Information & ideas

[gar]

130623-1532 EDT

From the following information what ideas are stimulated?

Recently our gasoline price inched over $4 per gallon. On Friday in Ohio I bought $40 of gas at $3.299 / gallon. Averaged over the year 2012 my cost for home heating natural gas was $0.893 / CCF, and for electricity just under $0.16 / kWh. Actual cost of electricity out of an existing coal fired plant is in the range of $0.03 to 0.04 / kWh.

One gallon of gasoline is about 33.4 kWh.
One CCF of natural gas is about 29.3 kWh.

A gasoline engine is in the range of somewhat over 30% efficient at its maximum point.
A new home gas furnace might be over 90% efficient, but may have maintenance costs.

A solar panel cost might be about $5 / watt installed. If one has a good location in our area the production might be about 1.1 * 200 = 220 kWh / year. The installed cost is about $1000. If installed on a house or building the real estate taxes would be about 40 * 1000 * 0.5 / 1000 = $20 per year. The gain not spent on buying electricity is about 220 * 0.16 = $35.20 / year. If the panel life time is 25 years, then capital cost is at least $40 / year. Looks like a big loss.

If I do my own installation of solar and plant the panels in the backyard not attached to real property, then no tax and about $3 / watt installed. This would look better economically.

My point on solar has nothing to do with the first comments preceding the solar. The purpose of the post is to stimulate ideas.

Correct any mistakes I may have in the above information.

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[K8MHZ]

130623-1532 EDT

From the following information what ideas are stimulated?

Recently our gasoline price inched over $4 per gallon. On Friday in Ohio I bought $40 of gas at $3.299 / gallon. Averaged over the year 2012 my cost for home heating natural gas was $0.893 / CCF, and for electricity just under $0.16 / kWh. Actual cost of electricity out of an existing coal fired plant is in the range of $0.03 to 0.04 / kWh.

One gallon of gasoline is about 33.4 kWh.
One CCF of natural gas is about 29.3 kWh.

A gasoline engine is in the range of somewhat over 30% efficient at its maximum point.


.

BUT, one gallon of gasoline occupies about one cubic foot. One CCF of natural gas occupies one hundred cubic feet.

 

[bob]

excuse me

 

[gar]

130623-1717 EDT

Suppose I can get 40% overall efficiency from natural gas to electrical output. Then my cost per kWh is 0.893 / (29.3 * 0.4) = $0.076 / kWh. To this has to be added capital and maintenance costs. But there is also some fraction of 60% worth of heat that can be extracted and used for house heating or cooling, and hot water.

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[K8MHZ]

130623-1717 EDT

Suppose I can get 40% overall efficiency from natural gas to electrical output. Then my cost per kWh is 0.893 / (29.3 * 0.4) = $0.076 / kWh. To this has to be added capital and maintenance costs. But there is also some fraction of 60% worth of heat that can be extracted and used for house heating or cooling, and hot water.

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Playing the devil's advocate here.....

BUT, for 6 cents more you can live without worrying about keeping the generator running. That include downtime for preventative maintenance.

AND....just because the math says you can generate electricity for less than 8 cents per kWh, what would that work out to in the real world? If it were as cheap as you say, there would be many people making their own electricity, factories included.

 

[CONTROL FREQ]

I don’t have any idea WHERE you bought gas in Ohio for THAT price on Friday… EVERYONE is complaining because THE NEWS says it’s $3.29, BUT the pump says more like $4.00!!!! If you were remotely close to a boat ramp, it was significantly higher….

I switched over from making pop; to making BEER! Probably about the time you saw my LAST post… Not that I haven’t been listening/watching… just chillin’ and grillin’!!

Want an interesting idea? TOO LATE… I’m gonna blow your mind if you like it… OR NOT! All you have to do is click it and learn; or don’t AND don’t.

http://www.nbcnews.com/id/41579366/...t/t/inventor-turns-brewery-waste-natural-gas/


http://www.purposeenergy.com/

 

[CONTROL FREQ]

AND on top of ALL that! I?D BE A ?SENIOR MEMBER? BY NOW, if I told everyone where I ate, what I drank, and all the details of every freaking job my boss ever paid for? GUESS WHAT? All of it is my job? I AM THE ELECTRICIAN. Anything goes wrong? They ask ME first. I ?troubleshoot?, they tell them to call a ?mechanic?, a ?Plumber?, a WHATEVER!!! ALMOST ALWAYS, someone else? (I have made mistakes, turned out?I WAS WRONG!)
:slaphead:

 

[CONTROL FREQ]

catch up with y'all later... the girls want dinner!!!:slaphead:

 

[jumper]

Control Freq,

You might want to tone it down a bit.

 

[mivey]

Actual cost of electricity out of an existing coal fired plant is in the range of $0.03 to 0.04 / kWh.

For the variable anyway. Probably should triple that for all-in costs. In some cases, environmental regulations have added more costs that what it originally cost to build the plants. They are truly trying to bankrupt the coal plants and they will have to keep piling it on before other options, like solar, can start to look economically worthy.

Roughly speaking, coal & nuke & NG are all around the 8-10 cent range all-in (for base load plants that run all the time). Nuke (base) is about 0.5-2.0 cent variable, coal (base to intermediate) ranges from 3 to 8 cents depending on the type burned, and NG is about 3 cents for combined cycle (intermediate) and around 6 cents for simple cycle (peakers).

A solar panel cost might be about $5 / watt installed. If one has a good location in our area the production might be about 1.1 * 200 = 220 kWh / year. The installed cost is about $1000. If installed on a house or building the real estate taxes would be about 40 * 1000 * 0.5 / 1000 = $20 per year. The gain not spent on buying electricity is about 220 * 0.16 = $35.20 / year. If the panel life time is 25 years, then capital cost is at least $40 / year. Looks like a big loss.

If I do my own installation of solar and plant the panels in the backyard not attached to real property, then no tax and about $3 / watt installed. This would look better economically.

The problem with your numbers is that you still need to have other units (the grid) standing by when solar does not generate, as well as the fixed costs associated with the infrastructure to get the power from the grid. Also, you can't just remove the variable cost above from the 10-16 cent retail rate to get the net stand-by costs/kWh. When you reduce the grid consumption with alternate sources, the remaining grid fixed costs are spread over fewer kWh and increase the $/kWh amount. Overlooking this fact is one of the fallacies of net-metering that gets washed over in the rush to force non-economical solutions to look better than they really are.

Demand billing for residential loads and small commercial supplemented with solar would make it more obvious to some consumers. The fact is that when you change the load shape, the rates no longer recover costs appropriately because the load shape that was used for the cost allocation process is no longer applicable.

To compare solar to the grid units, you need to look at the off-grid costs. With off-grid costs, you truly have replaced the grid. The problem with most off-grid solutions is that it requires a major life-style change because you have to really cut how much you use (which you could do while on the grid). Consider that grid-tied solar probably runs around 20-30 cents/kWh all-in. Off-grid is probably running from 70 cents/kWh to well over a dollar per kWh.

 

[gar]

130624-1015 EDT

mivey:

Thanks. Your response is what I was hoping for.

I am in agreement with your analysis of what happens to grid costs when there is a large supply of energy from the grid's customers. It really unbalances the cost relationships.

A long time ago when my uncle was chief field engineer for underground lines, 1950s, he said that an approximate distribution of costs was 1/3 generation, 1/3 distribution, and 1/3 overhead. Obviously there is some change to this relationship today. My 3 to 4 cent cost I mentioned was from a neighbor who is an energy buyer. However, there are peak times when the cost is very much higher.

Last fall we had a proposal on the ballot to mandate a 25% renewable component to our energy supply. It is good that this was defeated. There are many problems to achieve such a goal, even when supplied by the power company. System stability is one of the problems, and another is that, unless low cost storage can be developed, there is really no reduction in the capital equipment of the conventional type (coal, gas, diesel, nuke) that is required to meet energy demand. Just some of this won't run as much.


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[Sahib]

gar:
Sure, the POCO did not take into account the installed capacity of renewable sources such as wind power in their total power generation capacity earlier. But now the situation is changing. With installed capacity of wind farms measured in several megawatts, their contribution would surely make more conventional sources not required to meet base or peak demands as they are now taken into account by POCO in the total power generation capacity.

 

[mivey]

gar:
Sure, the POCO did not take into account the installed capacity of renewable sources such as wind power in their total power generation capacity earlier. But now the situation is changing. With installed capacity of wind farms measured in several megawatts, their contribution would surely make more conventional sources not required to meet base or peak demands as they are now taken into account by POCO in the total power generation capacity.

But still the availability factor is an issue. With conventional units they are available up to well over 90% of the time. Not so with some renewables. If you had a lot of solar arrays over a big service territory you might get enough environmental diversity to have a minimum availability percentage but it is not going to be a reliable dispatch resource like conventional units. You still need a reliable unit standing by for a large portion of the solar collection and those costs shouldn't be overlooked.

 

[gar]

130624-1527 EDT

One person at DTE indicated that the utilization factor was about 18% for combined wind and solar at the utility level. Round this up to 20%. For Michigan to achieve 25% of our energy from wind and solar would then approximately require the wind and solar system rating to be 25/20 times the present rating of the conventional system. It is much more complex than this, but this is a way to get a ballpark figure. This is just a gross energy calculation. Having this renewable does not greatly change the size of the conventional system because there are times when virtually no renewable is available.

When you start to make renewable a large part of the energy supply, then there is a system stability problem. Instantaneously solar and wind can not match demand well. Both solar and wind have some very large short time variations in available energy.

I believe in Denmark there is an island with a very large wind farm and they see a problem when the wind system approaches 15%.

Possible solutions to these problems are very large energy storage systems, or some way to adjust demand quickly. Michigan has one very large pumped storage facility, but no more can be built, and not because of a lack of water. See http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant
Upgrade will be to 2,172 megawatts.

Ludington can supply its rated output for 8 hours at its original rating. I believe some of the increased rating is a result of increased overall efficiency with new turbines. See http://www.energystorageexchange.org/projects/218

In Wisconsin there is an attempt to create an experiment where instantaneous demand could be adjusted by modulating the set point on customer's airconditioning thermostats. No one customer or area would have a major shedding of load. Rather a minor adjustment of the set points would create the load change, but the customer would not feel the difference.

.

 

[fmtjfw]

Your own generator

Your own generator

The problem with estimating your cost for a local generator is that the peak load you must have is much higher than your personal base load. The power company has the advantage of thousands of customers and their base load / peak load ratio is lower than yours. They also can choose to have units sized for the base load and only bring on other units as needed for peaking.

As a practical matter you are pretty much limited to a single generator due to capital cost. Your single unit will be much less efficient on base load and drive up your fuel per kwh cost, which will be the case for 90% of the time.

 

[gar]

130625-1359 EDT

fmtjfw:

My energy use for 2013 was 45700 kWh in natural gas, and 12038 kWh in electricity. Electric is fairly uniform thru the year. Gas per month is 332 peak, and 24 minimum. My winter night time load is about 0.8 kW, summer somewhat less, and spring and fall about 0.55 kW. So there are possibilities on the design of a system that achieves relatively high overall efficiency. One would get their peaking from the grid.

The point of my post is to get people thinking about other possibilities.

.

 

[mivey]

Possible solutions to these problems are very large energy storage systems, or some way to adjust demand quickly.

I think the large high speed flywheels are neat. Not sure about the economics.

In Wisconsin there is an attempt to create an experiment where instantaneous demand could be adjusted by modulating the set point on customer's airconditioning thermostats. No one customer or area would have a major shedding of load. Rather a minor adjustment of the set points would create the load change, but the customer would not feel the difference.

Dropping loads that can recover later (like irrigation) is another sucessful method.

 

[mivey]

The problem with estimating your cost for a local generator is that the peak load you must have is much higher than your personal base load. The power company has the advantage of thousands of customers and their base load / peak load ratio is lower than yours. They also can choose to have units sized for the base load and only bring on other units as needed for peaking.

As a practical matter you are pretty much limited to a single generator due to capital cost. Your single unit will be much less efficient on base load and drive up your fuel per kwh cost, which will be the case for 90% of the time.

Life style changes address some of these problems. Of course these life style changes can also be made with grid power and taking advantage of things like time-of-use rates.

 

[Sahib]

But still the availability factor is an issue. With conventional units they are available up to well over 90% of the time. Not so with some renewables. If you had a lot of solar arrays over a big service territory you might get enough environmental diversity to have a minimum availability percentage but it is not going to be a reliable dispatch resource like conventional units. You still need a reliable unit standing by for a large portion of the solar collection and those costs shouldn't be overlooked.

If solar/wind power sources are spread over different localities, connected to common grid and of large scale of several hundred megawatts, minimum availability of renewable power in the grid can be assured because if sun light/wind is not available in few localities, it will be available in other localities. That is why the POCO is beginning to include installed capacity of wind power sources in their total installed power generation capacity.

 

[gar]

130626-1024 EDT

A calculation from my last year's energy use, includes all taxes and other add ons.

Natural gas $0.893 / CCF.
Electricity $0.159 / kWh.

Historically the cost of natural gas was about 1/3 of electricity per unit of energy.

Using 29 kWh / CCF as an approximation for a natural gas conversion factor this results in a cost of about $0.031 / kWh.

Thus, the present ratio is more like 1/5. One implication is that a ground based heat pump is of no benefit.

.