Solar Panel Reliability an Issue?

Today, the New York Times published an article on defective solar panels.  The article is located here:

At issue is the corner cutting being taken by certain photovoltaic panel manufacturers, leading to premature panel degradation.  For instance, they mention one west coast installation where panels with an anticipated lifespan of 25 years began failing after just 2.  This led to losses of hundreds of thousands of dollars in missed revenue for the operator.

The solar industry is justifiably concerned with manufacturing integrity.  Solar power has been rapidly gaining credibility in both the residential and commercial sectors after early skepticism, but manufacturing defects that torpedo the lifecycle cost of solar installations could reverse that trend very quickly, and they know it.  A combination of industry-wide materials and manufacturing standards, coupled with performance warranties seem like it could address the issue, though they would probably add to the cost of solar, as well.  By the way, the panel failure rates seem to be in the 5% to 20% range.  A review by Meteocontrol in Germany also found that 80% of solar installations monitored in Europe were under performing, though the article did not specify precisely what this meant.

One thing that really interested me about the article was some information about the growth of solar power generating capacity.  The Times linked to a pretty interesting informational page at the Solar Energy Industries Association (SEIA) that shows United States photovoltaic installations in 2012 totaled over 3 GW!  Ten years earlier, photovoltaic installations totalled 0.02 GW.  That’s pretty astounding growth.  While the SEIA clearly has an agenda, I still thought their web page was interesting and informative, with very good graphics and charts.  You can take a look at it here:

For someone like me who doesn’t really spend much time analyzing solar, there is some good rule of thumb numbers for the cost of ph0tovoltaic installations:

Installed Price

One can also do a little math and figure out that SEIA estimates a typical installation in Massachusetts will require 4 kW capacity.  So if we look about $5/Watt x 4,000 Watts we get an installed price (admittedly very rough) of about $20,000.  Now of course, tax breaks and other incentives might lower this cost,  but it’s still pretty steep.

The payback on such a system is going to be dependent upon local utility rules.  If “net metering” is permitted, energy generated in excess of what is needed to operate your house can be sold back to the grid.  If net metering is not permitted, battery or some other storage strategy must be deployed to capture the full potential of the system.

If we assume that 35% of our energy use is at night or early morning (for my house, that percentage might be higher) and if our monthly electric bill is $125/month, then a non-net metered installation without energy storage will deliver the following simple payback without tax breaks or other incentives:

$20,000 / ($125/month * 12 months/year * 65%) = 20.5 years.

That’s a long time.  You are effectively operating in the red for 20 years.  So if these panels do not last well past 20 years, the net present value of the installation will be unimpressive (see earlier post on net present value calculations if you want a refresher.)

But this also drives home why the solar industry should be anxious about premature panel failure.  Without a guaranteed useful life that is comfortably longer than the simple payback of a system, photovoltaics cannot be considered a solid investment.


Weighty Matters

America, they say, has an obesity crisis.  And god knows I’m doing my bit to contribute.

But diet and weight may be far more  complex than we like to think.  I recently heard a woman assert on the radio that we (as in, the nutritionists) know how to get people lose weight: Eat less, and exercise more.

Unspoken, of course, is the fact that only a vanishingly small fraction of Americans can lose weight and keep it off with this approach.  So we may know how people should theoretically lose weight, but we certainly don’t know how to make it work in practice.

So eat less and exercise more seems more akin to a slogan than a working solution in the real world.

Now, some simple math lets us see why this is so, and it may also offer some insights into energy and metabolism too.

Before we begin, I’d like to point something out that is infrequently commented upon.  While plenty of us are overweight or obese, a relatively few of us are actively gaining weight or losing weight on an ongoing basis.  It’s common, for example, for someone to be carrying an extra twenty pounds for ten years.  Far less common to see them gaining more and more weight year after year after year in an unstoppable march of weight gain.

Which means that people who are overweight but at a stable weight are not chronically overeating (since they would then chronically gain weight.)  Instead, they are eating enough to maintain their weight.  They are in energy balance.  And so gluttons they are not.

Energy Balance:

The classic view of diet and weight is that we consume energy (in units of Calories with a capital “C”) that we use to keep our metabolism running and to perform physical work.  We also expel some energy as waste products.  If we eat more Calories than we burn or excrete, then we are in Caloric excess, and those unneeded calories will get stored as fat.  If we don’t eat more than we need, the energy balance equation is simply:

Calories In = Metabolism + Work – Waste.

You balance that formula and you’re good to go.

Well, now we are in a position to explore why this is too simple to serve as a good basis for dietary control.  Let’s get to the numbers.

In very rough numbers, an adult human being needs to consume perhaps 2,400 Calories per day.

A pound of fat contains approximately 3,500 Calories of energy (stored as triglycerides)

Now, over a two year period, what must go wrong so that a person gains, say, five extra pounds?  Let’s see:

Required caloric input is 2,400 Calories x 365 days/year x 2 years = 1,752,000 Calories

Calories associated with five pounds is 3,500 Calories/Lb x 5 Lbs = 17,500 Calories

As a percentage of this person’s diet, they need to over eat eat by:

(17,500 C / 1,752,000 C) * 100 = 1%

That’s right.  If our caloric input is off by 1%, we will gain (or lose) five pounds over two years.

Now here’s the question.  Who on god’s great earth can consciously regulate their caloric input with 1% accuracy?  Can you tell a 300 Calorie hamburger from a 303 Calorie hamburger?  How about a burger at 297 Calories?  I suspect not.

Indeed, if such a small caloric imbalance can lead to weight gain (or loss, I might add), we should actually be much more astounded that there are human beings in the world who can maintain a stable weight at all!

We should also wonder about traditional diets that call for steep reductions in caloric intake.  Many diets will call for someone to reduce their intake by 500 or more Calories per day.  But this is an asymmetric response to a condition that our formula tells us has come about by only the tiniest of caloric imbalances over time.  Something that extreme ( a 500 Calorie or 21% reduction in energy input) almost by definition cannot be maintained indefinitely.  So of course traditional diets fail.

The fact that most people maintain a more or less stable weight (whether slim or overweight) actually tells us something very interesting.  Since our daily caloric input varies from day to day and cannot be consciously controlled down to the level that the energy balance equation would dictate, it is clear that our bodies are able to accommodate fluctuating energy input to some extent without gaining or losing weight.  Perhaps (within reason) we metabolically slow down when food is scare, and we metabolically rev up when food is plentiful, allowing our weight to remain stable.  Perhaps.

Now, understanding that the energy balance approach is highly infeasible as a weight control tool does not mean that we have a good alternative at hand.  But it does suggest that looking around for an alternative to eat less and exercise more is probably an idea whose time has come.

EPA Greenhouse Gas Emissions Inventory

A really interesting document prepared by EPA is listed here:

It contains great information about sources and sinks of heat trapping gases.  It also includes very useful tables such as this:

GWP Table

Pretty great, right?  One thing that jumps out is that methane (CH4) has 21 times the global warming potential of carbon dioxide.

One can sometimes forget about all the great research and reporting work that the Federal Government does and makes available to its citizens, especially when the haters get going.  But when it comes to matters of energy, energy utilization and emissions, there is a wealth of useful and contextualizing information right at your fingertips thanks to Uncle Sam.

It may sound goofy, but this display of competence and professionalism makes me feel pretty proud about our Government.  But enough about politics.  Take a look at this report if you have a few minutes.  It’s worth a quick scan if nothing else.

Joe Nocera is at it again…

Well, okay.

On May 17th, the New York Times published “Energy Exports are Good!” by Joe Nocera.  It is a sufficiently confused bundle of thinking that it really merits reading:

Nocera begins by approvingly citing an editorial that had been written by Andrew Liveris, the Chairman and CEO of Dow Chemical.  Liveris (and Nocera) point to fracking for natural gas as

  1. Strengthening our economy
  2. Increasing our national competitiveness
  3. Creating jobs.

Nocera then rather obtusely argues that Dow Chemical is hypocritical because they want natural gas prices to remain low (to boost their profits) by limiting gas exports (oh my god, a regulated market!), yet they [Dow] own a stake in a natural gas exporting venture.

Which, when you think about it, is actually a kind of interesting situation for Dow, though not necessarily hypocritical.

Nonetheless, Nocera’s position is clearly that the unfettered marketplace should determine where natural gas extracted from America should go, and that unholy regulation of the market MUST NOT BE ALLOWED.  Oh, and that sure, yeah, gas in the good old U.S.A will stay cheap under this scenario.

Now, Nocera is confused on several fronts here, so let’s just take a stroll through some of his assertions.

Given his endorsement of the three items above, it is clear that Nocera views the combustion of fossil fuel (e.g. natural gas) as not a behavior that America must address.  As I have written (tiresomely, I’m sure) elsewhere, natural gas combustion results in the generation of carbon dioxide, and carbon dioxide causes ocean acidification.  But apparently that concerns us naught.

I suppose we can say that fracking strengthens our economy (point number 1), to the extent that all that drilling puts some people to work, and cheap natural gas makes our manufactured goods more competitive globally.  Of course, there are externalities that may not yet have been priced out.  For instance, if fracking ruins or uses up aquifers, how do we estimate that effect on our economy?  If people have water faucets that can be lit with a match because of gas entrainment in the aquifer, how do we price that?

Somewhat hysterically (as in funny), Joe takes care of the externalities question with a simple stroke of the pen:

“But the answer is to ensure that wells are drilled in an environmentally safe manner. That is true whether we export gas or not.”

Of course!  Why didn’t I think of that?  Maybe Joe can write a sentence saying that we’ll “ensure” cars won’t have accidents anymore, or that planes will never crash.  That’d be great, too!

Point 2 is really a subset of point 1.  Point 1, when you think about it, is a pretty vacuous slogan that kind of subsumes points 2 and 3, but no matter.

The question here is, how does fostering increased dependence on fossil fuels increase our national competitiveness?  Might a country that learns to innovate, to make things more energy efficiently, that begins to learn to cost effectively harness the sun, the winds and the tide for power be even more competitive?  Nah…

Point 3 is probably true, actually.  You’ve got guys looking for gas, guys drilling for gas, guys selling gas, and guys cleaning up the inevitable mess that all the fracking is causing – it’s jobs heaven.  Unless we find out the externalities and our renewed love affair with fossil fuel turns out to be a major strategic error.  In which case we’ve screwed the pooch.

Anyway, Nocera also makes an interesting claim about the wonders of unfettered exportation of natural gas – which mean old (and hypocritical) Dow chemical does not want, viz.:

‘Most studies suggest that the main impact of exports will be to increase U.S. production rather than take away other uses,’ [Michael] Levi says. Thus, it will not likely have a major effect on the price of gas.

So lemme get this straight.   Natural gas costs about $15 a decatherm in Japan, and about $4.00 in the good old U.S.A.  And Nocera finds a source who claims that for-profit energy companies are not going try to globalize natural gas as a commodity?  Hmm.  And I always thought increasing shareholder value was the ambition of publicly traded companies.

LNG Prices

On the other hand, we get a huge discount on the oil we drill here in the United States compared with foreign oil and…Oh, wait a minute.  No we don’t.  Oil is a fungible global commodity and oil from Texas sells for essentially the same price as oil from Saudi Arabia.  Bad example.

Joe ends his column by claiming that Dow was “having [its] cake and eating it, too”, but it’s really Joe who is doing this.  He sees no worrisome environmental issues with fracking or fossil fuel use, and he sees no adverse pricing effects resulting from the exportation of liquid natural gas – gas companies will willingly sell us cheap gas when they could substantially increase their profits by exporting.  The punchline, of course, is that Nocera calls Dow “hypocritical” because Dow knows that unfettered gas exportation will increase their cost of doing business in America.  But that isn’t hypocrisy.  It’s a logical business decision that happens to run counter to Nocera’s received wisdom about unfettered markets.

In point of fact, we are encouraging and increasing our national reliance on fossil fuels, we are ignoring (or treating dismissively) the environmental effect of fracking, and we are moving towards the globalization of the LNG marketplace, with the concomitant price leveling that we see with other global commodities.

Dow Chemical knows better, and so do we.

So when all is said in done, it’s almost admirable how Nocera stitched this narrative together.  Not convincing or logically consistent, but it was a good old college try.