Last month, I attended the AgZero – WAFarmers PowerShift Forum, where we got the good oil on the exciting future that awaits us as we turn off coal and gas and turn on renewables.

The keynote speaker was New Zealand cherry farmer Mike Casey, who has made a global name for himself by taking his entire farming operation all-electric, leading the way in the race to save the planet before the world goes into irreversible meltdown.

As a climate advocate, he is putting his money where his mouth is, which is a refreshing change from all those who like to beat the climate drum but demand others pay for it, starting with the world’s energy poor. His enthusiasm was quite infectious in a room of people that were obviously pro-renewable, albeit when the word “nuclear” was ever mentioned, the room seemed to instantly drop a few degrees.

Obviously, saving the planet for that lot did not include going as far as splitting the atom, despite the fact that 60 nuclear power plants are currently under construction and another 110 are in the planning stage. Clearly, there must be a lot of clueless economists in the 30 countries running, building, and planning nuclear power plants as we are constantly told that they are not a viable option for Australia.

Still, it got me thinking about the cost-benefit of taking our farms across to the green side of the electricity equation and cashing in on all this free sunlight we have. Putting aside the obvious fact that, without subsidies, there would be virtually no wind or solar farms or rooftop solar anywhere in Australia, which puts to bed the great big lie that renewables are cheaper (24/7) than old faithful down at Collie that puffs away keeping the lights on and the cold at bay on these cold, still winter nights.

Anyway, I have taken some time to delve into the cost benefit of lashing out on a solar battery unit and taking the farm partially or fully off-grid. To get to the real numbers, you have to dig deep and have some idea of your energy usage.

The fact that small businesses in WA, particularly high-energy users like vineyards, dairies, and other intensive farming operations which run cool rooms and tractors small enough to be electric, are not rushing to follow Mike’s cherry farm example is the first sign that, even at current power rates, farmers are doing the maths and the dollars don’t add up as Mike claims they do in NZ.

In his example, after rewiring solar and battery panels and moving to electrify 21 petrol and diesel engines, his operation now saves an average of $40,000 a year on operational costs through the electrification of its “fossil fuel machines”. He quotes a payback period of 13 years, but there is no detail on the interest, tax, or depreciation impacts or government rebates, which is where an independent audit would help prove his case.

The first thing to note is that New Zealand offers government rebates at up to double what’s on offer in Australia. Under the WA State government’s Distributed Energy Buyback Scheme (DEBS) for Synergy customers as of 1 July 2024, electricity exported back into the grid between 3pm to 9pm earns 10 cents per kilowatt-hour (kWh); but for the rest of the day this falls to 2 cents per kilowatt-hour (kWh) or 3 cents for those in the bush under Horizon Power.

These rebates are limited to a residential customer who consumes not more than 50MWh of electricity per annum with a generating capacity of no more than 5kW, which is not a big system. Note that a 6.6kW solar PV system with a 5kVa inverter is accepted as having a generating capacity of 5kW.

On top of this, the federal government offers the Small Scale Renewable Energy Scheme, which, depending on the size of the unit, offers rebates from $1,456 for a small 3.9kW system to $4,852 for a 13.2kW unit. Now, the larger 13kW unit would be what most wheatbelt farms would look at, which is what’s recommended for a five-person household living in an older style less energy-efficient home with someone home all the time. On average, that sort of household would consume around 30kWh a day in winter and 60kWh in summer. As a comparison, a small system for two people working would be 5kW.

But like trying to develop a formula for what size tractor suits the average farm, it all depends on what sort of work you are doing and when; 300hp can pull 60 ft of disks in June or 20 ft of tynes in March.

In the case of solar battery systems, is the house smart-wired with LEDs, and 5 star energy efficient appliances and do you mind tapping into the grid on hot days, or do you want to be fully off grid but you have an energy-hungry old weather-wall air con unit and a big old chest freezer?

In one example, the five person family can get away for 5 kW, in the other 13 won’t be enough.

Now assuming you buy a 13kW unit, installed after the rebate, you would be up for $13,000 for the panels and inverter, which would produce around 50kW a day, plenty for winter but just short for a hot summer’s day.

Assuming you want to store energy for overcast days or to pump back into the system then you will be up for a separate battery system which will set you back another $13,000 for a Tesla Power Wall unit of 13.5kW.

So all up, you are up for $26,000. If still interested, then I’m sure you will find the smooth-talking marketers you stop to talk to at the   Dowerin Field Day will tell you the payback period for a big family with a big system is seven years with annual savings of $5,000, but that assumes you are consuming 10,000kWh a year or roughly 36kWh a day and your annual bill is around $5,000, and you are not tapping into the grid when the battery runs low.

There are a lot of ifs.

The next part of the equation is rebates for pumping electrons back into the system so that those too poor to afford even a subsidised renewable system get to see their tax-paying dollars subsidise you.

How the Greens and the progressive Left think this is fair is beyond me, but then they show little interest in how the real world operates.

Now, if you lived in South Australia or the ACT, your feed-in tariff would be 8 cents, while Tasmania offers 9 cents, and the NT at 9.13 is the most generous of all, but WA is not so generous over 24 hours, averaging closer to 4 cents.

A outlay of $26,000 might not be enough to leave you with enough energy to run the farm workshop, plus the farmhouse and fill the new electric car and ute with enough electrons for a day’s work and a trip to Perth without tapping into Collie, so you will probably need to double the whole system unless you are happy to destroy the planet accepting coal-fired electrons on those cold winter nights. Mind you, if you still have a few mallees left to burn, you will be fine, just don’t tell any of your Green-voting friends what you get up to at night.

Double that $52,000 to $104,000 and double it again to $208,000, and the south west farmers will have enough to run the orchard irrigation pumps and cool room on the berry farm or the dairy.

But now we are talking big dollars. This may explain why few intensive operations have filled the shed roofs with panels as the dollars quickly add up. Certainly, there are a few stories in the media of farms installing big systems; I only found one in regional Victoria, which recently installed a 100kW solar system with 12 x 13.8kWh batteries to milk cows more cheaply in the early mornings and evenings. That’s a $200,000 investment, but they are hoping to get their money back in seven years. Or maybe that’s what the marketing people told them. But again, without an audited cost-benefit analysis, we can only take them at their word. Mind you, noting the looming blackouts that Victoria is facing, the return period is the least of their worries.

Not to mention the future cost of power which, despite the Prime Minister’s promise, is not coming down. In fact, at the rate power prices have been climbing for the past 24 years at just on 10 per cent a year (since 2000, electricity prices have increased by 238 per cent), as a result all farms should be considering putting in systems, even more so if the Chinese keep subsidising their panel and battery manufacturing industry and prices keep coming down.

Or the alternative is to wait for Western Power to come along and install one of their $300,000 standalone solar battery diesel units, which is the plan for 9000 farms across the south west network. Pity they did not simply give us all $300,000 and cut the wires to the farm; I’m sure most farmers would put in a Rolls Royce system and still end up with change in their pocket.

In the meantime, while you wait, there is nothing holding you back from investing in a biodiesel plant to run the farm machinery. But beware, if you thought a household solar battery unit was line ball, try doing the numbers on turning your canola into biodiesel. Google up the options, and there are no end of papers on the cost of small-scale biodiesel plants and the cost of production, but good luck getting it below $3 litre, and don’t even think about putting it into your dirty great big new diesel tractor as it voids the warranty.

What’s the takeaway? There is a reason few of the orchards, vineyards, or dairies in Australia have gone completely off-grid: the numbers just don’t add up. If they did, every farming property across the south west would have panels hanging off every inch of the shed roof.

If you are looking at a system, first get a advanced smart meter installed by Synergy for $101.30 (google Synergy Advance Meters) then give the data to an energy storage consultant and spend $1000 to design a fit for purpose system for you.   As they say, don’t believe the hype, you pay for what you get.