General Energy Use, Strategies and Systems

Energy Strategies:

5.9 kw PV array installed on south facing roof, grid-tied. There was already an existing solar hot water system on the roof, shared with the other unit of the duplex.

Zero Net Energy Definition Used Site Energy Use

Monthly Energy Data and Utilities

Energy Data Type:
Electric Utility:
WMECO, Eversource
Other purchased Fuels:


Datasets and utility bills sources and reliability:

Meters on building, reliable.


Cogeneration System Description:


Renewables and Energy Balance

Renewable Energy Sources:
Renewable energy is generated within the building footprint (e.g. solar PV on the roof)
Renewable Energy System Description & Details
Photovoltaic System: • 28 Sanyo HIT 210 watt modules • Sunny Boy 6000US grid-tie inverter • Peak DC power: 5,880 watts • Peak AC power to grid: 5,150 watts Specifics below refer to the PV system, but there is also a solar hot water system serving the duplex (which was in place before the renovation): Solar Hot Water: • Collectors: Two Thermo-Dynamics G32 panels, 64 SF total (feeds 2 duplex units). • Solar loop circulator: Hartell MD-3-DCH, 18 watts, 12 VDC. • Solar storage tank: Power Miser-12 (Sears) 80 gallon. • Estimated annual production (for our duplex unit): 3.9 MBTU.
Annual renewable energy generated 7,023 kWh
Annual Renewable Energy Generated Data Type Measured
Power Rating Renewable Energy System Type(s) Source of Annual Production Data
5,150Watts Photovoltaics Metered, gross annual production.

Storage and Installed Capacity

Energy Storage type

N/A, grid-tied PV

Energy Storage Capacity

Annual Energy Import/Export

Electricity amount (imported from grid) 5,116 kWh/year
Net electricity usage (purchased electricity) 431 kWh/year
Electricity amount (credited or exported to grid) 5,547 kWh/year