Taking renewables to the next level for industry
Decentralised energy resources such as small-scale solar PV have gone through the roof. The next challenge is: how do we optimise the use of this clean energy source and make it economical and viable? Sustainability Matters spoke to some of the experts at the ABB Customer World conference in March about this challenge and how technology that is already available may help.
The Clean Energy Regulator recently revealed that more than 1057 MW of capacity was installed last year — mostly from rooftop solar — beating the previous record of 1035 MW set in 2012. This equates to 3.5 million solar panels being fixed to Australian rooftops, or more than 9500 installed every day.
Despite the lack of financial incentives, residents of Australia have been doing their part for the transition to a cleaner energy. Many businesses are also doing their part, with drivers now coming from stakeholders and consumers even before financial incentives.
Chloe Munro AO, Australian Energy Market Operator and former chair of the Clean Energy Regulator, talked about the challenges facing the energy market in Australia at the ABB event. “Compared to what we were thinking in the late 90s, there hasn’t been a growth in total demand,” she said. “What has happened is demand has become peakier and it will probably become peakier and more volatile into the future.”
According to Munro, managing the volatility of demand is a challenge which won’t be solved just by looking at the generation or supply side of energy. “The thing that has been missing is demand-side participation,” she said. “There is huge opportunities to shift away from always having supply following load to actually managing load to the extent that it can follow supply.
“If industry is in a position to shape their load, it can be a very profitable thing to do without losing any productivity while reducing the cost of energy overall.”
ABB Business Development and Technology Manager for Microgrids Juergen Zimmermann agrees with Munro. He said: “High energy users in manufacturing that are grid connected are exposed to high power prices. In order to offset high energy cost, they could build their own power plant or contract it in from another renewable energy source such as rooftop solar PV. If contracted in, ABB Ability can link the actual process (what they are producing) together with the generation side. By connecting the two, the plant can manage the load to match the generation of energy.”
For example, Zimmermann explained that a system can be designed to predict when PV is going to drop due to cloud cover and for how long, say 10 minutes. The system could then be designed to automatically set the process to wind down (not stopped just reduce the heat, for example) for 10 minutes, then it would automatically bring the process back up once the cloud cover moves.
“With this true connectivity, users can actually connect the processes of the generation together with the process of production, so users can actually reduce their energy cost.”
Sims Metal has achieved this on a large 103 MW solar capacity for a steel mill where it used to pay high prices for electricity, said Zimmermann. In this example, he explains that the company has optimised the use of its own renewable generation by adjusting the production of the steel mill to match what the solar is doing.
“If you use your own renewables, the costs are predictable. Not only can you reduce your costs, you can also reduce your risks to the fluctuation in network costs, which are out of your control.
“Everyone is discovering new ways of using connectivity to optimise both the process together with the generation or with the market, depending on what the drivers are at this point in time,” he said.
Another way the energy generation and loads can be managed is through HVDC interconnecting, where two regions are connected, but this is a long-term investment.
“Ideally, it would be great to have a high-voltage DC interconnection between east and west and utilise the time difference. When the load is high in the east it may not be that high in the west and vice versa,” said ABB Country Managing Director Tauno Heinola.
Microgrids to the rescue
Another option that may be suitable for industry is microgrids.
Microgrids are basically small power systems that can enable both centralised and distributed energy sources of energy. Distributed energy sources (including demand management, storage and generation from renewable sources such as rooftop solar panels) can work in parallel with, or independently from, the main centralised power grid.
“There is no limit to the amount of renewables that can be enabled using microgrids,” said Zimmermann.
“Offgrid microgrids are pretty much a no-brainer,” he said. “In many remote locations, diesel costs have gone up so much while the cost of distributed solar has come down, so they have totally changed from centralised to decentralised power stations. Even without subsidies, it makes business sense.”
Microgrids have a unique ability in that they can be positioned directly at the source of the power.
“From a reliability and security point of view, the closer we can store energy to the actual loads, the more value we can create,” said Zimmermann. “If the distance the power has to travel is minimised, the power quality can be improved. This can help to improve the network capacity and potentially be used to meet peak demand flows.”
Zimmermann said AusNet has trialled a microgrid which was basically grid connected and the value that created was about peak lopping standard operation and better voltage control at the point of connection.
Grid-connected microgrids can also keep costs down ‘behind the meter’ but the value propositions are different as explained below:
1. Reducing peak demand
“The business case for industrial applications starts with demand charge reduction. This is obviously the low-hanging fruit,” said Zimmermann.
“Energy bills are made up of energy charges and peak demand charges and the easiest one is to simply take the peak away. This will create a revenue stream as you’re creating value from your storage system.”
2. Increasing self-consumption
“A microgrid can increase your self-consumption of rooftop PV. So instead of pushing your PV energy out into the market for a few cents, you actually store it and use it to offset your own consumption.
3. Improving standalone capacity
“The next benefit is around the standalone capability. If there is one factory that has some power quality issues at the end of the line, it is very important to say: if the line goes down, the microgrid can actually sustain for an hour or two of operation so we don’t have to shut down the plant.”
Zimmermann points out that none of these benefits on their own would be enough to pay for the microgrid, but the value stacking will possibly push it over the line.
At present, most energy generation is following the load. But by utilising digitisation solutions, such as ABB Ability, it is possible for the load to follow the generation, which could create a value proposition worth considering and take renewables to the next level.
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