Solar PV System for the Farm

Just the concept of our electric meter running backwards and our electric company sending us a check was enough to get us interested in a system. Throw in the Federal tax credits, as well as the CO2 savings and we decided to go solar.

Our goal for the system was to be net zero. Our local utility, CEMC, in conjunction with the TVA was offering a program that would initially pay us $1,000. On top of that, they agree to purchase everything we generate for 12 cents over the current per kilowatt hour (kWh) rate. In essence, it's a ten year purchase agreement that currently pays us 21.5 cents per kWh. It gets adjusted up every time they raise the kWh rate and the contract is for 10 years.

We decided on a grid-tied system rather then using batteries for two reasons: 1) the cost of the batteries would have added another $15,000. 2) the battery technology is just not there yet. Hopefully within the next three years the cost will decrease and the battery life will increase.

It's a 8.064 kW system composed of 36 Sharp, 224 watt panels that are pole mounted using Unirac heavy duty rails. We put them on the ground because we found out that putting them on the roof actually would cut down energy production due to the fact that solar panels operate more efficiently when they're cooler.

The system is tied together using a Sunny Boy inverter which is connected to a wireless router. This way we can see exactly how much electricity we're generating. Although it's only a few weeks old, we've generated over 600 kWh. On a typical sunny day we can produce approximately 50 kWh. It also has a neat feature that shows us how many pounds of CO2 we've saved and approximately how much CEMC owes us.

There's a fair amount of paperwork required by the TVA Green Power Switch Generation Partners program, not to mention multiple on-site inspections by the Tennessee state electrical department and CEMC. Also our existing meter had to be changed out for two new meters, one that shows how much electricity we're generating and the other one showing how much we've used.

All in all, it's pretty interesting to watch and we're looking forward to getting our first electric bill for $O.

More Photos

See more photos on Flickr.

Latest solar panel stats

Date Production
September 28, 2013 44.16 kWh
September 27, 2013 40.29 kWh
September 26, 2013 36.81 kWh
September 25, 2013 22.32 kWh
September 24, 2013 36.65 kWh
September 23, 2013 47.42 kWh
September 22, 2013 47.99 kWh