Renewable energy perspectives

Abstract

From the mountains to the sea, the Waikato region of New Zealand stretches from the snowcapped mountains of the North Island’s volcanic plateau surrounding Lake Taupo, through the broad Waikato River valley to the Tasman Sea. The region has the “capacity to power” up to 50 per cent of New Zealand, and exports over 75 per cent of the “electricity generated … to other regions”. The primary sources of electricity generation in the Waikato region are hydro, geothermal, and thermal (coal and gas); and recent growth in electricity development in the region has focused on geothermal and gas-fired generation. However, with “peaking” production from the Maui gas field offshore from the Taranaki coast, and the increased emphasis on a 90 per cent renewable electricity generation target by 2025: … the region is likely to play an important role in the development of future renewable electricity generation nationally. For example, limited capacity for new hydro dams along the Waikato River and constraints on further “assimilating discharges” for cooling from thermal power stations due to increasing demand for freshwater underpins the continued interest in geothermal and wind power and the interest in “emerging” technologies such as “underground coal gasification” and “marine energy”. In particular, accessing north Waikato coal reserves (over one billion tonnes), that is currently impractical and uneconomic using “conventional” open cast or deep mining methods, could become “a real possibility” using these new technologies. Against this background the Royal Society of New Zealand recommended that electricity generation should make the “transition” to renewable energy sources by 2020, including the use of less carbon intense bridging fuels, and with a “commitment to zero carbon emissions” from fossil-fuel generation through capture and storage techniques.