[aprssig] TAPR Dayton Solar Talk

[Glenn Little WB4UIV]

There would have to be some automatic, fail safe, 
means to disconnect your grid tie from the grid during a distribution failure.
Without this you would energize a section of line 
that the line workers are expecting to be dead.

73
Glenn
WB4UIV


At 09:00 PM 5/22/2011, you wrote:
>Would you have to contact your local utility to 
>let them know you are doing a grid tie inverter?
>On May 22, 2011, at 7:54 PM, KBØNLY wrote:
>
> > You are correct, our meters are forward only, 
> the local municipality will not allow nor 
> install net metering, its simply against their 
> policy here and not available.  I am hoping 
> some day they may change their thinking but for 
> now its not possible.  I know of one local 
> resident that installed a kW of grid tie only 
> to find out that he couldn't get the power 
> company to net meter his overage that he feeds 
> to the grid.  So what did he do?  Just live 
> with it, at least his meter isn't going forward.
> >
> > Most of us are now on digital meters, the few 
> that are still the old style mechanical units 
> still won't spin backwards.  I know this 
> because me and another guy took a 200w kit with 
> grid tie inverter and plugged it into his 
> outside outlet, which is on its own 20a circuit 
> and then shut off all the other breakers in his 
> panel so no power was being used from the grid, 
> then plugged in the inverter, the diagnostic 
> lights showed all was well, a clamped on meter 
> showed that the grid tie inverter was indeed 
> feeding the grid but the meter never moved 
> backwards after 4 hours of mid day sun and the 
> panels in full sun, so I suspect their meters 
> even the older mechanical ones are forward only.
> >
> > 73,
> >
> > Scott KBØNLY
> >
> >
> > -----Original Message----- From: Bob Bruninga
> > Sent: Sunday, May 22, 2011 7:27 PM
> > To: TAPR APRS Mailing List
> > Subject: Re: [aprssig] TAPR Dayton Solar Talk
> >
> >> However the biggest problem... with grid tie
> >> is no buy back program here, I can't spin
> >> my meter backwards feeding the grid to get
> >> credit or make money towards my bill.
> >
> > Just to clarify and to make sure we are 
> speaking apples and apples, I'd like to make a 
> few comments that may or may not apply.  First 
> of all, -every- meter will "spin backwards" 
> when you are generating more electricity that 
> you are using and you are actually feeding amps 
> back into the grid.  I put that in quotes, 
> because it is important to be specific.
> >
> > The disk by definition will spin 
> backwards.  The only question is whther the KWH 
> READING will "count" backwards?  In grid-tie, 
> there is no "buying or selling of 
> electricity".  It is much more simple than 
> that.  It is simply pushing your present KWH 
> reading forward or backwards.  If you are lucky 
> to still have a meter with mechanical DIALS, 
> then it will also COUNT backwards. In that case 
> you alrealdy have "net-metering" whether there is a law or not.
> >
> >> All I can do is slow down my meter by
> >> supplementing solar to cover my usage.
> >
> > Yes, if you do not have the old mechanical 
> meter but have an ELECTRONIC read out of KWH, 
> then it has smarts to NOT subtract numbers even 
> when the disk -IS- spinning backwards.  Such electronic meters have 3 settings.
> >
> > 1) "security mode" - no matter which way the 
> disk spins, the numbers will only ADD 
> FORWARD.  This prevents people from wiring 
> aournd their meter and trying to run it 
> backwards during some of the month to reduce 
> their bill. They will pay going either way.
> >
> > 2) Forward only mode.  This will charge you 
> for current consumed, but it will not add 
> numbers forward if the disk is spinning 
> backwards.  This means at least you wont be 
> charged for your solar excess, but you also 
> wont get any credit either (because the numbers wont count down).
> >
> > 3) Net meter - this is the ideal 
> setting.  Disk goes forward, and numbers count 
> up.  Disk goes backwards,and numbers count down.
> >
> >> but I can't spin the meter backwards
> >> to build equity to pay for the system.
> >
> > If it wont "count" backwards then you are 
> correct.  You will have to have a licensed 
> electrician to install your system in order to 
> get the poer company then to come out and 
> change your meter to one that will "count 
> backwards". But if it has mechanical dials, 
> then it is a net meter already and it will give 
> you credit for being pushed backwards.  So lets 
> be more specific about the terms.
> >
> > I watched my meter "SPIN" backwards by about 
> 3 kW when I first hooked up my grid tie 
> system.  Problem was, I nver waited to watch to 
> see if the NUMBERS counted down on my 
> ELECTRONIC METER. I got the bill which was $400 
> instead of my usual $200 one.  That's when I 
> learned about the difference between "spinning" 
> backwards and "counting" backwards.
> >
> > So, now I have been disconnected for a few 
> months while I find a master electrician to do 
> all the paper work to get me a NET METER.
> >
> > Now it COULD be that even a mechanical meter 
> might have a ratchet that might not let the 
> numbers go backwards, so the only way to be sure is to test it..
> >
> > Bob, Wb4APR
> >
> >> 73,
> >>
> >> Scott KBØNLY
> >>
> >>
> >> -----Original Message----- From: Bob Bruninga
> >> Sent: Sunday, May 22, 2011 5:43 PM
> >> To: TAPR APRS Mailing List
> >> Subject: Re: [aprssig] TAPR Dayton Solar Talk
> >>
> >>> However one point.. Grid tie solar is only
> >>> functional when the grid is powered.
> >>
> >> Thanks for bringing up this often very missleading topic...
> >>
> >> But in my area, the grid is up 99.95% of the 
> time.  The grid goes down maybe
> >> 4 hours a year or so (0.05%).  If the house load is about 3 kW with
> >> everything on normally, that is the loss of less than $2 worth of
> >> electricity.  Like any ham, Most of us already have many mechanisms for
> >> coping with those few hours.
> >>
> >>> However you can go with solar that uses a
> >>> battery bank and a whole house inverter that
> >>> has a grid tie option, when the grid fails
> >>> it switches your household to the inverter
> >>> and draws from the battery bank...
> >>
> >> But that is a major mistake that too many people make when thinking about
> >> solar.  It makes no economical sense to provide that $2 of power-out
> >> electricity per year by adding the additional $10,000 for the
> >> dual-inverter/charger and a wall of batteries.  There are much more
> >> economical approaches to back-up power than batteries...  And this has
> >> nothing to do with the economics of grid-tie solar.
> >>
> >> For economical solar, one must completely separate their 99.95% use of
> >> economical power (solar) from their requirement for a few hours of backup
> >> power.  The optimum solutions for each are completely separate.  THough to
> >> some, it might be worth spending the additional $10,000 for a few hours of
> >> backup ($2 per year), but that is a completely separate issue from
> >> economical solar.
> >>
> >>> like having an automatic transfer switch
> >>> and generator but its an inverter and batteries
> >>> charged by solar instead.
> >>
> >> But be careful.  Off-grid systems (with battery storage)TRIPLE the cost of
> >> solar for the same energy production.  My recommendation is to think of
> >> solar for economical energy for the rest of 
> your life, and then to think of
> >> a different economical approach to the few hours of power outage a year.
> >> Such as ....  An inverter from your car system, a small $250 generator, a
> >> pair of car batteries and an inverter...etc...
> >>
> >> Lots of ways other than throwing another $10,000 at the solar system for 4
> >> hours ($2) worth of darkness a year.
> >>
> >> In fact, it was that same idea of filling up 
> my basement with batteries that
> >> was so uneconomical that it kept me out of 
> solar for so long until I finally
> >> realized that batteries have nothing to do with economical solar power.
> >>
> >> Separate the two issues in one's mind and 
> then it is amazing how economical
> >> grid-tie solar becomes.
> >>
> >>> Maybe in another 20 years I can afford it myself..
> >>
> >> Another way to look at that, is... If you are paying $200 a month for
> >> electricity now, in 20 years, you will have spent $48,000 for electricity
> >> and have nothing to show for it.  But if you buy solar now, the government
> >> will buy HALF of it for you and for the rest 
> of your life, you will OWN your
> >> entire energy generation system and have free energy for life.
> >>
> >> That is why I am preaching so much.  My Ham 
> radio background and interest in
> >> emergency power and batteries so completely masked the true value and
> >> economics of modern grid-tie solar for too 
> long.  I want to help others see
> >> around that missconception...
> >>
> >> Bob, Wb4APR
> >>
> >>> From: Bob Bruninga
> >>> Sent: Sunday, May 22, 2011 9:56 AM
> >>> To: aprssig at tapr.org
> >>> Subject: [aprssig] TAPR Dayton Solar Talk
> >>>
> >>> The AMSAT/TAPR banquet talk at Dayton was about Solar and emergency power
> >>> for Ham radio.  In preparation, here are three ideas that amazed me that
> >>> might amaze you:
> >>>
> >>> 1) This week by googling solar panels, I found PRIME home solar (UL
> >>> approved) 220 Watt panels going for $1.39 per watt! (compare that to $6/w
> >>> contractor installed systems 2 years ago...)
> >>>
> >>> 2) Even if you want to use bargain panels and bargain micro-grid-tie
> >>> inverters, one way, is to pay a contractor to install the smallest fully
> >>> approved and electrical-permitted solar 
> system you can buy.  This  gets you
> >>> fully legal, connected, grid-tied etc.  Then add as many panels and
> >>> additional plug-in micro-grid inverters at your own DIY cost!
> >>>
> >>> Just remember, to connect + to + in parallel, and + to - in series... and
> >>> just plug in the DIY microinverters to the wall outlet.  (Note, the UL
> >>> approved microinverters should be connected 
> to a standard 20 amp breaker in
> >>> your breaker box by a master electrician).
> >>>
> >>> 3) Amazing angles!  No-longer does SOUTH matter!!!
> >>>
> >>> I hope everyone here has had the fun of playing with the on-line PVWATTS
> >>> for
> >>> computing annual solar ouput over any conceivable arrangement of azimuth
> >>> and
> >>> elevation angles.  I just compared a pure EAST/WEST facing roof to the
> >>> optimum South facing, just to see how bad 
> it would be.   AMAZING!  Here is
> >>> the PVWATTS page:
> >>> http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/
> >>>
> >>> DRUM ROLL:  A DUE EAST facing roof (with a 
> 20 degree tilt) will produce 85%
> >>> of the annual power as the ideal tilted southern array.  Amazing...
> >>>
> >>> BUT!!!  SO does the WEST side of the same house!  So, unlike the southern
> >>> home that can only use HALF his roof for power*, the EAST/WEST facing
> >>> homeowner can generate 170% more power than the sourthern facing owner
> >>> because he has twice the room to put the panels!!!  (Roof size and shade
> >>> are
> >>> the #1 limits to homeowner 100% production of their annual electrical
> >>> needs).
> >>>
> >>> *But wait, there's more!  Next for grins, I 
> used PVWATTS to tell the power
> >>> output from the NORTH FACING side of the South Facing house.  Who would
> >>> ever
> >>> even think of doing this?  But if the ROOF 
> tilt is the typical low profile
> >>> 20 degrees, guess what?  The NORTH side of the roof can produce 60%
> >>> (annual)
> >>> of the south side!  So the homeowner with his low-profile southern roof
> >>> maxed out with solar, can now increase his 
> total annual output by 60% (with
> >>> a double sized array (on a low tilt roof)). 
> He produces nearly zero in the
> >>> middle of winter from that side, but makes up the full 60% of his total
> >>> capacity for that array in the summer!
> >>>
> >>> Many hams who know that SOUTH IS BEST find 
> it hard to accept this.  But do
> >>> the PVWATTS calculations yourself.  Remember, the SUN comes up in the NE
> >>> and
> >>> sets in the NW during the summer when the days are 14 to 16 hours long.
> >>> This means that for the 3 hours in the 
> morning and 3 hours in the evening,
> >>> the IDEAL Southern array is not even seeing 
> the sun.  Sure, an east facing
> >>> array will produce little in the winter, but for GRID-TIE, the ONLY thing
> >>> that matters is ANNUAL total power.  and 
> all these other directions make up
> >>> for their poor winter performance by making 
> MORE power in the other months.
> >>>
> >>> Even laying flat on the ground will produce 
> 80% of the annual power (but be
> >>> a maintenance issue... Any panel should be 
> at at least 10 degrees to assure
> >>> rain-cleaning).
> >>>
> >>> Back to the EAST/WEST facing house... Doubling the array to get the added
> >>> 160% may not have been cost effective in the past, but with DIY panels at
> >>> $1/watt and DIY plug-in micro-grid inverters at about $0.30/W, it's so
> >>> cheap
> >>> to expand your array into less productive 
> angles, why not!  DIY panels and
> >>> added plug-in DIY microinverters can double the size of your "approved"
> >>> array for probably 1/4 the original cost of your contractor installed
> >>> system.
> >>>
> >>> Putting panels on EVERYTHING until you get to 100% of your annual
> >>> electrical
> >>> load is the goal.  You can do it!  Look outside the "southern" box.  (But
> >>> shade remains the #1 killer of even the greatest solar ambitions.  But as
> >>> costs are so low, look again...)
> >>>
> >>> Don't forget, the economics of homeowner solar is all due to GRID-TIE.
> >>> There is not a single battery in the 
> system.  Off-grid battery systems can
> >>> only deliver about 33% of annual energy for 
> the same $ investment plus the
> >>> added burden of lifetime maintanance.  GRID-TIE is the only way to go (if
> >>> you are on the grid)... Please see:
> >>>
> >>> www.aprs.org/off-grid-maybe.html
> >>>
> >>> Oh, and the BIGGEST FACTOR by far is the almost 50% Government Credits,
> >>> Rebates and Grants that come right off the 
> top of your installation costs.
> >>> I would bet these are going to be gone in a year or two (my state has
> >>> already reduced theirs by 1/3rd), beacuse the cost of home-solar produced
> >>> power is now LESS than utility power (with the 50% incentives) and so
> >>> EVERYONE is jumping into solar.  With tight budgets at all governmnet
> >>> levels, do not expect these incentives to last.
> >>>
> >>> Next week, I'll post slides from the AMSAT/TAPR solar talk.
> >>>
> >>> Oh, and please come join the 
> SolarDIY at yahoogroups.com discussion group made
> >>> up mostly of HAMS going solar.
> >>>
> >>> Bob, WB4APR
> >>>
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