Ask the EcoGeek: The Energy Cost of Solar
Dear Mr. EcoGeek,
I've heard that it takes more energy to produce photovoltaic cells than the cells will ever produce throughout their lifetime. Is there any truth to that, or are those naysayers just saying nay?
David
Spokane, WA
Short Answer:
Those naysayers are just saying nay! But that doesn't mean there's not more to this story.
Long Answer:
This myth was probably perpetuated by studying solar panels created for NASA. If you need something extremely efficient for use in outer space, yes, then it doesn't matter how much energy you use to create the panel. But for use here on Earth, it's ridiculous for anyone to say that solar panels consume more energy than they produce.
Of course, doing anything in this world takes energy. Whether it's building power lines or shipping oil from Saudi Arabia, it takes energy to make energy usable. In fact, there's a nifty number that puts all of this into perspective. It's called the “energy balance”, and it is, in short, the amount of energy you get out divided by the energy you put in.
So, for corn ethanol, for example, we get 1.3 units of energy for every 1 unit we put in, so its energy balance is 1.3. Whereas for Brazilian sugar cane ethanol, we get 8 units of energy for every one we put in. As for gasoline, its energy balance is about 5.
So what does this have to do with solar? It is a bit incorrect to apply energy balance to solar panels, because they don't actually contain the energy, so it's not something that I've ever actually seen done. But I think it makes sense to fudge it a bit in light of your question.
Data from a study (pdf) from Energy Environment and Economics Inc. showed that the average solar panel gets five times more energy out than was originally put in. Roughly the same “energy balance” as gasoline.
Still, no one is satisfied with that number.
Thousands of scientists, engineers and business people are working, right now, to increase solar's energy balance, and many have done it substantially. The simplest and most common methods include making sure that the panels are always at a 90 degree angle to the sun, increasing the life of the panels, and decreasing the amount of photovoltaic (PV) material needed in the panels.
As PV material (usually polysilicon) is energy intensive to create, a lot of folks are trying to figure out how to use less of it. One common method is to use mirrors or lenses to concentrate the sunlight on a relatively small amount of polysilicon material. Additionally, a whole other branch of the solar industry is trying to make solar panels from less energy-intensive materials, including the much-touted copper indium gallium selenide (CIGS) thin-film solar panels.
There may be some economic reason to not be an early adopter of solar, but there is certainly no doubt that they produce a lot more energy than they consume. And soon, they'll be producing even more.
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Tags: ecogeek, PV, Renewable Power, Solar
July 12th, 2007 at 8:46 pm
NO on AB118
Corn ethanol policy is good for gasoline refiners
Corn ethanol policy increases oil use and increases oil profit
The proposed car tax of AB 118 Nunez is an oil company welfare program
Italy used public/private partnerships as a business model in the early ’40s
In my opinion the corn ethanol waiver allowed in the 2005 fed energy bill would lower gas prices, improve miles per gal, lower oil use and improve the air.
Your phone book lists your elected officials, sharing your opinion with the folks that make our rules might help
Clean Air Performance Professionals
July 31st, 2007 at 9:12 am
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August 8th, 2007 at 5:59 am
Loophole fuels Detroit’s ethanol Politics and Policy fixation
Mileage credit pushes flex-fuel trucks despite lackluster efficiency of E-85
Editorial — Henry Payne, The Detroit News, June 8, 2006
A gallon of corn-based E85 ethanol fuel goes only three-quarters as far as gasoline, costs more at the pump and provides negligible environmental benefits.
So why are U.S. automakers beating a track to Capital Hill and promoting ethanol as an alternative for their vehicles? And why are they producing millions of flex-fuel vehicles that can use the blend of 85 percent ethanol and 15 percent gasoline when it is nearly impossible to find E85 at the pumps?
The answers, industry experts say, lie in the perverse incentives of the federal government’s mandated, and increasingly stringent, fuel economy program.
Perverse incentive for E85
The government manipulates its fuel economy ratings to give automakers an incentive to make flex-fuel vehicles so they meet federal fuel economy rules.
Ethanol is already one of Washington’s most infamous boondoggles, costing U.S. taxpayers $4.1 billion a year in federal subsidies. The money is a political sop to the farm lobby.
But because of ethanol’s mediocre mileage performance, the E85 blend is only in 600 of America’s 180,000 filling stations nationwide and a small but growing handful in Michigan.
How does a fuel that is 25 percent less efficient than gasoline help increase fuel mileage ratings and help automakers avoid fines that run into the hundreds of millions of dollars? Welcome to the looking glass world of federal regulations.
Manipulating CAFE rules
Corporate Average Fuel Economy (CAFE) rules set minimum mileage standards across all vehicle models. For cars, the average is 27.5 miles per gallon. For light trucks (sport utility vehicles, pickups, and minivans), it’s 21.6 mpg.
But under pressure from $3-a-gallon gas prices, the Bush administration is recommending that trucks produce an average of 24.1 mpg by 2012. The new rules will be a daunting challenge for automakers already struggling to meet the current standard.
An alternate fuel-friendly government, however, has created an ethanol loophole for carmakers. It lets manufacturers pump up their fuel economy ratings, particularly in the most popular vehicles that tend to get the least gas mileage, light trucks.
Running on gasoline, an SUV like the Chevy Tahoe achieves 20.1 mpg under CAFE’s test. Put E85 in it instead and the fuel economy plummets to 14.6 mpg.
America’s 100 mpg truck
But for the purposes of CAFE — and here’s where we fall down the rabbit hole, Alice — the government starts massaging the numbers. It only counts the 15 percent of E85 that is gasoline in its fuel economy rating, increasing the vehicle’s mileage figure a whopping seven-fold to 97.3 mpg.
Only Washington, D.C. could actually produce an imaginary 97.3 mpg sport utility vehicle!
The government then takes that number, averages it with the 20.1 gasoline number, runs it through a special formula, and — voila! — arrives at the flex-fuel Chevy Tahoe’s official CAFE mileage: a healthy 33 mpg.
Such high numbers, naturally, threaten to blow out the federal fuel economy program and make it too easy to comply with. So the feds added a rule: They capped the total benefit of ethanol vehicles toward the CAFE standard at 1.2 mpg.
Because automakers pay big fines on each tenth of 1 mpg that they are below the CAFE mark, a manufacturer like General Motors Corp. could face $180 million in fines for violating light truck fuel economy rules were it not for the ethanol provision. The cost of outfitting trucks to run on gas and E85 comes to about $150 a vehicle, according to General Motors — or a total cost of $60 million.
General Motors saves a possible $120 million by producing ethanol vehicles and avoiding CAFE fines — not to mention the huge public relations costs if it were caricatured in the media as a fuel economy deadbeat for missing federal targets.
Automakers argue that ethanol has other potential benefits.
“If we want a game changer, then ethanol is a very good play for this country,” Ford Chief Executive Bill Ford testified on Capitol Hill last month.
Ethanol’s benefits evaporate
But a comprehensive study in Car & Driver magazine’s July issue finds that ethanol’s alleged advantages evaporate, leaving only its CAFE credit as a reason for production.
For example, cleaner air is often raised as another reason to use ethanol, but the vegetable fuel increases hydrocarbon emissions as it reduces nitrogen oxide emissions. And ethanol consumes more fossil fuels to produce than it saves in use.
Despite a 51 cents-per-gallon tax break in the production of ethanol, plus a 5 cent-per-gallon exemption from the federal gas tax, ethanol still costs more at the pump than gasoline. As long as that remains the case, few service stations will continue installing pumps for a product that gives customers 25 percent less gas mileage.
So sure enough, Michigan U.S. Rep. Mike Rogers, R-Brighton, this week introduced another ethanol tax scam: Giving subsidies to install E85 pumps at service stations.
The bottom line is that ethanol exists solely for the benefit of the environmental, agricultural and automotive lobbies. Taxpayers are just left holding the bill.
Copyright © 2006 The Detroit News
http://www.autonewsservice.org/politics_policy/06_21_06/6.htm
* NO on “car tax” AB118 (Nunez)
* Clean Air Performance Professionals (CAPP) supports a Smog Check inspection & repair audit, gasoline oxygen cap and elimination of dual fuel CAFÉ credit to cut car impact over 50% in 1 year.
* Some folks believe corn ethanol in gasoline increases oil use and oil profit
* Ethanol uses lots of water
* A Smog Check audit would cut toxic car impact in ½ in 1 year. Chief Sherry Mehl, DCA/BAR, has never found out if what is broken on a Smog Check failed car gets fixed, never
* A corn ethanol waiver would stop a $1 billion California oil refinery welfare program coming from the federal government @ $0.51 per gallon of ethanol used
* About 60,000 barrels per day of the oil used by cars is allowed by the “renewable fuel” CAFE credit