Wayne.B wrote in
:

On Sun, 20 May 2007 05:51:09 +0000, Larry wrote:

at $1500, approximately 1/4 the cost of the usual diesel
genset in this class, you can replace it 4 times to the break-even
point, spreading out your operating cost over many years, not at at
the outset.

Here's my take on the numbers.

Let's assume a 1500 hour life which may be optimistic. That means you
are paying $1 per hour for equipment amortization which is more than
20 cents per kwh even if all your fuel is free. Fuel at current
prices would add another 20 or 30 cents.

Generating your own electricity is not cost effective if you can buy
it for 10 cents per kwh.



Do you think it's only going to last 62.5 days?! 1500/24 hours per day =
62.5 days! Maybe we should be more optimistic and add a zero to make it
15,000 hours. That's still only 1.7 years....

Now, using that figure instead of a two month life span, that puts it at
..10/hour for 5.2KW of power. Let's say a half load, 3Kwh for 10 cents
(free fuel but I'd have to add in some maintenance, oil changes, filter
changes, etc. so it's not accurate). That's only 3.33c/Kwh, 1/3 what
South Carolina Electric and Gouge charges, right? It gets cheaper as
load increases and less as load decreases, par value about 1000W of
load....

The numbers look different at 15,000 hours....not an unheard of diesel
runtime if you change the oil every 100 hours like you're supposed to and
service the air filter and oil strainer per the book. This little diesel
probably won't run that long, but I'm not sure. There's at LEAST 4000
hours on my Honda EU3000is gas genset on an air-cooled gas engine of no
particular great note....It still starts instantly, when called for. I
run it a lot all summer and in winter loaded with a 1500 watt electric
heater to keep my feet warm at work. I've never even changed its spark
plug! The spare is in a drawer in the truck.

Larry
--
Metallurgy has come a long way in the last 20 years.....

On Mon, 21 May 2007 03:21:06 +0000, Larry wrote:

The numbers look different at 15,000 hours

That's *not* going to happen with a 3600 RPM air cooled diesel. I'll
be surprised if it makes 1500 hours at half load, even if you change
the oil every day.

On Mon, 21 May 2007 03:21:06 +0000, Larry wrote:

There's at LEAST 4000
hours on my Honda EU3000is gas genset on an air-cooled gas engine

That's different. The EU3000i uses a variable speed engine if my
memory is correct so it's not always running flat out at 3600.

On Sun, 20 May 2007 22:44:01 -0400, Wayne.B
wrote:

On Sun, 20 May 2007 05:51:09 +0000, Larry wrote:

at $1500, approximately 1/4 the cost of the usual diesel
genset in this class, you can replace it 4 times to the break-even point,
spreading out your operating cost over many years, not at at the outset.

Here's my take on the numbers.

Let's assume a 1500 hour life which may be optimistic. That means you
are paying $1 per hour for equipment amortization which is more than
20 cents per kwh even if all your fuel is free. Fuel at current
prices would add another 20 or 30 cents.

Generating your own electricity is not cost effective if you can buy
it for 10 cents per kwh.


Let's take another shot at this one.
$1500 for 6kW of electrical power for 1500 hours
AND
6kW PLUS of heating over 1500 hrs
represents a combined heat and power capital cost of
8.3 cents per kWhr
Hence:
Generating your own power and heat can be cost-effective
if you buy power for 10cents/kW.hr

Brian Whatcott Altus OK

On Mon, 21 May 2007 06:44:30 -0500, Brian Whatcott
wrote:

Let's take another shot at this one.
$1500 for 6kW of electrical power for 1500 hours
AND
6kW PLUS of heating over 1500 hrs
represents a combined heat and power capital cost of
8.3 cents per kWhr
Hence:
Generating your own power and heat can be cost-effective
if you buy power for 10cents/kW.hr

That assumes you always run at full power and can take advantage of
the heat, and further assumes zero fuel and maintenance costs.

I rest my case.

* Brian Whatcott wrote, On 5/21/2007 7:44 AM:
On Sun, 20 May 2007 22:44:01 -0400, Wayne.B
wrote:

On Sun, 20 May 2007 05:51:09 +0000, Larry wrote:

at $1500, approximately 1/4 the cost of the usual diesel
genset in this class, you can replace it 4 times to the break-even point,
spreading out your operating cost over many years, not at at the outset.
Here's my take on the numbers.

Let's assume a 1500 hour life which may be optimistic. That means you
are paying $1 per hour for equipment amortization which is more than
20 cents per kwh even if all your fuel is free. Fuel at current
prices would add another 20 or 30 cents.

Generating your own electricity is not cost effective if you can buy
it for 10 cents per kwh.


Let's take another shot at this one.
$1500 for 6kW of electrical power for 1500 hours
AND
6kW PLUS of heating over 1500 hrs
represents a combined heat and power capital cost of
8.3 cents per kWhr
Hence:
Generating your own power and heat can be cost-effective
if you buy power for 10cents/kW.hr

Brian Whatcott Altus OK


If you can get electricity at $0.10/kWh, send some to me. I'll pay
you $0.12! (Our current cost is $0.186.)

There are some obvious problems with this type of analysis - mainly,
the genset is probably happy to deliver at one rate, but the typical
user's rate will vary considerably. And how does the heat factor in?
How much heat can a genset gen? Or are you thinking of reverse
cycle A/C?

On Mon, 21 May 2007 09:10:35 -0400, Jeff wrote:

* Brian Whatcott wrote, On 5/21/2007 7:44 AM:
On Sun, 20 May 2007 22:44:01 -0400, Wayne.B
wrote:

On Sun, 20 May 2007 05:51:09 +0000, Larry wrote:

at $1500, approximately 1/4 the cost of the usual diesel
genset in this class, you can replace it 4 times to the break-even point,
spreading out your operating cost over many years, not at at the outset.
Here's my take on the numbers.

Let's assume a 1500 hour life which may be optimistic. That means you
are paying $1 per hour for equipment amortization which is more than
20 cents per kwh even if all your fuel is free. Fuel at current
prices would add another 20 or 30 cents.

Generating your own electricity is not cost effective if you can buy
it for 10 cents per kwh.


Let's take another shot at this one.
$1500 for 6kW of electrical power for 1500 hours
AND
6kW PLUS of heating over 1500 hrs
represents a combined heat and power capital cost of
8.3 cents per kWhr
Hence:
Generating your own power and heat can be cost-effective
if you buy power for 10cents/kW.hr

Brian Whatcott Altus OK


If you can get electricity at $0.10/kWh, send some to me. I'll pay
you $0.12! (Our current cost is $0.186.)

There are some obvious problems with this type of analysis - mainly,
the genset is probably happy to deliver at one rate, but the typical
user's rate will vary considerably. And how does the heat factor in?
How much heat can a genset gen? Or are you thinking of reverse
cycle A/C?


If you want a genset to deliver rated power, you can sell to the
utility at their price. Diesels run up to 40% thermal efficiency.
That means that 60% of the thermal energy potential of the fuel goes
into the air. You don't want to extract too much from the exhaust
stack for various reasons, but the warmth of the cooling air is a
freebee.
This is "Combined heat and power" as a newish application already
in use.

Brian Whatcott Altus OK

Jeff wrote in
:

If you can get electricity at $0.10/kWh, send some to me. I'll pay
you $0.12! (Our current cost is $0.186.)


OUCH! Californicate?

Larry
--
Grade School Physics Factoid:
A building cannot freefall into its own footprint without
skilled demolition.

Brian Whatcott wrote in
:

You don't want to extract too much from the exhaust
stack for various reasons, but the warmth of the cooling air is a
freebee.


In the winter (not much winter as I live in SC) I run my little Honda
EU1000i suitcase genset INSIDE the stepvan to power and heat it. I
welded a pipe nipple to the tiny little exhaust pipe sticking out of it
and put a right angle fitting to convert it to 1/2" metal natural gas
line, the flex they use to connect natural gas appliances to fixed piping
safely. The line is nicely ribbed, making a very nice heat sink to
radiate exhaust heat in a little coil against the back door of the van.
This pipe goes through a hole in the van's deck and out about 6"
underneath. By the time the exhaust gets outside, you can hold the pipe
in your hand and the gas coming out of it is barely warm.....recovering
100% of the waste heat from the gas engine INSIDE the cold, leaky van
shop. It's a little noisy but I don't care. In Winter I can power and
heat the truck for about a gallon of gas for all 8 hours at work. The
genset is behind a cabinet and I glued foam around its position to form a
sort of sound cabinet out of the fixed cabinets and truck body. Plenty
of air inlet and outlet to move the heat into the space....(c;

I can't do this with the EU3000is as the exhaust outlet is buried into
the airstream of the cooling air inside the quiet cabinet. The new
diesel genset is easy with its external exhaust "stack" sticking up out
of it. You could even use some A/C ductwork to duct its heat into a
living space while venting the exhaust outside separately.

Hmm....I could plumb the cooling air outlet into the floor heat ductwork
of the hovel in winter....recovering heat and not loading the electric
plant...(c; That would increase my efficiency markedly, making the house
toasty warm in the process. I've already got CO gas detectors in here.

Larry
--
Grade School Physics Factoid:
A building cannot freefall into its own footprint without
skilled demolition.

* Larry wrote, On 5/21/2007 2:09 PM:
Jeff wrote in
:

If you can get electricity at $0.10/kWh, send some to me. I'll pay
you $0.12! (Our current cost is $0.186.)


OUCH! Californicate?

Larry

Boston