New to forum

Hi all,

Benn reading for a little while and I am considering going solar. I will need your guidance and advice on what I need.

First and foremost some information, I live in Palm Beach County "Florida", currently I use about 80 to 90 Kilowatt hours per day. How much energy can I expect a solar system to generate?

In my case I think that I would opt for a system that is tied into the grid, is this the best way to go? Hopw about vendors for all this equipment and approximate cost?

Thanks for the assistance.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,804 admin
    Re: New to forum

    You can use this link to check out how much power you can get from solar PV (Grid Tied is default) system...

    Assuming you are near West Palm Beach, FL... 1kW of solar panels will generate about 1,307 kWhrs per year...

    So, assuming you use 85kWhrs per day, that would be about 31,000 kWhrs per year...

    31,000/1,307 = 23.7 kWatts of solar PV panels to "zero out" your energy usage over one year...

    That will cost you (very roughly) around $180,000 to $237,000 (typically around $8-$10 per watt) to have Turn-Key installed--excluding any rebates/tax credits you may qualify for... (obviously, this is not a "small" system).

    Normally, your first efforts should be spent on conservation--as, for the most part, solar power costs more than utility power (at least at this time).

    ~2,700 kWhrs of usage per month is pretty high (for those of us in other states who don't use A/C, electric hot water, etc...). You might check with your local utility and see what programs they have that can help you with reducing your power usage (if possible).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: New to forum

    Thanks for the prompt reply, that is considerably much more than I anticipated. It would never recoup the investment considering the 25 yea lifetime of this systems.
  • BB.BB. Super Moderators, Administrators Posts: 32,804 admin
    Re: New to forum

    Redemption,

    Remember, I am not employed or make my living from doing solar estimates... I am just giving a very rough estimate of what you are looking at to go solar PV. And yes, Grid Tied solar is the cheapest, and the best, for your money... Although, having an off-grid capable system is very useful in hurricane alley there (perhaps, just big enough to run your minimum requirements).

    Florida has some of the best solar PV rebate plans ($5 a watt or so)--but they are frequently underfunded--so, from what I understand, it is mostly people that built their system last year (and applied) that would be getting their rebates this year (and hoping that the state funds the rebates for the next year).

    Conservation, solar hot water (domestic hot water, space heating), change in life style, energy star appliances (new A/C), insulation, double pain windows, shading etc. are all places where it probably makes more sense to put your money rather than just laying out a huge solar PV panel field.

    If you have more details on your power usage (size of home, swimming pool, computers, and such)--I am sure people down your way can give you some very good ideas of where to spend your monies first.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: New to forum
    BB. wrote: »
    Redemption,

    Remember, I am not employed or make my living from doing solar estimates... I am just giving a very rough estimate of what you are looking at to go solar PV. And yes, Grid Tied solar is the cheapest, and the best, for your money... Although, having an off-grid capable system is very useful in hurricane alley there (perhaps, just big enough to run your minimum requirements).

    Florida has some of the best solar PV rebate plans ($5 a watt or so)--but they are frequently underfunded--so, from what I understand, it is mostly people that built their system last year (and applied) that would be getting their rebates this year (and hoping that the state funds the rebates for the next year).

    Conservation, solar hot water (domestic hot water, space heating), change in life style, energy star appliances (new A/C), insulation, double pain windows, shading etc. are all places where it probably makes more sense to put your money rather than just laying out a huge solar PV panel field.

    If you have more details on your power usage (size of home, swimming pool, computers, and such)--I am sure people down your way can give you some very good ideas of where to spend your monies first.

    -Bill


    Thanks again for reply, I been trying to reduce my power consumption but it just never seem to go down enough.

    All my light are the new energy efficient lights, we do not have a pool. I do have a spa but it has been empty for the last six months. Computers, that is probably one my problems we have 5 in the house and two are always on. Tv's The 60 inch in the living room is on most the time my kids are in the house. The other tv's off and on trough the day, I stopped using the patio refrigerator and currently power fridge and a separate small freezer.

    I have an updated 4 ton trane, I think 16 or 17 seers, temps are usuallty 75 at night and during day 77 degrees. Other than changing my windows I do not see where else I can go to save energy. I had the electric company send a guy to see what I can do different and if there where any leaks or problems with my ac ducts. Everything seems to be ok, I think my biggest problem is the water heater, 6 showers per day.

    Any suggestions are welcomed, I tought about buying a device to measurre the consumption of all my tv's etc.
  • BB.BB. Super Moderators, Administrators Posts: 32,804 admin
    Re: New to forum

    The Kill-A-Watt meter for $30 (or less) is a great way to start.

    And, they just introduced a K-A-W power bar.

    You cannot really know how much power is being used without measuring it (name plate ratings frequently do not accurately reflect long term power usage--causing you to overestimate power usage--or under estimate power used when "off"/standby).

    The way I like to look at the power usage--and assign "blame" is to take your daily usage and divide by 24 hours...

    90 kWhr per day / 24 hours per day = 3.75 kWatts = 3,750 watts average load

    So, you have got the equivalent of a couple thousand watt items on 24 hours per day...

    Frequently--if your home is cooled by A/C--those lights/TVs/computers that are on 24x7 also have to have their heat removed 24x7 by your A/C--so if you can reduce your interior loads, you will also cut your A/C use by a lot.

    Your computers on 24x7 (monitors/printers/etc.) may account for 10% of your power usage--and, perhaps, another 10% due to your A/C running to cool them.

    Measuring their power consumption and figuring out if you can use a small laptop to replace the larger desktop systems may help a lot (my old laptop uses 20-30 watts vs a 100-300 watts of a large computer system).

    And while I believe in conservation, you probably don't need to bug any one about unplugging the cell phone chargers (when not in use) just yet--saving 1-4 watts ain't going to change your situation at this time.

    Also, it is not beyond the realm of possibilities that there are "other problems too"... For example, if you are in a condo-complex, accidental or purposeful wiring of other's loads into your meter. Or even the wrong meter is on your power bill (check the meter readings on your bill vs your meter).

    And, I personally, would not discount going to double (or triple in your case) pane vinyl windows with Low-E glass. Unless you have very tight fitting drapes--I have found that changing windows make a huge difference in my older two homes I did (one was 1950's, the other 1930's)... Even without adding wall insulation (in my 1950's home), it absolutely reduced the temperatures in our west facing bedrooms by 15 degrees in summer afternoons.

    And, take a look at solar thermal for your hot water usage... That is a pretty good investment. Smaller/cheaper solar thermal collectors than PV electric panels--but is a bit of plumbing issue (both installing and maintenance with pumps, tanks, electronics, and such).

    www.solarroofs.com has been recommend by another poster here before as a good do-it-yourself supplier. And a good site to read through for the basics.

    And read through these couple of links (mostly about hot-water projects--some other stuff too):

    Link 1
    Link 2

    There are also A/C systems that can produce domestic hot water too (plus heat pumps for space heating--if you don't have that already).

    I will leave it to others that have more experience in your area (Florida) and A/C about how much money/power you can expect to spend/save with conservation/AC usage for an average home there.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: New to forum

    Have you had your insulation checked?, you should have R40 ( about 14" ) in the attic, this is the #1 overlooked and low-cost way to reduce your bill. Also blow in enough to cover all the duct-work, makes a huge difference in keeping the air-ways cooled

    To do a typical house costs about 1K around here, just did a friends home 3 months ago and her recent bills dropped by 50% ( only about 4" was in the attic in a 1975 built home )

    Next for you would be solar-thermal for the domestic hot-water, about 4-5K of you pay someone to do the install turn-key, payback is about 2 years
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: New to forum

    As usual,,, Bill has it bang on!

    The general order of Solar power installation is, Conservation first, conservation second, conservation third, then, and only then solar hot water followed by PV solar.

    Consider a gas demand water heater, low flow shower heads, coupled with solar hot water, in Fl it should be a quick payoff.

    Every dollar spent on conservation will pay off by a factor of 5-10! In other words a pv system can be down sized for every KWH saved, with a requisite cheaper install cost.

    Good luck,

    Tony

    PS I use less than 90 kwh/month!
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: New to forum

    i did have a lengthy reply going before (keeping in mind i don't type that fast) and saw that a few posts were given even before i timed out my login writing a reply. i will summarize it rather than get into all of my comments and examples and just say that you are a good example of how people in general really are in the dark on their power consumption, what does better or worse, and what to do about it. i say monitor the consumption with meters(be it a kill-a-watt or just observing differences on the utility meter), watch abuses of power, and take further steps to lower that consumption. you think you aready did do that, but in fact i equate what you've done in terms of how one might consume a 7 course meal with extra portions and only eating half of the desert and washing it down with a diet soda. not to put your efforts down as they did make a difference, but comparitively it's very little.
    i would say that insulation will help and even getting solar thermal panels to help heat your water with could make the biggest differences along with some changing of bad habits. it may be a good idea for you to readup more and learn more of what you're doing be it here in this forum (reminding that the catagory of energy use and conservation is of that purpose) or any place else like home power magazine just to name 1. after this re-evaluate for pvs.
  • System2System2 Posts: 6,290 admin
    Re: New to forum

    Thanks all for the ideas and advice, I think the insulation in the attic is up to standard as the gentleman from the Electric company said it was ok. My house was built in 1990, i will purchase the devise to keep an eye on consumption.

    I had never considered direct effect of the head produced by my plasma to the bottom line, good job. I will start monitoring things and make posts here as I go, my house is 2200 under air. How would I find out what should be my average consumption, considering that I want my central air to run most the time. Do not mind opening windows in winter but in summer months that is not a good idea here.
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: New to forum

    Insulation is a good place to start to keep the heat out, I would check what the most current standards are for your area as the National Building code has recently been modified.


    Next is to check for air leaks around windows and doors and electrical outlets. Small holes/leaks add up real fast, if not sealed properly they can leak tons of cold ( or hot) air into your dwelling. there are companies that can do these sort of tests, where they put a big fan in the doorway and create a vacuum inside your house so they can check all places where the outer envelope has been breached during construction. check with your utility co?
    Sealed /twin pane window units are a must in my book, even triple pane is used in this area, also LOW E windows to keep the heat out , or in, depending on where you are.
    there is also a thin reflective film that can be put on the outside of existing windows that get full sunlight, really works well!

    My thoughts: more insulation the better. Passive systems (insul) are better than active(a/c) as you only pay once.;)

    Are your walls 6 inch or 4 inch?

    HTH

    Eric
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: New to forum
    Redemption wrote: »
    I think the insulation in the attic is up to standard as the gentleman from the Electric company said it was ok.

    Of course it's OK, he's SELLING you the electricity to cool your house with.

    It may also be time to rethink what a habitable temperature is, 80F, with low humidity, is a lot more livable than 78F @ 100%. Ceiling fans to "stir" the air around help too. In reverse, they still move air, but it's more noticeable around the edges of the room.
    Even adding a small porch as an entry way, will help, as an air lock, to keep conditioned air in.
    And adding solar thermal water heating panels, and a large 300 gl of storage for all those showers, will help a lot. Using solar to heat your water, will help, and kill the AC vent to the bathroom while the shower fan is running (sucking all the cold air out of the house) may be a help too.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
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  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: New to forum

    Second what Mike said, if the house was built 18 years ago, I can guarantee your insulation is the major contributor to your electric usage, your probably at R11 when new in 1990 and need to be at R40+. Even if it was built with R30, in 18 years, things settle and would be typically half that value

    So, number one on your to do list is to Call an insulation contractor in your town and get a quote for a minimum of 14" of the blown in fiberglass. Make sure that they include blowing enough in to cover the duct work and make sure they insulate over the garage. With the Florida building boom over they are eager for work. The 1400sf home I had done 3 months ago cost 600 bucks for about and R4 to R40 increase ( about 12 inches added )

    If your not going to follow up on this suggestion, there is no point in doing anything else, take this from another Florida resident!. There is no single better or cost effective change you can make than adding insulation to a Florida home
  • System2System2 Posts: 6,290 admin
    Re: New to forum
    Second what Mike said, if the house was built 18 years ago, I can guarantee your insulation is the major contributor to your electric usage, your probably at R11 when new in 1990 and need to be at R40+. Even if it was built with R30, in 18 years, things settle and would be typically half that value

    So, number one on your to do list is to Call an insulation contractor in your town and get a quote for a minimum of 14" of the blown in fiberglass. Make sure that they include blowing enough in to cover the duct work and make sure they insulate over the garage. With the Florida building boom over they are eager for work. The 1400sf home I had done 3 months ago cost 600 bucks for about and R4 to R40 increase ( about 12 inches added )

    If your not going to follow up on this suggestion, there is no point in doing anything else, take this from another Florida resident!. There is no single better or cost effective change you can make than adding insulation to a Florida home

    I will definitely make some calls tomorrow, I am really exited about the whole thing as you folks have given me some ideas that I had not considered before. I need to bring those $350 dollar electric bills to an end...

    Solar Guppy,


    When they blow the insulation they do so over the old one? Also I find myself going in my attic changing cables etc, "cable modem lines, Satellite". Will this stuff make it difficult to maneuver on the attic. Sorry if the question sounds dumb. Now as far as the solar thermal water heating panels, I am not too handy but have some good friends that are great with tools. Is this something we could do ourselves? Based on your experience any brand better than the other and maybe a recommendation on where to start pricing this stuff?


    Thanks.
  • BB.BB. Super Moderators, Administrators Posts: 32,804 admin
    Re: New to forum

    What I did in my attics was to put risers in, put in the insulation, then put strips of plywood on the risers (with a couple wood screws to keep things from slipping around, but allow access to underneath).

    The "solarroofs" link I supplied, was actually a recommendation by Solar Guppy based on personal experience.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: New to forum

    The insulation is just added over what ever is there. As for cables, you can do what BB suggests, I'd say think about any cables you might need and run then before the work. If you have to go in later, its really not a big deal , you might have to feel around with your feet, but its not that hard again first hand experience

    On the Solar Thermal, for DIY solar-roofs is good, look in the phone book for solar installers, probably about 4-5K for someone to do it for you hassle free and will save 50-100 month in electric depending on usage. You can get rebates from the State and Federal Tax credit as well
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: New to forum

    some of your concerns should also be asked of the insulation installer so you know how things are. questions are free to ask, but it's the answers we don't always like.:cry::roll:
    a side note of the insulation is that it is easier to understand than you think by the r factor and the opposite of the r factor is conduction or 1/r. i haven't looked this stuff up for awhile as you could actually figure out the btus gained or lost and its root start point is the square foot and involves the temperature differential as well as the r factor on an hourly basis. even if you have r10, by going to r20 would cut in half the btus of heat gained by the sun per hour. going to r40 would cut it in half again or being 25% of the original r10 gain per hour heat transfer. as you can see it windsup taking so much more insulation for each doubling of the r factor, which is the same as halving the heat gain or loss transfering through it depending on whether it is hot inside and going outside or visaversa. the costs of each doubling of the r factor and the space available for the insulation are limiting factors in how many insulate. of course you don't have to go in multiples like that as r factors go from near 0 to near infinity and are never quite reaching those points. simplified here is that if you have gained say 5000 btus in an hour with your present insulation with the same differential between outside and inside temps, doubling the insulation cuts the btu gained in that same hour in half making it 2500 btus gained and you can see that the a/c runtime is cut in half to do the same job of keeping that same temperature differential between inside and out.
    know that other factors will come into play as doors and windows have low r factors comparitively so most losses will occur in those areas. air leaks and flaws in the design or insulation are more factors above the common sense things i mentioned like leaving a door or window open.
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