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Cultivating Energy Savings in Farming

Environment Magazine Energy

To escape the clutches of commodity market economics, Hawke’s Bay farmers, orchardists and food processors are being challenged to work smarter across the value chain, and this includes improving their energy profile – using energy that’s cheaper, more efficiently.

Keith Newman04 October 2016

BB31

Photographs – Tim Whittaker

To escape the clutches of commodity market economics, Hawke’s Bay farmers, orchardists and food processors are being challenged to work smarter across the value chain, and this includes improving their energy profile – using energy that’s cheaper, more efficiently.

With doubts about the long-term sustainability of pumping up productivity per hectare, or the return on investment for energy intensive management systems, many are wondering which way to turn.

Napier-based agricultural economist Barry Ridler argues that we need less energy-consuming farming, not more energy-intensive farming. He warns that we’re pushing our arable land well beyond what is sustainable and wasting energy and investment in the process.

“If you think that New Zealand can double its agricultural output between 2010 and 2025, you’re in dreamland … Nature doesn’t allow that.” Ridler calls it the Canute complex, believing that because something’s written down on paper, we can make it happen.

Ridler, a former senior lecturer at Massey University, says the only way to achieve the high productivity goals encouraged by government policy is through costly, energy-consuming ‘complex systems’.

He says New Zealand should be developing our own technology and world class “intellectual firepower” to farm and crop smarter, competing on quality rather than chasing commodity market demands.

“We’re like Wyle E Coyote, so intent on chasing a particular roadrunner that we’ve gone over the cliff, getting further out and still not looking down.”

So, how might our farming sector move toward less costly and more efficient energy use?

Energy in the region

In recent Regional Council public consultation, energy use was identified as one of the ‘Big Six’ issues for the region in next decade. Council has begun to look at countering rising energy costs through a Regional Energy Strategy assessing options, opportunities and impacts of new technologies and alternative energy sources.

Any alternative energy business case will need to define current and future needs, develop more knowledge about biomass and biofuel from waste streams, and await wind and sun technology breakthroughs.

The MBIE Energy in New Zealand 2014 report targets 90% electricity generation from renewable sources by 2025, while acknowledging the importance of fossil fuels with “continued exploration and development…well aligned” with the Government’s broader agenda.

The 2013 data has the primary sector consuming less than one tenth of all business energy – agriculture, forestry and fishing use about 6%, with renewable energy comprising 38.2% of supply. About half of related businesses have energy saving and monitoring initiatives.

Diesel provides half of primary sector needs, two-thirds used off public roads, such as on farms, fields, and around mines.

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While Statistics NZ and the Ministry of Business Innovation and Employment (MBIE) regularly crunch national energy use numbers they’ve failed to deliver regional breakdowns.

George Hooper, a senior consultant with Advisian, a Worley Parsons company helping to assess Hawke’s Bay energy use, says data collection is expensive, not always accurate, but essential for year-on-year comparisons of what’s trending.

Where the primary sector falls down, he suggests, is maintaining and linking good data about energy efficiency across the entire value chain.

“Without some form of measure you don’t know if you have a problem or what the problem is.”

He suggests taking a lead from forestry, an industry under extreme price and competitive pressure, with strengths in certification and management practices, including waste reuse and co-generation.

The Hawke’s Bay Energy Futures Regional Stocktake 2015 compiled by Worley Parsons, a first step in highlighting critical energy issues, identifies primary and manufacturing industries as large users of thermal energy and petroleum fuels (including gas).
Energy Futures notes government interest in continuing oil and gas exploration and, while five wind farms west of Hastings have consents, they’re undeveloped because of “a national oversupply” of electricity.

Loosely, Hawke’s Bay’s generation capacity of 380 MW and demand of 300 MW mean “the region is essentially self-sufficient”.

Opportunities for solar are largely restricted to the electricity network, there’s little opportunity for geothermal beyond the Whirinaki plant, but potential exists for further hydro schemes, such via the Ruataniwha dam (although HBRIC has recently removed electricity generation from its plans).

Broader thinking and improved choices are urged, particularly around biofuels and other non-conventional renewable opportunities if we’re to have a sustainable “affordable and available energy supply”.

Hooper, who contributed to the report, sees energy use as “a system of systems” starting with what international markets want from our produce or goods and then how we achieve that.

“The real killer is how we harvest, move and process our goods because we’re still so reliant on fossil fuels. Tractors, transport, shipping, cool stores – all the way down the value chain are energy factors that contribute to the overall cost of delivery.”

Solar solutions slow

Scott Lawson of Lawson Organic Farms, a major producer of certified organic berry fruit and vegetables, says alternative energies including biogas, biodiesel and solar are always on the radar, but more information and a collaborative approach are needed.

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While biodiesel might be promoted as an alternative for farm vehicles and pumps, he says the latest diesel motors with electronic injection technology and emission controls are so efficient they restrict biodiesel use.

Lawson, actively involved in many farming groups and chairman of Hawke’s Bay Vegetable Growers, says solar is the low hanging fruit, but the challenge is in aligning it with demand times.

“From a vegetable grower’s perspective there are issues with the cost of solar-powered pumps for supplementary irrigation when they sit idle for 8-10 months of the year.”

He doesn’t think solar technologies are marketed well. While they can supplement demand in cool store operations, the battery technology isn’t there yet … “that’s why many people go for diesel pumps”.

Hugh Ritchie of Drumpeel Farms also remains shy of solar and wind because of the high cost.

“Unfortunately 70-80kw pumps place a big demand if you want to use solar and battery back-up; I’ve thought about solar for electric fences but the technology is not there yet.”

However, Waipawa-based Isaacs Electrical has found a solar niche with its industrial strength pump and controller for extracting water from streams, rivers and dams to water tanks and troughs.

They draw water to a height of 20 metres and pump 1,200 litres an hour over a kilometre during daylight hours. Once it’s in a tank, gravity takes care of the rest and a ballcock shuts supply once full.

“Landcorp like them because it’s often a 30-minute daily commute to refuel their pumps with 5 litres of gas. That’s a lot of man hours and fuel,” says Isaacs partner Gavin Steeter.

“Instead of letting cows walk into the stream or river to drink you fence it off and pump the water,” says Streeter, whose company sold 60 units into Hawke’s Bay last summer and is now filling global orders.

In order to minimise energy use across his own operations, Lawson uses track and trace systems to monitor everything from seeds to harvest and retail sales. “We have to get smarter in how we complete that paddock to plate and back to the paddock cycle.”

Consultant George Hooper is convinced solar will be an important contributor to our energy future. He talks of high temperature solar thermal to make steam and of the R&D going into direct solar for chemical reactions … “processed heat as opposed to electrical energy”.

Waste re-generation

Scott Lawson wants more informed advice from councils on alternative energy use. He commends Hastings District Council and others on research into primary production waste streams, including fertility recycling or turning vegetable waste back into the fields.

“It can be high energy use, but so is buying imported fertilisers.”

In order to minimise energy use across his own operations, he uses track and trace systems to monitor everything from seeds to harvest and retail sales. “We have to get smarter in how we complete that paddock to plate and back to the paddock cycle.”

Lawson cites Hastings-based Greenmount Foods, a major processor and exporter of vegetable ingredients, as a leader in waste stream use, producing biogas energy for its factory.

Hooper envisages new utilities bypassing the obstacles of seasonality, scale and perceived risk, using biomass, biogas and solar to on-sell steam and hot water.
The HBRC Stocktake commends precedent-setting Omarunui Landfill, run by Pioneer Energy with Hastings and Napier city councils, which creates enough electricity from methane in buried rubbish to power 1,000 households.

In the industrial suburb of Washdyke north of Timaru, Pioneer Energy uses coal and biomass to sell hot water, steam and electricity.

“They take all the risk and responsibility delivering the right energy for the right purpose and managing all the interactions,” says Hooper.

Xan Harding, Viticulturalist

Xan Harding, Viticulturalist

It’s all about fresh thinking and new arrangements that benefit everyone. “For Hawke’s Bay that might be an industry energy park bringing together diff erent energy supply options to promote wise use and sustainability and how to de-carbonise the supply chain.”

Winemakers lead

The Energy Efficiency and Conservation Authority (EECA), a Crown Entity established in 2000, says overall energy use is growing about 2% annually, with potential to save about 20% or $2.4 billion a year through efficiencies and renewable resources.

That includes finding clever ways to use lower grade or waste heat, good engineering and process design, and optimising the heat balance around a plant.
Hooper says local winemakers have a good track record. Among the EECA case studies is Craggy Range winery which has off set electricity costs through good engineering and a heat recovery system.

The system takes waste heat from air compressors and refrigeration for heating water and cooling, reducing energy use by 13%, cutting CO2 emissions by 157 tonnes, and paid for itself in four years.

Hooper says local winemakers have a good track record. Among the EECA case studies is Craggy Range winery which has off set electricity costs through good engineering and a heat recovery system.

Viticulturalist Xan Harding of Grapeology, a representative on New Zealand Grapegrowers and Hawke’s Bay Winegrowers, says most wineries are working to reduce power in refrigeration, lighting and processing.

He cites the new Delegats winery, northwest of Hastings, with its attention to energy-saving engineering design and processes. The company processes 20,000 tonnes of grapes annually in Hawke’s Bay and has sustainability measures in place from vineyard to bottle.

Harding says the industry, including around 254 vineyards in Hawke’s Bay covering 4,744 hectares, uses about half the pumped water of most other horticultural crops, and has relatively low input of fertiliser and pesticides.

Owners often work to reduce machinery passes by mowing and spraying at the same time, using sheep for summer leaf plucking and autumn and winter weed control.

Drought tolerant root stocks and imported strains requiring less intervention are being investigated. Lifecycle energy costs are achieved through glass recycling, the use of lighter bottles and shipping wine in bulk for in-market bottling.

On his own property, Harding uses 10kW from solar panels with a 3-phase grid-tied inverter feeding an 8.5kW submersible irrigation pump to bring up groundwater to match peak daily solar generation. Off peak it feeds domestic requirements with surplus going back into the grid.

Best practice benefits

Hugh Richie of Drumpeel Farms, never planned to be an energy-efficient farmer. That result came through changing equipment, adopting better business practices and putting back whatever is taken out of the land.

The 2014 Hawke’s Bay Farmer of the Year, with influential roles in land and irrigation research groups, says reducing cultivation automatically improves soil quality and “the amount of diesel it takes to sow crops”.

While selecting new equipment based on fuel efficiency may look good on paper, “if you’re farming practices are inefficient, it’s not going to make much difference”.

For the past fifteen years he’s only cultivated a quarter of his acreage using a strip-till process, planting maize, corn, squash and beans in narrow strips (12cm wide, every 76cm).

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“We use a direct seed drill for planting seed for wheat, barley, peas, grass, oats and other narrow row spacing crops, which is done in one pass over a paddock.”

Ritchie uses global positioning systems (GPS) to guide auto-steer equipment in straight lines so there’s no overlap for tilling, sowing, irrigation, fertiliser and weed spraying, which reduces water, fertiliser and chemical use.

Previously ploughing a 30 hectare maize block took 600 litres of diesel; using strip cultivation that’s down to 120 litres.

Scott Lawson commends the Landwise farming research group for its work in energy reduction, soil quality and productivity methods, including GPS ‘controlled traffic’ and strip cultivating. However, he says only early adopters, around 10%, have taken it up.

“There’s a lot of work to do yet … we need to grow the whole sustainability base and produce more with less input.”

One of the obstacles is “our lack of knowledge and cohesion at a local and regional level and understanding the linkages”.

Lawson agrees growers should learn from dairying and avoid commodity production.

“Hawke’s Bay has to be a high value-added food producing region; that’s where we’ve been in the past and where we need to go in the future.”

To achieve that “the processing guys” need to remain competitive internationally and come up with new ideas.

“This is part of the wider industry discussion we should be having, (including) the waste streams that could become energy streams. I don’t think we’ve spent enough time as a community looking at these things.”

Energy and irrigation

On his farms at Otane and Poukawa, Hugh Ritchie is exploring new technologies for pasture improvement in conjunction with AgResearch, including GM-type transgenic grasses that could double productivity for the same amount of water.

While water from the proposed Ruataniwha dam will be costly, Ritchie says it’ll make a huge difference, but the challenge remains to extract value while keeping costs down.

Ritchie plans to use variable rate irrigation (VRI) to deliver water exactly where it’s needed using a 30-foot boom with pivotal and lateral arms and computer controlled solenoids for each nozzle.

“You might end up using the same amount of water but the productivity output per unit of energy is more efficient with greater uniformity and less waste.”

According to Irrigation NZ (INZ), currently about 2.5% of the country’s electricity is used on pressurised spray systems covering 625,151 hectares; that could increase by 350,000 hectares over the next 20 years based on the Ruataniwha dam and other water storage proposals.

An INZ and EECA pilot programme with 12 farmers showed it was possible to save up to $7,444 a year by upgrading irrigation systems. An average investment of $25,888 could achieve payback within three and a half years and reduce irrigation needs by 10-15 days over a six-month season.

INZ believes 10-20% of electricity – 110,000 to 220,000 megawatts a year – could be saved through more efficient systems, suggesting farmers constantly monitor water needs, improve systems hydraulically and mechanically, and know when to turn them off.

However, some irrigation systems burn so much energy that calculations on returns, suggests Barry Ridler, are “aspirational really … la la land … complex systems just gobble energy across the whole spectrum.”

Trying to get plants to double their photosynthetic rate is nonsense.

“No matter what you do in the Ruataniwha, it’s not going to grow more than 15,000 kilograms of dry matter per hectare” on the very best of soils, given colder climate and a shorter growing season.

Ridler suggests farmers ask why they have to spend $85,000 or $110,000 on electricity for running more sophisticated systems, or why experts need to come out to regularly re-programme irrigation or GPS systems?

What if there are cheaper options than irrigation that use less energy?

“From a vegetable grower’s perspective there are issues with the cost of solar-powered pumps for supplementary irrigation when they sit idle for 8-10 months of the year.” – Scott Lawson

“We need to start thinking about simplicity and get back to some of the basics, often hidden by numbers, programmes and complex systems.”

Ridler’s computer modelling asserts that beyond a certain number of animals per hectare you get a “parasitic herd” taking revenue from the profit making herd.

If the natural capacity of a farm is 600 cows and the farmer adds irrigation and complex management to stretch that to 1000 cows, after five months you’ll need to buy in extra feed, possibly tonnes of palm kernel delivered from the port by 50 tonne trucks.

This new “production economics” doesn’t take into account the cost of importing feed, machinery to feed out or thousands of dollars in electricity for irrigation and effluent systems.

Open to options

Our dependence on fossil fuels is unlikely to change in the short-term, even if resilient alternatives go mainstream. George Hooper says the best thing the primary sector can do is be open to alternatives to augment electricity, diesel, oil and gas for transport, farm and other machinery.

A plant in Auckland makes bio-diesel; Fonterra makes ethanol from whey; there are options for making methanol from wood; you can grow algae for fuel; and a range of technologies are being used in China, Europe and the US. “Those opportunities are an important part of the story.”

Hooper says it’s time for a serious conversation about the cost of energy to Hawke’s Bay’s mainstay sector, what the alternatives are and how to work more collaboratively “so we make the right decisions”.

“If we can create more value for our growers by adopting good practices right through the value chain we all win … what we don’t want is an energy infrastructure that is going to restrict that.”

Keith Newman04 October 2016

BB31

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