# A Big Problem WIth Thinking That Solar Is An Effective Means to Energy Independence.

Viewing 10 posts - 1 through 10 (of 29 total)
• Sat, Apr 04, 2015 - 08:33pm

#1

#### .

Status Gold Member (Offline)

Joined: Oct 22 2008

Posts: 311

count placeholder

#### A Big Problem WIth Thinking That Solar Is An Effective Means to Energy Independence.

So, let’s examine this, shall we?

Per wikipedia, annual US electricity consumption in 2013 was 4.7 billion MW-hrs.

http://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption

From professional experience (I am an engineer and physicist, doing research in power management) I can also assume the following

Average effective area of a solar panel: 1.6 m

Average Effective Full Output  Hours Sunlight Per Day over the USA: 4.5

Typical power output of a 1.6 m panel ~ 240-250 W.

Thickness of the silver paste layer in a photovoltaic cell: 700-750 um

Density of Silver: ~ 10.5 grams/cm-cubed

From the above we can calculate the following.

Replacing just x% of the US electrical consumption, assuming 240 watt panels, 1.6 m-sq, at 4-5 hours equivalent full sun per day  would require the following quantities of silver:

 Percent USA Electricity Usage Replaced by Solar. Millions of Troy Oz Silver Required to Replace x% of Electrical Consumption with Solar Percent of 2010 Total Silver Production (per the Silver Institute) 1% 75.52 7.1% 5% 377.58 35.3% 10% 755.16 70.6% 20% 1,510.32 141.2% 50% 3,775.80 352.9%

The silver quantity is derived from the known thickness required for the silver paste layer of solar panels.

It turns out to be about 20 grams per panel, or 20 grams per 240 watts of power.

Now, there has been a thrust to try to find ways to reduce the content in silver (which is contradictory to efficiency, as silver, it is THEE base element with the highest electrical conductivity and reflectivity, both critical for efficiency), particularly with materials called photovoltaic metalization pastes, which reduce by a nominal fraction the amount of silver needed, but this has been an exercise in nipping at the edges. It does not seem to promise a quantum leap from what I see. What would be needed is a yet to be discovered, economically affordable composite material with super high conductivity and low manufacturing costs (if that were easy it would already be in consumer electronics as heat from power losses and parasitic power losses on battery life are already a super potent incentive to discover it, yet it does not exist). Now I know a lot of folks place their faith in “Don’t worry, Science Will Figure It Out” school of thought, but please, don’t. That is escapist thinking and is not at all a logical approach to addressing this problem, or any problem for that matter. Like I said, I am involved in power management R&D and very familiar with this kind of stuff, and while definitely optimistic about great improvements, I at not at all convinced that “The Big Happy Magical Rainbow of Science Will Save Us” applies here.  Science rarely succeeds in saving us to the degree that people hope it will (well, I take that back, it can and does, but usually over more than one lifetime, most folks don’t realize that the big breakthroughs are the culmination of decades of building block research on issues that would bore the average Joe to death, and yes,  while the rate of breakthroughs is increasing, the magnitude and complexity of the problems are too). A good figure of merit for the near to intermediate future is that 20 gram number falls to 15 grams, maybe 10.  Whoop-dee-doo! Doesn’t address the issue.

To power just 20% of US electricity, we’d have to procure 1.5 years worth of peak global silver production. 50% is 3.5 peak production years worth. That’s a problem. Particularly since silver is called a precious metal for a reason, and that those numbers would put explosive upward pressure on the metal’s cost, and, once we commit to this, what do you think other nations will start doing?

Solar photovoltaics are not a panacea. From a national energy policy perspective, we might want to consider molten salt solar thermal as a more viable alternative. But that has its issues too. Another time perhaps…..

• Sun, Apr 05, 2015 - 03:34am

#2

#### Peter Bartels

Status Silver Member (Offline)

Joined: Dec 27 2008

Posts: 194

count placeholder

#### Correction. The electricity

Correction. The electricity numbers are based on 2012.

• Sun, Apr 05, 2015 - 04:43am

#3

#### Yoxa

Status Silver Member (Offline)

Joined: Dec 20 2011

Posts: 286

count placeholder

#### I’m missing something here

I’m missing something here … to me it seems like these numbers are comparing apples and oranges.
The “Electricity Usage Replaced by Solar” would be an ongoing saving, whereas the silver needed to manufacture a solar panel would be a one-time requirement.

Using one of your stats as an example (5% replacement requiring 35.3% of annual silver production), if we used roughly one/third of annual silver production to achieve a ~5% reduction, and kept doing that, we could reach 50% replacement within a dozen years or thereabouts. That would obviously be a huge undertaking but not so impossible as your numbers seem to suggest at first look.

Do solar panels wear out? How often would they need to be replaced? That would need to be accounted for and might might change the projections a little or a lot.

I suspect that battery storage (or whatever) would be at least as big an obstacle as photovoltaic solar panels.

We should examine the assumption that rooftop solar setups would only be about generating electricity. Using solar to heat or preheat water could do a lot to reduce electricity usage for many households without requiring such high-tech inputs as photovoltaics would need. Water heat obviously wouldn’t feed back into the grid, but it could certainly help to make an individual household more self-sufficient.

I’m no expert, just someone with a lot of questions.

• Sun, Apr 05, 2015 - 06:05am

#4

#### Peter Bartels

Status Silver Member (Offline)

Joined: Dec 27 2008

Posts: 194

count placeholder

#### Yoxa wrote:I’m missing

[quote=Yoxa]I'm missing something here … to me it seems like these numbers are comparing apples and oranges. The "Electricity Usage Replaced by Solar" would be an ongoing saving, whereas the silver needed to manufacture a solar panel would be a one-time requirement. Using one of your stats as an example (5% replacement requiring 35.3% of annual silver production), if we used roughly one/third of annual silver production to achieve a ~5% reduction, and kept doing that, we could reach 50% replacement within a dozen years or thereabouts. That would obviously be a huge undertaking but not so impossible as your numbers seem to suggest at first look. Do solar panels wear out? How often would they need to be replaced? That would need to be accounted for and might might change the projections a little or a lot. I suspect that battery storage (or whatever) would be at least as big an obstacle as photovoltaic solar panels. We should examine the assumption that rooftop solar setups would only be about generating electricity. Using solar to heat or preheat water could do a lot to reduce electricity usage for many households without requiring such high-tech inputs as photovoltaic would need. Water heat obviously wouldn't feed back into the grid, but it could certainly help to make an individual household more self-sufficient. I'm no expert, just someone with a lot of questions.[/quote]

Questions are good. It means that you read my post and that made it worth writing already!

Using 1/3 of annual production is not a triviality. Given what we know from the Crash Course, and given what I know of silver deposits and reserves, and given a 35% increase in demand on the market, you would wind up with a positive feedback cost cycle based on skyrocketing demand coupled with finite and dwindling supply. You initiate a series of large buys in a very volatile and finite commodity, and what will result is a skyrocket in silver prices. Worse, our energy independence policy would likely spur other developed nations to get off the fence, thus also jumping into the market to attain silver for energy independence thus further driving up prices. On top of that reserves are dwindling, and since price is a function of both supply and demand, you will wind up with a second order price acceleration which then pushes silver parabolic, and hence the push the cost of solar energy parabolic. It's simple exponential mathematics. Look at it that way. Now keep buying up 35% of a limited resource annually, wash, rinse, repeat, and see where that goes. Nope, I still think molten salt solar reactors are the better approach for an ultra large scale project.

• Sun, Apr 05, 2015 - 07:30am

#5

#### Yoxa

Status Silver Member (Offline)

Joined: Dec 20 2011

Posts: 286

count placeholder

#### Quote: It turns out to be

[quote] It turns out to be about 20 grams per panel, or 20 grams per 240 watts of power.[/quote]
I’m visualizing that quantity; it’s less than the silver in one of my grandmother’s sterling teaspoons.

[quote] molten salt solar reactors are the better approach for an ultra large scale project [/quote]

That might well be true for ultra large projects, but wouldn’t a big part of the reduced vulnerability concept here be to have lots of small, decentralized power sources?

Remember good ol’ conservation and waste reduction. How much of that 4.7 billion MW-hrs was used less efficiently than it could have been?

Back to one of my earlier questions? Do solar panels (photovoltaic) wear out?

• Sun, Apr 05, 2015 - 09:45am

#6

#### Dirk Kessels

Status Member (Offline)

Joined: Sep 06 2009

Posts: 1

count placeholder

#### If solar panels wear out and

If solar panels wear out and silver is a much sought metal there will be a way to recycle 100% of the silver in the panels. Building more than 1% per year in solar panels is utopia we do not have the production capacity.

For me it is imperative that we go decentralized. This is the only way to get energy independence for common people and even nations. Let's be frank. If energy generation where more decentralized we would already be much further on the way of energy independence because there would be no reason to hamper the transition for personal financial benefit.

• Sun, Apr 05, 2015 - 11:03am

#7

#### Peter Bartels

Status Silver Member (Offline)

Joined: Dec 27 2008

Posts: 194

count placeholder

#### Yoxa wrote:Quote: It turns

[quote=Yoxa][quote] It turns out to be about 20 grams per panel, or 20 grams per 240 watts of power.[/quote] I'm visualizing that quantity; it's less than the silver in one of my grandmother's sterling teaspoons. [quote] molten salt solar reactors are the better approach for an ultra large scale project [/quote] That might well be true for ultra large projects, but wouldn't a big part of the reduced vulnerability concept here be to have lots of small, decentralized power sources? Remember good ol' conservation and waste reduction. How much of that 4.7 billion MW-hrs was used less efficiently than it could have been? Back to one of my earlier questions? Do solar panels (photovoltaic) wear out?[/quote]

Wear not? Well, they don't "wear out" per se, but what they do is lose a nominal fraction of their efficiency, but they are still quite useful 20-30-40 years later (which is why they are a good PERSONAL investment IMO) retaining 80+% of their original efficiency, which for electronics is outstanding, given the daily environmental abuse they are subjected to.

I have been planning on designing my own system, and my brother is a licensed installer (I have my PE license, but code generally dictates that licenced installers do the work for it to pass code in my state), I just need to get off my duff and do it. Put it this way, if the efficiency fall off over their useful lifetime was a concern to me, I would not have them on my personal agenda, nor would I be so highly in favor of them for a personal home energy system.

Don't visualize numbers. That will almost always produce erroneous gut feel solutions. 20 grams over the numbers that I showed adds up. It's the aggregate that matters when talking mega scale projects.

If I am coming across as a photo voltaic opponent then believe me, nothing could be more opposite, more further from the truth! I am saying that on a large national scale, with silver in limited supply, and known reserves in a limited supply, there is a practicality issue, where other types of renewables would be more favorable. That's all. 🙂

• Sun, Apr 05, 2015 - 01:28pm

#8

#### blackeagle

Status Bronze Member (Offline)

Joined: May 16 2013

Posts: 225

count placeholder

#### Energy independence: How to

Energy independence should be thought by individuals for themselves. It is a too large task to be carried out at country scale. Every person should build now its energy independence/resiliency. Yes, prices will go up with more demand. But at the same time, other options will become more interesting. This will promote a variety of solutions, almost always at the optimal price considering the current market conditions. Overall, this should reduce pressure on the large systems.

The knowledge that some materials are in finite supply, should not prevent us of going forward with our individual plans. Always good to be the first.

• Sun, Apr 05, 2015 - 01:52pm

#9

#### Yoxa

Status Silver Member (Offline)

Joined: Dec 20 2011

Posts: 286

count placeholder

#### Quote: If I am coming across

[quote] If I am coming across as a photo voltaic opponent [/quote]
I’m not reading you that way, I read you as pointing out that we need to make sure our thinking is realistic about what it would take to switch to photovoltaics on a large scale.

At my end I’m saying, we don’t have to assume that photovoltaics are the only tool in the solar energy toolbox.

[quote] Building more than 1% per year in solar panels is utopia we do not have the production capacity. [/quote]

If we want production capacity to expand, more of us need to buy the products.

If more of us made personal investments in solar energy we would benefit personally, but we’d also help to nudge the whole system in a better direction.

• Sun, Apr 05, 2015 - 04:57pm

#10

#### Peter Bartels

Status Silver Member (Offline)

Joined: Dec 27 2008

Posts: 194

count placeholder

#### blackeagle wrote:Energy

[quote=blackeagle]

Energy independence should be thought by individuals for themselves. It is a too large task to be carried out at country scale. Every person should build now its energy independence/resiliency. Yes, prices will go up with more demand. But at the same time, other options will become more interesting. This will promote a variety of solutions, almost always at the optimal price considering the current market conditions. Overall, this should reduce pressure on the large systems.

The knowledge that some materials are in finite supply, should not prevent us of going forward with our individual plans. Always good to be the first.

[/quote]

What options are you specifically referring to when you speak of "other options will become more interesting"?

I agree with you on the last statement. IMO buying solar early is like getting into new equity market early. One might counterargue that early entry brings with it the penalty of lack of economy of scale, and hence higher prices due to lower production, but that does not consider the impact that higher production would have on direct materials cost (DM, as we call it in industry) which will work against reduced production costs and DM increases as a function of production. Also, I was just talking about silver only. Rare earth metals are also used in solar energy and they too have limited production potential, so there is another factor that would increase DM.  The question is, with limited reserves of both silver and rare earth metals, does DM skyrocket when demand picks up, thus swamping economy of scale from large-scale production? If so then the earlier you buy the better. (I work in the electronics industry and am keenly aware of rare earth material stocks, and transient shortages (indicative of limited supply) gives us fits with respect to designing around that issue).

That aspect, and the fact that both energy and industrial silver prices are very low now, is making me seriously consider taking advantage of the present opportunity and getting some solar installed while it is at a great value!

Viewing 10 posts - 1 through 10 (of 29 total)