The Knegt 404G2E 55HP electric tractor arrived at the campus from the Netherlands last month and has been displayed at a community day at Lincoln and an innovation expo at Christchurch.
Lincoln University expects the quiet-running tractor will play a big role at the energy farm — a solar installation of 2800 photovoltaic panels, generating 2.3 GWh of renewable energy each year.
Solar generation will be combined with high-value agrivoltaics, through the production of horticulture crops such as cherry, blueberry and a vineyard and possibly the use of native plants such as snowberries planted along rows.
Just over half the 4ha site next to the campus will be in panels and horticulture.
Professorial fellow Dr Wim de Koning said electric transport was part of the university’s decarbonising plans for the energy farm and wider campus.
"We know there are sustainable alternatives for farming and decided to make the bold move once all the solar panels are installed to operate this farm without any fossil fuels being used. So, we needed something that was strong enough to do the agricultural tasks, but also small enough to work between the panels so we looked at a horticultural solution. This is a tractor’s tractor which isn’t autonomous or high tech and needs an operator and it is fossil free. We think it will do whatever we need it to do."
The Knegt will be put to work planting out the site, mowing, rotary hoeing, spraying, pruning, harvesting and carrying out other horticultural jobs.
Expected run time at full power is three hours and for lighter tasks six hours before it needs to be topped up with a fast charger during meal breaks.
Dr de Koning said the tractor was "no show pony" with the farm team putting it to the test soon at the university’s research centres and vineyard in preparation for it being based at the energy farm.
University staff plan to carry out experiments and crop trials in research to advance energy farms.
Rows of panels will be mounted on a tracking system, with two different heights allowing commercial crop production alongside and underneath them.
A smaller line-up of panels will be used for research as its main function, with manual control, height and panel designs, and panel technology explored.
Dr de Koning said they wanted to push trials at the site beyond solar generation.
"We human beings are notorious for not wanting to accept change sometimes even if it’s for the better. We will try to push boundaries and our Class Two soil where we will put our solar array on is suitable for horticulture. Between the rows of the solar panels we have enough space to put in blueberries, cherries and a couple of rows of vineyards and some perennials in the form of saffron, paeonies and other ornamentals. Then for the crop rotation we will look at brassicas we could potentially sell at the farmers market."
Low-growing berries and other shade-tolerant species are likely to be planted under the panels, without interfering with electricity production.
Livestock grazing is often used to manage grass growth in panel rows, but the university is confident more value can be earned from horticulture.
Dr de Koning said horticulture could be found overseas at solar farms, but this was the first time it would be carried out in New Zealand.
"We will benefit from the experience from other countries and universities which have already trialled this and we have integrated feedback into our solar array. We are doing this through the Centre of Excellence in Transformative Agribusiness and have two post-docs looking at the social acceptance of renewable energy in the rural landscape and another study looking at plant growth underneath panels anywhere in the world. Hopefully that will inform us of making the right decisions. We will give it our best shot and keep you updated on our progress."
Students would carry out water quality, biodiversity and other research in this living laboratory, he said.
The Knegt was funded by the Energy Efficiency and Conservation Authority, Meridian Energy and Power Turf New Zealand.
He said there was always a compromise when looking at alternative energy for farm machinery, with methane tractors running on biogas and diesel hydrogen hybrids as well as autonomous options mainly for spraying available.
However, they were happy with the "sweet spot" of electric tractors and solar generation as well as its run time, engine output and smaller size to avoid soil compaction, he said.
Resource consent has been obtained from the district council and the university is waiting for approval from Environment Canterbury to start the project.
Building is expected to be completed mid-way next year.
The energy farm will be combined with other solar generation on the campus to bring the university’s total capacity to about 3.56 GWh, for 18% of its electricity needs.
Most of the solar power will be used on campus, with surplus energy possibly going to the local community during low demand periods such as the end-of-year break and summer weekends.
The university’s goal is to become carbon neutral by 2030 and carbon zero by 2050.
Dr de Koning said the energy farm was part of its decarbonising journey by electrifying the campus.
Coal-fuelled heating would be turned off in December and the university would be working to generate much of its own electricity as an energy replacement, he said.
