[amsat-bb] Waiting for Solar Panel Efficiency (Ha!) rebuttal

Fri Jan 1 17:27:28 UTC 2016

Hi Burns,

I can not possibly comment on the US electrical systems and laws & policies
around them, but from a technical point of view there is a huge reason to
hold off on all these extra feed-ins. And that simple reason is grid
stability.

So regardless of any tariff schemes and/or the power companies trying to
keep their market, there is a substantial technical hurdle. I don't know
how it is in the US, but I did some research during an internship on this
in The Netherlands, and as a result, some kinds of inverters were outlawed
in the EU because they were really dangerous to the grid stability, and
also not safe in the end when instabilities did occur.
(and not all of those were made in china....)
Are they discouraging a growth beyond a certain size just to prevent this
issue?

Maybe this is substantially different in the US, since the grid looks
completely different.

Wouter PA3WEG

On Fri, Jan 1, 2016 at 5:36 PM, Burns Fisher <burns at fisher.cc> wrote:

> I guess there are a lot of folks interested in this even though it is only
> peripherally related to satellites...I hope there are not too many
> objections.
>
> But I wanted to ask if anyone has heard this rumor:  After a certain number
> of solar connections, power companies will no longer be required to do net
> metering.  I don't know whether a) they would just not allow any more new
> installations with backfeed at all or b) for new installations they would
> only pay wholesale, or c) somehow they average retail and wholesale prices
> for everyone who is backfeeding.
>
> I can surely understand why a power company would WANT to do that.  They
> are usually getting power that they have to pay extra for at a time when
> they need it less.  But it certainly reduces some of the financial
> incentive to install, if true.  Anyone know more?  It would probably differ
> by state...
>
> 73,
>
> Burns W2BFJ
>
> On Fri, Jan 1, 2016 at 11:21 AM, Robert Bruninga <bruninga at usna.edu>
> wrote:
>
> > > If the project is not operating by now, it'll cost 30% more after
> > midnight.
> >
> > No. The 30% federal tax incentive was to end by the end of 2016, not the
> > beginning.  AND does'nt matter anyway, since the do-nothing congress
> > actually included an extenaion in the spending bill.
> >
> > > Putting solar on an asphalt roof ... is a bad idea.  Not a place to
> screw
> > up.
> >
> > Use a reputable contractor with guarantee.  They know how to do it right.
> >
> > > 42 panels 50 lbs per (for 11 kW system)...
> > > Remember statics and dynamics??
> > > ... bracing rafters in a crawlspace is a mug's game.
> > > In Florida in summer? Fatal.
> >
> > 50 lbs per panel over 18 sqft is only a load of 2.8  lbs per square foot
> > and is insignificant compared to the required building code roof design
> > figure of typically 30 psf.  (Though in Florida the snow load is
> considered
> > 0).  The good news elsewhere is that solar panels melt snow far faster
> than
> > a normal roof, so there is no multiday buildup and icing load...
> >
> > > Today as of 3pm EDT the system produced  23 kWh.
> > > Best day so far was 100% FL sunshine and a COLD day: 82 kWh.
> >
> > Congratulations, sounds like you did it anyway...
> >
> > > HF RFI? Undetectable.
> >
> > Thanks, that is great news!
> >
> > > I got the last (3) 3.8kW transformer based inverters in stock.
> > > SMA makes nice gear. Cadwelds, IMC 3/4" conduit.
> >
> > I was totally shocked when I ordered an SMA inverter to add to my other
> > three XANTREX ones which only weighted 25 lbs.  The SMA was so heavy I
> had
> > to invite my son to dinner just to get help getting it from the porch to
> > inside the house!  Then had to feed him again a week later to help lift
> it
> > into place.  I think it is over 100 lbs? And compared to the XANTREX,
> there
> > were may nitpicks I did not like about the SMA at all.
> >
> > But then of course, XANTREX doesn't make grid-tie inverters any more and
> > SMA does seem to have very good reviews.
> >
> >
> > On Thu, Dec 31, 2015 at 12:25 PM, Bob <WB4SON at gmail.com> wrote:
> >
> > > > Sort of off the AMSAT topic, but the most recent estimate is that
> about
> > > 20
> > > > gigawatts of solar will be added in 2016 -- almost doubling the total
> > > > installed capacity of US solar power.  This is being primarily driven
> > by
> > > > residential installations.  Utility-scale installations are actually
> > down
> > > > 5%.
> > > >
> > > > One thing that was keeping mass market efficiency down was a glut of
> > > > production capability that existed through 2014.  Manufactures were
> not
> > > > keen on investing in new processes at the same time they were going
> out
> > > of
> > > > business or consolidating.  That glut has been drying up, prompting
> > Elon
> > > > Musk's to build a $1 billion dollar factory in Buffalo NY which will
> > > > produce 1 GW of panels annually by the end of 2016.  Those panels are
> > > > expected to be 22.1% efficient.  That's a pretty impressive gain in
> > > > efficiency.
> > > >
> > > > Often times market conditions, not technology, dictates what reaches
> > the
> > > > mass market, and that has most certainly been the case in the solar
> > > > industry.  That 50% increase in panel efficiency doesn't necessarily
> > mean
> > > > that the cost per watt will be reduced in the short term -- those
> > panels
> > > > may simply sell for 50% more.
> > > >
> > > > 73, Bob, WB4SON
> > > >
> > > > On Thu, Dec 31, 2015 at 6:07 AM, Nick Pugh wrote:
> > > >
> > > >> Good point Bob but include the real estate cost  in to the equation
> > and
> > > >> they improve.
> > > >> nick
> > > >>
> > > >> -----Original Message-----
> > > >> From: AMSAT-BB [On Behalf Of Robert Bruninga
> > > >> Sent: Wednesday, December 30, 2015 11:06 AM
> > > >> To: amsat-bb at amsat.org
> > > >> Subject: [amsat-bb] Waiting for Solar Panel Efficiency (Ha!)
> > > >>
> > > >> Compare the cost and efficiency of solar panels for cubesats and for
> > > your
> > > >> house:
> > > >>
> > > >> http://aprs.org/Energy/solar/efficiency-comparison-cost.png
> > > >>
> > >
> > _______________________________________________
> > Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions
> > expressed
> > are solely those of the author, and do not reflect the official views of
> > AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>