I am in the process of trying to go solar, but can't decide between a gridtie system or storage batteries. I've got a family of 4 and live in a 1250 sq. ft. 2-story brick home in a fairly densely populated suburb.

My roof is south facing and has no obstructions. I have yet to make any significant purchases, but I am really motivated to have a system up and running before the end of summer.

My concern is in having a gridtie system is that in case the power goes out, I will have no backup.

With a battery system I would look at it to supply mainly our water heater, washer/dryer, and kitchen. It would also be great to have power in case of any blackouts.

But with whatever system I decide on, I want it to be a building block to further improvements. A lot of people I've talked to are selling or upgrading their systems, and I don't want to have an obsolete system before I get it up and running.

Any suggestions or experiences would be greatly appreciated!

What state are you in, and do you get a rebate?

Rebates often don't apply to a battery backup system, leaving only grid-tie.

Battery backup has more maintenance to deal with too, and a space to legally store the battery bank. It's also less efficient system, but if you are not cycling the batteries daily, that may not affect your solar harvest.

You could install a smallish grid-tie system, using only half your roof, and then later, install the grid-tie/standby system on the other half.

With my gridtie system, I have plans in place to yank the DC wires off the inverter, and brute force charge a string of car batteries, for lighting only.

If you are in an urban area, how long have past blackouts lasted, hours or days/ weeks ??



PV electric for water heater is a nasty waste of expensive PV cells. Get and install 24/7, a solar water heater to preheat your hot water. fast payback & less cost.

there is a such thing as battery backed grid tie. it's not quite as efficient as batteryless grid tie though.

The New Xantrex WX-6048 inverter is almost as efficient as the GT .. close to a peak of 94%, about 5% better than anything else on the market

You do have to add the Charge controller and minor battery float tar losses but the WX is darn close to the perfect have your cake and eat it too

Hey, great help guys!

I live in Ohio in Columbus. And everyone I am asking about going solar looks at me like i have a three-eyed fish, (like guppy). The amount of natural resources available here, (ie, oderate climate, great farming, and abundance of rain). Is going completely wasted by most of the Ohioans who've lived their entire lives here.
There are 4 solar installers in the state of Ohio, and the closest one is 60 miles away. And I live in Columbus, the capital of the State!

Go Figure

We in Ohio don't have much in the way of incentives to move to renewable energy. A good resource is http://www.greenenergyohio.org/

There is an ELF grant that is usually dispersed by the time it is posted. It favors business over residential applications AND there is a strict limit on residential max kW usage which eliminates any who heat water electrically (unless your house is Energy Star certified). There is also a subsidized interest program (only on a loan's interest). The ELF can viewed http://www.odod.state.oh.us/cms/uploade ... FA0703.pdf

If you are thinking of adding wind power to your system, it would be better to go grid-tie with batteries. Most solar only grid-tie inverters work at a much higher voltages than 99% of wind turbines.

Thanks for all those who replied. To try to answer some of the questions that were presented: 1. We have had blackouts lasting one to two days max in my area due to severe weather conditions or serious summer usage. Therefore I think I'm looking at a GT with battery back up. I have a company coming out to do a estimate.

The initial price information for a GT system w/battery back-up is $15/kw for a 3 kW system.

Let me know if this sounds in-line with what the solar friendly states are paying.

Also I am looking for reputable installers for central Ohio if anyone has any ideas.

thanks again,

45K is alot of money! ...

One can get panels at www.sunelec.com for 3.58 watt

A Outback GTFX3048 is about 1700.00

A Outback MX60 is about 480.00

I just bought 200ah@48V of agms for 1200.00

So that puts the basics @ 15k ...

Of course there are BOS ( balance of systems parts , mounts, breakers wiring ect ) but 45K - 15K leaves 31K to cover everything and your looking at about 2 days labor ( full crew ) to do a roof mounted system

Hope this helps

Yes! That helps a lot. I am doing some more shopping around and another installer who is certified for the state of Ohio in my area is about 30% less.

I also talked to the city engineer today for Grandview Heights (my area), and when I told him I was planning to install a photovoltaic system, there was a long pause, and I had thought he had hung up on me. It was quite humorous and it looks like I might be helping him learn along the way.

Anyway, I really appreciate the helpful link and all the pricing and inverter choices. My question is, if I average about 95 kW/hrs per month and want to have a GT w/ battery backup, would I need two inverters, (1 GT and 1 charger), or would a single specific unit do both? And if so would you recommend any specific.

Also, I am considering having the panels mounted on my carport instead of my roof. It actually has better exposure to the sun and the city board would be less concered about it's visual impact, (by the way, a wind turbine is totally out of the question, unless it can be disguised as a pine tree). My carport is separated from my home by about 50 ft. Does it make better sense to have the inverter closest to the array and then run the AC current across to the house? And what about the battery back-up? Home or in the garage?

I'm a pain, I know, but thanks in advance

I'd keep the batteries out of the house. Not sure about an attached garage, depends on which batteries you chose, Concern is hydrogen fumes, and acid spills.

Keep the low voltage wires (12 or 24v) short, as they carry a lot of current, and let the higher voltage of the inverter travel the longer distance, you loose less power that way.

the garage in ohio will be cold in the winter and thus so would the batteries. everybody knows what happens to batteries in extreme cold, but mike is right about the acid and hydrogen being of some concern. get sealed AGM batteries and you don't have to worry. just be sure the charge is set correctly on agms as they don't like to be overcharged and you can't add water to a sealed battery.

Thank you both for those answers. I hadn't thought about the cold in winter effecting the batteries, so I'll keep that in mind. I was concered with having the batteries inside the hope since I have small children, so perhaps an insulated garage would be best.

Any suggestions for the single inverter for the battery bank and grid-tie?

I would say the new Xantrex XW-6048 first choice, outback GTFX3048 next. You also would need a charge controller, so WX-MPPT ( Xantrex ) or Outback MX60

AGM are great and at least here in Lakeland ( where US Battery is based ) they are not that much more than Deep Cycle LA's. I paid 130 each for 220ah/6V AGMS last month

AGM's are a great option! They are not quite as rugged as LA's. LA's perform better, but need more maintenance, if rapid charging, over charging, or deep discharging will occur. The expect life of an LA is better than AGM's, if cared for properly. You need to decide if modestly lower cost for LA's is worth your required efforts to give the expected life rating.

LA's would require spill pans. Hydrogen accumulation is not a major concern, unless in a tight confined space, which is one of hydrogen's problems as an energy source as it can seep through steel. Just the same, there is hydrogen near the vents of a LA battery during charge/discharge.

One way to save a bit on wiring is to go as high of a voltage, lower current for the same power, as possible. Multiple runs of AWG14 or AWG12 are cheaper than anything larger than AWG10 (roughly 1.5xAWG14=AWG12, 1.5xAWG12=AWG10, etc.) Be sure to account for expected losses before choosing conductors! You may, depending on your panel selection, do a run for each panel, which gives many options at the controller end for series/parallel connections.