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OK4U-100 grid tie inverter, where to buy?

W

WhyMe

Jan 1, 1970
0
Anyone know where to buy a OK4U-100 grid tie inverter? Or is there
something else out there I should be looking at? I have a Harbor
Frieght 45 watt set and I'm looking to grid tie it to slow down the
movement of the meter a little bit. In the future I will probably get
another HF 45 watt set. Is there anything else out there besides the
OK4U-100 for small systems?
 
R

Richard

Jan 1, 1970
0
From what i've been told they are out of production and no longer meet some
sort of standard preventing "islanding". Periodically they appear for sale
used on "greed"-bay. I think the smallest grid-tied inverter is a 600 watt
unit produced in the USA. There's a European 150watt version (50hz)
available.

One local retailer said that of the 4 they sold over 2 years, two came back
failed after a few months. And a local school has 12 of them (connected to
twelve 100 watt PV's) of which 3 have failed after barely 3 years of
operation. I'd maybe pay $50 for them in working condition, not the $450
they were asking here in Canada...
 
W

WhyMe

Jan 1, 1970
0
Do you happen to have the model number for the 600 watt grid tie
inverter or the Euro version?
 
R

Richard

Jan 1, 1970
0
The european version of the OK4U intertie inverter is a 120 watt version
that plugs into the wall. It's called the Soladin 120. It's available at:
www.soladin.com or www.mastervolt.com . I first heard of it while reading
Home Power Magazine's guerrilla solar article #25. It's still available for
download from their webpage.

The 600 watt version is made by the same company. Go to:

http://www.mastervolt.com/en uk/85/14/solar_grid-connected.html

and click on "solar inverters" on the right hand side of the page.

Hope this helps!
 
M

Mel

Jan 1, 1970
0
Richard a écrit :
The european version of the OK4U intertie inverter is a 120 watt version
that plugs into the wall. It's called the Soladin 120. It's availableat:
www.soladin.com or www.mastervolt.com . I first heard of it while reading
Home Power Magazine's guerrilla solar article #25. It's still available for
download from their webpage.

The 600 watt version is made by the same company. Go to:

http://www.mastervolt.com/en uk/85/14/solar_grid-connected.html

and click on "solar inverters" on the right hand side of the page.

Hope this helps!

SMA also has a 700W inverter IIRC
 
K

Kees en Bets

Jan 1, 1970
0
Richard said:
The european version of the OK4U intertie inverter is a 120 watt version
that plugs into the wall. It's called the Soladin 120. It's available
at: www.soladin.com or www.mastervolt.com . I first heard of it while
reading Home Power Magazine's guerrilla solar article #25. It's still
available for download from their webpage.

The 600 watt version is made by the same company. Go to:

http://www.mastervolt.com/en uk/85/14/solar_grid-connected.html

and click on "solar inverters" on the right hand side of the page.

Hope this helps!

I have the OK4U-100 inverter on the back of my (4) modules. They will be
replaced by the end of this month becase they are very unreliable. In the
Netherlands (were I live), about 5 years ago there has been an action in
which you could by 4 to 6 95 Wp modules with this inverter. This year the
organiser of the action is more or less forced to replace (for free) all of
the OK4U inverters because they show a high failure rate.
I ropose you look for something more reliable
good luck
Kees
 
J

jan siepelstad

Jan 1, 1970
0
Hy,

I'm also from the Netherlands and can confirm the complaints of Kees.
Look for something better than the OK4U.
 
R

Richard

Jan 1, 1970
0
Thanks for the heads up on the SMA 700! I didn't realize it existed and
this may be the right product I have been looking for for my small
apartment.



SMA also has a 700W inverter IIRC
 
W

WhyMe

Jan 1, 1970
0
Thanks everyone for the replies. I will stay away from the OK4U :)

What I want to do is set up a guerrilla solar system here in th USA.
Will these inverters from Euro work here in the USA? I've been reading
for the last couple of weeks and I'm a little confused of all the
choices out there. I figured I'd start small and work my way up. I
read in Home Power mag all about guerrilla solar and figured it was
the best way to start. Almost all the guerrilla solar articles in the
USA had the OK4U inverter so I figured it was a good inverter to start
with and very simple to set up. So what inverter do people in the USA
get when doing guerrilla solar setups?
 
G

Guest

Jan 1, 1970
0
Thanks everyone for the replies. I will stay away from the OK4U :)

What I want to do is set up a guerrilla solar system here in th USA.
Will these inverters from Euro work here in the USA?


The European inverters may be 230 volts at 50 hertz. Which
wouldn't work.
 
R

Richard

Jan 1, 1970
0
Hey WM, you'd have to find grid-intertied inverter with at least a 60 Hz
output to match North American standards and there doesn't seem to be a lot
of choice for the smaller systems (>1000 watts).

Like you I love reading those guerrilla solar articles in HP mag since I
first discovered it back in 1999. It appealed to my
stick-it-to-the-man/environmental/self-reliance/techno-geek sides. Heheh!
Those articles have inspired me to want to start my own. I've collected HP
since then (need any, let me know) but i've noticed that there haven't been
any GS as of late. May be because many areas are starting to allow
grid-tied systems.

It seems to me that most of the guerrilla intertied systems use larger Trace
(now Xantrex) units (ie: 4 kw SW4024's, etc). Occasionally I read about
some older synchronous intertie inverters that haven't been made for 20
years.

I started small due to financial and other reasons... besides, it's a great
way to learn (for me). I initially started off with four 30 watt
monocrystaline type PV's that I discovered laying unused in a backyard a
couple years ago. The widow at the house gave me a sweet deal for them! I
picked up some small gel-cells salvaged from unused UPS units and snagged a
cheap 8 amp charge controller. Played around with them for 1.5 years before
I was finally able to get serious and permanently set up my PV's. This
coincided with a new job with a telecom company which enabled me to snag
some surplus 12 volt AGM type deep cycle batteries (I have six 100 Ahr batts
now). I purchased a couple of cheap 300 watt Xantrex inverters that came on
sale and currently have all my domestic lighting and my TV powered off them.
6 months ago I managed to snag for nothing a 75 watt Siemens PV that was
part of an insurance write off from an RV which was destroyed when a tree
fell on it. The panel is fine and undamaged and the owner/victim wanted a
larger system on his new RV so it worked out great for the both of us. Now
some close monitoring shows that my cheap 8-amp charge controller goes into
thermal shut down when nearing 75% input current and on hot days (which we
have been recently experiencing lately here). But I have a line on an
unused Trace C30 charge controller which I made an offer on thru a friend
who also shares a mutual interest in solar/wind power. My next purchase
will be a decent pure-sine wave inverter, but I still keep a casual eye out
for surplus grid-tie inverters that may pop up. My plan is to buy one or
two 75-80 watt PV's a year. Ain't plug-n-play great!

I figure eventually I'll have a large system and grid-tie will be the
end-result.

Have fun!
 
W

wmbjk

Jan 1, 1970
0
What a terrible name. Like 'pirate radio'. Why not something a little
more benign, like 'low power solar AC voltage generation'. Guerilla has
a bunch of political marxist baggage associated with it....

The name was meant to convey that people were using these setups where
the power company either wouldn't permit it, or made permission
ridiculously difficult to obtain.

Wayne
 
Richard said:
Like you I love reading those guerrilla solar articles in HP mag since I
first discovered it back in 1999. It appealed to my
stick-it-to-the-man/environmental/self-reliance/techno-geek sides. Heheh!

A friend was going to go the guerrilla route, which I didn't understand at
all. In addition to being able to bank KwH, which he couldn't do, I got a
huge rebate for my new solar equipment. He thought "permits" were
expensive, but I think that was $37 for me.

Is there really any place where an unauthorized connection makes sense?
 
A

Anthony Matonak

Jan 1, 1970
0
A friend was going to go the guerrilla route, which I didn't understand at
all. In addition to being able to bank KwH, which he couldn't do, I got a
huge rebate for my new solar equipment. He thought "permits" were
expensive, but I think that was $37 for me.

It's only relatively recently that power companies have added
anti-reversing mechanisms to their KwH meters. Most folks likely
still have meters that will go both ways. If this friend of yours
had one of these older meters then he could 'bank' KwH simply
by running the meter backwards, or at least by slowing it down.

Anthony
 
It's only relatively recently that power companies have added
anti-reversing mechanisms to their KwH meters. Most folks likely
still have meters that will go both ways. If this friend of yours
had one of these older meters then he could 'bank' KwH simply
by running the meter backwards, or at least by slowing it down.

In this sense, "bank" is a specific term.
You cannot bank across a meter reading. If you generate more power for the
month without a net metering agreement, you get a $0 bill. I get a
negative bill.

Simply running the meter backwards does work, but not across a meter
reading.
 
W

wmbjk

Jan 1, 1970
0
On Wed, 19 Jul 2006 02:43:17 +0000 (UTC),
A friend was going to go the guerrilla route, which I didn't understand at
all. In addition to being able to bank KwH, which he couldn't do, I got a
huge rebate for my new solar equipment. He thought "permits" were
expensive, but I think that was $37 for me.

Is there really any place where an unauthorized connection makes sense?

I would think so. Anybody who's been on the wrong side of petty
bureaucrats can imagine what happens if the power company or building
department doesn't like a proposal. Read this
http://www.solarwarrior.com/pgebattle.html to see how far these things
can go. Such problems should decrease as officials realize that they
can't fight progress. But if someone has a very small setup, or is the
first in their area, then I certainly can't blame them for avoiding a
hassle if they think that one is likely.

Wayne
 
R

Richard

Jan 1, 1970
0
I think some provinces here in Canada still don't have any rules regarding
grid-tie systems on a residential scale. All have rules and regs regarding
commercial power generation systems... co-generation, etc.

Here in British Columbia, BC Hydro in 2005 finally allowed (quite painlessly
I might add) residential systems to be set up with very little hassle or
expense. They only want to be able to see a UL certified synchronous
inverter with anti-islanding protection and a disconnect. From what i'm
told they will swap out the meter at their own time and expense so that it
will measure both in-coming and out-going power. You still get billed for
the power you use, but the power you sell back is recorded then at the end
of the year and the credit is applied to the homeowners power bill. Don't
quote me on this but we pay 6.05 cents per kw/H and I think they buy it back
at 4 cents per kw/H.

I know my power meter is the older analog style without the ratchet
preventing the meter to spin backwards.

I only know of one person here who runs a "guerrilla" solar operation, so to
speak. He generates only enough to slow down his meter. However, when he
went away on holidays for two weeks, he forgot to shut it down and that
happened to occur when his meter was being read. The sharp-eyed meter
reader reported the "unusual operation" which started a large investigation
on meter tampering and grow-op. Nice thing to come back home to, eh?
Anyways, it was cleared up quickly.
 
A

Anthony Matonak

Jan 1, 1970
0
In this sense, "bank" is a specific term.
You cannot bank across a meter reading. If you generate more power for the
month without a net metering agreement, you get a $0 bill. I get a
negative bill.

Simply running the meter backwards does work, but not across a meter
reading.

I'll agree here with the added observation that if the power
company found you had a negative amount of kWh used during the
month and you're not on a net-metering agreement then they'll
probably have objections.

That said, most guerrilla solar installations are small enough
that they'll never come close to zeroing out the meter so this
is not really a problem.

Anthony
 
I would think so. Anybody who's been on the wrong side of petty
bureaucrats can imagine what happens if the power company or building
department doesn't like a proposal. Read this
http://www.solarwarrior.com/pgebattle.html to see how far these things


I think that is an extreme case. I thought so when I read it in 2001, when
it was posted.

It's hard to argue that no one would have noticed a guerrila hookup of 35KW
in this case.

One of the PG&E complaints was that his system was so large, they would
have to re-engineer their feed to his street to accept the power.

Ultimately, that was all tossed, and it was a long time ago, when the
locals probably knew less about solar.

Given a system of 10KW or less, the reabtes make it sensible to get a
properly permitted system. Unless you don't want to do a proper
installation, which I would frown upon, anyway.
 
Richard said:
told they will swap out the meter at their own time and expense so that it
will measure both in-coming and out-going power. You still get billed for
the power you use, but the power you sell back is recorded then at the end
of the year and the credit is applied to the homeowners power bill.

That sounds like a real bi-directional meter.
My meter measures only net input to me.

If I drive it backwards, it shows a lower number, and the simulated
spinning wheel has little blocks marching right to left instead of left to
right.

There's no difference between the bidirectionally of this meter and the
wheel style that it replaced.

I pay the "meter usage" each month, about $5, and I will receive a true-up
bill at the end of the year, with me owing them some money, or them owing
me nothing. I can't get money back at the end of the year.

PG&E will be moving toward more sophisticated meters for everyone that will
be readable online in near real time. The impact of that on solar net
generators is unclear, but they are already talking about a peak/off-peak
rate structure that will vary with actual system-wide usage, instead of the
fixed times that we have now, which are very advantageous for solar
generators.

Those new meters might actually measure power flow in each direction
instead of just going backwards like the current meter.
 
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