Thanks Alan.

New Zealand can accept "at least" 35% wind energy because they are half hydro.  Once they get close to 35%, they will study the issue more.

Does that mean that with a wind-hydro balancing system that you can install up to 70% of your hydro capacity as wind?

Note your point about droughts - its just that here in Scotland we've never had any direct experience of drought.  Though in Norway, lesser snow falls in recent winters have left many magazines half empty - skiing across those in winter can be interesting with massive tangles of ice blocks along the shores.

Does that mean that with a wind-hydro balancing system that you can install up to 70% of your hydro capacity as wind?

Sounds plausible to me.  You would also need good transmission linking the whole system.

Regards,
Thomas O. Gray
American Wind Energy Association
www.awea.org
www.ifnotwind.org