The Efficacy of Solar Power

[woolfe9999]

Fair enough but unfortunately the installed cost is not going to move as much because it doesn't benefit from technological improvements. Even if they panels went to zero the cost install 1 sqft of panels isn't going to move below a certain point. It puts a floor on the total system cost.

I'm not familar with the details of the other costs and whether they can come down. The analysis is probably different for a distributed model than a centralized one, the latter of which can benefit more from economies of scale. Both will become more competitive as other sources of energy increase in cost. Still, you have a fair point.

- wolf

 

[theeedude]

Yeah "green.blogs" is such a good and believable source .

It's not the source. The source is Harvard Medical School. But nice try.

 

[QuantumPion]

Again, you are already feeding them, you might as well get something back.

No. That is not how the world works. You have to feed them more if they are going to be doing heavy physical activity constantly. The additional food has to be at least equal in energy content as you would get out, and in practice is much more when you take into account the cost growing/harvesting/cooking the food as well. This is basic thermodynamics. Even if they were already using exercise bikes, and you were just taking the extra step of connecting the bikes to a generator to recover the energy - it is still a net energy loss, you are just losing less. Like regenerative braking on a hybrid car.

 

[silverpig]

Fair enough but unfortunately the installed cost is not going to move as much because it doesn't benefit from technological improvements. Even if the panels went to zero the cost install 1 sqft of panels isn't going to move below a certain point. It puts a floor on the total system cost.

You assume the installation method remains static.

There are "printable" solar cells. Now imagine "sprayable" solar panels. Put down your roofing shingles, spray on layer 1, spray on layer 2, hook a wire to the top layer, voila.

They are also talking about solar coatings for windows - they screen some light and turn it into electricity.

 

[the DRIZZLE]

You assume the installation method remains static.

There are "printable" solar cells. Now imagine "sprayable" solar panels. Put down your roofing shingles, spray on layer 1, spray on layer 2, hook a wire to the top layer, voila.

They are also talking about solar coatings for windows - they screen some light and turn it into electricity.

I do make that assumption. I'm skeptical that we will see anything like that reach commercialization in our lifetime. I think the more likely paradigm shift is that we prefab entire buildings with solar panels already built in.

 

[Zebo]

Solar like all energy is a derivative of oil. Or you think glass, silicon, batteries and polymers just appear on your roof. I'd like to see real numbers on this sometime. Last I heard is a average computer takes 2 barrels of oil to make. How much oil is a solar array for a house? A lot which is why solar costs so much. Until it's cheaper than oil, gas and coal directly these numbers will always look poor. As to why? Financials arnt the only consideration. If you're off grid you don't have to worry when grid goes down. I'm sure there are other reason but environmental can't be one of them as you dig deep.

 

[Nobuo]

I live in Arizona, and I just invested in a solar electric system for my house so I'll share my perspective.

My system is grid-tied (most utilities allow this in my state), so no batteries are required and the utility gives a 1:1 credit for excess power I send backward through the meter. Cost me about $4,000 installed with all the incentives factored in (3.7 kW system), and it will offset around 50% of my annual electricity bill. With my utility, that's around $750/year in savings, which should increase over time if electricity rates keep going up.

Government subsidies definitely affect the economics of it, but seems like a good deal to me as an individual homeowner at this point in time. I'm in AZ so my situation is a bit unique, but anyone in the Southwest should see similar results.

 

[RampantAndroid]

Solar will never, ever, be an efficient source of energy for general use on a large scale. The energy density is just too low. The unsubsidized cost of solar panels cannot pay for themselves in their useful lifetime. They're only useful for niche applications.

They're currently <30&#37; efficient with the actual energy hitting them. You can go on saying solar is hopeless if you like. I'm glad no one listens to you. You see, science is moving forwards. What today is 30% might eventually become 75%. Hell, it might lead to other innovations. If companies want to pursue it, let them. Keep the gov't out of it. Allow the market to take over.

I mean, imagine a system where shingles on new homes in places like Arizona (as nobuo points out) and they are 75% efficient panels. You lose some since you don't change the angles of them based on the season, or change their facing from dawn to dusk...but you absorb light...attics heat up less, meaning cooling costs drop some. The system can work quite well for certain applications. Is solar going to power the planet? I don't see it happening for a very very long time, if at all...but it does have it's place. It has a point and a purpose.

 

[dank69]

Fair enough but unfortunately the installed cost is not going to move as much because it doesn't benefit from technological improvements. Even if the panels went to zero the cost install 1 sqft of panels isn't going to move below a certain point. It puts a floor on the total system cost.

The installed cost per watt will come down as the watt per square foot goes up.

 

[mect]

They're currently <30% efficient with the actual energy hitting them. You can go on saying solar is hopeless if you like. I'm glad no one listens to you. You see, science is moving forwards. What today is 30% might eventually become 75%. Hell, it might lead to other innovations. If companies want to pursue it, let them. Keep the gov't out of it. Allow the market to take over.

I mean, imagine a system where shingles on new homes in places like Arizona (as nobuo points out) and they are 75% efficient panels. You lose some since you don't change the angles of them based on the season, or change their facing from dawn to dusk...but you absorb light...attics heat up less, meaning cooling costs drop some. The system can work quite well for certain applications. Is solar going to power the planet? I don't see it happening for a very very long time, if at all...but it does have it's place. It has a point and a purpose.

This is very unlikely because to achieve 75% efficient panels, you would need extremely complicated cells with a lot of junctions with a lot of different absorbers. A single junction solar cell has a maximum efficiency of 33%. A two junction cell has a maximum efficiency of 42%, a three junction cell 49%. I'd say 50% is probably a realistic upper limit on efficiency for solar cells. However, it doesn't need to happen. Cost efficiency really the important factor, and this I agree will continue to improve, as there are no fundamental physical limits involved (or at least much less stringent ones).

 

[mect]

I live in Arizona, and I just invested in a solar electric system for my house so I'll share my perspective.

My system is grid-tied (most utilities allow this in my state), so no batteries are required and the utility gives a 1:1 credit for excess power I send backward through the meter. Cost me about $4,000 installed with all the incentives factored in (3.7 kW system), and it will offset around 50% of my annual electricity bill. With my utility, that's around $750/year in savings, which should increase over time if electricity rates keep going up.

Government subsidies definitely affect the economics of it, but seems like a good deal to me as an individual homeowner at this point in time. I'm in AZ so my situation is a bit unique, but anyone in the Southwest should see similar results.

Nonsense, this would only require 5 years to pay itself off (a little over 10 if it were unsubsidized). Haven't you heard what people have said. Solar will never be feasible if it isn't subsidized. It would need to improve by a factor of 10 (or 100 according to one very knowledgeable poster) for this to happen. You think just because you actually installed a system you know anything about solar! /sarcasm

 

[the DRIZZLE]

They're currently <30% efficient with the actual energy hitting them. You can go on saying solar is hopeless if you like. I'm glad no one listens to you. You see, science is moving forwards. What today is 30% might eventually become 75%. Hell, it might lead to other innovations. If companies want to pursue it, let them. Keep the gov't out of it. Allow the market to take over.

I mean, imagine a system where shingles on new homes in places like Arizona (as nobuo points out) and they are 75% efficient panels. You lose some since you don't change the angles of them based on the season, or change their facing from dawn to dusk...but you absorb light...attics heat up less, meaning cooling costs drop some. The system can work quite well for certain applications. Is solar going to power the planet? I don't see it happening for a very very long time, if at all...but it does have it's place. It has a point and a purpose.

The total solar radiation per sq ft is so low in the northern states that even at 75% it probably still wouldn't make sense.

 

[mect]

One note, is despite everyone's misconceptions, you don't need to live in Arizona or Nevada for solar to be practical. Most of the United States receives at least 66&#37; of the sunlight that these desert areas do. Yeah, it isn't as good, but still only requires a 50% improvement in order to achieve the same efficacy as these prime regions.

http://findsolarpro.com/solar-resources/interactive-exposure-map.html

 

[Darwin333]

That entirely depends on what the maintenance costs are for each type of power. It might be efficient to maintain one large coal plant as opposed to a number of small coal plants, but the requirements and costs for solar are totally different. I genuinely have no clue what the maintenance requirements per year of solar panels are as compared to coal, but that would be a good reason why I wouldn't make that sort of blanket statement.

Maintenance costs for solar (panels) if you live in an absurdly dry area like the desert is hitting them with the water hose a few times a year.

Done.


Almost every other climate nature does that for you (rain).

Just about all solar under utility grade has virtually zero maintenance costs. You will have to budget new inverters approximately 15 years after the install but the panels, unless physically damaged, don't have anything in them to break. They get less efficient over time due to UV and a few other issues (mostly in the glass, not the cell itself) but if they paid for themselves a decade ago who cares that they produce 5 or 10% less today?

 

[the DRIZZLE]

The installed cost per watt will come down as the watt per square foot goes up.

When you combine the fixed installation cost with the realistic maximum efficiency for panels you hit a floor on the total price.

 

[RampantAndroid]

The total solar radiation per sq ft is so low in the northern states that even at 75% it probably still wouldn't make sense.

And that's fine - I'm OK with that (hell, I live in Seattle, I should know )

But there are places where it makes total sense as well. Cali, Ariz, Texas, FL and so forth. In my state, we have tons of hydro - most of the state is based on hydro power.

 

[dank69]

When you combine the fixed installation cost with the realistic maximum efficiency for panels you hit a floor on the total price.

Okay, then is it possible for a weekend warrior to install panels themselves?

 

[Moonbeam]

Solar cells as we currently know them have know theoretical efficiencies and I don't believe they are anywhere near 75&#37;. But efficiency is not the major issue. It's manufacturing and installation costs that will supply the major savings. Concentrated solar has the advantage of storing heat in molten salts that can produce power after dark and printed solar cells will be profoundly cheep to make. Major innovations in how solar is installed, modular units and roof tile units installed in new housing, will make solar far more desirable. A large number of innovations are in the works.

There is also the option of using DC instead of AC appliances eliminating the need for converters.

 

[Moonbeam]

Okay, then is it possible for a weekend warrior to install panels themselves?

New systems are being made that connect together easily.

 

[Moonbeam]

Solar power will never work. We need to feel hopeless:

http://blog.sustainablog.org/2011/11/solar-power-system-rotator/

 

[zanejohnson]

you do realize.. the sun is our only semi-renewable energy source, well that and geothermal, and wind...

yeah, in the future, our current systems will look retarded.

what we need to do is figure out to to more efficiently manipulate the wind, and use it..

 

[zanejohnson]

actuuuuuallllly what we need to do is hurry up and figure out anti gravity, psi energy.. etc..

 

[hal2kilo]

I'm not reading this thread. It doesn't matter you f'n spreadsheet kings of depreciation this and long term this. All, I know is that a country that you would never think could be a candidate for solar power, because of the incentives to home owners to put solar panels on their homes (Germany), is now a net exporter of power,

But keep spreading out those cos on your modern Jxxs harps till the cows come home and ingore reality

 

[IGBT]

Solar power will never work. We need to feel hopeless:

http://blog.sustainablog.org/2011/11/solar-power-system-rotator/

solar power does work. It purges eco-KOOKS of their money. I luv it.

 

[dank69]

solar power does work. It purges eco-KOOKS of their money. I luv it.

I see you love that eco kook term. I wonder, do you think this planet can support an unlimited amount of people?