The SolarMill, designed by WindStream Energy Technologies, consists of a set of vertical axis wind turbines coupled with a solar PV panel in an integrated electronic system. The system can be installed on rooftops and it is sold globally.
SDG 7: Affordable and Clean Energy
Target Users (Target Impact Group)
Household, Small and Medium-sized Enterprises
Distributors / Implementing Organizations
Users can obtain the product directly from the manufacturer.
The product is designed and manufactured in India.
Intellectural Property Type
User Provision Model
The users can purchase directly from the manufacturer by contacting them.
Distributions to Date Status
Although the exact number of distributions to date is unknown, this product has been distributed across India, Myanmar, Kuwait and Africa.
Power rating (W or kW)
System dimensions (m)
1.46 x 0.85 x 1.9 m
Battery capacity (mAh)
Description of solar panels
60 cell monocrystalline type solar panel
Grid compatibility (yes/no)
Description of mobility
The solar panel is a monocrystalline photovoltaic system consisting of 60 cells. The open-circuit voltage of the panel is 37.7 V and the short circuit current is 8.7 A. The maximum system voltage is 1000 V. The vertical axis wind turbine component has a cut-in wind speed of 2 m/s and a cut-out wind speed of 18.5 m/s. The wind turbine has a mechanical braking system to prevent any damage to the system if the wind speed goes beyond 18.5 m/s. The material used for the frame is galvanized G-90 steel and aluminium. The electronic enclosure rating of the system is IP53. The turbine is also manufactured using galvanized G-90 steel.
Provided by the manufacturer.
Manufacturer Specified Performance Parameters
The system is designed to generate energy even at lower wind speed conditions. Coupled with the solar panels, the system can generate energy 24 hrs/day and 365 days/year under ideal conditions. The system incorporates a Vertical Axis Wind turbine which can harness wind energy from multiple directions making it more efficient. It can be either used as an on-grid or as an off-grid system.
Vetted Performance Status
Testing has been conducted using the IEC 61400-2 standards.
Standard precautions for operating solar and wind turbine systems should be taken.
Complementary Technical Systems
An on-board battery charge controller grid-tied inverter is an optional extra to allow for the system to be connected to a battery.
Academic Research and References
This paper describes the wind turbine blade design & validation of the SolarMill system:
Mohd, S., & Fudhail, M., 2021, View of Optimization of the Helical Wind Turbine Blade, Journal of complex flows, Vol 3, No.1, pp. 1-6
This paper looks into hybrid renewable energy systems:
Al-Ajmi, M. S., et al., 2018, A True Hybrid Solar Wind Turbine Electric Generator System for Smaller Hybrid Renewable Energy Power Plants, MATEC Web of Conferences
Compliance with regulations
The product is certified to ISO 9001 standard. Tested and certified by a third-party organization and is registered with the Ministry of New and Renewable Energy (MNRE).
The system has been tested for its quality as per the ISO 9001:2015 standards.