wire trash basket can easily be inspected by sight and emptied when full... it's not like the garbage trucks are dispatched to individual trash cans. They have standard routes at standard times, the only question is whether they need to stop and check each can.
- gamblor956 14y ago
  Reading comprehension test: the article claims that the units communicate with a central trash pickup authority--units are only emptied when full. As a result, the trash authority can avoid fuel-wasting trips and optimize schedules on the fly to empty units when they need emptying. Supposedly, this optimization has, or will, yield roughly $1 million in annual savings.
  - VLM 14y ago
    See that's the part I don't understand. I did a separate numerical analysis that the largest cost of garbage pickup is paying people for windshield time not fuel cost. If you skip stopping at every can along the way, you cover the same distance slightly cheaper, but $900K implies an absolutely huge savings which doesn't add up because its nearly their entire departmental labor budget, not, I can drive from the dump to 3rd street in only 7 minutes now instead of 10 minutes because I'm not stopping at every can. I would have to check my numbers. It might be that garbage men total cost of salary and benefits is a (large) multiple of $30K/yr (getting into software engineer pay territory) in which case windshield time is even more incredibly expensive. Then it might work out that reducing labor cost by 10% or so would actually work out to 900K/yr.
    - tsotha 14y ago
      Presumably since the cans get emptied so much less often they can get big savings by skipping 3rd street entirely because none of the cans is reporting full.

opendomain 14y ago

I completely agree. I would LOVE for some green solution to our energy problems, but everyone seems to forget the initial cost. as far as I know, there are NO energy technology that returns on investment less than 10 years. This includes 'hybrid' cars.

dangrossman 14y ago

The city spent $2.2M for the compactors, including installation and a service warranty. The estimated cost savings from the spend was $13M over 10 years; if they saved $900,000 in the first year that looks like a reasonable estimate.

crapshoot101 14y ago
Thanks Dan - didn't see that in the article, but if that's really the return on capital, its a significant one. I'd poke a little bit more as to what the real opportunity cost was here (ie, did you absolutely need to spend the $2.2M to get the fuel savings, or could a more efficient system of checking them with cheap transmitting devices work), but that's context that should have been in the main article.
makomk 14y ago
Assuming they last the predicted 10 years. Someone else linked http://www.philadelphiacontroller.org/publications/other%20reports/BigBellyReport_7-12-10.pdf http://www.philadelphiacontroller.org/publications/other%20r... which says: "Issue: Contract compactor specifications on expected life of product vague and not supported by data. "The contract included compactor specifications that included an expected life of 10 years. When questioned about data or research to support this expected life, the BigBelly Solar CEO stated the life expectancy was an estimate based on the type of products and materials used in the compactors. He further stated that the compactor had a life expectancy that was estimated similar to an automobile; in that some repairs and parts may need to be made during the normal life cycle, but full replacement may not need to be made for theyears. When asked if there was any testing data to support the 10 year life expectancy, he indicated that he was not aware of any specific data."

ams6110 14y ago

Our city has these. The price I recall they paid was $4K per unit. I think they are using some really twisted math on these claims. A simple wire trash basket can easily be inspected by sight and emptied when full... it's not like the garbage trucks are dispatched to individual trash cans. They have standard routes at standard times, the only question is whether they need to stop and check each can.

gamblor956 14y ago
Reading comprehension test: the article claims that the units communicate with a central trash pickup authority--units are only emptied when full. As a result, the trash authority can avoid fuel-wasting trips and optimize schedules on the fly to empty units when they need emptying. Supposedly, this optimization has, or will, yield roughly $1 million in annual savings.
- VLM 14y ago
  See that's the part I don't understand. I did a separate numerical analysis that the largest cost of garbage pickup is paying people for windshield time not fuel cost. If you skip stopping at every can along the way, you cover the same distance slightly cheaper, but $900K implies an absolutely huge savings which doesn't add up because its nearly their entire departmental labor budget, not, I can drive from the dump to 3rd street in only 7 minutes now instead of 10 minutes because I'm not stopping at every can. I would have to check my numbers. It might be that garbage men total cost of salary and benefits is a (large) multiple of $30K/yr (getting into software engineer pay territory) in which case windshield time is even more incredibly expensive. Then it might work out that reducing labor cost by 10% or so would actually work out to 900K/yr.
  - tsotha 14y ago
    Presumably since the cans get emptied so much less often they can get big savings by skipping 3rd street entirely because none of the cans is reporting full.