here's one source: http://media.wiley.com/product_data/excerpt/7X/04714863/047148637X.pdf I haven't looked into this very closely, and others may have access to better numbers. Reuben Deumling On 5/4/07, David Delaney <ddelaney at sympatico.ca> wrote: > > > Wow! Less than 10 kWh / day. > > Where does that number come from? > >