Why use fossil fuels to power a tractor when another source of energy – sunlight – is available and is non-polluting, free and virtually inexhaustible?

This was the question that led American Stephen Heckeroth, founder of Homestead Enterprises in California, to start developing a solar-electric tractor five years ago. Not only is solar charging cheap and ecologically sound, but it is also well-suited for farming, since tractors are mostly used during sunny seasons.

His company’s solar-electric tractor is designed to be used in vineyards, in greenhouses, on golf courses and on small farms – all without the need to burn fossil fuels. The tractor uses batteries that can be charged directly from the sun using photovoltaics. The batteries also can be charged from a regular electrical outlet.

The seven to ten kilowatt-hour battery pack can power the tractor all day for light-duty applications, such as planting and harvesting, and the cost of charging is less than one US dollar.

Also, by placing the battery low between the drive wheels, operators can maximise traction and stability, increasing the tractor’s performance.

The tractor’s mid and rear three-point hitches, which use linear CATR40B actuators from SKF, can operate a farm implement or be used to exchange an auxiliary battery pack for continuous operation. With the addition of an onboard inverter, the batteries can be used as a clean, silent mobile power source for garden and construction tools or even to power a whole home.