John Shrall

This was the explanation I too received many years ago but at that time CFE was unable to execute the plan. Perhaps their computer system has been modified. Each month you have a credit you generate an acumulada. That credit would have to go into a bucket for this month. If you have an aplicada meaning you are eating away at a credit, it would have to come from the oldest bucket having a balance. Depending on your usage it could take more than one month's credit to break even. While CFE has the historical usage information accumulated monthly for a 2 year period, they had no such method to store similar information about solar credits. Bancomer does a similar thing with their puntos. After 12 months the oldest period drops off but in their case, the system is designed to track points by month. When you use points, they are debited from the oldest months on file until they're totally gone.

Efficiency of mini-splits vary a lot. Typically if you pay for a high quality unit up front your electric usage is less. To minimize surprises just get a piece of paper and write down the total kWh produced from the panel and then the in/out at the meter at the same time each day. From these 3 numbers you can compute total daily usage. It will vary somewhat on days you use washing machines, dryers or dishwashers but the remainder should be pretty constant. Measure plug in devices like refrigerators with a kill-watt. Any electronic device that is warm to the touch is drawing power. Not all solar systems generate power the same. The type of panel, orientation and elevation angle all come into play and can cause results to vary. Angle of the sun throughout the year and cloud cover also come into play. When I got my 3.072 kWh system (24x128 watt thin film panels) almost 5 years ago I was told to use a sun hour value of about 5.8. 3.072 times 5.8 yields an average of 17.8 kWh per day. My system peaks at about 20 when everything is humming but since installation that lifetime average of between 17 and 18 has held up.

The panel only shows what you generated. If you want to check total usage per day you have to read the meter let's say in the morning of day 1. At the end of the solar day or the morning of day 2 read the panel and again the meter. You take the net of the in/out of the meter and add it to the panel production. Unkess you are overproducing the meter net will be negative meaning you used some CFE power in addition to what you generated. In Ajijic the average sun hours per day is 5.7. You'll be using some CFE power overnight up until the time the sun gets high enough to start cranking out some kWh. At that point you'll use some and send the rest out into the system. I wrote a spreadsheet to enter the total production at tne end of each month to tell me the averages of my system over the year. Some months are better than others. After 5 years the averages aren't changing much.

I can't help much with local purchase and install info. We bought a house 12 years ago on the mountain that has continuous cross breezes. Never even close to needing A/C/ However we bought a house in Guayabitos a couple of years ago where A/C is mandatory for survival half of the year. As one might expect, the more the unit costs the better the long term benefits. It always works out that way. I installed LG Inverter V 1 ton mini splits in each of the 3 bedrooms. This was the high end 220V LG unit that was much more efficient as well as quieter than cheaper models. I also installed a 2 ton and 1 ton to cool the living area. We mounted the outside compressor in a variety of places. A couple on the roof and others on a metal platform hanging on the side of the house. The installers have to run a line between the outside and inside units so the longer the distance and more walls involved the price goes up. The biggest problem we faced was the drain, especially in our living area mounted on an inside wall. We had to chisel a channel for the drain sloped to the side of the house. The mini split will require a separate breaker or 2 if 220V. Does the house breaker box have enough windows as they are called in Mexico? Cable must be run to power the unit. Last June we had visitors at the beach. Two adults and 6 kids. We closed up the house at 4:30 and cranked up the 3 tons to cool the living area for cooking and eating. The units were quiet enough to be able to watch TV with no problems. At bedtime we killed those units and turned on those in the bedroom. Normally about 75-78 degrees plus ceiling fans were plenty. We were only there 2 weeks but the total 2 month bill was $1,500 pesos. With a single bedroom unit the costs would certainly be much less.

My AXA car insurance in Mexico includes a liability policy for travel to the US. I did have to ask the agent to make sure he provided the rider so I could print it and put it in the car. Unity covers the liability portion and it's the same form as you would receive when purchased for a US car traveling back to the States.