[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
this.
73,
Scott KBØNLY
-----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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