How Green is the PIP? Where Do You Live?

Just because wind turbines are shut off at night does not automatically mean that consumer green energy purchase turns them back on. It depends whether the *entire* clean fraction of the grid at night is already bought by others and specifically allocated to them.

It is a fact of life in the US that utilities want to run their plants as efficiently as possible, using the cheapest fuel available. They are sometimes hampered by regulatory requirements, but dimes to dollars, that means burning coal; or even better, burning coal at night. Spending you enviro dollars at the utility is very unlikely to get you more green kwh on the grid.

Since we (domestic US consumers) do not usually have the option to buy into green co-ops, PV and solar heating are the best alternatives to actually produce green kwh, or reduce consumption of dirty kwh.

Unused hydro is very different than shutting off wind turbines. If the hydro is not used at night, it is available for later use.

 

I'd like to think you are right, but I am skeptical.

Your utility says

To clarify why I am skeptical, look at this contrived example:

Marin country
10,000 kwh total energy use a day -- all imported

Export regions
100,000 kwh total energy a day produced, of which 10,000 kwh is clean and 90,000 kwh is dirty. 10,000 kwh dirty energy exported to Marin CO
10,000 kwh clean energy produced a day, consumed locally.

.....
Marin County proposes 'green purchase,' avidly taken up by EV'ers who add 5000 kwh a day of green EV demand.

ok...
Export regions now
Consume 5000 kwh clean energy a day
Export 5000 kwh clean energy to Marin
Produce 95,000 kwh dirty energy, of which 10,000 kwh exported to Marin and 85,000 kwh dirty energy consumed localy, an unchanged total of 90,000 kwh total energy consumed locally, but now with a higher content of dirty energy.

Net result: the additional 5000 kwh a day of clean energy demand in Marin CO results in additional 5000 kwh a day dirty generation in the exporter region.

--------
I congratulate and thank you for putting up PV. THAT makes a positive difference. I hope you do not read me as critical of you, quite the opposite. I do wish however to educate environmentalists so they are not fooled by green-washing.

 

Nope. The study said that even assuming the dirtiest coal generated electricity, the electric cars were less polluting. Many of us have option to pay for wind power electricity at a higher rate so even in a "dirty" region one could have a zero emissions vehicle. Cool!

• Nationwide, EVs charged from the electricity grid produce lower global warming emissions than the average compact gasoline-powered vehicle (with a fuel economy of 27 miles per gallon)—even when the electricity is produced primarily from coal in regions with the “dirtiest” electricity grids.
• In regions with the “cleanest” electricity grids, EVs produce lower global warming emissions than even the most fuel-efficient hybrids.
• EVs charged entirely from renewable sources like wind and solar power produce virtually no global warming emissions.

And the name of the company that destroyed the Gulf of Mexico was what?

 

Grrr

I like the UCS; heck, I send them money. This article however is spin.

Increased electricity demands do not make the sun shine brighter, or the wind blow harder (EV fans respectfully excluded as minor contributors.) Nuclear is baseload. So the increased demand is ENTIRELY covered by NG, oil, and coal*. The proportions vary from region to region, but are NEVER less CO2 intense than NG. Period. End of Story, until the grid is 100% green, and excess green capacity is available.

Now look at the UCS study again. A 'mostly coal' region EV is equivalent to a 27 mpg car, so a 54 mpg Prius is better than a 100% NG car, since the carbon intensity of NG is 55% that of coal.

That is for GHG; EVs fare considerably worse in Sox and Nox.

*I can think of two possible exceptions: One would be a grid where the fractional demand for green energy exceeds the green fraction in the production area. I do not know of any place that situation exists today.

The second situation would be regulations that require a fraction of total energy production be green; then that fraction would apply to the increased demand as also. As I mentioned earlier though, the regulations typically apply to consumption rather than production, so the utility simply buys unallocated green energy from other producers.

 

Contrary to my nature, I will not quibble here, and just agree with your post

The cynic in me however suspects that way before the shifting reaches its limits, NG will be reclassified as a 'green' fuel for portfolio compliance requirements.

 

We call it science.

Meaningless non-sequitor generalities don't change the scientific facts.

Wind power is zero CO2. A different end to the story.

Also wrong again as BPA is shutting down the wind power to run the hydro. Has to do with artificial rate structure that allows BPA to charge more for hydro. Hydro has severe environmental costs though not CO2 related. It has destroyed the billion dollar salmon, shad runs along with heat pollution of the water, along with the artificial lakes has terrible effect on water quality.

It also hurts the wind power industry and US economy effort to build sustainable energy industry and jobs and power plants.

Feds rule BPA wind-power shut-off was unfair: Federal regulators ruled Wednesday that the Bonneville Power Administration discriminated against wind-power producers when they ordered shutdowns of their operations this spring during a time of glutted electricity markets.

To this topic, wind powered PIP is a winner in cutting CO2.

 

Nah, still charmed.

Wind and solar exist, so I see no reason to consider nuclear. More specifically, I see no reason for the public to limit corporate exposure liability for environmental damage, the way it is currently for oil and nuclear.

 

No doubt.

The authors try to wiggle out of their poor reasoning in Appendix 'A', where they write

See the logical fallacy ? The decrease [or increase] in GHG is virtually imperceptible, too. comment in [] and bolding is mine.

The second logic fallacy is saying that additional green production in the future that exactly offsets the higher demand (say, from EVs) makes the EVs green by extension. This ignores the fact that had the EV demand not materialized, the grid would be that much greener. Unless you can convincingly argue that EVs are the cause of increased green energy production, this is just a game of musical chairs (or energy shifting, as bilofsky aptly names it.)

 

The utilities could not pass on the price -- it is too high. They would default to lower priced sources, which today are NG, solar, and wind.

If they become liable for fracking damage without liability limit, only wind and solar remain.

 

Yes. You've bumped into a solid scientific study with great documentation that disproves your unfounded personal opinions. You then quote their clear explanation that proves you wrong and then say "See?".

Yes we do see.

 

You have reminded me of a joke I heard long ago:

It is OK to talk to yourself;
It is OK to answer yourself;
Time to see the shrink when you say "excuse me, what did you say?"

 

Ah, the old "Marginal power" argument again.

By your logic, emissions from any load depends on when you first plug in (or unplug from) to the grid.

So if I look at my 1000W flood light that I've been running 12 hours a day (I'm scared of the dark) for the last 15 years, when I plugged it in it caused my utility to divert a bit more water to the hydro turbines to compensate with no extra CO2 emissions.

Fast forward to today where marginal power is imported from out of state generated by dirty coal plants and I defeat my fear of the dark allowing me to turn off my 1000W night-time load.

How much credit do I get for reducing my marginal load - is it 1000W worth of hydro? Or is it 1000W worth of dirty coal? Or do I claim a mix?

What if I replace my 1000W flood lights a month later with an EV that I trickle charge at 1000W or 12 hours a night? Who's on first?

My point is - if you count any "new" load on the grid as marginal power and thus generated by some dirty power plants - I'm going to argue that every other load on the grid is also 100% responsible for that dirty power - until it isn't, anyway.

Which doesn't make any sense at all.

Yes - adding a new load to the grid can raise emissions by whatever the emissions of the marginal power plant are. But those emissions are shared among ALL customers plugged into the same grid. Using average emissions is the only thing that makes sense.

 

It does seem to me that this is an oversimplification that makes the results pretty hard to put too much stock in.

The Prius is a perfect example of how 1+1 does not equal 2 in a non-linear system. The Prius uses the motor/generator to put an additional load on the engine under some conditions and reduce the load on the engine in other conditions. The efficiency of this conversion and storage is inherently less than 100%. So by simple linear math we can prove that the hybrid system will make the Prius less efficient than a regular gas vehicle, as the power added back by the motor is less than the power the engine had to provide to drive the generator.

Except that we all know this is not true. The engine is loaded by the generator when its running lightly loaded and its efficiency is poor. The motor supplements the power of the engine when its load is high (or very low) and efficiency would also be poor. By keeping the engine operating in a fairly high efficiency band any time its in use, significant amounts of fuel are not wasted in inefficient operating regions and overall fuel consumption is significantly improved. Accurately describing the non-linear behavior of the system is crucial to drawing the correct conclusion about the impact of adding the hybrid system.

Its not a perfect analogy, but the same is largely true of describing the impact of charging EVs on the grid. Part of the reason the night time GHG emissions look bad is because of the type of plants that have to be kept online at night, but part of the reason is also because those plants are running lightly loaded and consequently are running at low efficiency. As a result its not really valid to just say all these coal plants running at night are putting out X tons of GHGs, and increasing the load 50% by charging EVs will just cause 50% more coal to be burned and 50% more GHGs to be produced. Increasing the overnight load would likely allow those plants kept online (and those required to be kept "idling") to be run at a higher percentage of their design load and consequently operating at significantly improved efficiency.

Specific data is pretty hard to come by, and will vary greatly both seasonally and regionally. One example showing several plants operating between ~20% and 40% efficiency from 10% to 30% load are shown on page 7 here:
http://esd.mit.edu/symposium/pdfs/papers/connors.pdf
In a case like that an increase in demand that allowed the operator to increase the load on a given plant could put out 3X more power while only burning 50% more coal. Consequently the increase in load would only be responsible for 1/6 of the increase in GHG emissions that a simple linear calculation would predict.

So I guess I would argue that in addition to the factors others have mentioned, wind turbines being parked, surplus energy being wasted blowing off steam or heating water at plants that can't be shut down, etc, there is also significant potential for reducing overall emissions by increasing the load upon and efficiency of the significant number of plants that are underutilized at night and/or off season.

That would help explain why most utilities are so supportive of electric vehicles. In general its cheaper for them to pay customers to use less electricity than it is for them add capacity, but electric vehicles provide a significant opportunity for them to operate their plants more efficiently which for them translates to more profitably. For the rest of us it translates to less resources consumed and less emissions per unit energy for the entire grid.