NEWBIE: On Roof System to offset excessive kW

RevEltonJonesRevEltonJones Registered Users Posts: 4
Hello Everyone,

House is in Victoria, Canada.
Cost of kWh here is about $0.07 & $0.10. Cheap by San Diego Standards, but I am a fool to think it won't rise to north american averages.
3,000 sqft home, two floors, 70's wood frame home with R40 ceiling & R12 walls, new dbl glaze windows.
The house is a rental to University students (6), power incl'd
35,000 - 40,000 annual kWh.
No natural gas, everything is electric. (hot water, heating, several fridges/TV's/Monitors/PC's)
Net Metering is allowed here. Smart meters have already arrived.
It always easy to up the rent, but I was considering trying to lower the annual $4,000 electric bill.

I have seen the dramatic drop in the cost of solar panels over the last 10 years. (ul-solar.com as an example) wondering if it is time to consider covering the roof with solar?

If so, what type of system would be recommended.

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: NEWBIE: On Roof System to offset excessive kW

    Welcome to the forum.

    As a fellow BC resident I have two words: forget it. :blush:

    Our BC Hydro rates are going to go up to thirteen cents per kW hour and that still is no place near the cost of GT solar, especially buying the equipment at Canadian prices. You could expect GT solar to come in around $0.50 per kW hour, which is pretty expensive power.

    It sounds like you are trying to make the place efficient, but electric included when you can't control use is a losing proposition. And I know about the all-electric nightmare houses down there: switch the heat to gas is usually impossible because they left out the space to install the furnace and ducts!

    Probably the best thing you can do is add the electric cost into the rent as a separate charge, and teach them the meaning of the word "OFF".

    Been there, done that, moved to the Cariboo! :D
  • NorthGuyNorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: NEWBIE: On Roof System to offset excessive kW

    Unfortunately, Victoria is not a very sunny place, so it'll be more expensive for you than for most of the people. From economical viewpoint, it'll be impossible to make it work at currect prices.
  • RevEltonJonesRevEltonJones Registered Users Posts: 4
    Re: NEWBIE: On Roof System to offset excessive kW

    Okay I'm more confused, Germany is further north, possibly with less sunshine than Victoria and yet has one of the highest per-capita uses of Solar in the world. Hell they even have a couple Canadians manufacturing solar panels in the country. Can't imagine, based on their cost of living that the manufacturing of panels can be cheaper than say China/Taiwan. Using this place as a rental for the next 10-20 years you're sure this won't pay off?
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: NEWBIE: On Roof System to offset excessive kW

    here is part of the answer Feed in Tariffs http://en.wikipedia.org/wiki/Feed-in_tariff#Germany
     
    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
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: NEWBIE: On Roof System to offset excessive kW

    Different costs and different mindset: Germany has made a national commitment to replace nuclear power with solar. As such the cost is not such an issue.

    Here's some sample GT systems from the forum host: http://www.solar-electric.com/grsokiforho.html

    You need to use PV Watts and see how much power such a system would actually generate for your location. Then compare that total power generated to the Canadian cost including installation and taxes.

    And as NorthGuy said, Victoria isn't sunny (in Winter when you need that electric offset the most).

    The good news is that the solar prices are coming down (especially for GT which does not use batteries) and BC Hydro's prices will go up. It may not yet make economic sense, but it is getting there. There are many places in the U.S. where it does work out, so it's only a matter of time. If you want to get some local quotes by all means do so; I'd be interested in knowing what the per Watt installed costs have got to.
  • RevEltonJonesRevEltonJones Registered Users Posts: 4
    Re: NEWBIE: On Roof System to offset excessive kW

    Okay, I took a look at the 5,640 watt system Cariboocoot suggested. Would i be correct in assuming that the 5,644 watts or 5.6kW package, all things being perfect, would perhaps generate peak capacity on average for 6 hours per day for the year. (more in the summer, less in the winter) 5.6kW x 6Hrs = 33.6kWh. 33.6kWh x 365days = 12,264 annual kWh. About a third of our annual 35,000-40,000kWh consumed at the house in Victoria. 33% of $4,000 = $1,333. Or about a 9-year payback and about double this including taxes, duties, transportation and labour. Just trying to get my head wrapped around the concept.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: NEWBIE: On Roof System to offset excessive kW

    First of all, the average output from 5640 Watts of panel will be about 77% of that: 4342 Watts over the good sun hours of the day.

    Second, people always assume they get more sun than they do. You will not necessarily get 6 hours average year round. In Victoria the Summer hours are bound to be good and the Winter not so good. Plus, just because the sun is up doesn't mean it's on the panels. It would probably be more realistic to use 5 hours daily for year-round. Or plug the numbers into PV Watts (http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/International/inputv1_intl.cgi) and get:

    "Station Identification"
    "City:","Victoria"
    "State:","BC"
    "Lat (deg N):", 48.65
    "Long (deg W):", 123.43
    "Elev (m): ", 20
    "Weather Data:","CWEC"

    "PV System Specifications"
    "DC Rating:"," 5.6 kW"
    "DC to AC Derate Factor:"," 0.770"
    "AC Rating:"," 4.3 kW"
    "Array Type: Fixed Tilt"
    "Array Tilt:"," 48.7"
    "Array Azimuth:","180.0"

    "Energy Specifications"
    "Cost of Electricity:"," 0.1 dollars/kWh"

    "Results"
    "Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value (dollars)"
    1, 1.57, 198, 0.17
    2, 2.75, 322, 0.28
    3, 3.53, 453, 0.39
    4, 4.58, 564, 0.49
    5, 5.51, 684, 0.59
    6, 4.95, 588, 0.51
    7, 5.76, 694, 0.60
    8, 5.90, 723, 0.62
    9, 5.06, 604, 0.52
    10, 3.29, 409, 0.35
    11, 2.23, 271, 0.23
    12, 1.57, 197, 0.17
    "Year", 3.90, 5707, 4.92

    That last number is $492 worth of electric per year. Now what's that payback time of $12,000 US capital just for the equipment? Twenty-four years. How long will the equipment last? Panels are warranted for 20 years.

    See the problem?
  • RevEltonJonesRevEltonJones Registered Users Posts: 4
    Re: NEWBIE: On Roof System to offset excessive kW

    I forgot about the DC/AC conversion factor, but nonetheless, you have better explained why the system is not so cost effective.
    Thanks

    Two final questions and my guess one of them will be in a different forum:

    1. I remember reading about a switch in the USA that shuts down the house system when the grid goes down to prevent power back in the grid while the grid is being fixed. I think I remember something that suggests this is done differently in canada. Is this correct and if so how?

    2. I have read and seen a video of a new solar concept referred to V3Solar. (basically a spinning cone, reflecting light onto silicone and producing AC, at rates in the $0.05 per watt catagory) www.V3Solar.com . Is this for real or is this some Pump-and-Dump stock scam?

    thanks All
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: NEWBIE: On Roof System to offset excessive kW

    Two final questions and my guess one of them will be in a different forum:

    1. I remember reading about a switch in the USA that shuts down the house system when the grid goes down to prevent power back in the grid while the grid is being fixed. I think I remember something that suggests this is done differently in canada. Is this correct and if so how?

    This is anti-islanding. All legal GT inverters have it built in. There is no need for any external switch although some idiot municipalities "require" one. A standard GTI can not function without grid power present, and the hybrid type simply shut off their AC grid connection when they sense no power there (but continue to feed loads on their AC output).
    2. I have read and seen a video of a new solar concept referred to V3Solar. (basically a spinning cone, reflecting light onto silicone and producing AC, at rates in the $0.05 per watt catagory) www.V3Solar.com . Is this for real or is this some Pump-and-Dump stock scam?

    thanks All

    We don't miss much around here :D : http://forum.solar-electric.com/showthread.php?17315-V3Solar
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: NEWBIE: On Roof System to offset excessive kW
    2. I have read and seen a video of a new solar concept referred to V3Solar. (basically a spinning cone, reflecting light onto silicone and producing AC, at rates in the $0.05 per watt catagory) wwwDOTV3SolarDOTcom. Is this for real or is this some Pump-and-Dump stock scam?

    I can't say specifically that it is a pump and dump, but the technological innovation that is the heart of their scheme is totally bogus, and has been discussed here in the past.
    SMA SB 3000, old BP panels.
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