Can I power my home with my Sporty?

[Greg In Austin]

Yes, that is what I said earlier, our SMBs are NOT set up to output power the way we are talking about.

Our inverters are made to sense when there is a load and meet that load up to the maximum capablity. So to provide power to the house you have to plug a load into the SMB.

The MicroSince I have will output power up to its max as long as it senses power on the recieving end.

The exception I also mentioned earlier would be transfer circuits. These allow you to switch certain circuits in your home from the grid to some other source of power. The SMB could be configured to power a transfer circuit in the same way a generator could.
...and in this case a Microsine like I have would NOT work since it would not find power on the receiving end.

So the first thing that needs to be understood is the circumstances when this would be needed. Grid available? Grid not available?

[panion]

Just as I suspected, thinking caps on, fingers typing away.

Thanks for all the interesting info and keep it coming. Sounds like I need to research more into the microsine inverter that will work on 12v. I could easily rewire my solar to have a bypass right into the microsine and into the house. Time to start digging online.

Thanks Greg for taking the time to look up the microsine info.

Have fire extinguisher, not afraid to learn the hard way.

tom.

[Joanna]

Mike, my $x$ signature is feeble humor in the face of the biggest financial leap of faith I've ever taken (mortgage aside). No regrets, especially today as I'm packing the SMB to get my mom out of the way of Hurricane Dolly.
Wish us luck!

[Ford_6L_E350]

Originally Posted by Joanna

Mike, my $x$ signature is feeble humor in the face of the biggest financial leap of faith I've ever taken (mortgage aside). No regrets, especially today as I'm packing the SMB to get my mom out of the way of Hurricane Dolly.
Wish us luck!

Sorry guys, I don't mean to hijack the thread.

Joanna, good luck with Dolly. Hopefully, someday we will have similar warning time with earthquakes.

Mike

[daveb]

One thing I totally agree with Mike is you better know what restrictions your utility requires. Our utility will not allow batteries as a storage device and like Mike said we require special isolating equipment. Also not all meters will run backward. Our utility has a special meter to monitor flow and excess power will not be paid to the customer. In other words if you have enough solar to power everything in your house at once and you turn off a heavy load, the excess power will not be paid back to you. You only save from what you don't consume from the power company. But to make you feel good our utility is happy to take what you want to give away. The systems we require automatically opens when the power is out and we are supposed to know of all locations that have these systems. All utilities are different so you have to check. If I found back feed coming onto our power grid from your house not only would I cut off your power, legal action would be taken. Even a small amount of potential running through the secondary coils of a 12,000 volt transformer to its primary coils can kill a lineman.

Last time I checked watts = volts x amps. A single 60 watt solar panel only puts out a little over 3 amps at 17 or so volts. Three of these (like my vans has) won't do much to power stuff in your house and may not be worth it.

I'm not putting anyone down who uses solar incorrectly but if its working while your gone and puts power on to a dead utility system you might hurt or kill someone. It's the irresponsible people, batteries and generators that scare me the most. Do it wrong and you might damage your van or even worse spend some time in jail so check with the local utility before trying this.


http://www.jatsgreenpower.com/solar-basics.html

[Greg In Austin]

First, Federal Law says that every utility company MUST purchase any excess power produced by a consumer. What Federal law does not stipulate is whether they need to buy this electricity at wholesale oe retail pricing. That is where Net Metering comes into play. The majority of states have already passed net metering laws so that the electric providers must buy and sell at the same rate. In the past they would sell at retail and buy at wholesale and that was not nearly as beneficial to the consumer.

Second, grid intertie inverters are designed to ONLY supply power when there is power on the grid (as I described before). They shut down when the grid shuts down. This is why I asked the question earlier about under what circumstance the OP wanted to power his house. A gird intertie inverter (like the Trace Microsign we talked about above) will disconnect within nanoseconds when power is lost.

Yes, often times electrical codes will require special shutoffs on each side of an inverter. Pretty easy stuff to add switches, but with a grid intertie inverter completely un-needed.

I have not seen any meters that would not run backwards; we have had 4 differnt types of meters on our house in the last 7 years and all would spin backwards or were designed for capturing net metering activity. All the standard mechanical wheel meters will run backwards, and it is fun to watch. The newer meters that are set up for solar PV are electronic and will show three numbers, a gross electric used, a number for the amount fed back onto the grid and a net amount used.

As for what can be beneficial, I will get our chart and scan it tonight (if I can remember). It shows what a tiny 100w system can do for you. By knocking off the peaks of your usage in the spring and summer, it can have a nice impact on your electric bill.

We have had 60+ days ina row above 90 and already have had over 25 100degree days this year (normally we only have 12 100degree days) and we had the hottest June on record. Our electric bill for May was $25 and June was $83.

The idea of using your essentially idle solar panels to provide electric to the house is a great one.

As I said before, the SMBs are not designed to output power, but by hooking your solar panels up to a grid intertie inverter (like the Trace Microsine) you could produce some power. This would be essentially disconnecting your solar panels from the SMB for a period of time. This would take some rewiring, bt it is something I will add to my To Do list. I happen to have a spare Microsine to work with, so I don't have that investment to make. For someone who needs to find a similar small inverter that and an extension cord to use is about all that you would need.

The other way to provide power is through transfer circuits. These isolate the circuits and thus there is zero danger to any linemen. The circuit essential is designed with no power source, and you plug in the power source of your choice... generator, solar, batteries, etc.

[daveb]

Greg I didn’t what to sway this thread off topic dealing with large solar systems but there are protocols to follow and your system must be approved by the utility before going on line in most places and all can have differences. I somewhat agree with how you see the power buy back law but you can only net zero for the year at our system. For example if your house solar can run the entire house plus add say 1000 kWH minimum extra per month you would have to use that extra reserve you put into the system to get it back before the end of the year otherwise our utility is just happy to take it for nothing. This is a state law and different than the past. My true intent is to warn about just plugging in to your house during an outage. This would be something that many people with a way to power up their homes would be thinking about doing. Actually you can have a battery backup in many utilities but between battery cost, maintenance and the price of the transfer switch the cost will not be worth it, even in the long run at this time (especially in our district). At this point in time we will not allow batteries on residential solar systems yet I’m sure things will change in the future especially when battery tech improves. But other places are different and the price of power is also a big factor. A few years back many farmers went to diesel generators to offset the high price of electricity but now things have gone the other way. As far as metering again we require a performance meter and a bi-directional meter that has a standard LCD display with an arrow showing + or – flow. All mechanical meters will run backward like you say which is why people flip their meters upside down to steal power and also why we are changing them out daily. As far as switches we require an AC air gap switch, a standard breaker plus a DC air gap switch that meets proper standards (EVEN WITH A GRID INTER-TIE INVERTER). Remember I’m talking where I live; you might be under a different umbrella. Again these must be inspected by county/city personal and approved/inspected by the utility. The DC voltages can be up to 480 volts which will make your day if you get hung up in that. Inverters are to be approved by our utility and must be automated or grid inter-tie like you stated (most residential solar inverter are) which have the ability to disconnect from the system when the utility power is off. As you said they shut down super fast via a 60 cycle frequency detector plus are required to have a 5 min delay to go back on line as soon as it detects the utility power. So the solar will not work during an outage. That bootlegger system kind of scares me but I have never researched it. I will now. A SMB with an inverter and house battery setup most of us have could run some stuff during an outage. If you don’t use the correct safety procedures and someone gets hurt it would be would be similar to your parked van rolling down a hill and hurting somebody. I am not an expert on solar but OSHA says I must have limited training on it because I work with it. I also agree with you about using it in a correct manor and dairy farmers have used transfer switches for years. We have also taken action with a few that were not up to code. One of my best friends was almost killed when he got hung up in 12kV coming from a dairy generator miles away back feeding on our system. The transfer switch failed.
Your utility may not require what we do but it’s a good idea to check before you jump. Safety was really my main point and the consequences to SMB owners making an incorrect hookup.
Dave.

[Greg In Austin]

...but then we are not talking about huge systems....

There are probably not 200 home systems in the entire continental US that provide more power than an average sized home would use in an entire year, and if they do, they are probably not worried about it because the have no electric bill.

So lets talk about what the OP started this for. A small system that consists in part of the solar capability of the SMB.

Utilities and code can make rules that require switches, but that does not mean the rules will always be followed. That is why so many systems are desccribed as "guerilla" systems. They are systems that are small and do not follow all the rules. For years and years Home Power magazine had a monthly article featuring a new guerilla solar system. Our guerilla system has been online for years now with no failure (except when I accidently cut the cord) and it has never been inspected and will never be inspected. ...and it does still have a breaker helping protect it and other things since it is plugged into an outlet.

I would suggest that the house batteries in the SMB should NOT be part of any system to provide power to a house unless transfer citrcuits are being used. I am not sure how a transferr circuit could fail and allow current back onto the grid. All that I have seen and used are as good at isolating as any lock out tag out type switch.

The quickest and easiest way to utilize the solar panels is to just use the panels and a tiny grid intertie inverter. I seem to remember that when Trace stopped carrying the MicroSine inverter, that research uncovered that it was really a licensed product. The real manufacturer was another company who's name escapes me, somebody in Europe I think.

We may need a little more research to find out if they are still making the product. I have not heard of it being available in the US, but it might be elsewhere. (I will have to see where I stored our extra and see if I can find any marking on it).

.

[daveb]

Sorry Greg but I can’t recommend SMB owners doing this unless their utility gives a thumbs up. I’ve had too many close calls.

http://www.youtube.com/watch?v=PXiOQCRi ... re=related

Although I have had a few similar incidents happened to me on a slightly lesser level, (yes most were a F…up), having the hair burned off you sucks much less replacing your shirt (oh, and cleaning your shorts).

OK… this is big time over kill, (obviously a SMB can’t do this, I just think this is a cool clip) but many times it’s the little things that get us. I wish an SMB solar array could produce more than it does, but having the living crap knocked out of me by small system sucks when somebody makes a mistake. Unfortunately it's usually a skipped safety regulation on the part of the lineman that get him hurt. Being a 9 volt battery ran backwards through a 12kV transformer can put a man on the ground, I would hate to be in the same situation dealing with 100 or more watts.


Tom I’m guessing you have 3-120 watt panels on your rig. As I previously stated, there is a lot to loose in my opinion unless it’s done correctly. If the setup is done correctly, 200 to 300 watts might make some difference in your bill, but I doubt it would be much. Remember watts and kilowatt hours are different. It would be the same as turning off everything in your home and turning on three or four 100 watt incandescent lights (provided they actually consume 100 w each) for a given length of time. Worth it? I might be wrong, but as it was said “it’s free”. Like Mike alluded to; how much solar time would it actually take to pay for the inverter? This in itself would be a big consideration. It would be irresponsible on my part to suggest how to bootleg a solar system. It would be like if I were a ranger telling you it’s OK to have a fire when you’re not supposed to during a red flag fire condition. I am confident that most of us are responsible about fire because we are exposed to it so often. Electricity is a bit different. I have worked with multi million dollar systems that have failed so my trust in an inverter is not up to par. Also, standard breakers are not switches as many people think, and is one of the most common items to fail (due to a variety of reasons) that I end up troubleshooting. If you had a cabin or something like that where there is no power available I don’t see any problems at all using solar from your van. With the advent of these systems coming on line more and more, safety protocols in our industry have ramped up. We were freaked out when Chevrolet was speculating showing a commercial to the public about the “Avalanche” as a vehicle which could power your house during a power outage. Apparently this never happened and I’m glad it didn’t. Although generators have been more of a problem, advertising a way to do this via a vehicle was somewhat alarming. During a power outage in a typical subdivision now takes a two to three times as long to make the repairs as it did in the past because of the possibility of back feed.

And please don’t make me the squirrel

http://www.youtube.com/watch?v=0XBurkUkdFE&NR=1

Dave.

[Greg In Austin]

A small system can have a large impact.



Here you can see two years worth of Electric usage data before we installed our 100w guerilla system; the peaks during this time are in the first large oval to the left on the chart. After that there are an additional two years worth of data after the 100w guerilla system was installed; the peaks are shown in the second oval just to the right of the first oval.

If we put a line through the first peaks it would be somewhere arounf 1150 KWH.
If we put a line through the secons set of peaks it would be around 850 KWH.

This is a differnce of ~ 300 KWH per month. That is nothing to sneeze at. That is in fact more electricity than we used in April or May of this year at our home.

We do try to conserve, but at the time of the area of the chart we are lookingt at it was just me living in the house. The wife did not come along for until 2004, the end of the two years after the guerilla system was installed.

Could this complete difference be attributed to the guerilla system? probably not, but there were no changes to appliances or the house (until after Michele arrived )

But the difference before and after is astounding. You can see tha tthe 6 and 12 month averages were on a steady decline through that entire 2 year period.

So if you have some solar panels that are sitting around doing nothing while your SMB is plugged in in the driveway or garage, those panels could be working for you.