# Solar Panel Questions



## goto10 (Oct 5, 2009)

okay I have a few questions about solar. I've always had this dream of having solar panels on my house, all hooked into my house electric, grid-tied, just so I wouldn't have to pay for electricity. However, that seems to unrealistic, financially speaking. To go completely off solar, I would need a system that could generate 600+ kilowatts a month. So I got a kill-a-watt and figured out how much my tv, computer, other electronics use. So the new plan is to get a couple solar panels on my roof then bring the wiring into the house, probably my living room, have batteries set- up somehow in there and have an outlet that I could plug all my electronics into. So that's the plan, now the questions:

1. Do inverters have AC outlet plugs coming out of them? I can't seem to figure this one out, or do they need to be wired with an AC plug coming out of them in order for my to plug in 120 volt appliances. 

2. When you do a solar setup, the inverter is plugged into the battery, correct? Every time I see diagrams, it's like the inverter and battery are not directly connected like you would use one or the other not both. Then how do you use the battery?

3. What is with voltage. Do I need 12v or 24v or 48v? I think I read that the voltage has to do with how far the electricity has to travel. For my needs it would be from the living room roof, right down into the living room, so not that far, so should I go by 12v when buying parts?

4. Some batteries need venting, these batteries will be indoors and I think I read the gel batteries or is it deep-cycle or both don't need venting. So they would be okay indoors? Eventually I may have a lean-to greenhouse attached to the living room and I could keep the batteries outdoors in the winter in there, with wires coming inside the house but for summer the heat might destroy the batteries, rightt? 

5. Could I really plug some solar panel system directly into an AC outlet in my house and have it lower my energy bill? That's what these plug and play systems supposedly do but if that were the case then wouldn't everyone do it because getting solar hardwired is much more expensive.


----------



## wy_white_wolf (Oct 14, 2004)

goto10 said:


> ....1. Do inverters have AC outlet plugs coming out of them? I can't seem to figure this one out, or do they need to be wired with an AC plug coming out of them in order for my to plug in 120 volt appliances. .....


Some do, some don't. Most smaller ones like you would most likely be using do.



goto10 said:


> ....2. When you do a solar setup, the inverter is plugged into the battery, correct? Every time I see diagrams, it's like the inverter and battery are not directly connected like you would use one or the other not both. Then how do you use the battery?.....


Generally they have a Low Voltage Disconnect (load controller) and at least a fused disconnect between them. I think the diagrams your looking at show the inverter hooked to the charge controller or power center. It would have a built in load controller that they are using.




goto10 said:


> ....3. What is with voltage. Do I need 12v or 24v or 48v? I think I read that the voltage has to do with how far the electricity has to travel. For my needs it would be from the living room roof, right down into the living room, so not that far, so should I go by 12v when buying parts?...


All depends on what your powering and how much power you use. Higher DC voltages mean higher system efficiency and smaller cable sizes. Generally if your using under 1KWH hour daily 12v is fine. Over that and you should consider 24 or 48VDC. Keep in mind though with higher DC voltages there less items you can run directly without the inverter.




goto10 said:


> ....4. Some batteries need venting, these batteries will be indoors and I think I read the gel batteries or is it deep-cycle or both don't need venting. So they would be okay indoors? Eventually I may have a lean-to greenhouse attached to the living room and I could keep the batteries outdoors in the winter in there, with wires coming inside the house but for summer the heat might destroy the batteries, rightt? ....


Your mixing battery types and battery usage terms. A GEL Cell can be a deep cycle. One is what the battery is made from and the other is how it is intended to be used.

Only *sealed* batteries don't need venting. AGMs and GELs would fall into this group. Some Lead Acid batteries are sealed. Any battery that is sealed you don't want to over charge or equalize. Like your water heater they have a pressure valve in case of overcharging (when gases would be generated). But there is no way to add electrolites back into them if they do vent.

Smaller, properly designed systems with non-sealed batteries *may* not off-gas enough to be a hazard. 

Both cold and hot will decrease battery capacity. They, like people, like temps between 50F to 80F.




goto10 said:


> ....5. Could I really plug some solar panel system directly into an AC outlet in my house and have it lower my energy bill? That's what these plug and play systems supposedly do but if that were the case then wouldn't everyone do it because getting solar hardwired is much more expensive.


Not directly (at least legally)

You would need something to convert the DC to AC and match the freqency to the grid and disconnect it if the grid goes down. There called grid tied inverters. There are a couple of outfits that do make small ones that you can plug directly into an outlet. They are not code compliant in the US and the PoCo may disconnect you if caught with one hooked up.

As for lower the bill, they may actually increase you bill. While some meters do turn backwords, others only measure power passing through them regardless of direction. So you would be paying the PoCo for any power you sent them.

Newer "Smart" meters can tell the direction of the power that is passing through them and record both. The PoCo can then see you are feeding them power without a feed-in agreement.


----------



## SolarGary (Sep 8, 2005)

Hi,
If you want to start in a small way that is legal and code compliant, you might consider one of the Enphase starter setups:
http://www.wholesalesolar.com/enphase-solar-power-system.html

The smallest kits use one PV panel of around 200 watts and one enphase grid tie micro inverter. 

There is a bit of wiring, and you would need to get a permit. But, it would be a legal grid-tie system, and the utility company would install a net meter that would give you credit for any power you generate. 

This kind of system (with micro inverters) can easily be added to one PV panel and in micro inverter at a time -- its very easy to expand up to a 3000 watt system.

This is my system, which has 10 panels, but if you just mentally remove the right 9 panels, you have a one panel starter system:
http://www.builditsolar.com/Projects/PV/EnphasePV/Main.htm

To be honest, if you have limited funds to invest in solar electric, you would probably be much better off working the conservation and efficiency angle. For us, the best 8 of the conservation projects we did saved 10,350 KWH a year and cost us $378 (total!) -- the PV system saves 3,000 KWH a year and cost us $10,000 -- kind of easy to see where the payoff is!
Details here: http://www.builditsolar.com/Projects/PV/EnphasePV/Economics.htm

Gary


----------



## Jim-mi (May 15, 2002)

Suggest that you get a book or two and read read read.............


----------



## goto10 (Oct 5, 2009)

thanks for info everyone. SolarGary. that looks like a good option. I'm really ready to move on to Solar now because there isn't anything else I can do in my home to to conserve electricity, I already exhausted that angle of it.

Edit: If those Enphase microinverters produce 240 volts AC how do I use that in my home if everything is 120 AC?


----------



## Valleyguy (Jan 5, 2011)

In addition to what Jim-mi suggests, "get a book or two and read read read" contact the utility company and see what type of program they offer. Some are generous and others such as our electrical association is not. 

IF, if we hooked up to the grid we would get a whopping nickle per kWh. It's what they call "avoided cost". They really do not want our surplus and make that clear. A phone call will give you a feel for the local climate on the issue. This may help you decide if you are going to have an array that will produce plenty of excess or just offset a portion of your usage. 

As for the 240 volt AC question, if the power is feeding into your main panel, that is 240 volts split to 120 volts.

Rick
*Homepage*: www.power-talk.net
*Forum*: forum.power-talk.net/


----------



## Jim-mi (May 15, 2002)

To the "Enphase" question: Think of it as the Enphase is feeding its output thru your 'meter' into a big fuel tank . . the meter is going this way > . . . . . . . .now when your fridge comes on you are using from that same fuel tank, but your meter is going this way < . . . . 

hope thats not to werid . . . . . . . .lol


----------



## TnAndy (Sep 15, 2005)

goto10 said:


> thanks for info everyone. SolarGary. that looks like a good option. I'm really ready to move on to Solar now because there isn't anything else I can do in my home to to conserve electricity, I already exhausted that angle of it.


Really ? 

OK...

What's the average kw/hr/month you are down to now, and what was it before you started ?

What do you heat the house with ?

What do you heat water with ?

What are your cooking appliances ?

Have you gone to all CFL or LED lights ?

What age is your fridge ? and freezer, if separate ?


----------



## Wolf mom (Mar 8, 2005)

The last time the OP posted was June of 2015.....So I don't think he'll be around to answer your question, Rosebush....


----------



## Valleyguy (Jan 5, 2011)

Your question requires an extensive answer. It sounds like you are talking about a grid tie system. I would say, find someone in your area with a system already installed and talk to them. I couldn't even begin to help you with this, I'm off the grid. Hope you can find someone local to help you.


----------



## Markansas (Nov 24, 2021)

Valleyguy said:


> Your question requires an extensive answer. It sounds like you are talking about a grid tie system. I would say, find someone in your area with a system already installed and talk to them. I couldn't even begin to help you with this, I'm off the grid. Hope you can find someone local to help you.


thanks for that link here is one for both of you


https://diysolarforum.com/


----------

