The Kapuni Co-generation plant allows local Hawera industries to acquire energy (electricity and steam) from a single source and enjoy the benefits of onsite embedded generation.

This 50:50 joint venture between Vector and Bay of Plenty Energy (a retail and generation company owned by Todd Energy) is another example of the commitment to local generation projects.

Location

The Kapuni plant is located at the Vector Kapuni gas treatment station, approximately 85 kilometres south of New Plymouth.

The site is adjacent to the Kapuni gas and condensate production station owned by Shell Petroleum Mining while being close to high energy users such as Lactose (a Fonterra company).

Purpose

The plant provides heat and power for local industry. The plant has a rated output of 25 MW and, of this, nearly 20 MW is exported to the national grid.

Some 490,000 tonnes of steam a year is also produced for use in the Vector Kapuni Gas Treatment Plant. This steam allows Vector's Benfield plants to strip carbon dioxide from Kapuni gas to ensure that it meets pipeline specifications.

Steam excess to Vector's needs, around 200,000 tonnes per year, is transported via a dedicated 3 km long steam line to the Lactose dairy processing plant.

Benefits

Since the Kapuni Co-generation plant was first commissioned in 1998, incremental improvements have been undertaken to the plant.

Environmental efficiency can be achieved by using new generation technology. Smaller "embedded" generation units allow savings to be made while more efficiently using input fuel.

By producing heat and electricity onsite, losses due to transportation of the electricity or conversion into heat/cooling or kinetic motion are avoided.

Co-generation involves the combustion of fuel to produce two forms of energy output (typically heat or steam for manufacturing use and electricity).

Generating Plant

The plant consists of two 10.5 MW Solar Mars turbines which are fuelled with treated Kapuni gas from Vector's gas treatment plant. Two steam turbines, in addition to two gas turbines, combine to produce approximately 25 MW of electricity.

Waste heat steam from the gas turbines is used by Vector in their gas treatment process at Kapuni. This amounts to some 490,000 tonnes per annum. This steam is passed through a 1.5 MW back pressure steam turbine to achieve heat and pressure levels required by the factory and generate further electricity in the process.

Steam is also transported via a three kilometre insulated steam pipeline to Lactose at 34 bar. This steam is used in their dairy factory and final generation is undertaken via a 3 MW back pressure steam turbine located at the Lactose site.

Electricity is supplied to Lactose via a dedicated underground 11 kV ring main circuit owned by Bay of Plenty Energy.