Xantrex powerhub 1800 solar kit +/-??

Re: Xantrex powerhub 1800 solar kit +/-??

Is this what you are looking at, the kit from Northern Tool?

• Versatile NPower 110 Watt solar panels provide 14.5% module conversion efficiency per each 4.9in. x 4.9in. cell. Aluminum frame, tempered glass with EVA laminate and weatherproof film makes panels suitable for continuous outdoor use. Includes cable and MC4 plug system. Two panels are included in this offer; each panel is 42.5in.L x 31.8in.W x 1.4in.H.
• 12V, 110Ah UPG AGM (absorbed glass mat) batteries are shock-resistant and maintenance-free, producing higher cranking amps, extremely low (1-3%) self-discharge rate and greater vibration resistance. Non-hazardous, non-spillable battery design requires no water additions and rugged construction withstands harsh conditions. Two batteries included in this offer, providing a 12V, 220Ah syste

NPower provides a complete 1800 Watt solar solution! Now you can put the power of alternative energy to use with this complete solar energy package that includes a pair of 100 Watt solar panels, twin 12V AGM batteries and a Xantrex PowerHub 1800 charger/inverter that lets you convert and store energy and an NPower 30 Amp digital charge controller. This package lets you capture, store and deliver the power you need for a variety of applications, including your home or cabin. Running Watts: 1,800, Amps: 220, Power (Volts): 12, Battery Type: 12V, Battery Qty.: 2, Alternative Power Collection: Yes, Automatic Switch Back: Yes, Hardwired: Yes, Solar Power Compatible: Yes, Dimensions L x W x H (in.): 20 x 14 x 14

More or less, it is a MSW (modified square wave) UPS system with ~200-400 AH of (12 volt?) external battery bank.

In general, systems like these are designed to supply a moderate amount of power for a few hours--short term battery backup vs long term use at a cabin.

According to the data sheet (PDF), with one external battery bank (200 AH), it will run a 1,200 watt load for 1 hour.

Generally, a large MSW inverter with a "small" battery bank is not a great mix for off-grid power where you would expect to run your system for 1-3 days without sun (stormy weather).

So backing up... What are your loads and your overall needs for the cabin.

We stress conservation here--Generally for a cabin that would be a pretty small TSW (True Sine Wave Inverter) of perhaps 300 watts or so and 200-500 watts of solar panels.

With 500 watts of solar panels, that would support a ~260 to 530 AH @ 12 volt battery bank. And 500 watts of panels, assuming 4+ hours of full sun per day 9 months of the year, will give you ~1,000+ Watt*Hours of 120 VAC per day... And you could back that up with a 20-40 amp 12 VDC battery charger powered by a Honda eu1000i (900 watts, 20 amp battery charger) or eu2000i (1,600 watts, 40+ amp battery charger) genset.

The above system would be much better at supporting an off-grid cabin than using a 1,800 watt MSW inverter+200-400 AH of batteries.

Note that your off-grid loads should use as energy efficient AC (or DC) appliances as possible. No microwaves, electric coffee pots, refrigerators (refrigerators can make sense for a 9+ month per year off grid home, but requires a much larger system). All heating jobs should be handled by propane/alternative fuels (and propane refrigerator if not a full time home).

-Bill

Re: Xantrex powerhub 1800 solar kit +/-??

Backing up a moment--What are your power needs (Watts*Hours, Peak Watts), full time off grid or emergency power. Where will this be installed (someplace with good sun?).

I, personally, am not a fan of wind powered systems... I would humbly suggest that you install battery+inverter+solar PV + backup genset (or grid power) first... Then, once you have everything running, look at adding a wind turbine as an alternative power source.

Again, in my humble opinion, wind tends to be much more expensive and much less reliable than people assume from reading the marketing literature.

If you have prevailing winds >10-12 MPH, Trees "flagging" from prevailing winds, can install a 60' minimum tower, 30' above obstructions, and 300-500' away from up wind obstructions, can cost effectively service the turbine on your 60' tower, and the system can withstand storm winds for your area, and you have the cash available (no home loans), then perhaps a wind turbine would work well for you.

There are some plains states where there are no trees and strong winds (its own problems with turbines, blades, and towers blown down/over)...

But--again, lets start from your needs unless you are building a system with a fixed budget and you are trying to get the best bang for your buck... And even then, we need to know if it is 15-30 minutes a day running a 240 VAC 1.5 HP well pump, or 24 hours per day running lights, radio, charging cell phones... They are very different system designs.

-Bill

Re: Xantrex powerhub 1800 solar kit +/-??

Let us say you want to run the AC on full (900 watts) for 4 hours a day (or 300 watts on low for 12 hours per day).

• 900w*4hours = 300w*12hours = 3,600 WH per day for A/C.

Ok the break down, cabin will be used on average 2 times a week sometimes maybe for a full week. with 2 40watt lights. a book shelf sterio system 100watts +/-, a fan in summer maybe 2.

Assuming the 2x 40 watt lights are CFL/LED (i.e., very efficient) for 6 hours per night, 100 Watt stereo * 5 hours per day (recommend looking at a Car Receiver instead--probably a lot less power). Couple of DC fans at 5 hours per day * 10 hours * 25 watts:

• 2x40 watts * 6 hours = 480 WH per day
• 100 watt * 5 hours = 500 WH
• 2x 5 hours * 25 watts = 250 WH
• 900 watts * 4 hours = 3,600 WH
• =========================
• 4,830 WH per day total (summer)

And the peak watts would be:

• 2x40W + 100W + 2x25W + 900W = 1,130 Watts peak (1,500-2,000 watt inverter?).

Using PV Watts for Oklahoma_City, 1kW of solar panels (round number), fixed array and 0.52 end to end system derating (flooded cell batteries and AC inverter):

"Station Identification"
"City:","Oklahoma_City"
"State:","Oklahoma"
"Lat (deg N):", 35.40
"Long (deg W):", 97.60
"Elev (m): ", 397
"PV System Specifications"
"DC Rating:"," 1.0 kW"
"DC to AC Derate Factor:"," 0.520"
"AC Rating:"," 0.5 kW"
"Array Type: Fixed Tilt"
"Array Tilt:"," 35.4"
"Array Azimuth:","180.0"

"Energy Specifications"
"Cost of Electricity:"," 7.7 cents/kWh"

"Results"
"Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
1, 4.33, 70, 5.39
2, 4.99, 72, 5.54
3, 5.48, 84, 6.47
4, 6.01, 88, 6.78
5, 5.67, 82, 6.31
6, 5.94, 81, 6.24
7, 6.20, 86, 6.62
8, 6.27, 86, 6.62
9, 5.71, 78, 6.01
10, 5.54, 82, 6.31
11, 4.48, 66, 5.08
12, 4.38, 69, 5.31
"Year", 5.42, 944, 72.69

Pick 72 kWH per month (February) as the "break even" month for generator usage:

• 72 kWH / 28 days =2.57 kWH per day per 1,000 watts of panels
• 4.830 kWH per day summer / 2.57 kWH per day per 1,000 watts = 1,879 Watts of solar panels

A 2,000 Watt inverter, I would suggest a 24 volt battery bank:

• 2,000 watts * 1/21 volts inverter cutout * 1/0.85 eff * 1.25 NEC safety factor = 140 Amp 24VDC Fuse/Breaker/Wiring Minimum

Battery Bank sizing... 5%-13% rate of charge based on Solar array output current with 0.77 panel+charge controller deratings:

• 1,879 Watts * 0.77 derating * 1/29 volts charging * 1/0.05 rate of charge = 998 AH @ 24 volt maximum bank rating
• 1,879 Watts * 0.77 derating * 1/29 volts charging * 1/0.10 rate of charge = 499 AH @ 24 volt (optimum typical battery rate of charge)
• 1,879 Watts * 0.77 derating * 1/29 volts charging * 1/0.13 rate of charge =384 AH @ 24 volt minimum bank size (economically speaking)

A 10% rate of charge 499 AH @ 24 volts will last you:

• 499 AH * 24 volts * 0.85 inverter eff * 0.50 maximum battery discharge * 1/4,820 WH per day = 1.1 days without sun

To run longer without sun, you would need to multiply the battery bank size by 2 (2.2 days without sun), but that brings you down to the minimum 5% rate of recharging... Pretty much the minimum you should try.

It would not hurt to increase the solar array size if you had 998 AH @ 24 volt of battery bank... And if you tripled the bank size, you would need to increase the array by 1.50s to 3x to keep the array properly charged (minimum charging current). Of course, the larger array gives you a lot more power to play with (for you microwave, more AC, refrigerator, etc.).

But with more power, you need a larger inverter (more standby losses), etc...

If you start with living there 2 days a week, you could start with a smaller array and large enough battery bank for two days of no sun--And add more panels as you live there towards full time...

Of course, you may not need the AC in cloudy weather (I don't know if you you have high humidity on cloudy days or not for your region).

Also, if you run the A/C during the day, you will not have the 20% battery charging/cycling losses (run the A/C on low during day to keep building temperature and humidity low).

Anyway--I am probably losing myself here vs what you you need... Your thoughts?

-Bill

Re: Xantrex powerhub 1800 solar kit +/-??

When adding batteries in series--the Voltage adds and the AH remain the same.

When adding batteries in parallel--the Current (Amp*Hours) adds and the Voltage remains the same.

8x 6 volt 210 AH batteries at 24 volts:

• 4x 6 volt batteries becomes 24 volts @ 210 AH
• 2x of above strings in parallel (8 batteries total) becomes 24 volts @ 410 AH

Don't worry, series, parallel, and series/parallel setups yield the same amount of energy in the end.

Power = Voltage * Current--If you double voltage and 1/2 the current (rearrange the battery bank connections from parallel to series), Power remains the same.

-Bill