Grid Tie Solar Photovoltaic System Install (1 Viewer)

[alia176]

Im curious about solar....

I want to install solar panels on my home with a batt pack. I want to be completely off the grid, independent of service providers.

My question is,

What will i need? (besides the panels and batts)
What other sources of power generation are there? ( that work well, are feasible, and require low maintenance).
So, panels produce DC, could i wire some lights directly to the batt pack therefore i will have less power loss?

Green,

Would you mind starting a new thread on this topic? I think it'll be useful to others who are thinking the same things as you. I think you'll get lots of responses and I'd hate to have them buried inside Jon's thread.

Great graphical explanation Jon. Nice job.

 

[alia176]

The main disadvantage of a grid tie system is that you are not energy independent or immune to power outages. If I have a power outage in my neighborhood I loose power too, even in the day time. I priced a battery backup and it added nearly $10K to my cost. Keep in mind I have a larger than average system. For that price I would rather install a whole house natural gas generator for $3-5K for the rare instances of a power outage. If the perverbial crap hits the fan I'll have other things to worry about than powering my house/fridge etc.

Well put Jon, it is very expensive to go "off grid" I think. The power company up time at our place is very good, just about 98%. However, I do have a 6kw genie that I'll add to the system (safely of course), after I get signed off on the grid tie system Battery cost and upkeep is rather prohibitive and not to mention the amount of storage space they require.

 

[jonharis]

Holy crap. A friend of mine in Hawaii just texted me
That electric there is $0.38-$0.40 per KWh! That would make the pre solar cost to power my house $300-$400 month. No thanks. I'm sure solar is much more over there but even at double of what it is here it would still make sense.

 

[jonharis]

Well the system has been online for a few months now and continues chugging away, as I expected it would. Below are the last few months of production. With days getting shorter and the sun being lower in the sky, production is steadily going down. I am still in the black on my billing and hope to stay in the black through the winter. I have about 1800kWh banked at this point which i'm drawing on now. In August I used 20kWh more than I produced. In September, I used 158kWh more than I produced. This number will continue to rise as the winter goes on. I really want that hot tub.

One thing I have not had time to sit down and do are compare Xcel's numbers to Enphase numbers. Enphase states that they are not as accurate and there will be variation. I'm just interested to see how much it actually is.

One thing I can say about being able to see my production/consumption on a daily rate, I am more prone to do things that increase efficiency and save power. I feel much more in control of my own power bill which is cool.

I have washed the panels a couple of times when they are visibly dusty, about every 2-3 months. I don't do anything special, just make sure the panels are not hot and spray them down while standing on the ground. I have heard of people actually washing them with soap and a brush but think the rinse method is probably sufficient. I did notice about a 5% increase in total production on two similar, cloudless days right after washing which is equal to the power of an entire panel.

 

[LAMBCRUSHER]

With a screen name like that it only makes sense.

Here are some charts showing the difference between a off grid and grid tie system.

View attachment 642037

View attachment 642038

At a bare minimum for a DC offgrid setup you would need the panels, batteries and a charge controller. If you plan on utilizing this to power your home you need to convert the DC power into AC utilizing inverters or microinverters.

The main disadvantage of a grid tie system is that you are not energy independent or immune to power outages. If I have a power outage in my neighborhood I loose power too, even in the day time. I priced a battery backup and it added nearly $10K to my cost. Keep in mind I have a larger than average system. For that price I would rather install a whole house natural gas generator for $3-5K for the rare instances of a power outage. If the perverbial crap hits the fan I'll have other things to worry about than powering my house/fridge etc.

there are newer generation hybrid systems like the XW series from schneider(no affil) and others like Sunny Boy from the germans that offer grid tie and battery back up when utility is down and incorporate all the whistles and bells like integral transfer switches to protect our bros on the line and keep the municipalities happy. the generators are good for on grid systems with classic grid ties but the inverter ac disconnect must be open or else the array will smoke the generator. There are diode sets that can solve that for smaller output gensets, but the best thing to do there, is to have an E panel with all the bare minimum of circuits that will be used when the utility is down and then gen is running and a manual or auto transfer switch ahead of the E panel and downstream of where the array input breaker is. One with a classic grid tie in place could set up a 12-48VDC battery bank and secondary inverter to power the E panel instead of a generator, and it could take a maintenance charge from the grid, then go into invert mode when ac input fails.....Off grid systems are completely different beast, and tend to reflect so in price and labor(you as the end user having to do continuous work) to maintain the batteries and back up generator(must have for off grid dwellings).....there are ways.....we just installed a ground mount array grid tie onto a system that has whole house generator back-up on Auto mode; here we will use utility 240 VAC from a 20 amp 2 pole breaker in the utility distribution ahead of the transfer switch to close a normally open high amp relay contact which will make and break the inverter A/C input/output current carrying conductors(or even just one of the current carriers as that will halt inverter output) this will act as an automatic inverter shunt whenever utility is not present and good on both legs(which is what also keeps the genset from running and energizing)...HTH


don't tell anyone. It's supposed to be secret.....

 

[jonharis]

^ Very cool beta man! There is much in your thread that warrants further investigation. Ball park cost range for these grid tie backups? Honestly, I live in a location with 99.975% up-time so if i do look into the backup route it will be for SHTF scenarios, not because I live somewhere that regularly has outages. I can think of other ways to prepare for that that may be lower cost.

 

[LAMBCRUSHER]

XW inverter about 5-6K, charge controller about 5-6 hundred and batteries can range from 1600-2400 per 48 volt string for flooded lead acid batteries. ballpark. I understand that the price diff between grid tie and hybrid is roughly 6-9K total

 

[jonharis]

XW inverter about 5-6K, charge controller about 5-6 hundred and batteries can range from 1600-2400 per 48 volt string for flooded lead acid batteries. ballpark. I understand that the price diff between grid tie and hybrid is roughly 6-9K total

Wow. That's Well within the cost of a whole house (gas/diesel) generator.

 

[LAMBCRUSHER]

Wow. That's Well within the cost of a whole house (gas/diesel) generator.

yep, and no fuel/maintenance costs....the back up battery bank size will depend upon the amount of loads and time those loads will be required. the basic idea is to have enough battery to get thru a 24-48 hour period at minimum load. every system will be different

 

[LandCruiserPhil]

A hotel is $100/day and you can throw your towels on the floor.....Just say'in if the power goes out

 

[LAMBCRUSHER]

A hotel is $100/day and you can throw your towels on the floor.....Just say'in if the power goes out

that's not very land cruiser.....

 

[LandCruiserPhil]

that's not very land cruiser.....

Nope its Lexus

 

[LandCruiserPhil]

Jon, Not sure if you remember...I have been testing a .75KW system for the last 5 month. Here is some data from Scottsdale Arizona
677 KWH produced
AVG - 135KWH/month
AVG based on 1KW 180KWH/month
Panel set at 14° angle and 200°SW
Not been cleaned since installed
During the peak summer producing measurable output from 7AM-7PM

 

[Enigma]

Jon, whats the long term report on your solar system?