Solar system review

[mikejh]

Hey guys,

I am pretty new to solar, and this is going to be my first large setup and I wanted to know your oppinion/reccomendations for it.

I am using it to run several appliances. Refrigerator/freezer ect.

My draw is about 2.8KW, or 240AH per 24hrs.

My setup is as follows:

(4) grape solar 240W monocrystalline panels
(1) Instapark MPPT 50A charge controller
(6) Rolls surrette S-1590 2V batteries
(1) AIMS 5000watt power inverter (modified sine wave)

Should I get a in-line fuse, in addition to the one in the inverter? Also, the inverter has a battery voltage indicator, and the charge controller has a charge indicator. Should I also get a charge indicator to mount in the house, or is checking the charge controller/inverter going to be fine? My draw is quite low, so I am not expecting much more than 40% DOD.

I am making a tracking mount for the panels, which are located on the western central Washington border. We are at a pretty high elevation, and get quite a bit of sun.

If you could give me your suggestions and tips, it would be appretiated!

Michael

[Mike90250]

whoa !! Stop !!


4, 240W panels, is only 960W x 5 hours = 4800w
If you REALLY get 5 hours of usable sun, this may barely work. Rule of thumb with battery systems, with all losses added up, you need to harvest 2x your consumption, to be ballanced.

Taking batteries to 40% discharge, daily, will give you a very short battery life (2 years if lucky). 7 year life is based on 20% discharge.

Mod-sine inverter & motors = early motor failure, and an additonal 20% extra power consumption over nameplate usage.

[Sunking]

Depends on your location and winter insolation means you need a minimum 3.75 Sun Hours in December/January.

[mikejh]

In the winter, the sun usually doesn't hit our house till about 9:00 and goes down around 4:00, so we probably get 4.5 hours of good sun.

As for the 40% DOD, I am not meaning daily, I was meaning that is the about the most I ever expect to draw. The battery bank is about 1540AH at the 100hr rate. The only reason I got such a big one is because I may want to add to the load somday.

Do you know of a good place to get the wires neccesary to link the batteries, or should I just make my own?

Also, is the AIMs 5000 inverter a good one? It sounds like I should get the pure sine wave instead. I was just hopping not to have to being that I am not going to be running any computers/small electronic devices off of it.

Like I said, I am pretty new to this whole thing, and am open to any suggestions.

Thanks!

[Mike90250]

If you have grid power, be advised, solar & battery is going to cost a WHOLE lot of $$, compared to the 20 cents/KWh you can buy it for.
If you need power for blackouts, an inverter genset, with a 5 gallon can of gas, is a much better deal.

[Sunking]

In the winter, the sun usually doesn't hit our house till about 9:00 and goes down around 4:00, so we probably get 4.5 hours of good sun.

That does not mean anything. To get full insolation you have to have clear view of east-west-south horizon. With only direct sun in wnter from 9-4 is only to going to yield a couple of hours of insolation

[mikejh]

LOL. I know it is not a money saving thing. Yes, I have grid, but don't know how long it is going to stay up. I have a 15Kw genset already, setup with a transfer switch. It is great for pulling up water from the well and running the furnace ect, but it is quite expencive to run, and I am building this setup to run my 2 freezers and 1 refrigerator.

[Sunking]

LOL. I know it is not a money saving thing. Yes, I have grid, but don't know how long it is going to stay up. I have a 15Kw genset already, setup with a transfer switch. It is great for pulling up water from the well and running the furnace ect, but it is quite expencive to run, and I am building this setup to run my 2 freezers and 1 refrigerator.

Generator is still less expensive than solar for emergency backup.

[mikejh]

That may be true, but diesel doesn't keep to well, so the generator is only good for so long. Also, I only need to run it for a hour a day to pull water from the well. In order to keep the refrigerator cold, I would have to run it at lease 3 times a day.

Another thing is, in the winter, we stay sub-frezzing for over a month at a time, so my draw will be less. I am not sure how much though.

[Sunking]

That may be true, but diesel doesn't keep to well

Huh? Deisel keeps for years. Longer than a battery., especially in cold. Gasoline does not keep well, but diesel is oil.

[Mike90250]

OK, generator is out

4, 240W panels, is only 960W x 5 hours = 4800w
If you REALLY get 5 hours of usable sun, this may barely work. Rule of thumb with battery systems, with all losses added up, you need to harvest 2x your consumption, to be ballanced.

In winter, lets say you get 3 hours of sun
4, 240W panels, is only 960W x 3 hours = 2880w Can you live with that ? will it run your furnace blower, pump, and fridge ?

The penalty for failure is dead batteries that have to be replaced, upsized, and add another PV array & charge controller. Have that $$ standing by, or plan on using the genset for 30 min in AM, and 30 min PM to charge batteries while PV is undersized.

Additionally, you mention 15KW diesel genset ?? You do know that diesels need to be loaded to at least 50% load, or they "wet stack" meaning that they don't heat up enough to fully burn the oil, and it coats the eghoust system with sludge, and gums the rings up. Expensive overhall to repair. I'm useing 6hp, 3KW genset as main backup.

[mikejh]

Sunking, can I just have some help with my setup??? Who cares about Desiel! In some cases, you are very right, but there are times and situations that that is not true. All I would like is help with my solar setup, not desiel generator, which I might add, I know a LOT about. I am not trying to be mean, I am just a solar noobie and need help with my solar system, not my generator.

[Sunking]

I have already told you what you need to do it in solar. To be detailed I need your location. I know how many watt hours you need, and horizon limitations, I just need your location because you do not have 5 Sun Hours in winter unless you live on the equator. If you did, cold weather climate would not be a problem.

All I can tell you for sure based on 2.4 Kwh per day use is you need a battery capacity of 14 Kwh in a cold climate.

12 volts = 1167 AH
24 volts = 583 AH
48 volts = 291 AH

The battery will weigh roughly 900 pounds and need replaced every 5 years or less. That is about all I can tell you based on what info you have provided.

[mikejh]

I have already told you what you need to do it in solar. To be detailed I need your location. I know how many watt hours you need, and horizon limitations, I just need your location because you do not have 5 Sun Hours in winter unless you live on the equator. If you did, cold weather climate would not be a problem.

All I can tell you for sure based on 2.4 Kwh per day use is you need a battery capacity of 14 Kwh in a cold climate.

12 volts = 1167 AH
24 volts = 583 AH
48 volts = 291 AH

The battery will weigh roughly 900 pounds and need replaced every 5 years or less. That is about all I can tell you based on what info you have provided.

I thought I gave our location in the biggining, but I may not have. We are on the Western central washington border. The closest town that may be on the map is Goldendale, WA.

The S-1590s have about 1540AH at the 100hr rate, so the batteries are fine. So it sounds like I just need to get a few more panels.

[Mike90250]

Use this link

http://mapserve3.nrel.gov/PVWatts_Viewer/index.html

to input your zip code, your array specifics, and you will get a month - month listing of the power you can generate, I think they even have an option for tracker.

As is, even with a tracker, you need to account for cloudy days in the winter, and how you will keep batteries charged.

Often, a small backup genset is all that's needed to boost the batteries.

Is your pump 120VAC or 240VAC ?