Mariah Power's Windspire vertical-axis wind turbine.

Mariah Power, manufacturer of the Windspire vertical-axis wind turbine, shipped its first turbine in May. Rising energy costs and attractive incentives for renewable energy generations is driving demand for renewable energy systems such as the Windspire.

The turbine sells for about $5,000, which includes a high efficiency generator, integrated inverter, hinged monopole and wireless performance monitor.

“We set out to make a low-cost system the average person can buy,” says Mariah Power co-founder and CEO Mike Hess.

Mariah Power, backed by angel investors, Big Sky Partners and Greenhouse Capital, plans to open a $10 million venture capital funding round this summer, according to Hess. He would not reveal the name of the "Tier 1 venture capital firm" that he says will lead the round. Hess says the money will be used to build a manufacturing firm on U.S. soil. 

The Windspire, which was developed by inventors Chris Gabrys and Tim Rodgers with help from Sierra Pacific Power and Nevada Power Companies, is 30 feet tall and 2 feet in radius. It produces about 2,000 kilowatt hours (kWh) per year in 12-mile-per-hour average winds.

Comparatively, a 1-kW peak solar system generates about 1,600 kWh per year in a sunny climate and about 750 kWh per year in a cloudy climate, according to Solarbuzz research firm. Mariah Power shipped its first 20 turbines to dealers in May, and has received a total of 2,000 orders, according Hess. “We can’t manufacture them fast enough.”