Solar Power

[grooble]

"A farm 100 miles by 100 miles in the southwestern U.S. hypothetically could provide as much electricity as is needed to power the entire country," said SES general manager Bob Liden.<br /><br />http://www.livescience.com/technology/041115_solar_dish.html<br /><br />So why don't they do that? Do you think they will?

 

[fear]

"So why don't they do that?"<br /><br />The environmentalists would never let 100 square miles be developed all at once. It would just be too ambitious of a project as well. I think they should do it though if they ever find the means to. <div class="Discussion_UserSignature"> </div>

 

[grooble]

They could do it in 5x5 mile stages, over 20 years, i'm sure that would be ok.<br /><br />Set one of these up in Africa <img src="/images/icons/smile.gif" />.

 

[najab]

><i>The environmentalists would never let 100 square miles be developed all at once.</i><p>Ahh, don't you just hate word-problems. 100 miles squared is not the same thing as 100 square miles. 100 miles by 100 miles is actually 10,000 square miles - about the size of Massachusetts.</p>

 

[grooble]

Out the way sucka's, theres a world needs savin!

 

[yurkin]

The reason that this hasn’t been done is because solar farms cannot compete economically with nuclear or even coal power plants. Even though they don’t have to pay for any fuel the cost of operating them is still too high. So the cost of the electricity generated would be higher then what people would be willing to pay. So there’s no business incentive to do this and without that its not getting done.

 

[glutomoto]

Re: 60 sq. m. of them, which are easily installed on the roof of a modern home.<br /><br />I'll bet there aren't very many homes modern or otherwise that are as large as this, 60 meter = 196.850 feet.<br /><br /><br />Re: At 23% steady state efficient of the more modern amorphous silicon panels.<br /><br />Steady State is the key problem, efficiency is effected by; Solar site insolation, tracking angles, the days of available sunshine, dust, cloud cover, wiring loss, inverter efficiency, and panel aging. Maybe it will power a few homes, on sunny days.<br /><br />Re: Why it's not being done<br /><br />I think it is because so far solar pv is a net enery sink, in other words they use more energy than they give back.<br /><br /><img src="/images/icons/smile.gif" /><br /><br /><br /><br />As far as fiber optic for telephone infrastucture is concerned, I don't know. However our local cable network recently converted to a fiber optic digital network, and the prices have been going up and up and up. <br /><br /><img src="/images/icons/frown.gif" /><br /> <div class="Discussion_UserSignature"> </div>

 

[najab]

><i>I'll bet there aren't very many homes modern or otherwise that are as large as this, 60 meter = 196.850 feet.</i><p>Here we go again with the word problems - 60 square meters is (approximately) the same thing as 600 square feet, or about 20ft by 30ft.</p>

 

[glutomoto]

opps.<br /><br />thanks najaB <div class="Discussion_UserSignature"> </div>

 

[bobvanx]

I KNOW<br /><br />that when you add up all the costs of mining the coal, building the plant (both of which are usually most profitable when optimised for a 40 year life), buring the coal, cleaning up after yourself, and paying all the health claims, that government subsidies make coal fired power generation less expensive than PV.<br /><br />I KNOW<br /><br />that if the subsidies were removed, a PV farm as large as the pit the coal came out of is cheaper per KW, and has the same lifespan, and cheaper maintenance costs. And fewer/lower health costs.<br /><br />The really misleading thing the coal people do is bury, hide, or avoid mentioning all the places they are NOT paying the real cost to generate their electricity.<br /><br />The really misleading thing the PV people do is fail to mention that what power companies really need is steady baseline power generation. Electricity is used with a tenth of a second of its generation, and PV sucks for providing baseline power. As soon as you start trying to store the energy, PV gets expensive.

 

[nexium]

Hi steavehw: Let's test the aritmetic on competitive amorphous silcon panels. The contractor bids 3 million dollars (delivered to building site) on 60,000 square meters of solar panels = 1000 houses. Thats $50 per square meter. About 1/4 usual retail price for one square meter. I suppose some factory will sell that cheap, if the contactor pays one million dollars now for delivery beginning in weekly instalments, September 2005 though Febuary 2007, with sizable penalties for late delivery of any instalments.<br /> That comes to $3000 per house for the panels. Let's figure $5000 per house as labor cost will be considerably higher, until the laborers are trained and errors become rare. There is also considerable wiring to interconnect the panals and the inverter cost. The house design needs to be optimised for solar panels, perhaps $3000 including promotions to get buyers to pay a sizable premium for the houses, and a 20 year repair agreement on the solar electric system. That is $400 per year for 20 years for the home owner, paid up front. The interest on the upfront money may be offset by the higher price the home owner will likely get if he sells the house. Increased taxes and insurance will be about $100 per year. Did I miss anything other than a profit increase for the contractor? If not, it appears the home owner gets $1000 worth of free electricity per year, and it is competitive.<br /> While there will be a sizable electricity surplus for nearby homes on a cloudless June 21 at 1 pm, there will a shortfall typically on December 21, and every day starting an hour or more before sunset when 60 square meters of solar panel produces less than 600 watts. The principle house redesign is the portion of the roof facing south or south-west should be tilted 20 to 30 degrees, which is much steeper than roofs are usually built in the subtropical zone.<br /> The electric utility needs compensation, as the houses will deliver to the grid when the electricity is not needed and d

 

[CalliArcale]

I haven't the time to run the math right now, but going by purely anecdotal information, it seems that if you can afford the considerable start-up costs, solar power can indeed save you lots of money, and you may even make more electricity than you consume.<br /><br />Actually, there are many forms of solar power that can reduce your power consumption. Locally, here in Minnesota where the winters are long (though not so much as in most of Canada), there's as guy they showed on the news who uses it for heating. He doesn't sell anything to the power company, because it doesn't generate electricity at all. However, he's been able to eliminate his gas heater and the costly electric space heater in his studio (he's an artist). He claims that it has paid for itself. Two mitigating factors were that he was replacing both the floor in the studio and the roof of his house anyway (meaning there was an expense he'd be making regardless of whether or not he went solar), and he did most of the work himself. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[mrmorris]

You don't have to do the math. Use this calculator. You'll find out exactly what I did a few months back when we lost power for Charlie, Frances and Jeanne and I briefly considered adding PV to my house. I've been considering getting a whole-house generator for a couple of years (~$4500 with installation) and I thought -- why not do PV -- since that will give me a source of backup power when the utility company can't *and* lower my electric bills all year round.<br /><br />Nope. PV still isn't economical without rebates/incentives. See for yourself -- the calculator program is very comprehensive and easy to use. You can flip between several dozen modules from various manufactirers, alter the number of roof modules installed, inverters, etc. All in all -- no matter what options you pick -- right now PV costs more than it saves (a <b>lot</b> more than it saves). In five years, the price per watt may well drop enough to change this, but I doubt it before then. My guess would be ten years before it reaches breakeven.

 

[najab]

><i>PV still isn't economical without rebates/incentives.</i><p>Sadly, that is true. But that's largely because the oil and gas industry gets hidden subsidies from the Government. If ExxonMobil had to pay the cost of keeping an aircraft carrier battle group in the Gulf and all the other measures that the Government undertakes to keep the oil flowing, I'm sure PV would start to look much more attractive.</p>

 

[bobvanx]

I like how the "solution" is to create rebates and incentives for PV, rather than eliminate them for fossil fules and nuclear power.<br /><br />...not

 

[nexium]

High steve hw: I have not seen these references that analize the cost in detail. Everyone posting here is stating opinions they have seen or heard. Do you think my prepaid delivered price beginning Sept 2005 is high or low on 60,000 square meters delivered to the building site?<br /> Will the manufacture replace panels that fail Including shipping and handling costs on the 14,600th day = 40 years or before? If not, the manufacture is unsure that his production has a reliable life expectancy of 40 years. What percent of the photo voltaic panels built in 1964 are (or belong) in the land fill?<br /> About 90% of the USA population is in locals, which are partly cloudy half or more of the afternoons, and mornings are not much better and we can expect the noontime wholesale price of electricity to fall to about one cent per KWH in locals where one gigawatt of solar power is available, except on mostly cloudy days. Exceptions would be places like Manhatten Island where a gigawatt of solar power might cost 1000 times what it costs near Death Valley, because the tallest buildings shade the roofs of average height buildings.<br /> Deep cycle batteries are down to 50% efficiency or less by the 300th cycle and failing fast, so replacement batteries may be more than half the total cost over 40 years, even if they supply on the average only 1/10 th of the peak output of the solar panels. One experieced battery person told me that you halve the amp hour capacity of a cell the first time you drop it's optimum 2.22 volts to 1.8 volts (no load volts). A 240 volt dc battery has at least 108 cells, and is only as good as the weakest cell. Better batteries are available, but we probably can not get 900 megawatt hours delivered to the building site beginning Nov 7th 2005, even if the contractor prepays a million dollars today, unless the contractor is willing to pay double the price of deep cycle lead acid batteries. Neil

 

[mrmorris]

<font color="yellow">"Everyone posting here is stating opinions they have seen or heard."</font><br /><br />Not <b>everyone</b>. The link I posted above gives very detailed information and analysis of the costs and returns. It includes graphs that show Net cost, Daily Output, Monthly Output, Cash Flow, Discounted Cash Flow, Cumulative Discounted Cash Flow, Shading analysis, Electric Bill comparison, Tax Rates, Environmental Savings and simple payback. <br /><br />Now -- if you'd like to state that "<b>Most</b> everyone posting here..." -- s'okay.<br />

 

[nexium]

Hi mrmorris: I missed some of the details as I was unwilling to down load Megamedia (or whatever). The bottom line was a 4 dollar extra cost, monthly for perhaps 2% solar, which decreased to 3 dollars when I estimated lots fewer obstructions to sunlight reaching my solar panels = shading analysis. All my neighbors have tall shade trees, nearly all of which still have their leaves. Most sections of Florida have fewer clouds than Jacksonville or Baldwin, Florida, but my power Company does offer some incentives.<br /> The $ 994 barrowed at 4.75% interest obviously does not include the cost of the 30% tilt to the South. My roof only has about a ten degree tilt.<br /> I appologize for including you in "everybody" Neil

 

[nexium]

If some of you want to risk a slap on the hand, by your power company, or a minuet risk of disaster if your system kills a power company employee, you can be a pirate co-generator.<br /> Put up the solar panels. More than 30 degrees tilt to the South is best, if you live North of Jacksonville, Florida. Connect a deepcyle battery to each square meter of solar panel. Not critical, but the panel should produce 15 to 20 volts, at no load, in moderate sunlight. Connect a cheap 12 volt inverter to each 12 volt battery. About $40 for 500 or 600 watts. More is better, but the price rose rapidly, the last time I checked. Build a suicide cord = plug on both ends. Turn on the inverter, and a heater just before you plug it into any outlet in your house. You can then turn off the heater, unless you want it for heat.<br />Your electric bill should drop by a dollar or two. If you build several of these 12 volt systems, plug them into different outlets preferably with different circuit breakers. Although cheap inverters are not designed as co-generators, they only occasionally blow their fuses or shut down. If the power company is suppyling 121 volts, your inverters will float, without suppyling any power to the grid. If the power company is only suppyling 117 volts, the inverters will run near full output, increasing the voltage perhaps one volt. If the voltage falls much below 117 volts, expect all your inverters to do an overload shutdown. This protects power line employees who might not realize you are energizing the power line. Your inverters can supply you and your neighbors, if none of you have any heavy loads connected, so you might get no indication that the utility is not supplying any of the power. Obviously the risk increases as you add more inverters.<br /> If you are aware that the utility is not suppling power (or your lights are flickering) shut off any large loads such as your central heat pump, a cloths dryer, your cook stove, then switch off the main circuit break

 

[nexium]

Hi steve: I got 2/3 of a BSEE in electonics back in the 50s and have worked in related fields as a technician, occasionally Jr engineer. I have always wanted to know the details, which occasionally conflicted with what my boss wanted. I have learned a lot of science and a bit of engineering from space.com and similar boards.<br /> A rich, but very cheap friend and I have experimented with solar panels and batteries, which is one reason I tend to think bare bones. No one would want their children playing with the suicide cord. I suspect a large power line surge would kill all the inverters. A MOV = metal oxide varistor and 4 amp fast blow fuse in each suicide cord, might save inverters, but the fuse would blow occasionally when the inverter was not in danger. My guess is a 6 amp fuse would often blow milliseconds after the inverter died. The inverters have about a 9 amp surge rating for output, but I have no idea how much they can tolerate with power going in where it should be coming out. The middle of three inverters failed after several hours of start and stop operating with both inputs and outputs in parallel, possibly due to over heating, but we can not rule out the possibility that they did not lock phase soon enough. Neil

 

[nexium]

My guess is most manufacturers are a bit over optimistic, so 20% will probably avoid disappointment. I'm not sure 10% is realistic brake even, even if the amorphous silicon cells only cost $10 per square meter, as there are engineering costs, getting the 35 degrees tilt, inverters and batteries, a large electrician cost, if you do everything without cutting corners. If you do most of the work yourself, you should figure your time is worth at least $2 per hour. If the amorphous silicon cells replace shingles, who will know how to fix rain leaking in, if a few dabs of roofing tar don't fix the leak? Roofer standard practice is put all the old shingles in the land fill, rather than find the 2% that are letting the water in. A 20 degree tilt, instead of 35 may give slightly more output on June 21, but less than 10% that much on Dec 21. Neil

 

[nexium]

The simple answer is the watts produced varies as the sine of the error from vertical. It's 0.866 for 30 degrees and half for 60 degrees, however the photo cells typically have a transparent protective coating so essentually all the light is reflected at more than about 75 degrees, depending on the refractive index of the coating which sometimes is slightly lens shaped to increase the effective collection area, so the inactive area boardering each cell is not wasted, if the light is arriving close to vertical.<br /> Some solid geometry is envolved considering both the azmeth and elevation of the sun relative to the plain of the photo cells. If the azmith is off by 70 degrees and the elevation is off by ten degrees the angle is something like 75 degrees. They add vectorally.<br /> At your latitude the azmeth error can be as much as 110 degrees at both sun rise and sun set, as the sun rises at about 70 degrees and sets at about 290 degrees on June 21 = a difference of about 220 degrees. Please forgive any errors. It has been almost 50 years since I last took a course in physics of light. Neil

 

[eric_apollo]

Subject: User Name: Mental_Avenger<br /><br />To Whom It May Concern,<br /><br />The above person, user name Mental_Avenger has continued to purposely spread lies and disinformation about the International Space Agency and Mr. Rick Dobson.<br /><br />This person has taken a number of user names on Space.Com and on other Space Message Boards, to spread their lies and disinformation.<br /><br />This person has, and is, working either with, or on the behalf of, some unknown organization or group that has been conducting a focused smear and propaganda campaign now for a number of years against the International Space Agency and Mr. Rick Dobson.<br /><br />This person has been baiting people, and entering posts which the International Space Agency has made, with the "specific purpose" of slandering, causing trouble, and spreading lies & disinformation. And to specifically disrupt and derail these positive posts, and to chase people away. This persons malicious and vindictive actions have been constant and very threatening.<br /><br />We are asking that these slanderous and illegal acts be stopped, and that we obtain the personal information of this person for legal action for criminal defamation of character and slander, and to report this person to Law Enforcement for making terroristic threats against the Chairman & CEO of the International Space Agency, Mr. Rick Dobson. This person "Mental_Avenger" has been making a number of terroristic threats against the Chairman & CEO of the International Space Agency, Mr. Rick Dobson.<br /><br />The International Space Agency or Mr. Dobson has never done anything wrong on Space.Com, and has never been anything less than positive, or has presented anything other than uplifting and factual information to the Space.Com community and posting board.<br /><br />It is criminal to allow this person "Mental_Avenger" to defame, smear, and attack legitimate organizations and people with impunity. This is not a freedom of speech issue, as th

 

[glutomoto]

Re: Your electric bill should drop by a dollar or two.<br /><br />So then why go to the expense and take the risk, especially when it will take a dozen or more years, at a dollar or two a month, to pay it back ? <br /><br />Even for use as an un-interruptable power supply, what is the advantage of a dangerous and illegal setup ? <br /><br /><br /> :|<br /> <div class="Discussion_UserSignature"> </div>

 

[najab]

Actually, most electric companies are ambivalent towards this technology. Used judiciously it helps them, but used excessively it hurts them. Case in point: there was an electric company out West that estimated that they needed to build 5 new generating plants to meet demand over the next 20 years. Someone suggested that they promote conservation and so they sponsored distribution of compact flourescent lightbulbs. The lower useage means that they only have to build 1 new plant and get to extend the working life of their current plants. So, by getting people to use less, they avoided the capital outlay of 4 new plants.<p>Of course, they don't want too many people saving too much energy, or they would have to start _closing_ plants.</p>