Technically it is feasible to run an electricity system with 100% wind energy, however this may not be the most cost effective solution. The amount of wind generation that can be integrated depends on the nature of the electricity network or grid, as well as the other types of generation in an electricity system.
Some countries are already incorporating large amounts of wind generation into their electricity systems. At times wind provides up to one-third of Spain’s electricity. In Denmark, wind provides 20% of annual generation.
Currently, wind generation provides around 2.5% of New Zealand’s electricity. Given the strength of New Zealand’s wind resource there is no reason why this can not increase to the proportions being achieved by countries like Denmark and Spain.
Internationally, the effects of large amounts of wind generation on a system are seen as challenging but manageable. Work that New Zealand’s Electricity Commission is undertaking shows that, like overseas, the effects of greater amounts of wind generation are manageable and not costly.
New Zealand’s existing hydro generation provides an advantage for integrating greater amounts of wind generation. Hydro generation from lakes is a particularly good match for wind generation because hydro output can be changed reasonably quickly and easily to balance output from the wind farms.
A study led by Goran Strbac, Professor of Electrical Energy Systems at Imperial College in the UK, for Meridian Energy found that the that the cost of wind integration in the New Zealand market is many times lower than experienced in Europe, primarily because of New Zealand’s existing hydro generation.
The study found that the additional cost of integrating 2000MW of wind energy by 2020 would be around $2-3 per megawatt hour. If average household electricity use remains constant (8 megawatt hours per year), this would mean an increase in electricity bills of between $16 to $24. This amount is well below increases expected as a result of the Emissions Trading Scheme introducing a cost on greenhouse gas emissions from thermal electricity generation.