General Energy Use, Strategies and Systems

Energy Use:

This is a super-insulated, passive solar house with a 7.6 kW solar PV system. The heating and DHW is by a Daikin Altherma heat pump system supplying hot water to a radiant slab and radiators. The heat pump is rated to have a COP of over 4.0.

Energy Strategies:

We designed our house to reduce the heat lose and maximize the heat gain without over heating and then add solar PV to power our efficient heat pump system. We do have a small wood stove to use for extended below zero weather.

Zero Net Energy Definition Used Site Energy Use

Monthly Energy Data and Utilities

Energy Data Type:
Modeled, Verified
Electric Utility:
Eversource / Western Mass Electric Company
Gas Utility:
Other purchased Fuels:


Datasets and utility bills sources and reliability:



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
30 SolarWorld Sunmodule Plus SW 255 panels, Half at 45 degrees and half at 27 degrees. Each with a Solaredge P400 Optimizer. The inverter is also a Solaredge Inverter, model SE-7600A-US-U.
Annual renewable energy generated 9,987 kWh
Annual Renewable Energy Generated Data Type Modeled, Measured
Power Rating Renewable Energy System Type(s) Source of Annual Production Data
8,350Watts Photovoltaics CEC Production Data Summary.

Storage and Installed Capacity

Energy Storage type


Energy Storage Capacity

Annual Energy Import/Export

Electricity amount (imported from grid) 8,287 kWh/year
Net electricity usage (purchased electricity) 1,262 kWh/year
Electricity amount (credited or exported to grid) 7,025 kWh/year
Natural gas amount (purchased energy) 671 kWh/year