Grid Parity but not what you think

[rmay635703]

Back in prehistoric times grid parity was called
Electric Parity with natural gas
or less commonly
Natural gas parity with electricity.

The former refers to the price point at which electricity is cheaper to heat with than natural gas and the latter is when natural gas is cheaper for the production of electrity.

The company I work for has mission critical setups that allow them to run the place off waste oil / natural gas or off the grid. They no longer use the setup for primary electricity but historically companies did use whichever was cheaper, I started wondering.

What price per therm equates into parity with electricity at 10 cents per KW.
(and not for heating, that is too bloody easy, for actual production)

Then looking further I pay roughly $300 a year in hookup fees just to have electricity there, then usage based fees, lastly the actual cost of the electricity and end up using very little of it anyway.

Add to this there are co-generation setups that also provide heating or cooling from the waste heat generated making overall system efficiency 96%

Honda Worldwide | Technology Picture Book | Cogeneration

After reading about co generation I started thinking I could probably use a $50 conversion kit on the 3kw inverter generator I already have and I could probably figure out how to use heat from the genset in winter if I want.
(my peak usage is 3.5kw when my fridge is running, car is charging and I have a TV and a bunch of LED lights on, a bit of common sense and I could get this down the to 3kw max)

I would need to box it up and make a remote start to comply with noise laws but all in all looks simple. (also I am in a rented duplex so this is all mental masturbation but still interesting)

It appears I would actually get relatively quick payback (using very rough numbers) and oddly the price per KW does not appear to be much different than off the tap anyway, cheaper if I consider the fact I get winter heating energy.

Anyone have a better set of numbers? I figure the genset is 28% efficient, but it may actually be better, not sure which conversions are realistic for this comparison.

Looking further it appears natural gas produced electricity (at home) costs about half what electricity from the grid costs not considering fees, very interesting, this explains why the place I work used to generate their own electricity all summer.
I only pay $0.398 per therm, electricity would cost $3.077 for the same amount in terms of "heating" values.

Thanx
Ryan

[freebeard]

The company I work for has mission critical setups...I pay roughly $300 a year in hookup fees just to have electricity

I lost the thread somewhere around here.

Looking further it appears natural gas produced electricity (at home) costs about half what electricity from the grid costs not considering fees...
I only pay $0.398 per therm, electricity would cost $3.077 for the same amount in terms of "heating" values.

So you answered your own question?

After reading about co generation I started thinking I could probably use a $50 conversion kit on the 3kw inverter generator I already have and I could probably figure out how to use heat from the genset in winter if I want.

What does the conversion kit do? If you need further inspiration, here's a rocket stove/USB charger:

https://www.google.com/search?q=BioL...ve+USB+charger

[user removed]

I remember a parade of homes a couple of decades ago where a house had what looked just like one of those low rpm single cylinder engines from the late 1800s. It ran on natural gas and provided electricity, heat, ac, hot water for a close to 5k square foot home.

regards
mech

[freebeard]

Any chance it was a Lister? It's a water-cooled 4-stroke diesel design from Britain (pre-UK) and currently manufactured in India:

<<DIESEL ENGINE>>

It being water-cooled opens the door to co-generation.

[redpoint5]

Are you saying it could very well be cheaper to generate our own electricity from a NG genset than purchase it from the grid?

I'd do this tomorrow if true.

Here's what I pay:

Electricity
$12/mo connection charge
$0.08041/kWh

Gas
$7/mo connection charge
$1.01057/therm

There are 29.3001111 kWh to a therm. At a 100% conversion efficiency, I would pay $0.0344903129053323/kWh with gas.

If my math is correct, I would need to convert gas to electricity at 43% efficiency to break even on price, ignoring the monthly fixed costs.

I'm thinking 43% efficiency isn't doable, and even if it was, the maintenance costs would eat up any small savings.

You would need a battery to supply peak demands. Perhaps the genset would only run when the battery depletes to a certain threshold; running at peak efficiency whenever it is automatically started.

[user removed]

Originally Posted by freebeard

Any chance it was a Lister? It's a water-cooled 4-stroke diesel design from Britain (pre-UK) and currently manufactured in India:

<<DIESEL ENGINE>>

It being water-cooled opens the door to co-generation.

Very similar to the green engine in the link but certainly without exposed push rods and rocker arms. It was about 4 feet tall.

regards
mech

[rmay635703]

Originally Posted by redpoint5

Are you saying it could very well be cheaper to generate our own electricity from a NG genset than purchase it from the grid?


You would need a battery to supply peak demands. Perhaps the genset would only run when the battery depletes to a certain threshold; running at peak efficiency whenever it is automatically started.

http://www.marathonengine.com/costscomparison.html

Spells it out there, now if I could get a version for OFF GRID my problem would be solved.

Yes in a nutshell natural gas can be much cheaper at creating electricity than just buying electricity because of the fact that
1. Regional politics create rediculous pricing schemes (mainly for electricity)
2. Regional politics create rediculous fee scheduals

Your pricing is much different than my area, NG is very cheap here (has been for decades) and electricity is relatively expensive

My fees are much higher than yours and include usage based fees as well which further mud the issue on electricity.

In your case your electricity cost and natural gas costs are inverted compared to mine, even with this fact cogeneration is usefull if you have a long heating season and can do it cheaply

The reason is that even if your natural gas electricity is more expensive you are effectively using "waste" energy in the winter to create electricity and likely would burn the gas anyway but now also get electricity from it.

You also then save the fee, your fee is much lower than mine (about half) but it is still money you do not spend.

You also would have more control over your power and likely have a better opportunity and motivation (being partially off grid) to save energy/increase efficiency and reduce costs further.

But I digress

[redpoint5]

Our heating season is from Nov-March, with peak heating bills running about $100/month. The idea of using waste heat from the generator to heat the home is appealing. Having power when the neighborhood looses it would be fun too, although I imagine the grid has higher reliability than the equipment I would buy.

Now if only I could go off-sewer. Those blood suckers take almost $40 month regardless of utilization. I once asked to be disconnected since I was living alone at the time and could shower at the gym. It's not possible, because a sewer fee is levied on any home in the service area, and failure to pay the fee results in a lien against the property.

[rmay635703]

Originally Posted by freebeard

I lost the thread somewhere around here.

https://www.google.com/search?q=BioL...ve+USB+charger

Simple 90% + of my utility bills are fees and taxes, up to 10% is the actual cost of the energy I use, I don't like paying $1+ a kwhr delivered when the company I work for pays $0.055 cents a kwhr.

[rmay635703]

Originally Posted by Old Tele man

The electric companies here in ARID-ZONA seem to be making it "difficult" (financially semi-impossible) for individuals to connect PV-systems the grid...they're ONLY interested in THEIR own solarcell installations, NOT those of others.

Only way around (to a point) is to be off grid, either fully or partially.

No other way to avoid.