Question on Future Theories

**Wy_White_Wolf** · 08-26-2016, 11:07 AM

Use the power company as your battery. Grid tie system that runs the home and feeds back into the grid during the day to offset your nightly usage. Depending on the net metering agreement and rates it generally takes 5 to 7 years to see a ROI.

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**organic farmer** · 08-26-2016, 11:53 AM

Originally posted by Stolly08

So my coworker told me about the Tesla wallpack and I got doing research etc and been getting pretty hard into this solar research.

Non-solar people have gotten very excited about the tesla battery. Solar people are not as excited about it.

... So during my research on this site I'm gathering that using solar panels to run the entire electrical system of the house during the day and charge a battery system that would solely run the system at night isn't feasible? I was hoping to do this...

Why?

I use Photovoltaic panels to power my house with a battery-bank. Many homes in my town do the same thing.

I have no idea why you would think it was not 'feasible'.

... One thread I just read is stating that it's not possible to ever beat POCO prices due to battery costs?

Off grid system to run HVAC only, doable? - Solar Panels - Solar Panels Forum

https://www.solarpaneltalk.com/forum/solar/how-much-do-solar-panels-cost/324196-off-grid-system-to-run-hvac-only-doable

I live in North Carolina. We turn on the AC in April and we might still be running it on Thanksgiving Day. I'm renovating a small house and installing two

So my question then is what do most people do to actually "save money"?

The least up-front cost is to live in an apartment, on-grid, in a city [except that many urban areas are high COL].

In my region net-metering systems are a lot more expensive due to installer mark-ups, as compared to off-grid or grid-assist systems with batteries.

Presumably this is different in other regions.

Every penny I have spent on off-grid solar is depreciable. The IRS tables give a 7 year depreciation of solar power, so for 7 years I can write-off 1/7th of the total cost from my income tax filings. Even if it never made a single watt of power, after 7 years I will break even.

With leased net-metering systems, the home-owner does not get access to this. The corporation financing it, they get the benefit.

... Just put solar panels on the roof and wire them into the panel and essentially the house uses all the solar energy during the day and has to pull from poco as well? Then straight poco at night?

You could do that.

In which case, your solar panels would provide power during sunlight, reducing your PoCo bill by half.

... If that's the case I need to figure out how many panels I'll need to be cost effective. I will probably have two 3.5 ton ac units then besides that the standard home, I live in Georgia so it's hot down here so any help or direction the right way would be great! Thanks guys!

I have never seen any scenario where solar power to run A/C units is cost effective.

**jflorey2** · 08-26-2016, 12:42 PM

Originally posted by Stolly08

So during my research on this site I'm gathering that using solar panels to run the entire electrical system of the house during the day and charge a battery system that would solely run the system at night isn't feasible? I was hoping to do this...

It is feasible, just very expensive. Most true off-grid systems are installed because there is no other way to get power to that location.

One thread I just read is stating that it's not possible to ever beat POCO prices due to battery costs?

Correct. Not now, and not in the foreseeable future. If battery prices take a massive dive, then maybe.

So my question then is what do most people do to actually "save money"? Just put solar panels on the roof and wire them into the panel and essentially the house uses all the solar energy during the day and has to pull from poco as well? Then straight poco at night?

Correct!

**solarix** · 08-26-2016, 01:46 PM

My take on the Tesla Powerwall is they see expanding into the residential solar market as a way to grow their volume for their car batteries. The advantage of their Lithium batteries is the light weight of them. In stationary applications, you are paying a lot of that battery when you really don't care about how heavy it is. Home solar just needs to keep on doing cost-effective, efficient, very-reliable grid-tie systems for the next few years. Someday (well - today in Hawaii) when the percentage of intermittent solar gets to be an actual threat to grid-stability, then we're going to need storage integrated into your average solar system.

Hopefully by then, the Liquid Metal Battery will be available. Dirt cheap, powerful, long-lived, scalable to any size - that's what I'm waiting for..... Check out the Youtube talks by MIT professor Don Sadoway.

**SunEagle** · 08-26-2016, 01:54 PM

You should check out the battery system that Schneider is producing for Data Centers. They are in 5kWh blocks which can be stacked into a cabinet up to 20 high for a 100kWh system and then added on to the next stack.

They are called the EcoBlade and Schneider has shown some of the early version as a 10kWh system for homes. The last cost given was in the $500/kWh area which as they claim was below the Powerwall system. They also stated you did not need the solar pv system and inverter the Powerwall needed to use the EcoBlade but it could be added to a home with or without solar.

Still not cheap but interesting to see other companies advancing into the energy storage area.

**Stolly08** · 08-26-2016, 05:10 PM

Originally posted by organic farmer

Non-solar people have gotten very excited about the tesla battery. Solar people are not as excited about it.

Why?

I use Photovoltaic panels to power my house with a battery-bank. Many homes in my town do the same thing.

I have no idea why you would think it was not 'feasible'.

The least up-front cost is to live in an apartment, on-grid, in a city [except that many urban areas are high COL].

In my region net-metering systems are a lot more expensive due to installer mark-ups, as compared to off-grid or grid-assist systems with batteries.

Presumably this is different in other regions.

Every penny I have spent on off-grid solar is depreciable. The IRS tables give a 7 year depreciation of solar power, so for 7 years I can write-off 1/7th of the total cost from my income tax filings. Even if it never made a single watt of power, after 7 years I will break even.

With leased net-metering systems, the home-owner does not get access to this. The corporation financing it, they get the benefit.

You could do that.

In which case, your solar panels would provide power during sunlight, reducing your PoCo bill by half.

I have never seen any scenario where solar power to run A/C units is cost effective.

To your "why" question... I'm not meaning is it possible, I'm asking is it possible to do a system like that that will save me money over poco prices...
I don't need to be dependent on an off grid system. I'm looking for a way to save money and save the planet.
If it's not going to save me money I'm not going to do it.

**organic farmer** · 08-26-2016, 05:30 PM

Originally posted by Stolly08

To your "why" question... I'm not meaning is it possible, I'm asking is it possible to do a system like that that will save me money over poco prices...
I don't need to be dependent on an off grid system. I'm looking for a way to save money and save the planet.
If it's not going to save me money I'm not going to do it.

If you have PoCo grid easily available it is always cheaper to use Poco electricity.

**Stolly08** · 08-26-2016, 05:51 PM

Originally posted by organic farmer

If you have PoCo grid easily available it is always cheaper to use Poco electricity.

OK ya that's what I was getting at.

**Stolly08** · 08-26-2016, 05:58 PM

Thanks everyone for the help and clarification! Now the next step is to pick out the best deal. Roof space will not be an issue so if it's cheaper to get lower wattage units and throw a bunch up there let me know. But these look pretty legit lmk what you think.
http://www.thesolarbiz.com/LG-320-Wa...rame#gsc.tab=0
And
http://www.wholesalesolar.com/293061...micro-inverter
This seems kind of expensive coming in at $560 a piece?
How many would I need?
Better recommendations?

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would sure appreciate some business coming their way sometimes.

**SunEagle** · 08-26-2016, 07:49 PM

Stolly08
To answer your question. Most micro-inverters are one for each panel depending on the wattage. There are commercial micro inverters that are bigger and can handle 2 panels but my guess is that they are also probably almost twice as expensive as the smaller ones.

**Stolly08** · 08-26-2016, 08:36 PM

Originally posted by SunEagle

Guest
To answer your question. Most micro-inverters are one for each panel depending on the wattage. There are commercial micro inverters that are bigger and can handle 2 panels but my guess is that they are also probably almost twice as expensive as the smaller ones.

Gotcha appreciate it man! I'll keep reading and reviewing to see what people seem to like around my needs.

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