Wind turbine manufacturer Windflow Technology's first-half net loss widened by 50% to $1.62 million on the back of higher production costs.

Windflow said revenue for the six months ended December 31 rose 15% to $13.6 million, while production costs rose 17% to $12.7 million.

Production for this financial year was expected to be similar to last year at around 40 turbines.

The company burned through cash during the first half, with cash held at the end of the period down 79% at $2 million as a result of production-related costs and timing issues, and a legal dispute with customer NZ Windfarms.

The cash position was expected to improve over the second half of the year, although that depended on the success of NZ Windfarms' need to raise more funding to complete the Te Rere Hau wind farm near Palmerston North, the company said.

Windflow is also developing a 25-turbine wind farm near Wellington.