Viability of Solar Power

[CaptainPanic]

Mankind has changed the surface of the entire earth. We are sure as hell capable of covering some significant part of it with solar panels, if we want to.

 

The same thing goes for wind power. Biomass seems to be the only sustainable resource is not capable of powering the whole earth, because there is not enough surface area.

[Pangloss]

Empty flat-top buildings bug the heck outa me. Pure wasted space.

[Edtharan]

We would have over 51 billion square meters of panel, that's close to 20,000 square miles of panel or the equivalent of covering most of West Virgina over in panels.

Here is a question. How much area does the roof surface of every building in the US cover?

 

174 square meters of panel

A square 14m on each side would be enough to provide this. As the average house is much bigger than this (not to mention all the office buildings and other infrastructure), then this plan does not seem all that impossible.

[Pangloss]

Here is a question. How much area does the roof surface of every building in the US cover?

 

That's what I wonder, every time I fly over a city. All that wasted space.

[iNow]

You could spit ball a number.

 

Average square footage of a building.

Average number of buildings per square mile.

Square miles across the country.

 

 

Add it all up and you could be generating some amazing tetrawatts worth of power by placing solar panels on even 50% of that space.

[john5746]

Mankind has changed the surface of the entire earth. We are sure as hell capable of covering some significant part of it with solar panels, if we want to.

 

Yes, I think innovations in solar technology will make that very possible.

 

http://www.popsci.com/popsci/flat/bown/2007/green/item_59.html

 

http://www.nanosolar.com/

[Sisyphus]

Biomass seems to be the only sustainable resource is not capable of powering the whole earth, because there is not enough surface area.

 

You're right that the upper limit for energy efficiency is necessarily going to be lower for biofuels than for solar. However, it's not necessarily true that there isn't enough room. For corn, soy, sugar cane, or any of the current common crops, you're right. But algae-based fuel produces thirty times the energy per acre, and we could, theoretically, power the whole world with it. Not that we should, necessarily, but we could.

 

From that article:

 

"The United States Department of Energy estimates that if algae fuel replaced all the petroleum fuel in the United States, it would require 15,000 square miles (40,000 square kilometers), which is a few thousand square miles larger than Maryland, or 1.3 Belgiums.[4] This is less than 1/7th the area of corn harvested in the United States in 2000.[11]"

[swansont]

You're right that the upper limit for energy efficiency is necessarily going to be lower for biofuels than for solar. However, it's not necessarily true that there isn't enough room. For corn, soy, sugar cane, or any of the current common crops, you're right. But algae-based fuel produces thirty times the energy per acre, and we could, theoretically, power the whole world with it. Not that we should, necessarily, but we could.

 

I wonder how much of the yield is from faster growth, i.e. getting more crop cycles cultivated per year. I didn't see that mentioned in the article.

 

That's what I wonder, every time I fly over a city. All that wasted space.

 

Wasted but possibly not readily usable. One thing to consider is the structural strength of those roofs. I have some limited experience in issues of placing equipment on them; they probably weren't built with the idea of covering them with solar panels, because solar panels weren't anywhere near being a viable option when they were designed. So the cost of strengthening the roof and adding solar panels may leave you with a system that's still not economically viable.

[Phi for All]

Empty flat-top buildings bug the heck outa me. Pure wasted space.

Retro-fitting existing buildings with solar panels is one thing, a necessary thing imo, but integrating solar roof sheeting in new buildings is much more efficient in all respects. I realize this is more of a political question, but how does everyone feel about making it mandatory for new buildings to have Built-In Photovoltaic (BIPV) systems? Should this be left to municipalities to adopt as code or should there be a federal mandate?

[swansont]

Retro-fitting existing buildings with solar panels is one thing, a necessary thing imo, but integrating solar roof sheeting in new buildings is much more efficient in all respects. I realize this is more of a political question, but how does everyone feel about making it mandatory for new buildings to have Built-In Photovoltaic (BIPV) systems? Should this be left to municipalities to adopt as code or should there be a federal mandate?

 

You could meet in the middle with incentives to make it economically advantageous.

[Sisyphus]

Retro-fitting existing buildings with solar panels is one thing, a necessary thing imo, but integrating solar roof sheeting in new buildings is much more efficient in all respects. I realize this is more of a political question, but how does everyone feel about making it mandatory for new buildings to have Built-In Photovoltaic (BIPV) systems? Should this be left to municipalities to adopt as code or should there be a federal mandate?

 

I don't think a blanket solution like that would be feasible, especially at the federal level. For one thing, rooftop solar is only worthwhile if the roof actually gets a certain amount of sun. You wouldn't put panels in a forest (or other shady location), or on a north-facing slanted roof, or a north-facing hillside, or places like Alaska. I would rather see:

 

1) Economic incentives, rather than mandates. I don't think they'll even be necessary as solar gets cheaper and more efficient, but they could help.

 

2) Municipal-level codes. It might actually be feasible on that level in certain places. I'd even be happy with specific deals with local governments, to account for circumstance. "Want to build that housing development in our town? Make your proposal energy self-sufficient and sustainable, and we'll talk."

 

3) More local projects (as opposed to regional or individual). A "town wind turbine," for instance, would (I'm guessing) be much more economically efficient than little ones on every roof, you'd still get most of the benefit of local generation (less electricity lost in transmission), and there wouldn't be the massive red-tape and such to overcome with huge, regional plants.

[CaptainPanic]

You're right that the upper limit for energy efficiency is necessarily going to be lower for biofuels than for solar. However, it's not necessarily true that there isn't enough room. For corn, soy, sugar cane, or any of the current common crops, you're right. But algae-based fuel produces thirty times the energy per acre, and we could, theoretically, power the whole world with it. Not that we should, necessarily, but we could.

 

From that article:

 

"The United States Department of Energy estimates that if algae fuel replaced all the petroleum fuel in the United States, it would require 15,000 square miles (40,000 square kilometers), which is a few thousand square miles larger than Maryland, or 1.3 Belgiums.[4] This is less than 1/7th the area of corn harvested in the United States in 2000.[11]"

 

Let me doublecheck that, because sometimes algae productions are heavily overestimated, or the energy input of algae production systems are underestimated.

 

Ok, the US consumes an average of 3.3 TW, and 40% of that is petroleum (so: 1.32 TW). - a TW is 10^12 W, or a million MW, or a thousand GW.

 

I am assuming that the insolation value used in the study is pretty good: 6 kWh/m2/day, or 250 W/m2. - these are southwest desert values.

As a comparison for Europeans, the Madrid value (10 year average) is 4.62 kWh/m2/day, or 192.5 W/m2.

The 40,000 km2 (equal to 4*10^10 m2) receive a total of 10*10^12 W, or 10 TW.

 

So, as I thought, the US department of energy has indeed used the upper (only-reached-in-a-laboratory) value of algae production, where algae are supposed to approach solar panels. The US department of energy study apparently assumes that algae can convert >13.2% of the sun's energy into biomass (and perhaps completely neglects the CO2 mass transfer system, O2 removal, purification and drying steps). And I shouldn't forget to mention that mixing is of vital importance to achieve high algae productions. Mixing at huge Reinold's numbers (over 10000).

[Phi for All]

3) More local projects (as opposed to regional or individual). A "town wind turbine," for instance, would (I'm guessing) be much more economically efficient than little ones on every roof, you'd still get most of the benefit of local generation (less electricity lost in transmission), and there wouldn't be the massive red-tape and such to overcome with huge, regional plants.

Several years back I talked to a guy who was installing solar panels in small mountain communities and he quoted me his price for a single home. It turns out that for 50% more he could instead set up a community array that would power the whole village. It would definitely pay to look into community efforts for wind and solar.

[CaptainPanic]

I think every region should do what fits best. Densely populated areas could be better off with large scale energy suppliers, perhaps outside the city. This goes especially for those people living in apartment buildings, without a roof or garden of their own... In rural areas I think smaller scale is best as space is much less of an issue.

 

In the world of sustainable renewable energy there is not one single best solution. We should just get started with the whole thing... I sometimes get tired of all the talking

[Think it thru]

While far from perfected but of interest is the work of Dr. David Faiman in Israel. I want to clearly state that he is not using silicon photovoltaic cells, but another kind.

 

Dr. Faiman is focusing his work (pun intended) on using mirrors to focus light onto a 4 inch solar cell which is putting out 1500 watts instead of the standard 1 watt per normal sized cell.

 

Quite impressive numbers in the video.

http://www.israel-times.com/business/2007/08/israel-new-solar-energy-breakthrough-magnifies-the-sun-x1000-2865/

 

Further, on the average number of KWH used per person in the US---as far as HOME energy consumption goes I generally use less than 250 KWH PER MONTH with consumption sometimes falling below 180 KWH per month. That means my monthly home use is less than the average use per day. Typical electric bill is less than $25.

 

I hope to eventually switch to off grid solar, perhaps supplemented with wind electrical generation.

 

I'm with T. Boone Pickens, there is a lot of untapped and under utilized wind energy for the taking.

[Phi for All]

Here's what I want:

 

I want two fully electric cars like GMs EV-1 with the latest large format NiMH battery for a range of over 120 miles on a charge (cost unknown because GM only leased them and refused to sell, and this car isn't available right now but should be). I want the south facing elevation of my roof covered in solar shingles to power my house and cars (a robust array will run me $15k). I want an electric HVAC system powered by my solar array, which also cuts CO emissions to 0 (price varies, still shopping).

 

I end up being off the grid completely, I don't pay to fuel my car, heat and cool my home, light my home or run any of my appliances. I could probably start investing in DC-powered appliances and lighting for further efficiency and longer replacement times. My monthly expenses go down by several hundred dollars, hopefully enough to pay off the $80k-100k loan I'd take out to make it all happen.

 

Big question: What are the energy companies, appliance manufacturers and the automotive industry going to do to stop me? Parts for infernal combustion engines are huge profit centers that dry up with electric motors. AC-powered appliances burn out quicker and need to be replaced and repaired more often than their DC-powered counterparts. And the more people who get solar, wind and micro-hydro power, the higher the price will be for remaining grid customers, which will make solar, wind and micro-hydro even more appealing and cost-effective and cause more people to switch over.

 

What are those industries already doing to stop me?

[swansont]

What are those industries already doing to stop me?

 

They don't make many DC-powered appliances, but in a market economy those should eventually become more widely available.

[foodchain]

I know uni-solar produces a neat and flexible solar panel that is shade tolerant or can still function and is made general to be placed on specific types of roof.

 

I am still looking into tefzel and I find it hard to get much other information on what the product is made out of. Its to be a very long lasting item though, so massive and constant production should not be as large an issue.

 

Geodesic dome homes are a tickly option also, as some can be rather tricky to think about. One case in particular is the fact that such buildings can be rather efficient, in fact in many cases that can simply dominate this category when compared to other types of homes. I would think with how such buildings are designed that you could completely encase large portions of it in a flexible solar panel. The more tricky part of this is the insulation scheme in which you can find some things to take issue with. Though this depends I think if you want your dome home to be built of concrete or something else. The concrete ones supposedly can take class five storms or what not like hurricanes and stay structurally sound. Then again concrete production is a large source of CO2.

 

If you can get enough juice compared to lifestyle like you are saying then I think it could also power your cars. The amount of money that would be saved is a good amount, plus if you don’t use all the electricity you generate I think the power company has to purchase such from you.

[iNow]

I know uni-solar produces a neat and flexible solar panel that is shade tolerant or can still function and is made general to be placed on specific types of roof.

As I understand it, one of the problems with the flexible panels/sheets for solar photovoltaics is the difficulty in encapsulating the chemicals. Basically, we can do this very well already with glass and crystalline silicone, even thin film, but the flexible stuff tends to leak these carcinogenic chemicals after a few years of being exposed to the elements all day and night. While this leaking is really bad for health, it also causes the unit not to operate as efficiently. Both of these issues are bad for that market.

 

If they can fix the encapsulation issue, then it will have much more going for it. Not yet, though...

[Phi for All]

If you can get enough juice compared to lifestyle like you are saying then I think it could also power your cars. The amount of money that would be saved is a good amount, plus if you don’t use all the electricity you generate I think the power company has to purchase such from you.

If enough people convert to solar, you can bet the energy companies will squash the overage buy-back policy in a heartbeat. Since our utilities are now mostly privately owned, they will be working hard to keep us from going off the grid, in much the same way insurance companies use part of your premiums to figure out ways to deny your claims.

 

In much the same way, I'm sure auto makers (internal combustion) will be using part of every sale dollar to discourage the market from wanting them to retool for electric vehicles. We know the oil industry is against electric (I found out recently that Toyota had an EV version of the RAV4 SUV that, just like GM's EV-1, got killed by Chevron, who stopped selling them their patented large format batteries) and is doing everything they can to pitch the hybrids that use some gasoline. My point is that there are a bunch of markets that hate the idea of us running our homes and cars for free or at a substantial savings because they can't make any money off us. We'll need to be very watchful for lobbyists and PACs who are pushing for legislation to stop us from going off-grid.

[swansont]

OTOH, some utilities have been pushing for distributed generation (that they help manage) probably because it means less money needs to be invested in upgrading the distribution network.

[CaptainPanic]

I think Phi for All described the problem with solar power (and wind power) very well... Sustainable energy means that some companies will have less revenues.

 

But then again, I've seen industries thriving while prices went down. Computers have become better and cheaper over the last years. In 1998 I bought my pc for almost twice the price as my latest computer... and that's despite 10 years of about 2-3% inflation. Phones too have become cheaper, and phone companies now even offer fixed line phone for free...

 

Therefore I haven't lost all hope. It's true that energy companies would lose revenue from direct sales of electricity/gasoline... but they do have lots of expertise, and will be making money from us one way or another. I believe it's just a matter of conservatism and stubbornness that we're not converting a lot faster.

 

Besides all that, I think that going off-grid is more expensive, because you'll need relatively lots of storage for energy. The bigger the grid, the less (relatively) storage you need.

[swansont]

I think Phi for All described the problem with solar power (and wind power) very well... Sustainable energy means that some companies will have less revenues.

 

What if the overall demand increases faster than the "self generated" sector? Imagine replacing most gasoline with electricity. In the US, that's about a billion kWh per day of electricity required, which is comparable to residential electricity usage. IOW, demand doubled, and this without more gadgets and a larger population. I'm not worried about corporations' ability to turn a profit.

[CPL.Luke]

hmm phi for all it seems a couple o our posts in the thread on GM over in politics actually belong in here, although if they don't get moved I recomend your guys check out a couple of posts in the thread GM "chairman" last letter. There toward the end, but I dug up some of the cost analysis on present technologies, and the cost history (real value) of both grid power and solar power.

 

it can be summed up as such, a person who installs a solar power system on their house will pay 3.7 times more for electricity than a person who buys the power from the grid. (excepting subsidies and the like)

[iNow]

Why are people still discussing this issue only in terms of money and economics? There is FAR more at stake here other than just the bottom line.