Please help with configuration please

System

OK, so I am not new at this as I have been off grid for a year with a diy project. I decided for many reasons to do away with the off grid and go with a grid tie system. With that said, I need to start FRESH and new. I need someone to help me thru this thread in installing a grid tie system from scratch piece by piece if I can.


Since I AM poor this isnt a fast project for me. More like one piece at a time. What I want to start with FIRST is starting at the electric companies meter up to the panels.

If I start this way I can install ONE panel and be on grid as I caqn later add MORe panels as I go. So In order for the electric co. to give me the net meter (there meter for solar is what I am referring too) I need to have it connected with at least ONE panel. I am going to use a 2500w pure sine inverter and to start 1 185w panel.

OK so now that you have a idea, from THERE meter what do I actually need to do to start this off.

Thanks
Marshall

System2

Re: Please help with configuration please

ALSO, I am NOT going to be using the current parts for this grid tie EXCEPT for the panels. Everythning else needs to be purchased here.

BB.

Re: Please help with configuration please

The only way that you can add one panel at a time is with a Enphase type micro inverter--One GT inverter per panel.

Central inverters, typically, use around 5-20 panels per string to operate the inverter (they are usually high voltage and require around 200-600 volt strings to operate). It depends on the exact inverter and panels you choose as to the array configuration that will work.

Also, grid tied systems require building permits/inspection and utility approval (and frequently inspection). Adding one panel at a time would, in most areas, require a new building permit/inspection each time--Probably not economically viable.

Another issue is if you add panels over a year or two--Many times the panels change models and/or become difficult and more expensive over time. And with central string systems--you may have difficulty getting "matching panels" to build out your string.

If you have been off grid--I assume that you have worked hard at conservation for your home (insulation, energy efficient appliances, etc.). In general, it is almost always cheaper to conserve than to build a large solar PV power system.

-Bill

Cariboocoot

Re: Please help with configuration please

Welcome to the forum.

I guess I have to be the bogeyman and point out that doing a grid-tie system a bit at a time isn't a very good idea. The reason being that all such systems need to be done with the cooperation of authorities and utility. They will want to see a complete plan and sign off on the whole install after inspection. They won't be amiable to a plan of, say, buying another microinverter as you can afford it and adding it in.

Thee next bad news: a 2500 Watt grid-tie inverter is not going to run off one panel. Check out the specs on some "central" GT inverters like the SMA Sunny Boy: http://www.solar-electric.com/smasugrtiein.html You'll see they need hundreds of Volts to run. This is typical; only the microinverters run one panel per unit.

So how many panels do you have now and what are the specifications on them?

System2

Re: Please help with configuration please

I use to be on here before and lost the username and password so I started a new one. My old username I think was vandeusen.... anyway, i have a total of 8-185w panels. As far as permits, not really required here and the only thing that they are concerned about is getting it hooked up correctly., Heck, they also informed me that they will NOT buy any extra that I provide them. (yes its prob. illegal but hey thats ok I wont install MORE then I need anyway)

If I had ONE panel and everything hooked up all the way to there meter they would just swap out the meter on there end. Once there gone, I can add as I can. I know that its probably easier to do it all at once but funds dont allow that and I dont do credit. (cash only personal choice)

what I also have right now is a 5000 watt inverter but its a modified and thats being used currently. I can go with that if need be but I keep hearing its better to go sine and I was told that I dont need a 5000 watt sine.

with the xantrax 40a charger (spelled wrong) charging the batteries to help out I have my electric bill (some is on elec.) is around 40 a month as it is but if I ran strictly on there power the average bill per month is 200 so as it is im fine but i am tired of monitoring the batteries so I want to do something that eleminates the batteries.

I am open for alternate to include not having batteries which is what I believe to be only grid tie as a option. Am i wrong?

Frxddy

Re: Please help with configuration please

I am new to this so my input may be skewed by lack of knowledge.

I have two "first reactions". One is: You can do your idea using Enphase micro inverters. One panel, one inverter. Apply to the electric company for net metering. Follow the rules. They will tell you what and who has to sign off before the connection takes place.

My second reaction is: What are you going to do with the off grid system? Will that stay a totally separate system? If so, OK, but, if your plan is to connect the off grid system to the net metering, you MUST inform the electric company and do what ever they ask. Safety is paramount and if you hook something to the grid that has not passed inspection you are setting up a circumstance that could cost you life and liberty.

Cariboocoot

Re: Please help with configuration please

Please note you can not use an off-grid (battery based) MSW inverter for grid tie. You must use an inverter specifically designed to integrate with the utility.

I'm more than a little concerned bout the local authorities indifference to following rules and common sense. I am not surprised the utility won't buy surplus power; many don't. Whether or not your state requires them to do so is a legal issue I have no knowledge of. Be warned, however, that should you produce surplus power there is the distinct possibility you would be charged for it instead of credited should the wrong meter be in place.

More troubles: the 185 Watt panels would be undersized for the Enphase units, which start at 190 Watts. They may not be on the list of approved panels either, which is another "legal out" for warranty/insurance purposes. If these are homemade panels they are a definite no-go, regardless of the opinion of the local authorities. What they say now ("Oh, it doesn't matter") and what they'll say if the house burns down ("Those panels weren't UL certified; it's all your fault") can be two widely different things.

And yes, the only way to eliminate batteries from the system is with grid-tie set-up which uses the utility as the "battery". The trouble is, if they're not going to buy when you've got "surplus" then you're not really "storing" anything with them; you'll merely be reducing costs while the sun shines. That's not very efficient either.

All together you've got 1480 Watts, which would run two of these: http://www.solar-electric.com/suboy70700wa.html ($2,800) or under-power eight Enphase units ($1,840). I'd go with the microinverters: get one, see if it helps the electric bill any (remember there will only be power produced during the day - no banking of surplus), and add as you can afford (make out a plan for having all of them to get the wiring and connections sized properly).

On the whole, this too is a less than perfect solution. Maybe you'd be better off switching to AGM batteries and a monitor to keep an eye on things. Automatic utility takeover is possible too, if you don't already have it (charge batteries from the grid if they get low, regardless of time of day).

BB.

Re: Please help with configuration please

MarshallV,

I have sent you a PM with the User Name and a new password for your old forum account. Feel free to use it from this point forward (if you like).

Regarding monitoring your battery bank, have you looked into getting a Battery Monitor? Makes battery monitoring pretty easy--just look at the meter for 0-100% state of charge and do what is needed to keep battery above 50% state of charge (and recharge with genset if below 75% state of charge for more than overnight).

You can use a Hybrid Inverter to give yourself grid tied power with off-grid/battery backup... A Xantrex XW system for ~$3,000 just for the inverter itself.

Regarding the utility not buying your power (net metering or similar)--It is a business decision on their part to not loose money on your account and keep their other customers from subsidizing net metered/solar PV customers. I understand their position. In California, the State PUC has forced the major utilities to offer net metering--but only up to ~1% of total system generation capacity.

I am not sure how you are going between $40 per month with off-grid solar and $200 a month grid bill... From your old signature, you are around 500 watts of solar panels which, on a good month, may generate around:

• 0.500 kWatts of panels * 4 hours per day sun * 30 days = 60 kWH per month

That is only $6-$20 per month worth of electricity. That makes spending $3,000 for a Hybrid Inverter a pretty poor financial choice. Especially once you add maintenance costs (battery replacement every X years, inverter replacement every 10+ years or so, etc.).

-Bill

System2

Re: Please help with configuration please

I should also mention that one of my biggest problems with off grid is that I would like to be all electric. That means I would need 220v and myy current situation only allows 110v and I believe I have to install another system to handle the 220v. So, if I go gridtie then I can run everything on one system

the difference between the off grid and on with current system is that the only thing on elec. is 220v and xantrax charger helping the batteries. The elec. co here charges .115 per kwh and with all there fees its 200 bucks and i refuse to pay that... I'll be amish first..LOL (no insult to amish wish they will welcome me into the family..LOL)

BB.

Re: Please help with configuration please

Wow, $200 and most of that is fees per month. That is too much.

You have several options for 220vac. Xantrex Magnum both make split phase 120/240 vac inverters without extra hardware needed for operation.

Or what is your 220vac load? Can that be replaced with something more energy efficient?

Lastly use a step up transformer. They have lots of standby loses so if you can turn off the ac input, that will save you energy.

-Bill