Electric cars are a pipe dream

Discussion in 'General Science & Technology' started by Syzygys, May 20, 2010.

  1. adoucette Caca Occurs Valued Senior Member

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    I just gave distribution losses as one cost of central generation, there is also all the infrastructure of the power company that has to be paid for, including profits, which is why the cost to the consumer is far higher than the cost of generation.

    In the US the average cost of a kWh is ~12 cents.

    Using those Sun panels I linked to earlier at $373 for a 210 Watt panel, to configure a house in the South West to provide an average of 760 kWhs in the summer, takes 21 panels ($7,800), plus two inverters and installation, wiring and mounting rack costs of another $8,800, for an installed cost of ~$12,000 (with 30% tax credit), the system is good for 25 years or more.

    But they will displace about $92 per month of electricity in the first year (and electrical rates go up over time, about 2% per year) so over the first 20 years the system will avoid electrical costs of $26,856 and with 10 year, 5% financing of the whole installation the monthly cost of the system will run about $30 more than the cost of electricity for 10 years and then start saving, such that after 20 years the PV system will have had a total cost including interest and maint (buying 2 new panels after 10 years to allow for the slow degradation of output for instance) of $16,250 or a savings of a bit over $10,000.

    Not a bad deal actually.

    Take away the 30% tax credit and the numbers aren't as good of course, as your total cost is $21,000, but the tougher problem is your monthly cost for electricity for the first 10 years is about double your normal rate.

    So in reality, without the 30% tax credit, the cost of PV panels need to drop to around $1 per watt, but at that point nearly everybody in the Southwest should consider installing as many panels as they can afford.

    Note, this analysis assumes you use all the electricity you generate or you can "spin the meter backward" when you produce more power than you need (which currently is pretty common). Lose that capability though and then you don't want to install more wattage then you use on average during the daylight hours.

    Arthur
     
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  3. universaldistress Extravagantly Introverted ... Valued Senior Member

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    Sorry for confusion, I meant everybody who already has a car, and it is kind of implied that this is a state of trasition towards a cleaner energy future. Have you been reading the context of this thread? Step by step.
     
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  5. universaldistress Extravagantly Introverted ... Valued Senior Member

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

    Once again, pay as you go charge as you drive? Why carry batteries, fuel? If you charge all the time, no prob.

    Also separately to above, not sure this is still relevant because of conflicting views on a charging station's workings but couldn't the electricity itself be super cooled, or the cables supplying it? to drive down heat at its source at the electrode?
     
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  7. Stoniphi obscurely fossiliferous Valued Senior Member

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    Bravo! This is the kind of stuff that will make the difference in the end. I have been living with solar for 32 years now, plan on expanding my setup too.

    If you have a few handyman skills you can fabricate that rooftop solar system for a lot less, Arthur. Boston Electric has been installing rooftop systems on individual homes with South facing roofs for years now and has thus avoided building 2 new coal fired power plants as a direct result.

    Detroit Edison is quietly doing the same thing here - they have asked me to participate, in fact. I won't because I too wish to make some money off solar - electric generation in the near future, my current heating system has convinced me of its efficiency over the long term.

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    Carry on.
     
  8. X-Man2 We're under no illusions. Registered Senior Member

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    The cost of Solar has come down significantly over the last few years.But it needs to drop further.


    A group of people got together to pool ideas on how or if Solar price could be brought down.The good news is that even without any radical breakthroughs, there are plenty of cost reduction opportunities in today's technology.And they can be implemented in the near term.



    http://tinyurl.com/4unzxmj
     
  9. adoucette Caca Occurs Valued Senior Member

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    Possibly, but the big savings would be in labor to construct the panels, and considering you currently get a 30% tax credit for buying them (but no such savings on your labor if you make them) I'd still prefer to buy these low cost commercial units that come with a 25 year warranty. (besides making 21 of these 39"x65" panels wouldn't be cheap and it would be a significant chore, and the actual cost with credit is only $5,400)

    I also inadvertantly included two inverters (which I normally only recommend for off-grid sytems), but in a grid-tie system you would intall one larger one and save $2,500 by doing so. Thus your installed price comes down to $9,700 and your monthly cost over the first 10 years is essentially equal to your current cost, but the system savings over 20 years goes up to $12,000.

    Note, my mounting costs are higher than you will see listed for systems on the internet, but that's because systems rarely include mounting rails/wiring which aren't added until you decide where to mount the system. But I make the assumption that you are not going to put these on your roof since most roofs are not at the proper angle for best output and routine maint of roof mounted panels is problematic (routine cleaning or removing leafs and snow for instance), not to mention the substantial extra costs incurred when the roof eventually needs repair because to do so generally means removing the entire system, and normal roofing companies won't do this as panels in the sun are always producing power.

    Arthur
     
  10. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Interesting link, but it has some misrepresentation. The most serious is: "Instead of using expensive PV cells, the solar telescope uses commercially available triple-junction solar cells, which have three junctions that each capture energy from different wavelengths of light. These solar cells have more than double the conversion efficiency of conventional (single-junction) cells. ..."

    single junction Silicon based PV cells, looking at our sun thru clear air have a max efficiency of 22% as photons with less than the band gap energy make no ellectricity and only the band gap energy is usefully collected from the more energetic ones (the rest of their energy becomes heat.) By a multi-layer cell you have more than one band gap and get about 40% conversion, BUT it is never cheaper to make three different layers with different gaps. This normally is only done when weight is important, (space craft solar cells)

    Yes theirs will require half land area - it is twice as efficient and much more expensive to double the individual cell efficiency. Also I bet part of the power collected is used for active cooling of the cells. They can not work without cooling in 1000 suns.
     
  11. adoucette Caca Occurs Valued Senior Member

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    Billy, if you had gone to the actual source in the link I posted you would have found that there was no misprepresentation by the company building this device:

    Yes they point out that triple junction are more expensive per cm2 but worth the extra cost in this concentrated delivery system
    Yes they point out the need for cooling.
    etc etc

    http://www.rehnu.com/technology/receivers-and-cooling

    Arthur
     
  12. Skeptical Registered Senior Member

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    Grid parity is the term used to describe the point at which the cost of solar cells equals that of grid distribution. Currently only Hawaii in the USA has grid parity, and that only because their electricity is so damn expensive - generated with diesel.
    http://en.wikipedia.org/wiki/Solar_cell

    Sure in another decade or three, the cost comparison may change, and I welcome it. But you are "heads in the sand" if you think that solar cells can offer you a price advantage today.
     
  13. F-X ♫♪ Mostly Harmless ♫ ♪ Registered Senior Member

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  14. billvon Valued Senior Member

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    21,644
    A few points:

    1) Roof space is free (no land required) high (less shading) helps in the summer (reduced heating of attic) and generally most homes have a roof aspect that gives you 90% of what you'd get with a fixed standalone mount.

    2) It's pretty easy to work on them. Pull the DC disconnect and then disconnect the panels one by one, starting from the grounded side. That way you see a max of about 40 volts, which isn't very dangerous. (and the connectors protect you against inadvertent contact.) The roofing company may not want to do that - but you can.
     
  15. adoucette Caca Occurs Valued Senior Member

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    Yes, and if your roof is facing the right way you aren't too bad off, but many are facing the wrong way.
    Secondly, if your roof has even partial shade it will do in the output, many do.
    Third you can't easily get leaves off in the fall, which will kill the output (a small amount of shading on a panel effectively eliminates the entire panel)
    Fourth, you can't get snow off, which can cause days of outage in the North, just when you really want them to be providing power.
    Fifth, you can't clean them and in a lot of areas (like Southern Calif, enough grit settles each night and rain is infrequent that this is an issue).

    So, like I said, I assume you can't, of course the mounting costs simply aren't that high, so it isn't really that big of an issue as far as cost of the entire system.

    Arthur
     
    Last edited: Mar 9, 2011
  16. adoucette Caca Occurs Valued Senior Member

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    7,829
    Well there is that 30% Gov Subsidy that makes it work quite well today.
    Again, I posted just one of many sites where you could order the materials (ordering over internet saves sales tax, which for this system is far more than shipping).

    A 6,000 watt system in a place like Southern California will generate an average of 1,000 kWhrs a month.

    You can configure and install a 6,000 watt system using standard commercial products carrying a 25 year warranty for ~$12,000 (after the tax credit), this would include 29-210 watt panels at $373 each, a 7,000 watt inverter that turns your panel output into pure sine-wave output, an auto disconnect (takes your system off the grid if grid power goes down) as well as the necessary wiring, combiner boxes and panel mounting hardware.

    Financing that system at 6% for 10 years will cost you $1,650 a year and so you will pay a total of $16,500 for the system. Maint of the system and two more panels after 10 years to account for panel degradation, will cost you an additonal $1,700 over 20 years (maint is low)

    BUT

    Your 1,000 kWhrs from So Edision will cost you .16 cent per (according to the EIA) or $1,920 a year, so you are ~$300 a year in the black right from the start.

    But your electricity will go up over the next 20 years, even at a very optimistic rate of 1% per year, and so 20 years of electricity from the power company amounts to $42,276, meaning you are up by ~$24,000 over that 20 years, and the good news is your system is probably good for another 10 years at least.

    So, NO, I do not have my head in the sand.

    Feel free to check out my figures, as to price of components, watts delivered per day in the South West, life of systems, financing costs, maint costs and electricity costs etc.

    Arthur
     
  17. X-Man2 We're under no illusions. Registered Senior Member

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    403
    Agree with Adoucette's assessment last post.I think it important to understand electricity is going to rise while solar is going to fall over time.Obviously at first places with decent sunshine and high electric rates will fair well,while others will follow later.
     
  18. Stoniphi obscurely fossiliferous Valued Senior Member

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    3,256
    I intend to fabricate the rooftop system after I have rebuilt the roof to accommodate a new workshop garage addition. The slope will be sufficient to cater to the upkeep and maintainence needs of the solar. I may fabricate a tracking system to increase the efficiency as well. I intend to use 'surplus' cells and do all of the fabrication myself, so the estimated materials cost will be quite moderate.

    Yes, my labour will be gratus, but I really enjoy these projects. The rooftop solar will be no harder to keep clean than the second story wall mounted type 3 passive system already on the house. I have telescoping poles to assist with that.

    All in all, this is a very entertaining way to begin coping with what we need to do.
     
  19. F-X ♫♪ Mostly Harmless ♫ ♪ Registered Senior Member

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  20. Stoniphi obscurely fossiliferous Valued Senior Member

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    I have lived with my passive solar heating system for 32 years so far. It has proven to be cost - effective for me, and I live in Detroit - Northern latitudes. Very good for wall - mounted solar stuff in the winter.

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  21. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    That is an important point. Your electric bill is almost entirely capital cost. The fuel on average as I recall for a kwh is less than 2 cent. (In case of hydro-election the fuel cost is zero, nuclear is very low –much less than 1cent/kwh.)
    Yes, and few mention the hidden subsidity given to grid connected PV systems, which is at least equal to 30%. They pay very little compared to their no-PV neighbor, so contribute very little to the capital cost. In some case they pay nothing but collect funds from “running the meter backwards”

    The grid connected PV user is getting a very good deal by using the grid as its large near zero cost storage battery. Essentially he is “free loading” on his non-PV neighbors. Current there are so many more of them that the added cost of providing these large virtual batteries increases their electric bill only slightly (<10%). Not only are the grid PV system “free –loading” but they are adding to the capital cost.

    The capital cost is closely related to the peak power demand any time in the year, although not linearly as gas turbines are use to service it. They are less efficient, but have lower capital cost per KW of capacity. They must as they sit idle 90+% of the time. If there are a few cloudy or rainy days, The PV grid connected users expect the electric company to have installed capital cost generators to service them just as if they were paying full electric bills

    If and when the grid connected PV users are say 15% of all users, and the other 85% understand that they are paying the capital cost for these PV user, they will revolt. Most likely in the form of a fixed minimum capital charge, just for the connection, even if you don’t use it or use only 1KWH plus a fuel cost separate in the bill which is directly proportional the KWHs used.

    Recall from your first comment that more than 80% of the electric bill is capital cost. If the difference between the non-PV’s bill and the grid PV user bill were only 20% more for the no-PV home then the already poor economics without the open 30% subsidity would make it more attractive to buy you private storage battery than to fairly pay for the stand-by electric company’s “virtual battery” the grid PV user current enjoyed for free. I.e. this “hidden subsidy” involuntarily granted to the grid PV user by the no PV customers of the power company is at least as large as the open 30% from the government.

    The no PV electric customer will not continue to be exploited by the “free loading” grid PV customers become something like 15% of all customers. The grid PV’s “free loading” will end. Their electric bill will include a fair charge for the extra, and seldom used, generation capacity that all the local grid PV demand be there when two or more cloudy days occur. Also note that they all want service in the same days – this makes annual the peak load demand both greater and a higher factor over the based load demand.
     
    Last edited by a moderator: Mar 9, 2011
  22. Skeptical Registered Senior Member

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    Cost of solar power for a small home.
    http://www.nmsea.org/Curriculum/7_12/Cost/calculate_solar_cost.htm

    "Small Cabin: Choose

    Ppeak, usage = 1 kw.

    Eused = 5 kwh,

    Tsun = 6 hours.

    From these we find that:

    Inverter: $1000

    Panels: $6666

    Batteries (upfront): $1000

    Batteries (life-cycle): $4000

    Costupfront = $8666.

    Costlife-cycle = $11,666

    Costkwh = $.255 per kwh - (26 cents/kwh)"



    Cost of the domestic solar cell electricity comes to 26 cents per kilowatt hour by this reference. Substantially more than grid power.

    I am the first to admit this will come down in time. But right now we have ostritches arguing.
     
  23. F-X ♫♪ Mostly Harmless ♫ ♪ Registered Senior Member

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    Wind power also has zero fuel costs.
     

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