4 ms·

Microgrid Keeps the Power Local, Cheap, and Reliable

22 points by iProject 14y ago

miahi 14y ago
They say they save $100,000 per year, but what was the cost to implement this, and how much does the battery maintenance cost?
- maxerickson 14y ago
  This page: http://www.acgov.org/government/news/smartgrid.htm http://www.acgov.org/government/news/smartgrid.htm Says $11.7 million. But that is the project cost, not the additional cost of using this system to provide backup power to the jail.
  - miahi 14y ago
    So they can save those $100,000 per year after 100 years. Good luck with that.
    - maxerickson 14y ago
      It depends on the characteristics of the alternatives that they had. Given that the prison is designed to house 4,000 people, I imagine the cheaper alternatives were still in the millions of dollars.
      - droithomme 14y ago
        The cheap alternative here as far as power is concerned is grid electricity and have natural gas turbines for electrical backup. Blackouts never last more than a day in this area, and very rarely that long, so being able to run the air conditioning is not important, you need to run lights, security cameras, and the door locks. However much they are generating with solar cells it's not even a fraction as much as they would save in switching to a geothermal heatpump system for the heating and cooling needs, which would have been a fraction of the cost of the solar system, and a minute fraction of the ongoing costs including battery replacement. This is about certain people getting contracts to sell stuff to the government. Anyone competent who is really interested in a good solution wouldn't have built this system.
    - droithomme 14y ago
      117 years, but only as long as we completely ignore that all the batteries have to be replaced every 5 years, the solar cells every 20 years, and the diesel generators have to be continually maintained and swapped out with new fuel - if you just store diesel passively long term, even with fuel stabilizers, it goes bad, so use it or lose it with that.
jws 14y ago
…it makes sense to use the system's ability to temporarily decrease power consumption at the jail for things like the air-conditioning or lighting to create more excess power to sell to the grid. Nothing says "for profit penal system" like turning off the environmental support systems when you can make a lot of money diverting the power for sale.
droithomme 14y ago
Diesel generators and massive arrays of toxic lead acid batteries, which have a lifespan of at most 5 years, are not "green energy" and I'm a bit tired of all these articles in the press by persons claiming to be "alternative energy editors" and such who are promoting them as if they are because it's very clear they are not really advocating for truly sustainable energy. Even adding in the solar panels, they have a lifespan of 25 years due to eventual UV breakdown of the components, and the vast energy required to refine and purify the silicon wafers and extract the rare earth elements used in the construction eliminates the advantage of the technology as either sustainable or green. The wind turbines are good, but have widely variable output, are only sensible in a small number of areas with a lot of wind, and again, require batteries for 24/7 secure energy such as at this jail facility, again eliminating the advantages that would enable it to be reasonably classified as green or sustainable. With this particular jail, there is less than average wind and more than average overcast days in Dublin California where the jail is located, making these poorly matched alternative energy choices for this area, and which only ensure these systems are even less effective, and making clear that during power outages the diesel generator and batteries are going to be the real source of power. The mention of air conditioning being powered by solar cells is particularly evidence of the bizarre reasoning of the article, which I leave to the reader to ponder why this is so. One may wish to start by asking how many residential installations are able to power air conditioners directly from photovoltaic cell arrays. This is a boondoggle to be sure, but does not mean energy reduction shouldn't be pursued. For some prisons in desert areas such as Arizona, much energy could be saved by switching from air conditioners (if they use them; not all prisons do) to passive evaporation towers such as have been used in the middle east and africa for hundreds of years. Dublin California is not a candidate for this technology with average daily humidity of 76.24%, close to the national average of 77.52%, but many prisons, schools, offices and houses are.
- sebbi 14y ago
  I don't understand your argument for solar panels being unsustainable and not green enough. I'd like an explanation for that ... Last I heard is that solar panel price is quickly approaching raw materials costs and thus it will ultimately be cheaper than coal in most regions of the planet. And doesn't the price reflect what resources are being used in manufacturing the product? If it's cheaper to make and results in equal power output, isn't it a better solution then?
Nux 14y ago
We need a Zed-P-M!
aidenn0 14y ago
The picture of the bank of SLA batteries just reminds me how crappy energy storage still is; Those are just small improvements of what would have been used the year I was born.

22 points by iProject 14y ago

miahi 14y ago

They say they save $100,000 per year, but what was the cost to implement this, and how much does the battery maintenance cost?

maxerickson 14y ago
This page: http://www.acgov.org/government/news/smartgrid.htm http://www.acgov.org/government/news/smartgrid.htm Says $11.7 million. But that is the project cost, not the additional cost of using this system to provide backup power to the jail.
- miahi 14y ago
  So they can save those $100,000 per year after 100 years. Good luck with that.
  - maxerickson 14y ago
    It depends on the characteristics of the alternatives that they had. Given that the prison is designed to house 4,000 people, I imagine the cheaper alternatives were still in the millions of dollars.
    - droithomme 14y ago
      The cheap alternative here as far as power is concerned is grid electricity and have natural gas turbines for electrical backup. Blackouts never last more than a day in this area, and very rarely that long, so being able to run the air conditioning is not important, you need to run lights, security cameras, and the door locks. However much they are generating with solar cells it's not even a fraction as much as they would save in switching to a geothermal heatpump system for the heating and cooling needs, which would have been a fraction of the cost of the solar system, and a minute fraction of the ongoing costs including battery replacement. This is about certain people getting contracts to sell stuff to the government. Anyone competent who is really interested in a good solution wouldn't have built this system.
  - droithomme 14y ago
    117 years, but only as long as we completely ignore that all the batteries have to be replaced every 5 years, the solar cells every 20 years, and the diesel generators have to be continually maintained and swapped out with new fuel - if you just store diesel passively long term, even with fuel stabilizers, it goes bad, so use it or lose it with that.

jws 14y ago

…it makes sense to use the system's ability to temporarily decrease power consumption at the jail for things like the air-conditioning or lighting to create more excess power to sell to the grid. Nothing says "for profit penal system" like turning off the environmental support systems when you can make a lot of money diverting the power for sale.

droithomme 14y ago

Diesel generators and massive arrays of toxic lead acid batteries, which have a lifespan of at most 5 years, are not "green energy" and I'm a bit tired of all these articles in the press by persons claiming to be "alternative energy editors" and such who are promoting them as if they are because it's very clear they are not really advocating for truly sustainable energy. Even adding in the solar panels, they have a lifespan of 25 years due to eventual UV breakdown of the components, and the vast energy required to refine and purify the silicon wafers and extract the rare earth elements used in the construction eliminates the advantage of the technology as either sustainable or green. The wind turbines are good, but have widely variable output, are only sensible in a small number of areas with a lot of wind, and again, require batteries for 24/7 secure energy such as at this jail facility, again eliminating the advantages that would enable it to be reasonably classified as green or sustainable. With this particular jail, there is less than average wind and more than average overcast days in Dublin California where the jail is located, making these poorly matched alternative energy choices for this area, and which only ensure these systems are even less effective, and making clear that during power outages the diesel generator and batteries are going to be the real source of power. The mention of air conditioning being powered by solar cells is particularly evidence of the bizarre reasoning of the article, which I leave to the reader to ponder why this is so. One may wish to start by asking how many residential installations are able to power air conditioners directly from photovoltaic cell arrays. This is a boondoggle to be sure, but does not mean energy reduction shouldn't be pursued. For some prisons in desert areas such as Arizona, much energy could be saved by switching from air conditioners (if they use them; not all prisons do) to passive evaporation towers such as have been used in the middle east and africa for hundreds of years. Dublin California is not a candidate for this technology with average daily humidity of 76.24%, close to the national average of 77.52%, but many prisons, schools, offices and houses are.

sebbi 14y ago
I don't understand your argument for solar panels being unsustainable and not green enough. I'd like an explanation for that ... Last I heard is that solar panel price is quickly approaching raw materials costs and thus it will ultimately be cheaper than coal in most regions of the planet. And doesn't the price reflect what resources are being used in manufacturing the product? If it's cheaper to make and results in equal power output, isn't it a better solution then?

Nux 14y ago

We need a Zed-P-M!

aidenn0 14y ago

The picture of the bank of SLA batteries just reminds me how crappy energy storage still is; Those are just small improvements of what would have been used the year I was born.