Think twice before going ‘off the grid’

Micro grids could provide a revolutionary approach to energy – sustainable, low carbon communities, towns and cities powered by clean energy with smart grid technologies

Gary Tippett, University of Melbourne

Published 28 January 2018

Australia is currently experiencing soaring power costs that are dramatically intersecting with the increasing availability of affordable and efficient renewable energy, such as solar panels and battery storage units.

So why wouldn’t it seem attractive, even liberating, to take your home and yourself “off the grid”?

The Solar Settlement, a sustainable housing community project in Freiburg, Germany. Picture: Wikimedia

You could draw your electricity from your roof via an inexhaustible sun, while saving dollars and escaping gouging corporate providers. At the same time, you’d be doing your bit for the environment. Perhaps, as a step further, you could take a small community of like-minded people with you.

Certainly, Australians are embracing solar.

In 2017, we added more than one gigawatt of rooftop solar panel capacity for the first time, an increase of about 50 per cent over the previous year. Rooftop installations grew to 172,152 units – often in greater size, with five-kilowatt systems increasingly typical, according to consultancy firm Green Energy Markets.

The major drivers have been hikes in electricity prices and media attention around them, which have turned energy costs into a hot-topic issue, says Professor Pierluigi Mancarella, of the University of Melbourne’s Department of Electrical and Electronic Engineering.

“People seem to feel somehow that they are being ripped off,” says Professor Mancarella, the University’s Chair of Electrical Power Systems.

“At the same time, there is news everywhere about renewables and batteries becoming better and cheaper.”

So for many, a logical next step may be leaving the established distribution networks.

“Everyone talks about going off-grid, but I don’t really know how many people do a proper cost/benefit analysis.”

Those who do, he adds, almost invariably stay with the current system.

“Essentially, there must be a good reason why we have networks or grids . This is very basic power system economics; it’s the first lecture. You do not just buy energy per se; you buy energy and a number of other things, the most important of which is reliability.

Going off-grid requires installing photovoltaics as well as battery energy storage. Picture: Getty Images

“People are not just paying for the kilowatt hour of electricity they are consuming; they are also paying for someone to ensure the lights will never go out.”

Going off-grid requires installing photovoltaics and battery energy storage, but it’s an unseasonably grey and cloudy January afternoon. Look out the window, he suggests: how much energy can those panels produce over the next few overcast days?

“And, what’s the cost of batteries that can store energy for a few bad summer days like this for a community, let alone in winter? It’s immense – 10 times the cost of what you’ll pay for grid connection.”

Professor Mancarella is a world-renowned specialist in the techno-economics of energy networks, the modelling of integrated energy systems, infrastructure planning and the integration of low-carbon energy technologies into power systems. He came to the University of Melbourne in September 2016 from the University of Manchester, where he still has a part-time post as Professor of Smart Energy Systems.

In 2017, he provided input to the Independent Review into the Future Security of the Energy Market by Australia’s chief scientist. In December, he was presented with a Victorian Endowment for Science, Knowledge and Innovation (veski) fellowship worth $150,000 over three years for his research project – “The ‘FlexCity’ revolution: techno-economic modelling of urban energy systems as the clean power stations of the future”.

The project aims to take “a revolutionary approach to planning and operating communities, towns and cities as flexible, low-carbon Urban Virtual Power Plants.

“The aim is to create a ‘FlexCity’ powered by clean energy with smart grid technologies where buildings, districts and local players actively participate in the operation of the system to create new, sustainable energy-related businesses.”

It is, Professor Mancarella says, pretty much the antithesis of going “off-grid”.

Communities, towns and cities can actively participate in the operation of a smart grid. Picture: Shutterstock

“As well as PV-batteries, we also have some sort of smart-grid technology that potentially could co-ordinate the actions of PV-batteries and other resources, such as thermal storage, in some, let’s say, community energy management system,” he explains.

“Rather than going off-grid because the grid is bad, why don’t you actually join the grid, participating actively in system operation?

“Because of the controllability you have now in your system, with resources and the smartness to control those resources, you can now actively play in the grid and possibly provide services to the grid. Effectively, the community becomes a virtual power plant.”

In this intelligent system, customers trade within the grid, selling in energy – and “reliability” by, for instance, being paid to disconnect some load if there is a problem in the grid.

“So, suddenly, remaining in the grid becomes your new business case,” says Professor Mancarella.

“The grid is really there for a trade. The fact that you now add local generation where the consumers are doesn’t change the role of the grid, it only changes the fact that these transactions, instead of being sort of uni-directional, now become bi-directional.”

The key driver, he says, is the urgent need to ‘de-carbonise’ the energy system but within a proper commercial framework that can support the necessary changes.

“We have operated a system like the current one for 130 years and now we’re really disrupting that system. No wonder it’s not happening overnight.

“Australia is in a particularly unfortunate situation at the moment. While it has huge natural resources, on the other hand, it comes from a history of being a major exporter of fossil fuels. So, culturally and economically, there is such a strong lobby around those.

In a grid system, energy transactions become bi-directional instead of uni-directional. Picture: Shutterstock

“This is part of the challenge – while we have the tools technically, we need to change the commercial system that is part of the incumbent socio-economic environment.

“You can’t just say: let’s forget what we’ve done the last 100 years, let’s forget industry. This legacy is important and politics is important to drive towards the necessary change.”

Renewables must – and will – take over, he adds.

“The question is how you integrate these technologies into the current system to make it work properly.”

Banner: Getty Images

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