Is electric really better?

[Herm]

The efficiency of a nuclear plant is not that important, the fuel cost is a minimal part of the expenses.. but obviously if you could boost the efficiency you would get more energy out of that plant and less waste heat that has to be dumped. A new generation of nukes (if they ever get built) that achieves higher temperatures would be more efficient, and could be useful for making cheap hydrogen. Efficiency of wind power is meaningless since wind is free.

Ultra-Supercritical coal burning plants are achieving 45% efficiencies, compared to the average 28% that coal usually achieves. They use special steels to increase steam pressure and temperature.

The typical gas peaking plant runs an open cycle and gets very low efficiencies, but they are cheap and only used for short periods to meet demand. A combined cycle gas turbine, with 2-3 reheat stages can achieve 60% efficiency.. close to the theoretical limits.

 

[Stoaty]

Without getting too far into, let alone agreeing on, what the "externalities associated with coal" are, I agree completely that including the externalities will increase the cost of electricity produced by coal fired power plants.

For a scientific perspective on the externalities associated with coal see "Full cost accounting for the life cycle of coal" published in the Annals of the New York Academy of Sciences:

http://solar.gwu.edu/index_files/Resources_files/epstein_full%20cost%20of%20coal.pdf

Cost of these "externalities" is calculated as ranging from 9 to 27 cents per KWh, with a median cost of 18 cents.

 

[aqn]

Ultra-Supercritical coal burning plants are achieving 45% efficiencies, compared to the average 28% that coal usually achieves.

FWIW, two references I can find claim 31% (article dated 2007) and 33% (1999 figure), respectively:
"...the average efficiency of all coal power stations in the world currently stand at around 31%...".
"The average thermal efficiency of coal-fired plants went from 33.15 percent to 33.54 percent in 1999."

 

[Yodrak]

The 2nd reference is 10 year old information. I can't access the first reference, but note from the title that it's a world-wide figure, not USA. Just observations, each of us can attach our own sense of significance.

My sense is that an average efficiency figure in the low to mid 30s is probably more accurate than a figure of less than 30%. Interesting information, but whatever figure is closer to the truth, how does that affect the core discussion?

I think we all agree that coal-fired electricity generation produces a lot of CO2, that other methods of fossil-fuel electricity generation produce less but still significant amounts of CO2, and that producing CO2 contributes to global warming. Where opinions start to diverge is over what should be done about it, what can be done about it, and how quickly should or can something be done about it.

FWIW, two references I can find claim 31% (article dated 2007) and 33% (1999 figure), respectively:
"...the average efficiency of all coal power stations in the world currently stand at around 31%...".
"The average thermal efficiency of coal-fired plants went from 33.15 percent to 33.54 percent in 1999."

Ultra-Supercritical coal burning plants are achieving 45% efficiencies, compared to the average 28% that coal usually achieves.

 

[DaveinOlyWA]

When in Alaska the nuclear plant cooling water was circulated thru out the base to provide steam heat for personnel quarters. There was no cooling towers. In summer when warming was not required it was used fort other things.

Unfortunately the public would never accept this perfectly safe solution for cheap heat simply because of the source

 

[AndyH]

True. However, having significant amounts of wind generation increases the amount of backup capacity required because wind is more 'fickle' than other types of generation.

Myth:

Wind energy is unpredictable and must be “backed up” by conventional generation.
No power plant is 100% reliable. During a power plant outage—whether a conventional plant or a wind plant—backup is provided by the entire interconnected utility system.
The system operating strategy strives to make best use of all elements of the overall system, taking into account the operating characteristics of each generating unit and planning for contingencies such as plant or transmission line outages. The utility system is also designed to accommodate load fluctuations, which occur continuously. This feature also facilitates accommodation of wind plant output fluctuations.
In Denmark, Northern Germany, and parts of Spain, wind supplies 20% to 40% of electric loads without sacrificing reliability. When wind is added to a utility system, no new backup is required to maintain system reliability.

Multiple sources, including this: http://www.nrel.gov/docs/fy05osti/37657.pdf

 

[AndyH]

Where opinions start to diverge is over what should be done about it, what can be done about it, and how quickly should or can something be done about it.

Opinions...diverge? How about where facts are firmly planted? What part of "it's already happening - get off your butts and act before you really screw things up" is so difficult to understand?
http://portal.acs.org/portal/acs/co...geLabel=PP_SUPERARTICLE&node_id=1907#P36_8165

Even in the face of uncertainty, the most prudent action by the United States and other nations is to minimize greenhouse gas emissions using current technologies to avert the most severe projected effects of climate change while also gaining the benefits of reduced fossil fuel combustion (NRC, 2010b).

http://www.aaas.org/news/releases/2007/0218am_statement.shtml

In addition to rapidly reducing greenhouse gas emissions, it is essential that we develop strategies to adapt to ongoing changes and make communities more resilient to future changes.

The growing torrent of information presents a clear message: we are already experiencing global climate change. It is time to muster the political will for concerted action. Stronger leadership at all levels is needed. The time is now. We must rise to the challenge. We owe this to future generations.

http://nationalacademies.org/onpi/06072005.pdf

The scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action. It is vital that all nations identify cost-effective steps that they can take now, to contribute to substantial and long-term reduction in net global greenhouse gas emissions.

Patient: Doctor Doctor - it hurts when I do that.
Doctor: Don't do that!

If you find yourself digging a hole and desire to get out, step one is STOP DIGGING.

 

[ERG4ALL]

My understanding is that the electrical generation is tiered to meet demand. The baseline required is fulfilled by the most difficult to turn on and off, e.g. nuclear. Then other generation capabilities take over the next level, perhaps coal and hydro. Eventually the peak demand is satisfied by gas turbines that can relatively easily be turned on and off. What I like about have a PV array is that it produces its power when the grid needs it the most, i.e. during the daylight hours. So we send excess PV power to the grid during the day and charge our LEAFs at night from the most stable generation sources at night. Unfortunately my local Congressman wants to cut any subsidies for PV and EVs.

 

[Yodrak]

A utility requires sufficient generating capacity to meet its peak demand plus a reserve margin to cover plant outages and the outage of transmission lines that bring in power from other surrounding utilities. Typically a utility must have generating capacity in an amount equal to 115% of its estimated peak load. Some systems might be a few percentage points less or more.

Wind can contribute only a small portion of its capacity to the installed capacity requirement. A 100 MW wind farm will be counted as maybe only 20 MW towards the capacity requirement, whereas any other type of generating plant will be counted as the full 100 MW towards the capacity requirement. Why? Because one of the significant factors that creates a peak load situation is that there is no wind blowing.

True. However, having significant amounts of wind generation increases the amount of backup capacity required because wind is more 'fickle' than other types of generation.

Myth:

Wind energy is unpredictable and must be “backed up” by conventional generation.
No power plant is 100% reliable. During a power plant outage—whether a conventional plant or a wind plant—backup is provided by the entire interconnected utility system.
The system operating strategy strives to make best use of all elements of the overall system, taking into account the operating characteristics of each generating unit and planning for contingencies such as plant or transmission line outages. The utility system is also designed to accommodate load fluctuations, which occur continuously. This feature also facilitates accommodation of wind plant output fluctuations.
In Denmark, Northern Germany, and parts of Spain, wind supplies 20% to 40% of electric loads without sacrificing reliability. When wind is added to a utility system, no new backup is required to maintain system reliability.

Multiple sources, including this: http://www.nrel.gov/docs/fy05osti/37657.pdf

 

[DaveEV]

Wind can contribute only a small portion of its capacity to the installed capacity requirement. A 100 MW wind farm will be counted as maybe only 20 MW towards the capacity requirement, whereas any other type of generating plant will be counted as the full 100 MW towards the capacity requirement. Why? Because one of the significant factors that creates a peak load situation is that there is no wind blowing.

The real reason is that wind's capacity factor is typically 25-40%. Nameplate maximum production doesn't have anything to do with it - it's how much power the turbines produce on average.

 

[Yodrak]

No.

Agreed that wind's capacity factor is typically 25-40%, but that's energy production and has nothing to do with a utility's capacity requirement.

Nameplate rating also has little to do with satisfying capacity requirement for most types of power plants. Demonstrated output capability of a generating facility is what is used, which is often different from the nameplate ratings of the equipment.

In any event, as I said, capacity requirement is a function of the expected peak system load, and one of the characteristics of the peak load situation (for a summer peaking utility) is that it's a hot day, after a series of hot days, there's no wind blowing. Some authorities think that giving wind generators credit for 20% of their capacity is being quite generous, since wind turbines often are not able to operate at a peak load times.

The real reason is that wind's capacity factor is typically 25-40%. Nameplate maximum production doesn't have anything to do with it - it's how much power the turbines produce on average.

Wind can contribute only a small portion of its capacity to the installed capacity requirement. A 100 MW wind farm will be counted as maybe only 20 MW towards the capacity requirement, whereas any other type of generating plant will be counted as the full 100 MW towards the capacity requirement. Why? Because one of the significant factors that creates a peak load situation is that there is no wind blowing.

 

[AndyH]

In any event, as I said, capacity requirement is a function of the expected peak system load, and one of the characteristics of the peak load situation (for a summer peaking utility) is that it's a hot day, after a series of hot days, there's no wind blowing. Some authorities think that giving wind generators credit for 20% of their capacity is being quite generous, since wind turbines often are not able to operate at a peak load times.

Do those authorities look at the wind input in terms of a single specific turbine, or the wind input from a specific field, or the total wind input from all sources when they determine the credit percentage?

And how does that percentage change as we plant more turbines?

And as long as we get enough wind, solar, and storage to cover our 24/7 needs, do we really care about ultimate efficiency? Especially as land-based wind generation becomes less expensive than electricity generated by coal?

 

[Yodrak]

It's based on collecting historical data looking at a load area and determining, on the highest load days, how much output is coming from the wind turbines in that area that are available to operate. A single utility might collect data for its own footprint, a power pool will collect data for its member utilities, a regional transmission organization (RTO) will collect data for its regiion and for sub-areas within its region if it's large and diverse enough. Based on the data it collects each responsible system operator, be it a lone utility, a power pool, or an RTO, will determine how much wind generation it can count on during peak load conditions.

The percentage does not change by adding more turbines, it's not a function of how many turbines there are. It's a function of how much a wind turbine can generate when there's little or no wind compared to what it can generate when there's sufficient wind for it to generate its maximum output.

I don't understand your comment about "do we really care about ultimate efficiency".

Do those authorities look at the wind input in terms of a single specific turbine, or the wind input from a specific field, or the total wind input from all sources when they determine the credit percentage?

And how does that percentage change as we plant more turbines?

And as long as we get enough wind, solar, and storage to cover our 24/7 needs, do we really care about ultimate efficiency? Especially as land-based wind generation becomes less expensive than electricity generated by coal?

 

[DaveinOlyWA]

it has already been proven that unless you live in an area where 100% of your electricity comes from coal, you will be putting less GHG into the air than if driving a HYBRID.

electricity from NG would put up to 40% less GHG from driving a Leaf, so ya, if not in the part of the country where 25% get more than 80% of their power from coal the answer is yes electricity is better

 

[Caracalover]

it has already been proven that unless you live in an area where 100% of your electricity comes from coal, you will be putting less GHG into the air than if driving a HYBRID.

electricity from NG would put up to 40% less GHG from driving a Leaf, so ya, if not in the part of the country where 25% get more than 80% of their power from coal the answer is yes electricity is better

Even in the other areas, EV's are better. Did you know that with just the electricity used in oil refineries in 2010 you could power 1988 trips to the sun or 184,908 million miles in an EV? Now add the amount of electricity used to keep 24/7 gas stations open and air conditioned, and you could add a few thousand more trips, I am sure.

http://theev.biz/ev-info/us-oil-refineries-offer-evs-1988-trips-to-the-sun/

 

[AndyH]

The answer provided will change depending on the point of view/frame of reference of the person providing the answer. A coal-centric speaker will tell us how much better/safer/cheaper/patriotic coal is while they downplay other options. If we ask that same person how to evolve our energy use, they'll map a very conservative, slow, 2-3% per year roadmap to the destination they can see from their foxhole.

But we don't have time for that.

Here's what happens when we truly use a clean sheet of paper as a starting point:

We can get completely off oil, coal, and nuclear by 2050 while cutting natural gas use by about one third. This require zero input from our severely disfunctional politicians in Washington DC. It can be led by business for profit - even if no externalities are brought onto the balance sheet. It's doable today with no new technology.

[youtube]http://www.youtube.com/watch?v=y1eMN1IDhDU[/youtube]

 

[jwatte]

We can get completely off oil, coal, and nuclear by 2050 while cutting natural gas use by about one third. This require zero input from our severely disfunctional politicians in Washington DC. It can be led by business for profit - even if no externalities are brought onto the balance sheet. It's doable today with no new technology.

I'm kind-of old and cynical at this point, but I do believe I have my heart in a pretty good place.
This statement makes me feel very, very good! Let's hope this can actually happen.

 

[AndyH]

Another presentation - this one starts with reforming transportation. This is the single best look at weight/efficiency/energy use in vehicles that I've yet seen.

The first section is vehicles and oil, the second is homes/buildings (31:19), and the third is power generation (39:40).

At 52:45 Lovins presents four possible grid electricity futures and compares/contrasts cost and risk. This really shows why centralized coal and nuclear generation plants are not cost effective today even if we disregard climate and grid reliability risk. Very nice analysis!

[youtube]http://www.youtube.com/watch?v=U_EKZvb7gc8[/youtube]

jwatte - I understand! "Reinventing Fire" significantly upgraded my outlook! :lol:

 

[Yodrak]

Agreed. And thanks for sharing the view from your foxhole. We do need to look at the situation from all points of view.

The answer provided will change depending on the point of view/frame of reference of the person providing the answer. A coal-centric speaker will tell us how much better/safer/cheaper/patriotic coal is while they downplay other options. If we ask that same person how to evolve our energy use, they'll map a very conservative, slow, 2-3% per year roadmap to the destination they can see from their foxhole.

 

[AndyH]

Agreed. And thanks for sharing the view from your foxhole. We do need to look at the situation from all points of view.

No worries.

Who - other than Lovins - is developing solutions from a big-picture perspective? I'm looking for additional sources. Thanks!