This article first appeared in the January/February, 2018 edition of The Wine and Viticulture Journal. Published by Winetitles Media, Adelaide. https://winetitles.com.au/wvj/

Soft power: contemporary approaches to energy efficiency and management

Introduction

Regardless of one’s view on how Australia found itself in its current situation with energy supply, the fact is that as business managers. we must deal with the world as it is and not as we wish it to be. Australia now has some of the most expensive and least reliable power in the developed world. This is especially so in South Australia and Victoria, with predictions about future price rises varying depending on which report one reads.

For these reasons, it is prudent for any winery or vineyard management team to take the time to consider how and where they are using their energy with a view to improving both cost and reliability. Of course, there are the environmental benefits of being more efficient with carbon-based energy but, frankly, if maximising carbon reduction per dollar invested was one s aim, overhauling the winery electricity system is highly unlikely to be the most effective way to do so.

This article recommends improvements to energy efficiency [mostly electrical) with a view to making the business more robust, not to try to save the world.

More with less

It is human nature [and basic economics) to devote more focus to the efficient use of scarce resources. And, when it comes to energy, some early examples are very well illustrated in the original Yeringberg winery, built by David Mitchell [Dame Nellie Melba s father and builder of the Royal Exhibition Building in Melbourne). Built around 1870, before mains power or water, the building [a national treasure, in my view) is replete with design features that make the most of the energy available at the time – mostly sun and sweat. Two of the more elegant examples are the use of frosted window panes on the north-facing windows and clear glass to the south in order to even up the light within the building and moderate temperature [Figure 1). When it came to loading red must into the fermenters, the use of rail tracks, trolleys and catwalks suspended from the ceiling was less about appeasing Gaia and more about efficient movement with the technology available at the time [Figure 2).

With respect to contemporary winery methods and equipment, however, there are several newish) options which have slashed energy requirements per tonne, case or litre, depending on how you like to benchmark such things.

One of the first is flotation for the clarification of juices for some white and sparkling wines. While hardly a new or revolutionary method in 2018, the difference in energy consumption compared with traditional cold settling enormous. For example, where one may have previously taken a tank of juice from 25*C (or more) down to 5*C for settling, then warmed it back up to 18*C for inoculation, the same tank can now be clarified and fermentation commenced within a few hours with only a fraction of the cooling energy requirement. 

The resource savings go beyond just the refrigeration, however. When the energy required to produce the cement and stainless steel (both require eye-watering amounts of it) for the additional winery capacity (tanks, buildings, water, etc.) is factored in, the savings are even more compelling.

Next-generation machine harvesters are also having a profound impact on winery operations, process flow and energy consumption. With hitherto unimaginable levels of fruit purity (low MOG) arriving at the wineries, there are some impressive examples of having great success with direct tipping of machine-harvested red fruit into fermenters (open fermenters, mostly), totally removing the need for destemmers, must pumps and even staff members in some cases.

The next example is not rocket science. It is so simple that it may seem trite to include it but, sadly, too many wineries fail to grasp the significance of insulation and passive cooling operations. Leaving aside the obvious example of storage tanks, the areas too often overlooked include things such as must lines and refrigeration lines, plus the simplest thing like leaving warehouse or barrel store doors open. The energy savings from installing automatic warehouse-style doors on a winery buildings can be incredible, especially during the summer of course. Ordering staff to close the barrel store door each time they drive through is a simple idea but very poorly followed when things get busy.

Passive cooling options for buildings needn’t be expensive either. These systems simply monitor the internal air temperature and if it is appropriate, pump it into the building to cool it rather than draw on refrigeration equipment.

Other off-the-shelf equipment that is delivering real results in wineries today is heat recovery from refrigeration plants. There are many models and suppliers to choose from but the principle is straightforward – simply pre-warm water using the excess heat from refrigeration plants while they are working. If one is after hot water at, say, 80*C for brettanomyces control in barrel washing, it makes a big difference if the in-feed water is already at 40*C, rather than 10*C.

An example of the future of energy management from the brilliant presentation of Roger Boulton, from the University of California Davis, at the 2016 Australian Wine Industry Technical Conference was that a pulsed jacket flow for refrigerant brine. In this case, automated solenoid valves are used to hold cold brine in tank jackets to maximise heat transfer (increase of 3-5*C). By sending a smaller volume of warmer brine back through the return steam, the refrigeration system works more efficiently in the long run.

There is usually some very low hanging fruit [so to speak) around wineries when it comes to energy efficiency improvements and even simple things such as switching to LED light bulbs or running the office air conditioning at 25°C instead of 20°C in summer can make meaningful differences to baseload power consumption. For example, those two examples may well cut consumption by 6 amps and 4 amps, respectively, or 1.0 to 1.5kW.

“…It’s the peaks, Stupid…”

In addition to reducing the overall quantum of energy consumption, it is important to consider usage patterns and remember that infrastructure is usually designed with peak demand in mind -or at least as it is understood at the planning stages.

When it comes to electrical supply, the challenge is exactly the same as in so many other aspects of our field -the increasingly compressed nature of our processing. For example, a small winery may find itself drawing no more than 40 amps for most of the year but struggle to keep the draw below its maximum capacity of 100 amps during vintage. In addition to pushing the capacity of the board, some of the components of the costs of electricity supply relate to peak draw within a particular period – no matter how short that may be.

For these reasons, it is prudent to consider ways to manage these peaks which usually relate to start-up current draw of electrical motors and boils down to two key points: trimming peak load (per motor) and offsetting them from one another.

Many electrical motors found in the wine business, whether they be on irrigation pumps, air compressors, refrigeration compressors, must pumps or anything else, use direct-on-line (DOU starters which tend to draw very high current at start-up. Another more expensive but increasingly popular method is the use of variable speed drive [VSD). or ‘soft starters·, which can minimise the initial current draw. Figure 3 is a sketch of the two different types, showing start-up current draws typical of some winery equipment.

Figure 3, while a little crude, illustrates the potential problem for a winery with a board capacity of, say, 1 DD amps if several DOL motors were to start up at the same time.

With this in mind, it is easy to see the potential value of integrated management systems that can ensure these peaks do not occur at the same time and the capacity of the site is not breached, leading to tripped circuit breakers or blown fuses.

Radio telemetry may sound exotic but it is a simple mechanism by which start-ups of motors can be staggered, and the equipment is readily available and affordable. Furthermore, it is easy to set simple rules around a hierarchy of equipment where a must pump will take priority over the start-up of an air compressor for example. Much better to push the compressor back by a few seconds to avoid fruit spilling onto the floor!

Packin’ heat: Batteries and Solar

There has been no shortage of media coverage about energy storage through the next generation of batteries. While it may be imprudent to hold one·s breath until a battery plant is able to supply a capital city during a blackout, it is certainly the case that some wineries (and breweries) are already operating perfectly successfully using industrial battery storage.

Despite some exiting signs of the future potential of lithium-air batteries (possibly four times the capacity), the ‘here and now· reality is lithium-ion.  Even though their efficiency has been difficult to improve, there have still been phenomenal commercial gains in recent years with costs [per kW of storage) being approximately 10% of that of five years ago and good improvements in production efficiency-witness Tesla’s ‘Gigafactories·, for example.

We are now at the point where solar and batteries are a key part of the energy mix at more commercial wineries around the world (if not the entire supply) and this shows no signs of slowing down. While some sites may remain restricted by their roof area for solar panels, the frustrations with power outages and cost increases show no realistic sign of slowing either.

Another, probably less familiar, example of how batteries can be used is a system that can be very helpful in remote areas or to temporarily supplement supply, called a remote area power system [RAPS). With systems such as these the batteries are supplied by solar panels but supplemented with a diesel generator as required. With the batteries acting as a buffer, the generators need only operate when required and only in their most efficient range of RPM which can yield reductions in diesel consumption of more than 60%.

When it comes to solar power, the improvements in performance and price have been astonishing making it a much more realistic option to supplement supply or take over entirely. I think it was Roger Boulton who said in his presentation at the 2016 Australian Wine Industry Technical Conference that in the last three years, solar efficiency (yield per m2) has improved 25% alone, while prices continue to halve approximately every 10 years.

The technology is now at the point where batteries and solar are a genuine part of suite of energy options for modern wineries, worthy of careful consideration to improve the profitability of the businesses. They are certainly not expensive indulgences for the vanity of eco warriors.

Why pay more? 

While not actually a method for improving energy efficiency, power factor correction (PFC) is something that can help businesses reduce their electricity bills for essentially the same production capacity.

Remembering that this is an article by a winemaker for winemakers, not electrical engineers. Frankly, PFC is a little beyond your correspondent to explain in sufficient technical detail but it is the management implications that are most important.

One simple way to think of it is as the difference between ‘real’ power (that which the site uses) and ‘apparent’ power (that which the site pays for). Therefore, the lower the power factor (PF), the more one pays for the same energy. Compared with a theoretical maximum PF of 1.0 (impossible in a real operation however). a poor PF of 0.7, for example, could see a business paying 30-40% extra for its power.

As a guide to its significance, it is perfectly possible that a winery with an approximate capacity of 500 tonnes and a poor PF could be paying $250,000 per annum more for its electricity than it should. An experienced electrical firm can take the necessary measurements and direct businesses towards the best set of equipment to improve it.

Management

In modern manufacturing, there are certainly some impressive and sophisticated process control systems available. At the elite level is a control system architecture known as SCADA (Supervisory Control and Data Acquisition) in which components such as sensors, telemetry systems and contactors are networked.

Applied to a winery environment,  a SCADA system would be able to, for example, use weather forecasts for an upcoming hot spell to pre-emptively lower the temperature of a barrel store, warehouse or brine temperature. They could also manage peak demands by shifting non-critical activities to lower use periods, such as pumping extra air into effluent system tanks or perhaps doing so when solar energy supply was abundant.

For most wineries in Australia, however, systems such as these are currently not realistic, being too expensive, complex and/or difficult to manage. That said, it is worth remembering that 15 years ago, that is exactly how many people would have described solar panels and battery systems.

What gets measured gets managed

With so many options and jargon and with management teams still under so much pressure, it is understandable that one might be left wondering where to start. In that regard, the best place to begin is with an energy audit. There are many experienced specialists who are able to measure and quantify the energy use patterns around a site so that improvement efforts can be focussed where they will make the most difference. Without it, most of us would just be guessing.

Having a robust estimate of how much heat enters a warehouse or barrel store on a hot day through poor insulation, seals and leaving doors open will make it much easier to justify spending, say, $50,000 on maintenance and automatic doors.

We’re gonna need a bigger board

It is also encouraging to remember that there are almost always some simple ways to make big improvements to efficiency and reliability which are not as expensive as one might think.

One of my favourite capital expenditure and reliability examples is that of a vineyard which found that an irrigation pump, which was perfectly well maintained, would pass all pre-season tests but then tripped out and failed during hot spells – exactly when it was needed most.

What was happening on the hot days was that the voltage was dropping on the main lines from approximately 440 volts to 380 volts due to increased demand in the area and increased resistance of the lines in the heat. As a result, the pump was drawing an even higher start-up current, which was tripping the circuit breakers.

Given the cost of the fruit losses, the business decided to spend approximately $100,000 upgrading the supply and was poised to sign the contract when a chat with a good electrical engineer led to a better option. They installed a $17,000 VSD on the pump and it hasn’t skipped a beat since.

Mark O’Callaghan is senior consultant and director at Wine Network Consulting. Mark joined WNC in 2073 after working independently for two years. Prior to this, he spent 74 years with Accolade Wines (formerly BRL Hardy), including eight years as senior winemaker and winery manager for Yarra Burn in Victoria’s Yarra Valley. He has also made wine in McLaren Vale, Heathcote, Great Western, the Pyrenees, Austria and Sicily.

Vineyard and winery software management systems

For his next article later in the year, Mark intends to look at vineyard and winery software management systems, after hearing that many wineries are grappling with integrating various systems for vineyards, bulk wine, accounting, online sales, customer relationship management, and so on. ff you’ve experienced similar issues, or are indeed a service producer who can offer a solution, then Mark would be delighted to hear from you via email: mocallaghan@winenet.com.au.