I just looked at the results of the poll I posted in the sidebar when I launched this blog. I ask there, what are the causes you want to live off-grid. One of the main causes is at the moment the “to reduce utility costs”. When I cast my vote in that poll I didn’t check this option. I simply don’t believe that living off the grid is a good way to reduce utility costs.

I am not sure about the conditions in the United States, Canada or Australia, but here in Poland alternative energy sources are very expensive. To be more specific:

  • last year I bought a 40 W photovoltaic panel for 530 PLN, now the same panel is sold at 450 PLN (autumn sale 😉 ) — $160 or €107, or $4/W = €2,7/W, far from the level of $1/W, believed to be the point when PV panels are cost-efficient,
  • wind turbines with peak power of 1,000 W cost about 6-13,000 PLN ($2,125-$4,600 or €1,425-€3,090).

Of course you can make your own wind turbine. I don’t think one can make his on photovoltaic panel from scratch, though. Nevertheless the amount of energy you get from your solar/wind power plant is very small.

It was calculated that wind turbine installed in Poland in a place where you have good wind conditions gives the annual mean output of 10% of the peak power. So this 1,000 W wind turbine would work for 8,760 hours (the lenght of one year in hours) with mean output of 100 W, producing total amount of energy close to 900 kWh. If one kWh in Poland does cost less than 0.50 PLN ($0.18, €0.12), it would take over 13 years for the cheapest wind turbine to make the money you spent on purchasing it. And this does not include the energy loss while storing it in batteries!

Solar energy does not solve the problem. There’s a great PV potential estimation tool, and it shows that the PV panel I mentioned would produce only 36 kWh each year, if is mounted to a fixed plane, optimized for the output power. In 25 years the total electricity production would be worth the money spent on the panel! If you install a 2-axis tracking device (I believe it’s called a solartrack), you could increase this to 45 kWh per annum, but that also does cost a lot.

I think it is justified to disconnect from the utilities in only two cases:

Drilling a well or buying a large tank for rainwater might be cheap, so I think it is worth it.