The owners decided to go off-grid because the ability to sell power in New Brunswick was not quite there. They wanted power independence so that they would no longer suffer from grid down situations like hurricanes and other weather-related power outages. The owners also care about the environment and want to reduce their impact as much as possible. They had access to credit to do this and so because they could afford to and felt that it was necessary to become early adopters to be able to share the possibility within the community and their group of friends and family.
In November 2017, the owners started changing electrical appliances over to propane and they installed an on-demand propane hot-water heater and had the old tank removed (saved $35/month). They also had the propane technician hook up a propane cookstove in the kitchen and a propane dryer in the laundry room (both of which were bought used). The power bill dropped to less than 300kWh/month and they knew they were getting close to being able to go to off-grid solar. The owners still had freezers and some small power demons to root out but they began to get quotes for the solar system. Everyone gave different numbers and prices for what would be needed and what it was going to cost. The owners took their time deciding which contractor they wanted to work with and in the end, it came down to communication and cooperation over cost. They chose MJM because he was willing to work with them on an unconventional design and helped save us money on various aspects of the install.
In the summer of 2018, financing was secured and they started to prepare the house walls for the install of the solar panels. The panels and electrical systems were installed in October and the generator was installed in early November. The owners finally flipped the main breaker and went off grid during a grid down storm in early November. A few weeks later the power company came and finished unhooking the owners from the grid and took the line off of the house, and they haven’t gotten a bill since.
The owners have a 5kW array of solar panels mounted on the walls of the house to protect them from snow and ice that tends to cover most rooftop systems in the wintertime. The battery back is composed of 16 six-volt Lead Acid Deep Cycle batteries in series to produce a 48 Volt system that the AC inverter converts for the house to run on. They have an 11 kW propane generator that starts automatically when the voltage drops below 46 Volts. The owners try to conserve power as much as possible to keep from running the generator until they absolutely have to. Usually they can go 2 dark days before they need to run it for 3 hours to charge up the system.
The energy audit that was commissioned identified heating as the owners’ main energy expense so they built solar air heaters to install on the rooms that needed extra heat, the kitchen, living room and bathroom all share a wall with the sun. These simple handmade units have saved the furnace from needing to run during the day when the owners are away. The air heaters create 30-40C air in with -15C to -20C outside temperatures. The owners are hoping to not have to burn wood in the spring and fall, and to not burn as much in the winter, due to the heat produced by the solar air heaters.
They have been off grid for about 4 months through the darkest months of the year and they will be adding 6 more panels in the spring to boost our production for next winter. Additionally, they will be adding more solar air heaters to heat the basement, and more of the upper floors. Finally, they will be adding a solar thermal system to preheat their water to cut down on propane usage. The solar thermal will also bring the potential for in-floor radiant heat, further cutting down on the wood needed to burn to stay warm.
Solar PV System: $27,000
Generator and Install: $7,000
Propane System and Appliances: $7,000
Return on investment at the rate of old power bill:
(Off Grid System $41,000) / ($1700 Annual Power Bill) = 24 years to pay back the system with power bill savings.