Dharma Wheel

Kim O'Hara,

Has anyone in the industry done accelerated exposure testing? If so, what fails?

There are many factors. For example surface damage to the panels. This happens through exposure to wind and weather, and the more obvious physical damage such as trees, dust, hail, and so on. If there are scratches on the surface, you may in a worst case scenario have water seep through the surface, and thus short-circuit the solar panels. So, you need to constantly make sure that the surface of the panels are clean, because pollen, dust, and so on lowers the efficiency of the cells.

It has also to do with the chemistry behind it all. They are designed to react to photons hitting its surface of the cell. This process affects its longevity. If one or more cells are in the shade for far too long can create so called hotspots, and that accelerates the degradation as well.

Here's Fraunhofer on this issue of longevity: http://www.fraunhofer.de/en/press/resea ... les-7.html

And here's more on cell degradation: http://pveducation.org/pvcdrom/modules/ ... lure-modes

Norwegian wrote:Kim O'Hara,

Has anyone in the industry done accelerated exposure testing? If so, what fails?

There are many factors. For example surface damage to the panels. This happens through exposure to wind and weather, and the more obvious physical damage such as trees, dust, hail, and so on. If there are scratches on the surface, you may in a worst case scenario have water seep through the surface, and thus short-circuit the solar panels. So, you need to constantly make sure that the surface of the panels are clean, because pollen, dust, and so on lowers the efficiency of the cells.

It has also to do with the chemistry behind it all. They are designed to react to photons hitting its surface of the cell. This process affects its longevity. If one or more cells are in the shade for far too long can create so called hotspots, and that accelerates the degradation as well.

Here's Fraunhofer on this issue of longevity: http://www.fraunhofer.de/en/press/resea ... les-7.html

And here's more on cell degradation: http://pveducation.org/pvcdrom/modules/ ... lure-modes

Thanks - that's an answer.
What I get out of it is that there are several good reasons any particular solar panels won't last forever but that there are enough variables to make their actual lifespan hard to predict.
On the other hand, manufacturers wouldn't offer 25-year guarantees unless at least 90% of the panels will last that long, and the degradation is slow but cumulative so a 40-year average life does seem reasonable and some may last considerably longer.


Kim

Zhen Li wrote:I don't think a figure of 40 years is anything to be up in arms about. After all, just about any power plant would be lucky to get past regulators running that long without major updates and replacements of key parts.

That's an ideal estimate. Lifespans in reality are overall much shorter.

Then of course we must mention that extraction process for the rare earth materials in solar panels, wind generators, batteries, etc., are pretty devastating to their local environments because China/Inner Mongoloa is about the only place where rare earths are recoverable without significant quantities of radioactive materials, and even then they are strip mined.

The anthropogenic climate change model is really quite a hopeful thing. It means that humans can exercise a great deal of influence over climate. Now I am aware that the warming earth is not desired beyond a point, but of this world's mass extinctions, they are related to catastrophic cooling. Because of the cyclic nature of climate, this cold earth extinction will no doubt arrive again, but imagine that we can ameliorate this with increased greenhouse gas emissions?

Now to deal with global (Sure as hell not local!) warming with decreased green house emissions.

Malcolm wrote: Then of course we must mention that extraction process for the rare earth materials in solar panels, wind generators, batteries, etc., are pretty devastating to their local environments because China/Inner Mongolia is about the only place where rare earths are recoverable without significant quantities of radioactive materials, and even then they are strip mined.

Every solution seems to pose new problems.

Malcolm wrote:Then of course we must mention that extraction process for the rare earth materials in solar panels, wind generators, batteries, etc., are pretty devastating to their local environments because China/Inner Mongoloa is about the only place where rare earths are recoverable without significant quantities of radioactive materials, and even then they are strip mined.

One might say that ideally the whole of human society would not harm another living creature. We would all live on sunlight so that we would not have to kill a carrot, much less a cow, for food and we would float high above the grass so that we did not crush and kill it ... nope, 'fraid not. We're here, we're animals and need to eat other organic stuff, and we have as much right to fulfill our needs as other animals do. The best we can do is not inflict unnecessary damage, gratuitous suffering, on the rest of the world.
And in those terms, it is much less bad for us to dig up what we need for solar panels than to dig up the coal we would need to generate the same amount of electricity.

Knowing that there is no perfect scenario, I will cheerfully grab every amelioration, every improvement, in the way we treat the world - and each other, for that matter.


Kim

Kim O'Hara wrote: And in those terms, it is much less bad for us to dig up what we need for solar panels than to dig up the coal we would need to generate the same amount of electricity.

If it scales, sure. So far I see no evidence that it does.

Evidence:


...or choose your own favourite after oogling "solar power generation" and clicking the "Images" tag on the results page, which is all I did.


Kim

Kim O'Hara wrote:Evidence:


...or choose your own favourite after oogling "solar power generation" and clicking the "Images" tag on the results page, which is all I did.


Kim

That is not scaling. That is ugly as shit. Also, it is an extremely inefficient use of land area.

The main problem with renewables at this point is lack of storage options (battery technology is still not very advanced), variability in power generation, and the fact that natural gas and coal plants must continue to be used to make up for deficiencies. So called smart grids might be a solution, but the problem with all these technological computer-based fixes is that they introduce increasing complexity thus creating more opportunity for calamitous failure, terrorist attack, and so on.

If any thing, centralization of power generation not a desiderata.

Malcolm wrote:

Kim O'Hara wrote:Evidence:

...or choose your own favourite after oogling "solar power generation" and clicking the "Images" tag on the results page, which is all I did.


Kim

That is not scaling. That is ugly as shit. Also, it is an extremely inefficient use of land area.

Hi, Malcolm,
I'm not claiming PV power is perfect but surely it's better than (e.g.) http://upload.wikimedia.org/wikipedia/c ... ia_002.jpg which really is as ugly as shit and an inefficient use of land area - and in the end pollutes the atmosphere and adds to climate change as well. Perfection is not achievable so what I'm looking for is harm minimisation.

Malcolm wrote:The main problem with renewables at this point is lack of storage options (battery technology is still not very advanced), variability in power generation, and the fact that natural gas and coal plants must continue to be used to make up for deficiencies.

Acknowledged - but (1) I still feel that keeping a few million tons of CO2 out of the air must be a good thing and (2) the technology is improving really quickly.

Malcolm wrote:So called smart grids might be a solution, but the problem with all these technological computer-based fixes is that they introduce increasing complexity thus creating more opportunity for calamitous failure, terrorist attack, and so on.

Yes, that is problematic. However, the problem is not unique to renewables. Do you remember a big blackout a few years ago? One fault spread through the not-smart-enough grid and knocked out most of the eastern US - and it had nothing to do with renewable power.

Malcolm wrote:If any thing, centralization of power generation not a desiderata.

I'm not sure what you mean by that ... you may have to use a few more words.


Kim

Kim O'Hara wrote: I'm not sure what you mean by that ... you may have to use a few more words.

Houses and buildings should be designed, and retrofitted where possible, to generate their own power and provide it to the grid.

Malcolm wrote:

Kim O'Hara wrote: I'm not sure what you mean by that ... you may have to use a few more words.

Houses and buildings should be designed, and retrofitted where possible, to generate their own power and provide it to the grid.

This is my dream! I would love currency that's based on energy as well

Malcolm wrote:

Kim O'Hara wrote: I'm not sure what you mean by that ... you may have to use a few more words.

Houses and buildings should be designed, and retrofitted where possible, to generate their own power and provide it to the grid.

I agree that's a good way to go. It is also a strategy which PV power is ideally suited to, so I'm more and more puzzled by your negativity about PV.
Here in Australia it's not terribly difficult to go entirely off-grid and it's easy to have grid-connected solar but I wish there was some way that our domestic solar systems could keep operating as stand-alone systems when the grid went down. At the moment that's not permitted - every grid-connected inverter has a mandatory automatic cut-off when the grid goes down. There are obvious safety reasons for it but it does mean that if we lose power because of a cyclone we can't make do with the power we could still be generating at home. 5kwh per day (which is about what we make) would keep the fridges cool, top up car batteries that we could use for temporary lighting at night, recharge mobile phones and laptops, and maybe even cook a few meals.
If we are ever in a position where the grid goes down often I think I will go stand-alone (need to buy a few more panels, a different inverter and some batteries, that's all).


Kim

There is no green energy so far that doesn't require ripping into the earth. The Saudi Arabia of green energy is Tibet.



http://e360.yale.edu/feature/a_scarcity ... gies/2711/


http://tibetanplateau.blogspot.com/2011/07/wdfwe.html

Kim O'Hara wrote:

Malcolm wrote:

Kim O'Hara wrote: I'm not sure what you mean by that ... you may have to use a few more words.

Houses and buildings should be designed, and retrofitted where possible, to generate their own power and provide it to the grid.

I agree that's a good way to go. It is also a strategy which PV power is ideally suited to, so I'm more and more puzzled by your negativity about PV.

I am not so much negative about PV power generation as I am about its manner of implementation. Solar panels on a roof is one thing. Acres and acres of solar panels creates hot spots and dead zones, which add to local ambient temperatures and in many cases, at least in northern climes, require the extinction of grasslands which are just as crucial the Co2/O2 balance as trees and rain forests are.

Malcolm wrote:

Kim O'Hara wrote: I'm not sure what you mean by that ... you may have to use a few more words.

Houses and buildings should be designed, and retrofitted where possible, to generate their own power and provide it to the grid.

That is obvious (and has been since at least 1973). However support for this is not really possible through capitalist means. Most people in the US, for example, are impoverished and cannot support the minimum $10,000 required for a minimal setup (that number is easily 2-3x's higher in actuality). Some states (like Maryland) do in fact help home owners with fairly substantial subsidies for this purpose. Even so, this has not really caught on. Whenever I raised the subject for rewables at my former condo, it was batted down with any available excuse. We had a large roof area that was unused and could have installed solar panels and some wind generators. I was doing to go in with some people and propose that we finance it together but then the Second Great Depression hit.

American's have reflexively become the nation of "Can't do" since the retreat from space at the end of the Apollo missions (1973) and justify everything on the basis of very short-sighted "pragmatism". A counter example is Germany who decided to move to renewables in the 90's and are now producing 25% (2012) of their electricity from renewable sources at a fraction of the US renewable energy potential (the US has the largest store of renewable energy resources on the planet, and not just solar or wind, and is lagging embarrassingly).

Kirt

Malcolm wrote: I am not so much negative about PV power generation as I am about its manner of implementation. Solar panels on a roof is one thing. Acres and acres of solar panels creates hot spots and dead zones, which add to local ambient temperatures and in many cases, at least in northern climes, require the extinction of grasslands which are just as crucial the Co2/O2 balance as trees and rain forests are.

Solar panels on every roof (or at least most of them), including commercial buildings, aggressive wind power installation, solar furnaces storing the energy in molten salt.

This by itself will reduce dirty energy production by about 50% and can be achieved within 20 years. However we will need oil, gas and coal over the next century and will have to implement safe nuclear design (which does exist).

All new buildings build on the Swedish and other 0 carbon emission models (which will take a while to actually implement on a large scale).

Kirt

kirtu wrote:safe nuclear design (which does exist).

No, it doesn't. And the energy needed to extract uranium is hugely expensive, leaves radioactive waste behind, etc.

NO NUKES!

Malcolm wrote:

kirtu wrote:safe nuclear design (which does exist).

No, it doesn't. And the energy needed to extract uranium is hugely expensive, leaves radioactive waste behind, etc.

NO NUKES!

It is unfortunately what we will have to do. Humans are great engineers and we can engineer truly safe reactors. Unfortunately, I admit that most "safe" design follows based on the result of accidents and this cannot be tolerated moving forward.

But pebble-bed reactors fueled by thorium can be made with a safe design.

Earth is full of energy exceeding it's wildest needs. We merely lack the vision to implement a free energy-safe and intensive future.

Kirt

They might get fusion to work better in the future. It needs more research.

I think as far as global warming is concerned, the chain has already been pulled. We need to we swimming a lot faster towards renewable energy or we are going to end up in the 'do-do'.