Volvo Cars, A-hus and Vattenfall recently launched the six-month One Tonne Life project—an attempt by a family (the Lindells) to cut their carbon dioxide yearly emissions from seven tonnes per person to a more sustainable one tonne.
Car. Volvo has provided a C30 Electric (earlier post) for use in the project. The Volvo C30 Electric is powered by a 24 kWh Li-ion battery pack (22.7 kWh used to power the car) that is recharged via a regular wall socket. A full charge takes about eight hours; range on a full charge is up to 150 kilometers (93 miles).
The Lindells will charge the electrical car in a smart charging station in the carport. Solar cells on the house roof and exterior provide the house with electricity. The One Tonne Life house has solar cell panels both on the roof and on the exterior wall facing south which generate, for instance, the required electricity for supplementary heating, ventilation, the fridge and the freezer. All surplus electricity can be used to charge the family’s electrically-powered Volvo or be used in the joint electricity grid. The solar cells are supplied by a manufacturer that is partly owned by Vattenfall. Besides the solar cells, there are solar collectors on the roof of the carport which generate energy used to heat water and for heating.
When the house generates more electricity than it requires, the surplus is delivered to the electricity grid. Increasing small-scale and local electricity generation is a step in the development of a sustainable energy system. The solar panels meet a large portion of the household’s heating and hot water requirements during April to October. When the sun is not shining and the accumulator tanks have no solar power stored, the Lindell family get renewable energy from Vattenfall. The family can also choose electricity from low emission energy sources: from hydro, wind or nuclear power.
Using the EnergyWatch analysis tool, which is connected to the electricity metre, the family can measure electricity consumption in real time.
House. The One Tonne Life house provided by A-hus has triple-layer walls with exceptional insulation capability and minimal air leakage. Other important features are improved insulation in the roof and foundations, as well as low-energy windows and doors.
A wind-catcher in the entry hall prevents large airflows between the inside and the outside. This creates a comfortable climate inside the house and the energy consumption becomes lower. Protruding frames around the windows shade the interior when the sun is high in the summer sky, yet let in the winter sun’s energy when it is low on the horizon.
In order to ensure a supply of fresh air to the well-encapsulated house, there is a ventilation unit that sucks out spent poor-quality air and replaces it with fresh, tempered air delivered to the bedrooms, living room and other public areas. The heat in the spent air is recycled.
The building’s heating requirements are largely met by the incoming air, the occupants’ body heat and heat-generating household appliances. Supplementary underfloor heating is installed on the bottom floor. The solar cells on the roof and the south-facing facade generate electricity that provides additional heating or is used to recharge the electric car.