TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Solar Carport

Discussion in 'Energy, Environment, and Policy' started by shark2k, Dec 17, 2008.

  1. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    PV Solar installations

    Touché. Makes perfect sense. I was actually thinking about it more in just the quickness of filling up though. I agree with everything you said though. It will be nice to be able to produce your own "fuel" though. We are getting solar panels (actually, my parents house, but I still live there) this coming summer (been working on getting them since ~February '08) so an electric car would be nice because I would definitely be contributing a lot less pollution.

    -Shark2k
     
  2. graham

    graham Active Member

    Joined:
    Dec 2, 2007
    Messages:
    1,572
    Location:
    Aptos, California
    Once you have solar panels on your house (and assuming you have excess capacity) it just makes sense to have a car you can fuel from the roof. The environmental benefit is a nice-to-have, certainly - but mainly it just makes sense because you are generating your own electricity! It makes you want to convert as much non-electric stuff to electric as makes sense.

    I originally got solar with the intent of eventually getting an electric car... and all the manufacturers stopped selling them. I am so glad Tesla came along.
     
  3. AntronX

    AntronX Member

    Joined:
    Nov 17, 2008
    Messages:
    255
    Location:
    Miami, FL, USA
    How big is your system? Grid tied or off-grid? I want to buy two 180 watt Evergreen panels and MPPT charge controller to make off-grid test system to power my two computers and audio gear. A local solar panel store got those panels for $3.18 per watt. I already have 12V 200Ah AGM battery and xantrex prosine 2.0 inverter. I have it setup as the UPS for all of my electronics and few table lamps.
     
  4. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    Graham: My parents don't have enough roof real estate to cover our cost 100%, but we would be covering about 50% (maybe a little more) of our cost.

    My older brother has been trying to get my parents to get solar for a couple years, and in my last year, roughly, of college I started pushing my dad and than we started going through the process. My brother's biggest push was because of electricity prices and how solar would be great in keeping cost down (once it's paid for itself) and the environmental impact also. It is looking like we will be paying somewhere in the low to mid teens for solar panels after rebates and tax incentives (i.e. $11,000-$15,000) which is pretty good.

    So getting solars panels and then getting an electric car was never the intent. Of course, I would love to get an electric car just so I don't have to be dependent on fuel companies (and it would save so much not having to buy gas every one or two weeks).

    Sorry bout getting off topic.

    -Shark2k
     
  5. graham

    graham Active Member

    Joined:
    Dec 2, 2007
    Messages:
    1,572
    Location:
    Aptos, California
    PV Solar installations

    From this thread:

    http://www.teslamotorsclub.com/news-articles-events/1962-roadster-top-gear.html

    My PV installation is 8.1 kw on my roof, I have about 14kw capacity with my inverter, so I have a bit of room for expansion on my generation side... but am running low on surface area as I only have a 1200 sq ft home.

    My system is grid tied, but has a battery backup. So instead of going just to feed the grid, it feeds my battery system first, and the rest of my house runs off of that UPS. I have 24 giant lead acid batteries that all of my 15 amp circuits run off of (although my 30 amp circuits are still directly on grid). If my utility power fails, my batteries automatically kick in, and my house continues uninterrupted. The power in my neighborhood was so noisy that my system has paid for itself just in the electronic equipment that no longer dies on a regular basis due to brown outs.

    I have not yet gotten an external generator in case the power is out for a long time during the rainy season when I don't generate as much electricity from the roof. I plan to add that some day.
     
  6. graham

    graham Active Member

    Joined:
    Dec 2, 2007
    Messages:
    1,572
    Location:
    Aptos, California
  7. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,250
    Location:
    Silicon Valley
    I have only 4kW... Grid tied with no battery backup.

    My power bill is basically $0 except for the $12/month grid connect (meter) fee.

    I have an old ICE generator that I fire up if the power goes off for a while. I just use it to keep the fridge and icebox cold since power outages are so rare where I live.

    My EV is usually charging other than at home so my PV only contributes a little to the EV... Mostly just covers our regular energy use (lights, TVs, washers, etc.)
     
  8. Palpatine

    Palpatine Banned

    Joined:
    Sep 6, 2008
    Messages:
    1,357
    Location:
    Seattle
    #8 Palpatine, Dec 17, 2008
    Last edited: Dec 17, 2008
    That is my goal also. I have two electric vehicles already and my Tesla will be the third.

    The Vectrix is about 3.7 kwh, or about 4 kwh for a full recharge with losses included. It is good for about 30 to 35 miles of hard riding.

    The Hymotion Prius is about 5 kwh and typically I see about 5.2 kwh drawn for a full recharge. It is also good for about 30-40 miles of electric boost (100+ mpg) on my Prius.

    The Tesla will be a bit different. I don't expect to need a full recharge each time. I typically drive 30 miles per day. So maybe 10 kwh per day for the Tesla?
    And if my wife is driving the Hymotion Prius that will be another 5 kwh per day.

    My goal is to offset 100% of my EV/PHEV miles from the solar system and also have some of the house electricity covered.
     
  9. vfx

    vfx Well-Known Member

    Joined:
    Aug 18, 2006
    Messages:
    14,792
    Location:
    CA CA
  10. AntronX

    AntronX Member

    Joined:
    Nov 17, 2008
    Messages:
    255
    Location:
    Miami, FL, USA
    Very nice! Do you have to clean them often? I want to build something on a small scale for experimenting. I also want it to power something I use, like my computer or few lights. I've read somewhere that cold weather increases PV cell efficiency. I was wondering how much more efficiency i can get from the panel if I water cool it on very hot summer days. I would seal up the back side of the panel and pump cold water from the lake through it.
     
  11. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    I don't think you quite understand that based on your next sentence. From my understanding, the efficiency is increased when there is less humidity, not from the panels being cooler. I noticed you are in Florida, which means the panels won't be as efficient as, say, Maine where it tends to be cooler (which means less humidity). I'm not sure if you need to clean solar panels. They are usually placed on your roof (which can be high in some instances). Of course I wonder if there is a benefit from that.

    -Shark2k
     
  12. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    #12 shark2k, Dec 17, 2008
    Last edited: Dec 17, 2008
    Just wanted to give the actual specs of our system. It is gonna be a 4.725 kW system. Based on the calculations the solar company did they say we should produce 4,965 kWh annually and that would cover about 55% of our energy (it's listed as % of ON PEAK Energy Produced by Solar). It will be a grid-tied system with no battery backup. A battery backup would not be with it for us because we do not lose power very often (it is pretty rare for our area).

    For a little idea of our energy use, it is 9,086 kWh annually. According to the rep from the company we are actually a little lower than average on the annual energy usage. So it will decrease our energy bill by about half which is nice, so I'm happy (even though it's my parents house).

    After thought (since it's in the quote thingy):

    Eliminate the production/emissions of:

    Carbon Dioxide (CO2) 8,336 lbs/yr
    Nitrous Oxide (NOX) 15.6 lbs/yr
    Sulfates (SO4) 22.9 lbs/yr
    Equivalent of Planting 2 acres of trees

    -Shark2k
     
  13. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,250
    Location:
    Silicon Valley
    Oh I have another 80watt panel on my EV that keeps the 12v system topped off and can run the big stereo and TV in the back as long as needed while parked. That panel is sized for RV type use where it is just over 12v so you don't really need a regulator. It has a cheap control box that just cuts out the panel if it gets over voltage.

    --


    Regarding the house panels - hours of sunlight is more important than cool panels. I would trade a long hot summer day for a cold winter day. The best would be a long day in summer with a cool breeze.

    Also more important than temp is angle to the sun and any possible shading. When the sun starts to drop in the horizon do any trees or buildings cast any shadows on the panels?
     
  14. graham

    graham Active Member

    Joined:
    Dec 2, 2007
    Messages:
    1,572
    Location:
    Aptos, California
    I probably should clean them frequently to remove the dust that builds up, but I am far too lazy. If I think about it, maybe once a summer when it hasn't rained in a while I turn the garden hose to the roof to remove some of the dust from the beach and salt from the air. Mostly I just wait until it rains to do that for me.

    I met a guy once who used to hose down his panels on hot days because cooling the panels would make his meter spin faster... but once again, me with the lazy.

    However, I do have to do battery maintenance twice a year - which is a drag - so my system is not entirely maintenance free. I could have gotten maintenance free batteries, but they were like twice the price and half the capacity.
     
  15. doug

    doug Administrator / Head Moderator

    Joined:
    Nov 28, 2006
    Messages:
    15,914
    Location:
    Stanford, California
    What kind of batteries are they, and what kind of maintenance is required?

    I appreciate your initiative to make your own thread, btw. Complete with links!
     
  16. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    Really? Did you actually see this happen or did the guy just tell you that? I was under the impression that less humidity made the more of the "rays" reach the panels so they performed more efficiently. Of course I'm not an expert on this stuff (just really interested) so any correct info I get is always good.

    As to the cleaning, I always just figured leave it to nature to clean it off :D.

    -Shark2k
     
  17. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    Doug

    :biggrin: Of course graham still needs to mention the kind of maintenance, but one of your questions was answered.

    -Shark2k
     
  18. graham

    graham Active Member

    Joined:
    Dec 2, 2007
    Messages:
    1,572
    Location:
    Aptos, California
    #18 graham, Dec 17, 2008
    Last edited: Dec 18, 2008
    I have 24 of these guys:
    rollssurrette_s530.jpg

    They are 6 volt lead acid in 3 series of 8 (3 banks of 48V). Each are 2 or 3 times the size of a normal car battery and I think they weigh about 150 lbs a piece.

    There are two pieces of maintenance required. 1) because they are not sealed, you have to make sure they have enough liquid to cover the lead plates, and 2) every six months they need to be "equalized" where you pop the tops off, and flood the battery with a bunch of current for about 3 hours which boils the sulfuric acid and gets it everywhere (nasty).

    Because I use "water miser" caps, I only check the water levels when I do the equalization every 6 months instead of every month like I would if I kept the standard cap.

    Happy to do my part -- we were going off in the weeds a bit from the "Top Gear" topic :smile:
     
  19. graham

    graham Active Member

    Joined:
    Dec 2, 2007
    Messages:
    1,572
    Location:
    Aptos, California
    He just told it to me, I have not experienced it first hand. Although I have heard other people say similar things, so if it is untrue it must be a common urban myth!
     
  20. shark2k

    shark2k Member

    Joined:
    Nov 14, 2008
    Messages:
    455
    Location:
    West Orange, NJ
    Darn those urban myths :tongue:.

    -Shark2k
     

Share This Page