Really we have some of the most cost effective Grade A panels available on the market today, for mono crystalline type we have prices as low as 2.25 per watt. The cost of solar power becoming more popular these days, especially since they are becoming more mainstream. You can use them as a power backup as well removing the need to use a gas generator when the power goes out.
Solar panels can also be used for on grid homes as well. The methods of control can utilize every cent from solar power before it flips over to the grid. It's easy really, the sun is converted into solar dc electricity and stored in cells. There is then an inverter to raise it up to house power for consumption. The trick is using a photo sunlight cell to shut a relay in series with the utility side power when there is sunlight present. So when the sun is out you will run from solar power. At night the photo cell pulls the grid relay shut and runs your off grid power and at the same time recharges the batteries in the event of a power shortage eliminating the need for a gas generator. During daylight hours if there is not enough sun to keep up with the solar then a second relay is used to override the photo cell relay to top up the batteries off the grid.
This is done with a battery relay sensor. When the batteries drop to a certain point the voltage sensor triggers a relay tricking the larger relay into thinking its nighttime and goes to "grid mode". You can have this on a preset timer to ensure that the system does not stay in that mode and returns to the solar. The interesting feature of this control method is that the last cycle of solar that day will stay in solar mode until the batteries are drained. After dark when the system flips back to grid mode to recharge the batteries it will remain in that mode until the next morning giving the cells a rest and leaving them fully charged in the event of a power outage. The process then repeats the next day.
Well as you can see the solar power takes priority over everything else in the system. It also will increase the life cycle of your batteries. I know it sounds a bit confusing but this control method gives your solar panel home an advantage above the rest because you are using it for multi purpose and do not have to touch a thing. The cost for parts of this control method are approximately 500.00, if you can install it yourself and a worthwhile investment or addition to your solar project considering what it does.
