Achieving Climate-Positive, Energy-Positive Homes: 60 Years of Northeast Climate Housing

We analyze the operating-energy histories of three homes of different ages that have approached or attained net-use of no fossil fuels and climate neutrality. The first house (H-60) with 1,200 ft² is a conventional 1950s house that has been caulked, insulated and equipped with an airtight woodstove and a 3.3 kW photovoltaic system that reduced its annual use of fossil fuels by 86%. Its total annual energy use excluding any passive gain is ∼57 billion joules. House two (H-30) with 2,300 ft² is a 1980s, passive-solar house with a recently added 4.0 kW photovoltaic system that reduced its annual use of fossil fuels by 71%. Its total annual energy use excluding any passive gain is ∼58 billion joules. House three (H-1) with 1,300 ft² is a 1 year old, passive solar house with a 3.1 kW photovoltaic system and an evacuated-tube solar hot water system that uses no fossil fuels, exports annually ∼900 kWh to the grid making it energy and climate positive, and provides all operating energy from on-site sunshine. Its total annual energy use excluding any passive gain is ∼29 billion joules.