alt.energy.renewable

bsr3997@my-deja.com wrote:
> On Feb 14, 1:43 am, Dan Bloomquist wrote:
>> bsr3...@my-deja.com wrote:

>>> If you are going to be a critic try reading the artical first. They
>>> are working with a delta of 120 and could get by with 100 according to
>>> the manufacturer of the equipment. It doesn't need to be "really cold
>>> outside" since they have 1500 gpm of cold water. It clearly said that
>>> after running through the power plant the hot water was used for
>>> heating buildings before being injected back into the ground.

>> I don't get it. You claim a delta T of 120, that means the sink is 165 -
>> 120, or a net heating of 45f. Is this the back end of oil heating?
>> Sounds pretty dumb as to lead to so much infrastructure. Please provide
>> a cite. I have already said that this is a unique situation in the
>> world. How is your reading comprehension?
>
> I included this link http://www.yourownpower.com/Power/ in my first
> post to this thread. You included it in a response to me. Did you by
> any chance go to it and read? It answers all the questions you are
> asking. If you want specifics about tempertures and flow rates look
> here
>
> http://www.yourownpower.com/Power/2007GRCPaper.pdf

No where in that paper do they make it clear that they will both sink at
a very low tempreture _and_ use that sink for domestic heating.

>
> The site is not as unique as you make it sound. There are plenty of
> similar areas along the west coast. And looking at this map
>
> http://www1.eere.energy.gov/geothermal/geomap.html

3 kilomters!? The Chena thing works because they _don't_ have to pump
much of a head.

> I would say there are probably a lot of places where you could get
> temps of 180F or so without drilling to deep. According to the first
> link,

I lived in Northern Ca on a piece of property with hot springs. Fun for
bathing and heating a couple of houses. Hardly 'a lot' compared to the
demand for electricity in Ca.

>
> "In the case of Chena Hot Springs, it appears the water is circulating
> to a depth of approximately 3000-5000ft and reaching a maximum
> temperature of 250ºF."
>
>>> Prooving that they could work with a delta of 120 has opened up a lot
>>> more potential sites then would have been possible using conventional
>>> equipment.
>> Proofing what? Please provide an explicit link. I'm listening...
>
> Prooving that you don't need hot spots that can produce super heated
> steam to produce power, and that relativly cheap AC equipment can be
> used.

They had water they didn't have to pump, and lots of it, free piping
they scavenged. 400kw is not a lot of electricity from 1500gpm.

>
> From http://www.yourownpower.com/Power/grc%20paper.pdf
>
> "4. The cost advantage of HVAC equipment over power generation
> equipment allows an economically viable product despite the inherently
> (= second law of thermodynamics) low thermal efficiency of low
> temperature waste heat power recovery."

Wow. They plan to use an air conditioning compressor in reverse? I guess
if they get away with it. But:
"This temperature is in general too low for ORC duty. However, given the
year-round availability of 3 0C (37 0F) river water ORC-operation with
an 8% thermal efficiency is possible."

So, where is the domestic heating from the sink?

> There are also a lot of places where there is waste heat that could be
> utilized. Some examples are even shown here
>
> http://www.yourownpower.com/Power/grc%20paper.pdf
>
> "4. EXISTING INSTALLATIONS
> Three 200 kW power producing installations using different waste heat
> sources have been in operation since January 2004. The exhaust heat of
> an Pratt and Whitney FT12 gas turbine is used as heat input source for
> the organic Rankine cycle in East-Hartford, CT.

There is nothing new here. Combined cycle plants have been around for a
long time.

> A second installation
> uses the heat from a landfill flare in Austin, TX while the exhaust
> heat from three Jenbacher reciprocating engines powers the third
> installation in Danville, IL. Figure 5 shows pictures of
> these installations."

Huh? you have a gas flare and call that low grade heat? How does that
make sense? And once again, there is nothing new about combined cycle.
That someone is using diesel to produce electricity in the first place
is very dumb.

> All of the above used air cooling.
>
> "5. LOWER TEMPERATURE ORC APPLICATIONS
> Cost-effective ORC operation requires a minimum temperature difference
> between evaporator and condenser saturation temperatures of about 50K
> or 100F"

And again. You need an enormous amount of heat the likes of one unusual
Chena Hot Springs.

>>> And the equipment used is less expensive than the
>>> traditional equipment to boot. I would say they've got something to
>>> feel good about.
>> Equipment scales to delta T. At least from what I know. If I am wrong,
>> please provide your cite...- Hide quoted text -
>
> Mass produced AC equipment is less expensive than specialized high
> temp/pressure power equipment.

Yea, I see these guys claiming $5/watt and they had the heat. They don't
say what it would cost if they had not scavenged pipe and who knows how
much labor. Much less develop sources of heat if they didn't just have it.

> http://www.yourownpower.com/Power/grc%20paper.pdf

You have already posted that link.