The world’s first hybrid device ‘SolarMill’ which harvests both sun and wind energy

Small-scale and urban wind power hasn’t seen nearly the same adoption rate as small-scale solar has, but that hasn’t seemed to stop anyone from working on advancing the technology for rooftop wind power and micro-wind generators, even though wind power pundits maintain that small-scale urban wind power isn’t all it’s cracked up to be, and that payback times can be very long.  

Small-scale solar works great for generating renewable energy from your rooftop. The technology is mature, the cost is dropping, and panel efficiencies are rising. And even though the sun isn’t shining half of the time, when it is shining, solar panels will produce clean power dependably and silently for many decades, with minimal maintenance. Small-scale wind power generation isn’t nearly as predictable, especially in the urban environment, such as placing a turbine on a rooftop, where low wind speeds and variable wind directions may not be optimal for producing electricity.   

However, an advantage that wind has over solar power is that turbines can continue to generate electricity when the sun goes down, so one solution is to combine the two into a hybrid renewable energy system. In an enterprise which could bring hybrid renewable energy to Indian rooftops, WindStream Technologies, a U.S.-based renewable energy technologies manufacturer, has launched its trademark product – SolarMill, at its newly inaugurated facility in Maheshwaram mandal of Ranga Reddy district as report published in The Hindu.

The devices are designed to work in both on-grid and off-grid environments. Instead of a footprint dedicated to a singular solution, WindStream Technologies’ engineers have designed a unique set of vertical axis wind turbines, added the highest quality solar panels, and a patented system of integrated electronics, to create a hybrid device with the highest energy density in the market.  

  A SolarMill Hybrid generator on display in Ranga Reddy District near Hyderabad (Image credit: TheHindu)

Combining solar PV and vertical axis wind turbines into a single modular unit, the SolarMill is said to be the world’s first integrated hybrid technology. The prototype of the portable device consists of three vertical axis wind turbines fixed beneath one or more photovoltaic panels, to produce 2.5KW of renewable energy. The turbines need a minimum wind speed of two metres per second for generation.   

Based on the climatic conditions, wind speeds and local needs, the devices may be integrated seamlessly, representatives of the company said. A solar and wind analysis will be done before arriving at the combination of solar and wind components. The devices are designed to work in both on-grid and off-grid environments, hence, are suitable for mini or micro grids in remote locations, Venkat Kumar Tangirala, president of WindStream Technologies India & South Asia said.   

A 50,000-sq ft production facility in Maheshwaram will soon begin to roll out the products in large numbers. Thousand units are likely to come out next week, Dan Bates, president and CEO of the company, informed. Besides claiming that this is the first fully integrated hybrid renewable energy device, the company also cites lowest cost per installed watt (35 sq ft for one kilowatt), flexibility between battery and inverter, and easy plug-in facility to attach two devices as its USPs.   

The appliance is designed for 25 years durability, and comes with a five-year warranty. It is presently priced at about Rs.1.32 lakh per KW, Mr.Tangirala informed. So far, 10 to 15 installations of SolarMill across India account for 10 to 20 KW power generation. However, several more installations are in the pipeline, among them a pilot from Indian Railways to power its unmanned level crossings.   

The company seeks to expand production to north India, and other districts of Telangana. While the focus is not on exports now, the products may be shipped to Malaysia, Sri Lanka and Indonesia in the coming days, Mr. Bates informed. The company may also begin manufacture of one more product – TowerMill in India, which could power the telecom towers, he said. Telangana Industries Minister Jupally Krishna Rao formally inaugurated the manufacturing facility and launched the product. He promised complete support for setting up production units in all the 10 districts of the State.