With machinery manufacturers delving more and more into the use of electric motors to power cars, tractors, harvesters and even trucks, and the governments around the world implementing policies for less carbon emissions, the need for alternative energy sources is becoming more of a focal point. At the same time, the traditional power that we rely on in agriculture is becoming less and less reliable due to ageing infrastructure. No farmer wants to see machinery shut down during harvest, or seeding waiting for power lines to be repaired. Perhaps it is time for farmers to consider alternative energy sources.
Milne Feeds sales manager, Paul Nenke, says: ‘When I hear people say that tractors and harvesters will never run on electricity, I look at the common phone. Fifty years ago, who would have believed that land lines would be a thing of the past and that most business would be done from our pockets?’ The mobile phone has replaced an incredible number of items, from the road map to the bank deposit book. In a similar way, the future will undoubtedly see many new ways of farming.
Renewable energy on farms is likely to come in many forms, including solar panels, wind turbines, solar hot water, solar photovoltaic thermal, concentrated solar thermal, organic Rankine cycle, geothermal energy, tidal power and wave power. The goal of renewable energy farming is to create clean energy whilst maintaining, if not improving, crop productivity. Not all agriculture will have access to all these options; for example, wave technology will only be available to aquaculture farming but, nevertheless, it will be available.
Here's a closer look at some of those options:
• Solar hot water - in the past this has been cost prohibitive as a renewable power alternative but, with the increased cost of gas and coal, solar hot water has become more cost effective and is being used in intensive farming such as hydroponics, dairies, piggeries and poultry.
• Solar panels - have been widely embraced in recent years, with many farms making use of this alternative energy source. As battery units become cheaper, we will see even more utilisation across regional farming operations. One of the biggest challenges for solar power is energy storage, however, developments with battery farms and storage mechanisms are likely to overcome this in the future. When it comes to alternative power sources, this is one of the cheaper options.
• Wind turbines - have had quite a large uptake within the farming areas around the world. In Australia, some farms have installed turbines as a way of making an additional income. With legislation pushing for more carbon neutral power options, expect to see more of these.
• Solar photovoltaic thermal - a combination of solar PV with solar hot water heating. At present there are few commercial solar PVT products available in Australia. This could change in the future as fossil fuels keep going up in price, and could also work with saline water, which WA has an abundance of.
· Concentrated solar thermal - uses mirrors to focus the sunlight into a fluid, such as water, oil and even molten salt. Some of us may have seen this in one of the James Bond movies but it is actually a reality. The captured energy can be stored and used for heating or to generate electricity. One of the bonuses of this system is that the heat can be stored and used to produce electricity, even at night. Australia has plenty of sun and this system can be built on land in areas that may not be agriculturally viable, such as salt affected land.
· The organic Rankine cycle (ORC) - a process that generates electricity from lower-temperature waste heat. ORC technology can be used by rural producers and farmers to recover electricity from waste products, or low-grade heat produced from geothermal, solar or bioenergy sources.
· Geothermal energy - is a renewable heat source that relies on heat generated from deep within the Earth. In most parts of the world, the geothermal temperature gradient is about 25 °C per kilometre of depth from the surface, although some areas exhibit higher temperatures. Utilising this energy is currently beyond most agriculture producers but in the future this could be another useful possibility. The energy can be processed into electricity by pumping water through the ground to where it becomes steam. It is then released and made into electricity. There are a number of plants producing this type of energy in New Zealand.
· Tidal power and wave power - even though out of reach for most agricultural businesses, this alternative energy can work for aquaculture. In the the north, it could help generate power for agricultural use. Currently, tidal power is not widely utilised, but Australia is home to some of the largest tides in the world. The large tidal movements of Broome are an example. When these large tidal movements are harnessed, they have the potential to produce a large quantity of electricity at an economical price.
Whilst many are still in the development phase, these renewable energy sources could help agriculture not only reduce the carbon footprint, but also diversify farm operations and income, which in some cases might help in drought proofing the farm. And who would say no to a large cheque for use of the farm to produce energy? Aside from the obvious environmental impact, there are many benefits of alternative energy sources. One, in particular, that comes to mind is the potential to create more jobs out in the country, which will bring more families to regional WA, that in turn will help our local communities to thrive.
