Installing solar panels along the roof of their herringbone dairy looks like being one of the more rewarding onfarm infrastructure investments Waikato farmers Campbell and Susan Thomas have made.
The Nganinapouri couple were always intrigued by alternative energy, but the capital outlay was always too steep for the economic return, Campbell says.
“The biggest catalyst for us to put it in was that we could do it with the ASB Rural Environmental Compliance Loan.”
To be able to borrow the money at 4.5% for a maximum term of five years made solar power an attainable option. The couple took up a National Fieldays special from What Power Crisis and Meridian to buy a 10kW unit for $28,995 plus GST, which was installed in March.
They hope the solar power system will pay for itself, as they expect to get a 16% return on the unit, providing they can use 80% of the power.
“It will be paid off in about seven years depending on how much power we can utilise out of it,” he says.
The 10kW unit draws its power from 40 photovoltaic panels that all face north along the roof of the herringbone dairy.
The panels soak up photons from the sun and convert them into an electrical charge as DC power. This power is then sent to a solar inverter which converts the DC electricity to AC. Any surplus electricity the system generates is automatically exported back into the main electricity grid.
Meridian currently pays 25c/kWh for the first 5kWh of excess energy each day, then 10c a kW/h.
It costs 25c/kWh to purchase energy from the grid, which is where the incentive is to use the most of their own solar power, Campbell says.
“There is no point putting in a big unit if you’re not going to be using it, there’s no return when you’re buying it back at twice the price.”
They are still working out how best to use the system to reduce buying energy from the grid.
Forty panels facing north soak up photons from the sun and create power.
During the morning milking they have to tap into the grid until there is enough sunlight to start producing power, but they can delay other jobs until there’s adequate power from the solar panels. For example the effluent pump isn’t turned on unless it can run off the solar power.
“We will have to tweak our system a bit to get the best out of it. They’re will be little tricks we can do.”
Campbell trained as an electrician, but when he and Susan married and started their family of four boys they moved back to his family’s farm in 1993 to be the third generation to have farmed there.
They sharemilked 140 cows on the original block of 65ha and bought a neighbouring 40ha block in 2000. They bought the family block during the 2007-08 peak season, a testing time. Recovering from that they bought 20ha across the road in 2010 and increased cow numbers to 390.
They started leasing another 20ha in the 2013-4 season and now milk 420 cows through the original herringbone, which they had extended from nine to 28-aside.
They’ve invested in an underpass, in-dairy feeding, a new feedpad with concrete feed bunkers and, more recently, fenced off all waterways and built a new effluent pond which has reduced pressure on the paddocks in the wet months.
Campbell and Susan still work onfarm when needed, but have a farm manager, Rodrigo Perez, and farm assistant, Gemma Brice. Two of their sons have left home, Josh, a drain layer and Hayden, who is studying agricultural science at Massey University. Scott and Bradley are still at Hamilton Boys High and Ngahinapouri Primary School.
Rodrigo came out from Chile and has been with them for six years. They offered him 8ha of the new lease block to rear his own calves last season as recognition of his stepping up while they’ve grown their own business from 300 to 420 cows during the last six years.
Campbell relief milks while Susan still rears 85 replacement calves every year, which are then grazed at Huntly.
Campbell also helps Rodrigo carry out artificial insemination for the herd using CRV Ambreed genetics. Their herd’s Merit Index is 73.
The herd is about one-third each Friesian, Jersey and crossbred. The empty rate is usually below 7%, but it was 14% this year after they were hit by theileria during mating. Campbell hopes the cows have now built up resistance and are immune to the tick which carries the disease.
KEY POINTS
Owners: Campbell and Susan Thomas
Farm area: 135ha (effective)
Cows: 420 Friesian, Jersey and crossbred
Production: 154,000kg milksolids (MS)
Supplement: 300 tonnes meal – whole grain, canola and tapioca
Crops: 8ha maize, 5ha turnips/rape
Farm dairy: 28-aside herringbone
Effluent irrigation area: 20ha
Solar power unit: 10 kilowatt (kW)
Farm working expenses: $3.99kg/MS.
