Adding solar back-up to remote home for winter storm.

[trk692]

Greetings!
i have been reading a lot but this is my first post.
I've lived in a remote location in the Oregon Coast Range for 20 years. We have gravity spring water, wood heat and grid electricity. We're the next to last house on out power company's line and experiences outages regularly in winter. Recently I've begun experimenting with solar power to run my automatic chicken coop door - small charge controller, wheelchair battery, 15w panel. Delightful! Ready to move to the next step.
Usually in winter when the power goes out (avg 100 hours off each winter) we break out battery-powered LEDs and hook up our satellite internet reciever and router to an inverter running off our van's battery. Completely less than ideal. This winter i want to do better, and be able to charge phones and laptops and run a small iPod dock stereo/radio.

Lucky me, i just inherited two USA-made 120-watt Astropower AP1206 panels. They've been sitting in a friend's shed since Y2K - very dusty and cruddy but not bent or cracked. I also already have a fairly new Cobra 400w inverter and a bunch of single conductor 10 gauge wire, also some 8 AWG i could make up into inverter cables.
In addition to proper fusing and disconnects, obviously i need a charge controller and a battery bank. Would like a controller with a lot of metering so i can see what's up with the system. 12v ought to be fine.
given the size of the panels and the existing inverter, could anyone take a shot at suggesting appropriate CC? I'll be sticking with 12v. batteries i know, i'm on my own and have to do some more figuring of loads/times but any suggestions in relation to all the other gear?
Thanks in advance. This is forum has a lot of great info.

TRK
Swisshome Oregon

[inetdog]

Welcome to Solar Panel Talk, TRK!

More information on your loads would be a help.
And if the outages are multiple days, you should definitely include at least a small generator in your plans. Often out here power outages are associated with storms that may reduce or eliminate solar recharging for a couple of days too.

[russ]

Insolation values from PV Watts for Tillamook, OR

1.70	41	3
3.53	79	6
4.70	114	9
4.98	113	9
4.90	116	9
4.80	108	8
6.32	144	11
6.01	139	11
5.39	122	10
3.31	78	6
2.16	49	4
1.77	43	3
4.13	1,147	$ 90

[SunEagle]

Insolation values from PV Watts for Tillamook, OR

1.70	41	3
3.53	79	6
4.70	114	9
4.98	113	9
4.90	116	9
4.80	108	8
6.32	144	11
6.01	139	11
5.39	122	10
3.31	78	6
2.16	49	4
1.77	43	3
4.13	1,147	$ 90

russ

To clarify shouldn't you mention to the less obvious that the data is based on a per kW of solar panel DC wattage and also show the $/kWh rate used in the Energy value column.

[trk692]

Welcome to Solar Panel Talk, TRK!

More information on your loads would be a help.
And if the outages are multiple days, you should definitely include at least a small generator in your plans. Often out here power outages are associated with storms that may reduce or eliminate solar recharging for a couple of days too.

Thanks!
We're simple-living prepper types and in 20 years have learned how to live around the electricity here, but the gift of these solar panels made this whole idea possible, so we're taking the plunge.

My loads are variable seasonally. For instance a summer outage demands a fridge be hooked up, in winter we just take food outside to a secured cold-box. We don't have a freezer due to the instability of our power, and mainly rely on fresh and non-refrigerated food. Winter outages call for light. Year round needs are communications: satellite reciever and router, laptop and device charging. Cooking and water heating are either wood or gas, depending on the season. Don't need a well, water is gravity feed. I can do hand laundry quite well if needed.
Another friend gave us a gas generator that didn't work, husband cleaned out the bad gas and tuned the carb and now it's fine. So we do have that for topping up the battery bank if needed. Prefer not to use it much, loud, smelly and the nearest gas is 30 mile round trip. In winter we're often isolated by road conditions as well, so building and maintaining a good battery bank is of interest to me.

I've done some math - came up with 3000 watt-hours per day - being extravagant. Small dorm-fridge, LED lighting and the all the computer stuff.

using the calculations on this page: http://www.leonics.com/support/artic...es2_12j_en.php
i think it wound up being 490 Ah per day for a load (taking into account DOD and all that)

i have two 120 watt panels and am 800w inverter already.

Math is not my strong point but i am not afraid of electricity. It has rules.

[Sunking]

I've done some math - came up with 3000 watt-hours per day - being extravagant.

Careful what you ask for as Oregon is one of the worse places in the country for solar. For year round that will take:

Panel Wattage = 2600 Watts
Mppt Charge Controller = 60 amps
Battery = 48 volts @ 300 AH or $3500 worth and 900 pounds of lead.

Throw those panels away as you will need a lot more of them and they should be the same make and model.

Good Lick with that. Oh, the batteries have to be replaced in about 5 years.

[trk692]

Careful what you ask for as Oregon is one of the worse places in the country for solar. For year round that will take:

Panel Wattage = 2600 Watts
Mppt Charge Controller = 60 amps
Battery = 48 volts @ 300 AH or $3500 worth and 900 pounds of lead.

Throw those panels away as you will need a lot more of them and they should be the same make and model.

Good Lick with that. Oh, the batteries have to be replaced in about 5 years.

Wrong answer! Ain't throwing good stuff away, shedding theoretical loads makes more sense at this point. Been getting by with ZERO non-grid watts, so ANY watts are good watts. Brighten up, eh?

Yeah, Western Oregon is best for microhydro, but i do hate the noise mucking up the lovely forest soundscape.

Let me rethink & rephrase: - i just got 240 watts of free solar panels. I'm going to figure out a way to use this to make some spare electricity to run my sat-net/router and charge my iPhone in the winter. Running a cord out to the van battery is so blah.
I can get by with SMALL.
I figure 300 pounds of battery ought to be enough.

shine on,
trk

[Shockah]

Wrong answer! Ain't throwing good stuff away, shedding theoretical loads makes more sense at this point. Been getting by with ZERO non-grid watts, so ANY watts are good watts. Brighten up, eh?

Yeah, Western Oregon is best for microhydro, but i do hate the noise mucking up the lovely forest soundscape.

Let me rethink & rephrase: - i just got 240 watts of free solar panels. I'm going to figure out a way to use this to make some spare electricity to run my sat-net/router and charge my iPhone in the winter. Running a cord out to the van battery is so blah.
I can get by with SMALL.
I figure 300 pounds of battery ought to be enough.

shine on,
trk

In regards to your rephrased question:
300# of battery is too much for 240watts of panel to sustain.

Realistically:
240W panels in 1.7 insolation (December & January,,, you gotta build for worse case scenario)
with a PWM CC
will sustain 200WH (watt-hours) of daily use. (i.e. 20watt bulb for 10 hours).
An AGM 12volt 85AH (amp-hour) will fit well as it will be discharged only 20% between daily charges and survive a cloudy day or two in between.

[Sunking]

Let me rethink & rephrase: - i just got 240 watts of free solar panels.

There is nothing to figure out. You will need a good AGM 12 volt 50 to 100 AH battery, 20 amp MPPT charge controller, and a 200 watt inverter. In summer you can make up to 400 watt hours, and winter around 200 watt hours.

[Mike90250]

Yeah, Western Oregon is best for microhydro, but i do hate the noise mucking up the lovely forest soundscape.

Where do you get noise from microhydro ??


Anyway, a 12V system will not run much in the way of a Fridge, the compressor starting loads are generally too much for the cheap inverters, and the larger inverters consume (waste) too much power in idle.

Mod sine inverters (the cheap automotive store inverters) are not good for motors, they cause the motor to consume 2@0% more power and run too hot.

For a couple led lights, sat receiver, laptop and TV, the Morningstar sure sine 300 is the way to go. But even it can't start a fridge.

[inetdog]

Where do you get noise from microhydro ??

I cannot say from personal experience about microhydro, but I would expect most or all of the noise to come from the discharge pipe of the turbine or wheel, except where the turbine is a more or less open Pelton type with jets.
On the other hand hydraulic ram systems for pumping water tend to be pretty noisy just from the nature of their operation.