General Energy Use, Strategies and Systems

Energy Use:

This home began in 1996 as an all electric, high performance, modest cost to build home that is durable, comfortable, and supportive of the health of its occupants. In 2006 it became a Net Zero Energy Home through the use of purchased sustainable energy from NC Green Power. We purchased on a monthly basis an amount of kWh that yearly exceeded our total annual use. We could easily do this because our home was not an energy hog and an institution had been created in our state that provided this service. We have continued to enhance the efficiency of our home over the years. Plus we added a 3.5 KW PV unit with battery backup in 2011 and another 3.4 KW PV unit in 2015. With the 2015 addition we reduced our NC Green Power purchase to a total of 6000 kWh annually. Beginning in 2006 until late 2015 we annually purchased 13200 kWh [11 blocks of 100 kwh for $44.00 each mo.] This purchase power approach is our key strategy that we want to highlight.

Energy Strategies:

Start with a wonderfully comfortable, simple home that is energy efficient. Enjoy it. At ten years of use start and continue purchasing sustainable power to be put into the electrical grid in an amount that exceeds the total energy use of the home. Enjoy it a whole lot more knowing that for an extra $44.00 per month paid through the electric utility you have demonstrated the feasibility that anyone can have a Net Zero Energy Home. A personal choice to impact climate change and help secure the continued potential for human beings to have a place to live. Encourage others...

Zero Net Energy Definition Used Source Energy Use

Monthly Energy Data and Utilities

Energy Data Type:
Electric Utility:
Duke Energy Progress
Other purchased Fuels:

We are an all electric home. Originally the utility was Carolina Power and Light. Then it became Progress Energy. Then it was purchased and now the name of the grid we are attached to is Duke Energy Progress.

Datasets and utility bills sources and reliability:

We have kept a record of the monthly electricity use by reading the house utility meter monthly since 1996. We wanted calendar month data as opposed to the mid month billing that the utility provided. However, on an annual basis they would essentially be the same and I imagine they have historical records. Once we added PV at our home to the mix we not only recorded the utility meter data, we recorded the data each month from the PV system meter. By the way, we have a net meter agreement with the utility. For the purchase power, NC Green Power will have all the records of our monthly purchases. They would have all their data with regard to contracts with producers and with purchasers.


Cogeneration System Description:


Renewables and Energy Balance

Renewable Energy Sources:
Clean energy is imported from off-site (e.g. utility wind power), or renewable energy certificates (RECs) are purchased
Renewable Energy System Description & Details
We purchase kWh through NC Green Power. They write contracts with multiple types of producers that put kWh into the electrical grid. All the producers are providing sustainably produced electricity. It could be solar electric, landfill gas run generator, wind, or other types.
Annual renewable energy generated 13,200 kWh
Annual Renewable Energy Generated Data Type Measured
Renewable Energy System Type(s) Source of Annual Production Data
Other We added up our total annual electricity use for our all electric home with electric water well pump. Divide by 12. Purchase from NC Green Power 1100 kWh per month [13200 kWh annually]. Pay them their $44.00 per month as an added charge on our monthly electric utility bill. They have all the contracts and meters. We just pay to play.

Storage and Installed Capacity

There are 8, 380ah, 6 volt lead acid L16 batteries in the battery box. They are kept charged by the system to be ready for a grid power outage.

Energy Storage type

Backup batteries [2011 system] are kept charged but are only used during those times [multiple times in our location] when the grid goes down. The transfer is automatic when the grid goes down. Sometimes we do not even realize that the grid is down. When the grid fails, the heat pump, range, dryer, and the water heater are locked out. All remaining electrical functions are available for use. With prudent use we can go for days with the grid down. Yes we have backup heating with a wonderful, sealed combustion wood stove. Plus we have an outdoor grill for cooking and heating water and lines for drying clothes. Our primary interest is keeping the water pump working and running the refrigerator and freezer, plus maintaining communications.

Energy Storage Capacity 18 kW