A close look at solar-powered robot harvesting technology
Among the various emerging designs for robotic harvesters are those that are solar-powered. Both autonomous and environmentally-friendly, these harvesters are attracting strong interest, especially as smaller photo-voltaic panels grow more efficient and cheaper each year.
Let’s look at two solar robot harvesters now on the market, the first from FineField of the Netherlands. Its Harvy500 is targeted for automated blueberry harvest, but FineField also offers two harvest-assist models, Harvy200 and Harvy200s.
The company has sold 39 Harvy500 units so far, to blueberry operations in Europe (the Netherlands, Belgium, Germany, France, Portugal, Romania, Poland), Israel, Canada, the US and Australia. It can harvest up to 1.000 kg an hour.
Fall Creek Farm and Nursery, a blueberry genetics and nursery company in the US state of Oregon, has made a minority investment in FineField and uses the Harvy500 in its harvest operations. The company deferred to FineField for comments, but Fall Creek co-CEO Cort Brazelton has noted in a press release that FineField harvesters reduce fruit bruising. For its part, FineField says its harvest quality is better than handpick, as is its groundloss, which sits at about 5%.
The Harvy500 was first successfully tested during the harvesting season of 2019 and was fully operational by 2021.
Text continues below picture
How it works
The machine moves along at a set speed and skims the tops of blueberry bushes, removing berries for deposit into packing containers below, with leaves and twigs gently blown away. When full, bins are moved automatically to a storage area within the unit for pick up.
The machine also has a ‘side wheel’ assembly that comes down when it’s finished a row, enabling the machine to directly move sideways to the next row.
In terms of operation, it’s self-driving, explains FineField Business Director Marcel Beelen, “with a remote control that’s only used for maneuvering the harvester into another row and controlling things like height of the machine, driving speed, etc.”
There are no plans to make the unit fully autonomous, he says, because cost would be too high. Also, the unit doesn’t stop if it hits an object, and therefore its use by be supervised by an operator.
Solar integration
The FineField development team chose solar power rather than a power design where batteries are charged up and swapped mainly because of convenience. “Battery swap in the field requires logistics,” says Beelen. “Batteries are heavy and in addition, because we don’t use custom-made batteries, swapping them can become difficult if the battery supplier changes the form of the batteries, which already happened to us.”
In terms of the biggest challenges with incorporating solar power, these were aligning the amount of solar power produced with the power consumption level of the harvester. The team also needed to solve the issue of enough battery capacity to make sure the harvester could run all day in case of clouds.
The company is looking at other berries like haskap that initially don’t need machine adaption. Beelen adds however, that “if it turns out that with small adaptions are suited for more fruit categories, we will certainly investigate adapting the harvester.”
Text continues below picture
Tea harvest using solar
England’s only tea plantation, Tregothnan in Cornwall, also has a robotic tea harvester that’s solar powered called the ‘Teabot.’ It is available for purchase with no sales yet, but Tregothnan has received enquiries from across the tea-growing world, as well as academia and from extension personnel.
The robot has a range of 8 km, which is about 10,000 tea bushes or 2 tonnes of tea leaves.
When Teabot fills its bin, leaves are discharged into bulk bags made of collapsible fabric for pickup.
Similarly to FineField, Tregothnan claims their solar harvester harvests at a higher quality overall than a human, with very precise snipping blades. “We have found that our quality of pluck is exceeding hand plucking over a 2-hour period, as human fatigue has a detrimental effect on pluck quality,” says spokesperson Jonathon Jones.
How it works
The Teabot’s sensors allow it to operate at night. Differently than the Harvy500, Teabot is controlled with remote control right now. Jones adds that it also operates with full GPS guidance for autonomous operation, “but we have not activated this as our new ‘river gardens’ are not in full production until 2026. We will also activate object detection and fine leaf selection.”
He also notes that Teabot is already currently capable of autonomously travelling to the processing factory via private estate roads, “but we do not anticipate having to activate this functionality until 2028.”
Solar power was easy to incorporate as the panel dimensions were part of the design. The 18kw array will charge interchangeable batteries if required.
There are steep-terrain versions of Teabot in development as well as those that are designed to pluck white tea leaves.
