
Microgrid Keeps the Power Local, Cheap, and Reliable - iProject
http://www.technologyreview.com/news/428533/microgrid-keeps-the-power-local-cheap-and/
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droithomme
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.

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easp
Please provide citations for your assertion that solar panels require vast
amounts of energy to produce.

When I looked into the question a few years ago, the best sourced estimates I
could find put the EROI at less than two years.

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jws
_…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.

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aidenn0
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.

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

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maxerickson
This page:

<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.

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miahi
So they can save those $100,000 per year after 100 years. Good luck with that.

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maxerickson
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
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.

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Nux
We need a Zed-P-M!

