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Residential solar panels?

Discussion in 'Fred's House of Pancakes' started by inkydoo, Jan 1, 2005.

  1. inkydoo

    inkydoo New Member

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    I figure this is the greenest group of people (at least, in a concentrated place) I know... So, does anyone on here have experience with solar panel installations on homes? I'm looking into it (Austin Energy has a nice rebate program going right now), but so far I don't know anyone else who's had it done and could give me any warnings, advice, encouragement, etc.

    I'm not looking to get off the grid or anything (at least not yet), but just to cut down on my net usage and put all this Central Texas sunlight to some good use.
     
  2. Wolfman

    Wolfman New Member

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    No solar panels here, yet. However, go to www.homepower.com. These guys specialize in alternative energy, and are a wealth of information on solar systems. The magazine gets heavy ad support by various solar panel manufacturers. I used to subscribe to the magazine.
     
  3. bparrish

    bparrish Junior Member

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    Second the motion on home power.

    Just a few short comments from my own experience with this.

    If you can go 'non battery' based, it's less expensive and probably more efficient. Battery-based systems require the DC voltage to match the charge voltage for the batteries which MAY not be the most efficient location on the VI curve for the panels. (There are things called maximum power-point charge controllers which mitigate some of this - which I may do sometime, but haven't yet). However there are several newer grid-tie (and non battery based) inverters (sunny boy and a similar product made by 'sharp' - the local pharmacy is using four of the 'sharp' units) that allow you to put all of your panels (on each inverter) in series. This means you have a fairly high DC voltage (so be careful!) on the solar side of the inverter, but it means you can get by with a much smaller wiresize.

    I did a battery-based system (because our power here is somewhat unreliable - fails 2-3 times a year for >1 hour, sometimes much worse), but if I had it to do over again, I would look at these newer inverters (and no batteries!), and maybe a generator for the occasional outage. If you had no grid, or lost power multiple times a week, battery-based would probably make sense.

    If you can get the same company to install and sell you the components, warrantly issues are a LOT simpler. My installer went 'out of business', and I've had some issues that involved installation. The 'dealer' has tried to be helpful, but is limited as to what they can do (they're reselling me a panel that failed due to installation, but at their cost).

    Remember all this stuff is real expensive to SHIP. (i.e. hundreds of dollars for 20 or so panels - I have 40 x 120W panels).

    A great gadget is the 'solar pathfinder' which will show you how much sun you'll get at a particular location at any time during the year. If you have someone come do a survey, they'll probably have one, but you can buy one yourself. They're pretty expensive, but if there is ANY question of trees (antennas, chimneys or whatever), it's worth it to have one.

    PG&E has a time-of-use tarrif which we are on, which means power is MUCH more expensive from noon to 6 on weekdays (esp. in summer), but if you can NOT use any power during that time (or miminize use), you can sell-back to PG&E at retail (meter runs backwards) at 30 cents/kwh or thereabouts, and buy back after 6PM at 7 or 8 cents/kwh. if that's of interest. Your mileage will vary iin different states with different utilities.

    There's also a three-tier time-of-use tarrif (mostly for folks with electric cars - or at least there was at one time).

    See www.solarwarrior.com for a description of a HUGE system with some folks that have electric cars. I thought they were on the above mentioned tarrif, but a quick search of their website doesnn't indicate that they are... but take a closer look if you're interested.

    I hope these few comments are helpful. Feel free to email me if you want any additional info or have questions about my experiences. I'm far from an expert, but will try to help if I can. (I have cousins in Austin, TX, and I LOVE that city!)
     
  4. inkydoo

    inkydoo New Member

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    Thanks for the input, bparrish, particularly on the battery issue, since it's the biggest issue beyond whether I'm willing to do this or not. Our power blinks out for short periods (<1 minute) probably 5-6 times a year, and I have a lot of electronics in my home for which this is a Bad Thing ™. I know this isn't a good reason to put a battery backup on the system, but on the other hand, I can sort of rationalize it by saying that it will save the cost of adding them down the road if I did decide to go off-grid (say with the addition of wind or improved panels). I suspect the choice will be more obvious when I see the difference in price tag (as a friend in wind energy pointed out, I could buy a lot of UPSs for a lot of years for the cost of adding batteries to a solar installation).

    I'm hoping to start talking to some local companies in the next week or two to really get a better idea of what I'm in for. The good news is that there appear to be a number of installers in Central Texas who've been doing this for decades, and so have lots of expereince.
     
  5. jamarimutt

    jamarimutt New Member

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    I have a pair of solar panels connected to a 38 gallon tank. Although the company advertised that we would have hot water for up to four days during overcast and rainly days, the fact is that on such days we need to plug-in the system. Our system includes a built-in electric heater in the reserve tank. Make sure your system has such a heater; otherwise, on occasion you'll be showering with cold water.
     
  6. V8Cobrakid

    V8Cobrakid Green Handyman

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    It's good to see this post. I have been looking into going solar. Preferably completely but in parts seems more practical. the system that was described on www.solarwarrior.com is about the size of system my house would need to run. We pull electricity all day long. I'm switching all lights over to compact florescense which will cust our cost by about 1/3.
     
  7. skruse

    skruse Senior Member

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    Photovoltaic (electrical) or solar (hot water) panels are an excellent choice. Prior to purchase you should complete an energy audit of your home - monthly energy use per square meter and obtain an energy efficiency index (EEI). EEI > 20, house is a serious energy waster, EEI 10 to 20, there are several major areas where you can reap major benefits, EEI < 10, a few areas for substantial savings.

    It is always cheaper and more cost efficient to hold onto to what you already have vs. "go get more." Retrofit your house based upon your climate (heating and cooling degree-days) and budget. Caulking, insulation, dual pane windows and compact florescent (10,000 hour) bulbs go a long way. Wrap pipes and water heaters. Putting foam gaskets behind every switch and outlet plate (2 hours of labor, $20 cost) is equivalent to closing a one square meter hole in the front door. Put "storm liners" on your existing drapes or install "warm window" (5-layer) roman shades. Purchase energy efficient appliances (washer and drier, refrigerator-freezer, HVAC).

    Visit www.rmi.org - Rocky Mountain Institute.

    PV panels are silent and highly desirable, but should be cost-effective over a 5- to 10-year period.
     
  8. V8Cobrakid

    V8Cobrakid Green Handyman

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    just don't end up like our house.. we pull somewhere in the range of 53,000kwh a year
     
  9. bparrish

    bparrish Junior Member

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    If you go battery-based, then you either need to have enough batteries to run the whole house, or, if you are going to just try to keep some circuits active, then you need to put in a separate power panel for the 'critical' circuits. (This isn't as bad as it sounds, you put a breaker in the main panel and pull the 'critical' circuits over into another panel). I hired an electrician to do the "AC Side" of the installation, and another fellow who had experience with the photovoltaics (but not with subpanels and so forth) to do the work on the roof, combiner boxes, and connection to the inverter on the DC side.

    We chose several circuits to be on the 'critical power', excluding things like the washer/dryer, a/c compressor, toaster (although we kept the HVAC blower on battery since we have propane and a woodstove - allowing movement of warm air into extremities of the house). My installation was complicated by the fact that there is already a second power panel (220V) in another part of the house on which I wanted to have backup power... so even though the AC side of my inverter is 110 V, I put in a step-up transformer and a transfer switch to switch the other circuits from grid to solar in an outage. I didn't want to run the transformer all the time, since it cuts into efficiency, and also this way the other side of the house can draw more current when we're NOT running solar (without the bottleneck of the inverter + transformer). I don't know if this is all making sense, but if you read homepower and take a look at one of the diagrams of a battery-based / grid-tied system you'll see what the complexity is.

    By the time you've bought the batteries and done significant rewiring to separate out critical circuits, you probably could have bought a pretty good handful of relatively small UPS's. (Note that UPS's use power - as does the battery-backed-up inverter - when you run on the grid and the sun is out... it has to keep the batteries charged. UPS's have to have batteries changed after a while, but so does your batteries for the emergency power).

    Regarding Compact Fluorescent lamps, (I REALLY like these!) we have about 90% CF's in the house. I first started experimenting with them in 1984 or so. We still have some incondescent floods on motion detectors outside, since they are only on a small fraction of the time... and the CFs are a bit dicey when it gets cold. When we did a major remodel in 1994, we put in about 20 compact fluorescent FIXTURES (recessed) that take bulbs without ballast which cost only about $7 each, and are much smaller and less clunky than traditional CFs (although in the last few years the CFs are getting smaller and cheaper all around!). Note the $7 each is for the BULBs, the fixtures were about $45 each (in 1994), compared with $15 or so for incandescent fixtures. With CFs, one thing we do is to put the date of installation on all CF bulbs, and if they go out in, say a month or two, I will return them! So far, I've gotten refunded every time (plus Sylvania sent me a bunch of bulbs when I sent them infoon a particular bad lot I got hold of - I think they said that the bulbs may have had vibration damage in shipment, but I'm not sure - it's been a while).

    If you consider that some folks still put in, say 10 flood fixtures in a kitchen at 75 watts each, that's 750 watts to light the kitchen. If you use 17W CFs, it's only 170 watts. So it's worth considering.

    I think Sierra Solar in Grass Valley will still send out a free catalog, and they at least used to have a pretty good website which seems to still be active and updated (http://www.sierrasolar.com). They supplied most of the hardware for our installation. We've been fully installed for a couple of years, and I haven't kept up with all of this, except for a few colleagues at work that have done more recent installations. Their catalog also has (had?) low power refrigerators, solar hot water, wind power, photovoltaics, inverters, charge controllers, whatever...
     
  10. hdrygas

    hdrygas New Member

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    My experience is now 15 years old. I had installed solar hot water heating (at considerable cost) in the PNW (near Seattle) by a major company and had nothing but problems. After a memorable Christmas Eve when it froze up then thawed and flooded the garage and free replacement X2 Reynolds went out of business and I was left high and dry. We had no water for two days during Christmas I had the thing disabled and then paid to have it removed and disposed of. As near as I could tell it was designed for way southern California and the first temps below 32 degrees permanently disabled it again and again. I will not go back until I am forced to adopt solar technology.
     
  11. Sufferin' Prius Envy

    Sufferin' Prius Envy Platinum Member

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    If it is electric solar you are looking for and in no immediate need, you may want to wait for this to hit the market:

    TORONTO — Researchers at the University of Toronto have invented an infrared-sensitive material that's five times more efficient at turning the sun's power into electrical energy than current methods.
    http://www.ctv.ca/servlet/ArticleNews/stor..._49?hub=SciTech
     
  12. inkydoo

    inkydoo New Member

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    I was referring to photovoltaic as opposed to solar water heating, though if there were a rebate on that, I'd consider it too.

    I read in a Federal publication that you could get your last year's Kwh from your utility, but I've yet to call them up. My last month was 611 Kwh, but I suspect that's the low point of the year here in Texas. My guess is the mean will be around 1000Kwh (I guess that's 1Mwh?). It's a relatively new house (about 7 years old) with relatively efficient appliances. I'm sure we could improve efficiency somewhat, but it's not like I'm dealing with a 30 or 40 year old thing that barely has insulation, etc. Our utility also has some rebates for appliances and AC units, so I'll check those out.

    Some of your posts are making me feel like I hardly know enough to get into this. I don't even have a clue what a step-up transformer is (does it have anything to do with that cartoon show from the 80's :wink:) I've obviously still got a lot of reading and research to do.

    As for the crazy spray on stuff... It looks cool, but part of my incentive is a rebate from the local utility that probably won't last for another five years. Then again, as I understand it, replacing the solar panels later on wouldn't be nearly as expensive once the inverter and other stuff is wired in.
     
  13. daniel

    daniel Cat Lovers Against the Bomb

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    When President Carter put incentives on renewables, my mom (in southern CA) had a solar hot water system put in. It was great. Seldom had to use the grid back-up. After many years of trouble-free operation and significant savings, it began to rust and leak. By then the incentives were gone, and my mom was getting old and didn't know how long she'd stay in her house, so she had it removed and went back to conventional water heating. But she never had any regrets about the solar system while it lasted.