A short history of my system and how well it works.

As I have mentioned in some other threads, I purchased a full off grid system in the US and had it shipped ahead of me to my new home in Chile. I purchased batteries from a business in Chile.

The system I purchased:
Xantrex XW4548 export inverter
Xantrex XW-MPPT60-150 solar charger
Xantrex XW System Control Panel
Kyocera KD205GX-LP (205 watts) solar panels quantity of 9
Midnite Solar E-Panel MNE250XW distribution panel with breakers
Midnite Solar Combiner Box MNPV3
Tri-Metric 2020 with shunt and 48V adapter
Exeltech 1100 watt 120 volt true sine inverter
Various other bits and cables and wires

You can see my setup and the batteries I purchased in Chile here:
http://lesnagy.ca/?p=167

Now the batteries I purchased seemed to only have 1/3 or their rated capacity when I started to use them, and during the 8 months it took to try and get the company to replace them, then give up and buy batteries from the US, they dropped to 1/8 capacity. The short story of these batteries is that they appear to be very old stock, probably purchased by the company I dealt with for nothing and resold to me as new fresh stock with their new labels on them.

So I purchased 12 UB-8D AGM UPGI (Universal Battery) batteries from a US reseller. The good news is that these batteries seem to be working to spec or above. I have been using them for a month and they follow the discharge curves as published by UPGI almost perfectly.


Now on with the overall performance of my system since the new batteries were installed.

Constantly during 24 hours I use somewhere around 280 watts as a minimum value. This load comes from a fridge, lights, and a couple of notebook computers.

During the day I use a 900 watt coffee maker that runs for about 10 minutes, a 2400 watt electric kettle a couple of times a day for 3 or 4 minutes, a 1400 watt microwave for 5 to 20 minutes, a desktop computer that I turn on to do specific work that draws around 500 watts with the monitors. I also have a satellite TV receiver and a 32" HD TV with a 5.1 surround system and a 200 watt sub-woofer. My gas stove also has an electric grill at 2500 watts that gets used very occasionally.

For comfort, I have an in the wall Air Conditioner/ Heat Pump at 900 watts and a electric blanket on the bed at 60 watts. I have used the AC/Heat Pump for hours at times and the electric blanket almost every night all night. The electric blanket as a duty cycle of about 60% and AC/Heat Pump varies according to the ambient temperature.

After setting up my Tri-Metric for the new batteries as specified I have watched the system closely using the information gleaned from the XW System Control panel and the Tri-Metric.

Given the general usage of my system as listed above, I have not had the batteries drop below 76% consumption and never below 49.1 volts. An average harvest from the panels has been around 10 kWH per day. I have seen a peak of 13.5 kWH a couple of days. This is with my panels still lying on the ground and they are now starting to be partially shaded by the container they are sitting beside during the morning and afternoon. I am sure that when they are optimally placed (hopefully very soon) on a frame and angled to the sun I will be able to harvest closer to 15 kWH or more per day.

I have made no real effort to conserve energy other than to not get carried with energy usage. After my 8 months with failing batteries perhaps I pay more attention to energy than I might have. It took me a week to stop being obsessive with watching the Tri-Metric like I had to with the old batteries. It is also a relief to not need to tolerate the noise of a generator every night for an hour or two to keep the batteries alive for the night.

So it is possible to live basically "normally" totally on solar power with just a little bit of care. My location helps greatly here for this however. My house is at 2450 meters (8000 ft) altitude, more than 300 clear days per year, and the driest desert in the world. I could not have better sun conditions I think.

As far as the equipment I purchased goes I have a few comments.

I like the Xantrex XW setup. It has its faults like inaccurate meter readings at the low end and flaky generator syncing. The Midnite Solar panel is a MUST IMHO for this kind of system as it made wiring nice a neat and puts everything you should have for for all your connections and breaker all in one nice tidy package. A battery monitor is a must for any system and the Tri-Metric does a nice job for a basic system.

The solar panels have performed as they should and they have also proven to be tough. I had one panel on a piece of cardboard and the wind caught it and flipped it over onto the one beside it. I was horrified when I saw the situation but when I flipped the panel back over all I found was a slight rub mark on the glass of the panel where the flying panel hit it with its corner on the way down.

The Exeltech inverter has performed flawlessly while powering my lathe and other tools that I brought with me from Canada. It was cheaper to buy the inverter than to buy all new tools and motors.

The biggest lessons learned are that you should have a generator no matter how good you think your system is for those just in case times, and that the best batteries for the desert are AGM type. They are worth the extra cost, plain and simple.

I hope the information in this post is helpful to someone as I certainly have gained a lot of knowledge on this forum and gained a lot of experience in a very short time.