100% renewable?

The Greens say their policy is:

Create long-term enforceable targets for renewable energy production to deliver a 100% renewable electricity generation system by 2030

Under Labour renewable generation dropped from 70.6% in 1999 to 65.4% in 2008.

Since 2008 it has increased 79% in March 2011.

Note this is electricity generation, not all energy generation.

National’s target is to be 90% renewable by 2025, and looks like well on the way.

But there is a big difference between 90% renewable and 100%. It’s like the difference between sanity and insanity.

If you have 100% renewable, then you have real issues with the security of supply. Basically if you have a period with little rain, wind and sun, then you run out of electricity. You don’t need a huge amount of non-renewable such as gas, but you want to have some so you have security of supply.