Jotzo and Kemp suggest Australia can be carbon neutral by 2050 though:
But rather than make a whole of nation calculation, can a single householder maintain their lifestyle and be carbon neutral? The back of my ActewAGL electricity bill indicates that a one person household uses about 10 kWh of electricity a month.
- "Ambitious energy efficiency improvements throughout the economy.
- Low carbon electricity supplied by either 100% renewables or a mixture of renewable energy and carbon capture and storage (CCS).
- Electrification and fuel switching towards biofuels and gas.
- Reducing non-energy emissions through carbon farming and forestry, process improvements and CCS in energy intensive industrial applications."
A Nissan Leaf electric car has a range of 117 km with a 24 kWh battery, or 0.2 kWh per km. The average car is driven 12,881 km a year, or 1,073 km a month, which would require 220 kWh.
Assuming your job takes another 2010 kWh per employee per year, or 168 kWh a month.
That is in total, per month:
- Home: 10 kWh
- Transport: 220 kWh
- Job: 168 kWh
- Total: 398 kWh
Annual average solar radiation for the least sunny parts of southern Australia is 12 MJ/m2 per day, or 101 kWh/m2 per month. Assuming photo-voltaic system with 15% efficiency, this would be 15 kWh/m2 per month.
So the householder would need 27 m2 of solar panels. A modest one bedroom, one story home would have a roof area sufficient for this and so be able to generate enough energy for a reasonable Australian lifestyle.
Please note that I have not allowed for the energy needed for food production, manufacture of goods or their transport, nor losses for storage of energy. But also I have not allowed for the savings in energy from multiple dwelling households and use of public transport.
Also there is the issue of cost. Assuming PV solar panels cost $2,000 per kW (including installation) and get 3 hours of peak sun a day, producing 91 kWh a month. To power the single dweller's lifestyle will cost about $8,700 in PV panels. However, if these were installed as part of a manufactured home's roof the cost may come down to $4,400 (and lasting 10 years).
But the householder will also need batteries to store energy, which is where renewable energy becomes expensive. The 24-kWh battery pack for a Nissan Leaf costs $6,500 and is expected to last 8 years. The householder will need 13 kWh a day, even when the sun is not shining. Enough batteries for three days electricity supply would cost $10,600, or about $111 a month.
However, this all assumes no energy saving measures, which Jotzo and Kemp point out can make a difference. As an example, while the typical one person household in Canberra uses 10 kWh of electricity a month, my energy efficient apartment uses about half that. Also I can walk to work, at my home office or corporate office, most days and so drive my car about one tenth the national average. As I need little more than a computer, my workplace uses about one half the amount typical. Adding up all this, per month:
- Home: 5 kWh
- Transport: 22 kWh
- Job: 76 kWh
- Total: 103 kWh
The above figures are approximate "back of the envelope" calculations. However, they are relatively conservative and suggest a comfortable Australian lifestyle could be carbon neutral using current technology.