Study Finds That Without a Price on Carbon, Regular Hybrids Can Lower Lifecycle CO2 Emissions As Effectively as Plug-in Hybrids, and At Lower Cost
11 December 2008
 |
| No CO2 price scenario. Final penetration of plug-in hybrids and regular hybrids in 2030 is plotted with corresponding changes in cumulative emissions from 2012 to 2030. The dotted line shows the incremental emission changes of plug-in hybrids compared to regular hybrids. Click to enlarge. |
A new working paper from Duke University finds that in the absence of a price signal for CO2, regular hybrids can lower lifecycle carbon dioxide emissions as effectively as plug-in hybrids, and at a considerably lower cost.
In the paper, Eric Williams, co-director of Duke’s Climate Change Policy Partnership (CCPP), compares the two hybrid technologies to see which could lead to lower carbon dioxide emissions, operating costs and overall consumer costs. Williams used six plug-in hybrid penetration scenarios, each of which begins in 2012 and ends in 2030 with a final penetration into vehicle stock ranging from 2% to 56%. He also analyzed four additional scenarios, based on penetrations of 2% and 56%, that have CO2 prices of $20 and $40 per ton. He found that:
 |
| With CO2 pricing. Final penetration of plug-in hybrids and regular hybrids in 2030 is plotted with corresponding changes in cumulative emissions from 2012 to 2030. The dotted lines show the incremental emission changes of plug-in hybrids compared to regular hybrids. Click to enlarge. |
-
Without a CO2 price signal, plug-in hybrids are essentially no better than regular hybrids at reducing lifecycle CO2 emissions;
With a significant CO2 price signal, plug-ins reduce moderately more CO2 emissions than regular hybrids;
Plug-in hybrids are significantly more expensive than hybrids at current gas prices; plug-ins become cost-effective at $6 a gallon.
The evening and night-time (off peak) charging of plug-in hybrids makes base-load power more attractive to utilities, Williams reasons. Currently, utilities build only enough base-load power to allow their base-load units to run almost continuously. To meet peak demand, utilities build units with low capital cost and high operating cost, knowing that these units will be needed for only short periods of time and can be turned off when demand drops. The largely night-time plug-in hybrid electricity consumption changes the shape of the demand curve so that utilities can build and run more base-load and fewer peaking units.
Taking a 56% plug-in hybrid penetration as an illustrative example, additional plug-in hybrid electricity consumption is directly responsible for 16.5 GW of new coal capacity by 2030. Renewables also increase by around 2 GW by 2030. Over 17 GW of combustion turbines and nearly 5 GW of oil and gas steam plants are avoided or retired as a result of plug-in hybrids. Overall, capacity needs are lower with plug-in hybrids because the base-load capacity that is built in response runs more frequently and alleviates the need for around 4.5 GW of total capacity. Lower penetrations of plug-in hybrids have similar results, though combined cycle builds tend to be less consistent (builds go up and down) at different plug-in hybrid penetrations. Generally speaking, without a CO2 price present, investment in coal and avoidance of combustion turbines (and to some extent oil and gas steam) is proportionate to plug-in hybrid electricity consumption.
—Williams (2008)
In terms of actual generation, not capacity, Williams concludes that generation increases by around 235 TWh with a 56% penetration of plug-in hybrids whether or not a CO2 price is present. This generation increase is needed to meet the electricity demand of plug-in hybrids. Under this scenario, coal generation increases by 190 TWh by 2030, while generation from natural gas and wood biomass increases by 15 and 18 TWh, respectively, and generation from other sources increases only slightly. Different penetrations of plug-in hybrids follow similar patterns.
If a $40-per-ton CO2 price is present, then a 56% plug-in hybrid penetration results in an additional 132 TWh of coal generation, 75 TWh of nuclear, 14 TWh of wood biomass, and only 5 TWh of natural gas generation by 2030. Both coal and natural gas generation are lower with a $40-per-ton CO2 price than without, and nuclear fills the gap.
It’s not a simple equation. Plug-in hybrids save gasoline but consume electricity. In most of the country, electricity generation relies on fossil fuels, which means that plug-ins would lead to an increase in electricity sector fossil fuel consumption and CO2 emissions. At the same time, plug-ins would reduce direct vehicle emissions. Taking this into account, I wanted to see how net emissions change, regionally and nationally, as a result of plug-ins.
—Eric Williams
The answer to that question, he notes, depends largely on whether there is a price signal for CO2 emissions. If federal or regional climate legislation places a limit on the amount of CO2 allowed, it will create a price signal that will drive the electricity sector to become more efficient and less carbon intensive. In this case, Williams says, plug-in hybrids would typically enjoy lower CO2 emissions nationally and in most regions compared to regular hybrids.
However, in a few carbon-intensive regions where electricity generation relies heavily on coal, plug-in hybrids would have lower net emissions than conventional vehicles, but not lower than regular hybrids. With respect to carbon mitigation, policymakers may want to focus on regular hybrids for certain regions rather than plug-in hybrids, even with a CO2 price signal.
—Eric Williams
In the absence of a price signal for CO2 emissions, Williams’ analysis gives the edge to regular hybrids. Nationally, plug-ins and regular hybrids reduce CO2 emissions by about the same amount without a CO2 price signal, he finds, but regular hybrids can do it more cost-effectively.
CCPP is an interdisciplinary research partnership of Duke’s Nicholas Institute for Environmental Policy Solutions, Nicholas School of the Environment and Center on Global Change. CCPP researches carbon-mitigating technology, infrastructure, institutions and systems to inform lawmakers and business leaders as they lay the foundation of a low-carbon economy.
Resources
Realclimate.org aka RealAlarmist misanthropes.
2008 AGW demise. RIP.
Posted by: | 14 December 2008 at 11:30 AM
http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html
Posted by: ai_vin | 14 December 2008 at 12:51 PM
Quoth sulleny:
It bugs me when someone gets things so completely backwards. V2G could have prevented the 2003 blackout, by absorbing the blocked power flows (charging on the supply side, feeding the grid on the demand side) for the minute or so it would have taken the grid operators to deal with the situation by e.g. shedding load. V2G, as a potentially massive short-term power source/sink, could make the grid far more secure by multiplying the effective amount of spinning reserve.This begs the question of what those RPU's run on. The only fuels delivered to homes on a large scale are natural gas, fuel oil and propane. Relying more heavily on these makes our vulnerabilities worse.
Getting back to lifecycle costs, the (PH)EV with modulated charging or V2G can reduce the need for the grid to supply spinning reserve, regulation and reactive power. This allows the grid's costs to be reduced and the efficiency to increase. These benefits are properly credited to the vehicle.
Posted by: Engineer-Poet | 15 December 2008 at 06:49 AM
EP:
The problem is single point power sources and massive "smart" grids. Since a V2G scheme can only return energy produced by single point sources e.g. the local coal fired power plant - we still rely on one or two regional sources to generate (most) of our energy. The 2003 cascade event was an apparent series of failures of these large single point power plants and circuit breaker systems.
If we move a huge portion of electrical demand off grid to RPUs the number of single point generating plants AND spinning reserves AND V2G "smart" switches AND connected EVs is reduced. By as much as 1/3 total electrical consumption (DoE's residential estimate.)
While the need for commercial/industrial electrical demand will not decrease and can be serviced by HVDC circuits bringing distant wind and solar renewables, nuke and NG-fired plants - we CAN offload residential demand to NG-fueled RPUs now. A V2G component would then become a component of the residence/neighborhood providing reserve and backup services on a far smaller and less costly scale.
The security issue is the most important. With hundreds of thousands (millions) of homes generating their own electrical power/heat via CHP - single point power outages become a non-issue. AND single point targets are minimized. Distributed power generation will always be far more secure than single point grid systems.
Posted by: sulleny | 15 December 2008 at 08:57 AM
@E-P & sulleny
Electrical and mechanical equipment fails at know rates issuing shrapnel, smoke, and fire. So you want to multiply that a few million and put this equipment where children sleep? Good plan!
The safety record of the electricity generating industry for protecting our customers is 100% going back as far as I can remember. We do not hurt our customers. Our industrial safety record too.
Furthermore, it would be difficult to find something more reliable that the US grid. Rather than invent some absurd V2G scheme, a better approach would follow the practices of well managed utilities that do not have rolling or cascading blackouts by adhering to FERC and NERC guidelines.
http://www.ferc.gov/industries/electric/indus-act/reliability.asp
http://www.nerc.com/
It is absurd to suggest that ‘V2G could have prevented the 2003 blackout’ if for no other reason than it started at time when BEV would have been mostly depleted.
Although it has been a while but I have lots of experience with RPU except in this case they were SPU since they were on navy ships.
There is no compelling reason for small distributed generating units or V2G. Therefore consumers will not accept such technology. E-P & sullenly both confuse and do not understand interesting theory with practical application.
Posted by: Kit P. | 16 December 2008 at 05:58 AM
@Kit,
Well, I see that you are a electric utility man which is fine. Sooner or later the efficiency of CHP systems will make economic sense. That is the beginning of the transition of residential consumers to self-contained power systems or RPUs.
It will not kill the grid or the utilities. It will make them safer, cleaner and more reliable. If we can reduce the demand on grid by nearly 1/3 the use of alternative resources will be better applied.
I wouldn't worry about safety and children at home. We already have oil/gas fired furnaces, 200 amp three phase circuits, stoves, ovens, microwaves, and garbage disposals. They too are dangerous if handled improperly. But for the most part - they are not.
Posted by: | 16 December 2008 at 10:15 AM
The Kit P troll should read the report I link below. It officially contradicts many of the claims he repeats about power grids. Then again, we knew he wasn't actually a powerplant engineer.
Quoth sulleny:
There's nothing "single point" about a grid. That's why it's a grid; it connects many generators and many loads. The last time I looked at the tables for Michigan, there was a page-full of power plants just for the area from Ohio up to Midland.Faulty conclusion drawn from false premise. Besides, the very phenomenon of the 2003 blackout, which came about because of the transport of power far from where it was generated, proves your claim false.
No, you nitwit, the powerplants did not fail. They tripped off-line when they were loaded outside their specifications (including Eastlake Unit 5, which tripped because it was being asked to produce more VA than its rating... an operator error). Some took e.g. condenser damage when steam had to be dumped to prevent overspeed, but that was after the grid problem took the plants off-line. The ultimate problem was precipitated by computer systems failure which caused the grid operators to ignore developing problems, and the proximate cause was multiple shorts caused by lines contacting trees. Just go read the official report.
Two things from the report are worth repeating. First, the definition of security:
Also, the sidebar on reactive power on page 26:The addition of V2G-capable EVs and PHEVs to the grid means both a huge increase in the amount of spinning reserve and the reactive-power generation capabilities. Had even a few hundred MW (as few as 50,000 vehicles) of V2G capability been available, the reactive power capabilities could have kept Eastlake Unit 5 on line and the blackout would never have occurred. V2G could also have fully compensated for the trip of Eastlake Unit 5 while grid operators shed load to rebalance the system.Each RPU is a single-point generating plant. Worse, RPU's make no sense except as cogenerators, and would either have to be scheduled as needed to provide heat or suffer terrible efficiency losses compared to large plants. What you say makes no sense whatsoever.
Posted by: Engineer-Poet | 16 December 2008 at 06:50 PM
Both RPU and V2G are solutions looking for a problem. The reason they will never be adopted as solutions is that while technically feasible they are not very good solutions to grid reliability issues.
The way the electric industry solves problem is by addressing the root cause. Quoting from E-P link, “This same phenomenon was seen in the Pacific Northwest blackouts of 1996, when long lines tripped before more networked, electrically supported lines.”
The 1996 blackouts did not affect my family because the local power plant and grid were well maintained and managed. The operators on shift said it was close however.
One of the indicators of good management is learning from industry experience. My family again missed the 2003 blackouts because my utility and a previous utility learned and made improvements. The utility will explain why your rates are going up because of maintenance or capital improvement in the grid. If you had read the root causes of the 1996 event, then you would understand the reasons.
For those who do not what a root cause is something by itself that could prevent the event and be corrected. In the 1996 blackout smoke from forest fires was a contributing factor. There is nothing the grid operator could do about smoke, however, “Inadequate System Understanding” related to smoke is a root cause that can be corrected.
Here is a root cause for 1996 and 2003 that all should understand, “After 15:05 EDT, some of FE’s 345-kV transmission lines began tripping out because the lines were contacting overgrown trees within the lines’ right-of-way areas.”
And a second from 2003, “… if manual or automatic load-shedding of 1,500 MW had occurred within the Cleveland-Akron area before that outage, the blackout could have been averted.”
RPU and V2G would not address any of the root causes in the report.
E-P has lots of misconceptions like,
“Some took e.g. condenser damage when steam had to be dumped to prevent overspeed”
From E-P’s link, “Extreme system conditions can damage equipment in several ways, from melting aluminum conductors (excessive currents) to breaking turbine blades on a generator (frequency excursions).”
In this case the cause of the trip is protecting equipment when the grid fails.
“At 15:46 EDT the Perry plant operator called the FE control room a third time to say that the unit was close to tripping off: “It’s not looking good . . . .We ain’t going to be here much longer and you’re going to have a bigger problem.”
This second case is when the power plant is lost because it was not designed for grid instabilities.
So what is being done? FERC & NERC standards have become mandatory. While legislation was proposed before 2003, congress did not act. The Feds can now force utilities to make required changes then the utilities can force PUC to allow the cost to be passed through.
Second, new power plants are being designed handle grid instabilities better. The old thinking was to protect the plant when there is no reason to keep it running with no place to send electricity. For example, the new plant that my company is working on will be designed for 100% steam dump capacity up from 25% for equipment protection.
New plants will be less likely to contribute to grid instability and be able to return to operation faster when the grid is restored.
Posted by: Kit P | 17 December 2008 at 08:48 AM
Quoth the troll:
Dead wrong as usual. From the report, pp. 4-5:The need for reactive power helped take Eastlake Unit 5 off-line:
Lack of reactive power was a major part of the cause of the 8/14/03 blackout. V2G is well-suited to providing reactive power on demand (report off-line, Google cache):
I recall that I got the item about condenser damage from a dead-tree news report the next day, but it either is not on-line or was erroneous and has been corrected. Either way, it appears to have been in error and I retract it.
Which begs the question, why is the grid unstable? Insufficient reactive power is a big factor, as is lack of fine real-time control over demand. V2G directly addresses both of these.
Posted by: Engineer-Poet | 19 December 2008 at 06:57 PM