[aprssig] TAPR Dayton Solar Talk

KBØNLY kb0nly at mchsi.com
Sun May 22 23:32:32 EDT 2011

Depends on local code, around here any device directly or indirectly 
connected to the grid which generates power must be permitted and reported. 
I had to have an electrical permit just to put in a six circuit transfer 
panel for my generator.

Basically they want to know where they are so that if there is a problem 
they know where to go.  Some have a building code that specifies the grid 
tied solar system must even have a disconnect on the outside of the house 
near the electrical entrance as well.  I have done a lot of research on 



-----Original Message----- 
From: Bradley Haney
Sent: Sunday, May 22, 2011 8:00 PM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] TAPR Dayton Solar Talk

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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