Issue 09, 2006

NIWA helps Auckland's big clean up

Last month, NIWA measured the exhaust emissions of about 50 000 cars in Auckland, as part of the regional council’s ‘Big Clean Up’ campaign.
When a car drives past our gear, an electronic sign tells the drivers whether their emissions are ‘good’, ‘fair’, or ‘poor’. Vehicles rating ‘poor’ were in the highest polluting 10% of the Auckland fleet, and the ARC has been writing to owners, encouraging them to tune their car.

Tackling wind variability
One of the most critical issues for energy generation is reliability of supply. Rainfall, and hydropower generation, has a marked seasonality in New Zealand, which is overcome somewhat if water can be stored in lakes or reservoirs. The strength and consistency of wind can also be seasonal and often the highest wind speeds occur when rainfall and stream flows are lowest.
Such happy symmetry suggests some parts of the country are well suited to a mixture of wind and hydro generation.
But the wind also blows more on some days than on others.