Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Solar Technology for Residential Use

  1. Apr 7, 2012 #1
    Hi, I am a student at Lehigh University. I don't know if this is a appropriated place to post this, but I kind of need some help on this.

    In one of my project courses, I am placed in a team with students of various majors to develop a solar collector (not solar panel, but a solar dish) for residential use. Pretty much the theory is to harvest the power of the sun and integrate that with our current power system. The product is targeted to be affordable, easy to maintain, and efficient.

    I got a survey that if you guys could answer, that will contribute greatly to our project. Thanks!

    http://img191.imageshack.us/img191/7213/surveypic.png [Broken]
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Apr 8, 2012 #2
    I don't mind answering the questions - if I understand why you would need the answers in order to reach your team goals?

    Also, what sort of "collector?" Where will it redirect the energy it collects to ... water? Oil? And how will it be utilized?

    I have to say that the survey is, well, open-ended at best ... more appropriately, it is rather vague imho.
  4. Apr 8, 2012 #3
    Well, the survey to written to get a general sense of where the technology and market is at. The questions might seems vague, but they can actually help us determine a target product cost range, which play a big role in determining the designs.

    The collector is a solar dish similar to the design below. However, the heat is redirected to a Stirling engine through a cavity receiver where we can harvest the kinetic energy as a form of electricity.

    The electricity then get integrated as part of the current electrical system. However, the product is not designed to replace the current electrical system.

  5. Apr 9, 2012 #4
    Okay, thanks. Check your private message - I have sent you something that might prove slightly more productive.
  6. Apr 9, 2012 #5


    User Avatar
    Gold Member

    Hi, Bill. I, too, am struck by the ambiguity of some questions. Overall, though, it appears to be a decent survey. Since it isn't an interactive chart (ie: I can't click on an answer), I'll go ahead in free-form with my own clarifications.
    —south-central Alberta, Canada
    —I never cared about the environment until a few years ago, and still detest Greenpeace (but not as much as PETA). I'm changing, though, so I'll say about 6.
    —When you say "effective", do you mean "efficient" or society-altering? If the former, it depends upon the technology in place. I still prefer the black ABS pipes with water over photovoltaic cells. I don't know enough about Sterling engines to comment upon your system, although I like them in principle.
    —I'm not exactly trying to reduce my bill, but it's happening anyhow. My computer, fridge & freezer are on 24/7. The TV is about 18/7. I bought a high-efficiency dishwasher a few months back, because I can't do them by hand any more. I use it about every 2 or 3 weeks. When it's dark, I have the light on in my front porch ever since the home invasion a couple of years back. It's a 23-Watt CF unit. My kitchen light, which I rarely use, is also a 23-Watt CF. The only incandescent bulbs that I use are in my bathroom, because I prefer the spectrum of it, and my external side entrance/driveway light because I don't think that CF's are weatherproof. I don't use any other house lights, since I can see just fine by the TV and porch lights. I don't even use the bathroom light for urination, because the porch light shines in there enough to aim by.
    —Product lifetime is more important than investment. I'm answering this and similar time-dependent questions as if I had some significant amount of time left. I don't, but I can fake it.
    —If the longevity question refers to the entire system, then it had better be at least 50 years. If, on the other hand, it refers to individual components thereof, 20 would be acceptable.
    —What do you mean by "maintenance"? Things like lubrication or replacement of the working fluid could be yearly or even more frequent. I wouldn't want to change seals more than every 5 years. A motor and/or gear train could require repair or replacement every 20 years or so without unduly irritating me.
    —I'd like anything to pay for itself within 2 years, but realistically I'd accept 10.
    —This one is a repeat of #5
    —I am in no position to complain about paying for utilities. They keep me comfortable, and more importantly, alive. They're steep, particularly since we are an energy-producing province, but it's a small price to pay for not freezing to death.
    Last edited: Apr 9, 2012
  7. Apr 9, 2012 #6

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper


    Southeast Connecticut
    long lifetime
    30 years
    payback period depends on type of product; thermal panels should payback in 3 to 5 years, PV systems should payback in 10 to 15; wind and geothermal are highly dependent on location .
  8. Apr 10, 2012 #7
    1 - USDA Hardiness Zone 8 - Southeastern U.S.
    2 - 8
    3 - If we are talking photovoltaic efficiency, a 3. Although some of the electronic peripheral technology associated with the photovoltaics such as converters, regulators, etc., probably rates an 8 while the storage technology, (batteries, something we are deeply invested in improving here at the University of South Carolina), rates a 2 or less at the moment. If we are talking talking water heaters strictly for hot water consumption in both residential and commercial dwellings ... it probably rates a 6 in its current offering. Basic solar water heaters could be offered at higher levels of efficiency but the technology is cost prohibitive to the average user. Solar collectors, (ambient), used for millennium, are difficult to rate because, argh, nevermind ... I cannot spend another second trying to answer this particular question.
    4 - Yes
    5 - Both are equally important.
    6 - What specific type of Solar Energy System and at what cost? Please include individual design costs, (not R&D related), for a specific application/location, installation costs and maintenance costs. I was fortunate enough to have the knowledge and wherewithal to apply mine own design to my own personal system on my own property. However, most consumers would require a consultant of some sort to design the system that best suits their individual needs based upon various factors such as, location, position and design of dwelling/structure, energy requirements, etc. I am not familiar with current tax laws/incentives with regard to what might be depreciated these days, but the general, common sense, rule of thumb for the average consumer would dictate that the higher the cost the longer the product/system would be expected to operate at a standard level of effeciency - like a good pair of shoes or a great car or truck. Drive-train warranties (engines and transmissions) are offered which are exponentially longer than warranties offered on less exspensive components of the vehicle's overall system. Of course, as with everything, so much depends upon how it is maintained during its lifetime. Segue 3, 2, 1 ....
    7 - Minor maintenance, yearly. Major tune ups every five years but based upon the limits of your question maintenance would end in five years or??? Service contracts offered in advance that would cover both so that future expenses could be budgeted well in advance. My answer assumes minimum 10 year increments with regard to product lifespan.
    8 - Depends upon the initial cost. You cannot dictate the market value of a product based upon what the consumer is willing to pay and over what period of time he is willing to pay for said product. Your entire line of cost/value based questioning violates certain basic capitalistic market principles. Design the product first, then put it out there and see what the market will bear. If it is a good, affordable, product that does what it is advertised to do, then the consumer will pay.
    9 - Both are equally important.
    10 - ... that they are a necessary evil that are totally out of the consumers' control. That the numerous regulatory commissions designated to oversee costs which are passed-on to consumers are, combined, one of the most corrupt and politically motivated bureaucracies in existence in this country today, from the Federal level right down to the local COOP level.

    With regard to your product lifespan question. The average consumer would probably expect two things in order to justify a large investment in alternative energy systems on a residential or small commercial scale.

    A - The base system (the system's drive-train if you will), should last, and continue to operate at a high level of efficiency, during the average expected habitation(al)-duration (sic) of the dwelling's inhabitants/owners. In other words, roughly 20 years for residential, probably less for commercial. How long will someone live in the home or occupy the building before it is sold or before they relocate? And what added value will the system bring, or what possible decrease in value might the system cause, at the time of sale?
    B - After all costs are calculated, including long term maintenance costs, that the depreciated costs are LESS than current conventional sources. The sheer convenience factor involved would dictate this in a capitalistic society. In other words, most alternative energy systems would be less convenient than being hooked-up and living-off-of the grid system. Therefore, the only justification for converting to independent systems would be a reduction in costs over the investor's (see A above), lifespan of the system and/or the value added during the eventual resale of the property. Of course, potential tax credits and savings realized from such would have to be calculated into this aspect of consumers' expectations when considering the return on their investment.
    Last edited: Apr 10, 2012
  9. Apr 10, 2012 #8


    User Avatar
    Gold Member

    Mr. Bosun, thank you for pointing out something that I didn't think to mention because I took it for granted—any of my answers would depend upon the solar technology costing less than what I currently pay in an oil-based society. There's no way that I would pay extra so that somebody else's kids can have a clean planet. It might be different if I had any of my own.
  10. Apr 24, 2012 #9
    You're welcome ... but even then, if it was only slightly more, perhaps there would be those willing to make that sacrifice for the good of the cause. I doubt it however and, bottom line, it's all about money in the end.

    Heck, this whole alt energy idea is far more about money than need right at the moment.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook