Australia’s Pacific Island neighbours are pushing for 100 pct renewables. But is it possible?

Facing the devastating impacts of climate change, Pacific leaders are pushing to achieve 100% renewable energy in the next decade to act as a demonstration to other countries and regions as they fight for the survival of the countries and people.

But is this feasible?

Some say the sweet spot for renewable energy is 80%, with each percentage point above that requiring a doubling in investment.

It’s also counter intuitive but getting to 100% renewable energy may also require investment in new diesel generators that have greater flexibility, dialling down or even switching off when renewable energy is abundant and otherwise providing assurance that standby capacity is available if needed. 

It’s important that donors show flexibility in this regard, and avoid blanket bans on investment in fossil fuel generation such as the situation that prevents the use of gas to replace wood for clean cooking. 

Before investing in new renewable energy assets, grid upgrades may also be required to support the two-way flow of electrons as consumer energy resources like solar PV, batteries and other smart devices play a more important role in balancing supply and demand. 

What are other jurisdictions doing?

South Australia has shown that it is possible to get 100% renewable energy at times, including 100% solar PV and 100% wind energy, and has a goal to do that on average all the time by 2027, up from 73% over the last 12 months, with the benefit of exports, imports and standby gas plants.

There are three key technologies to support 24/7 renewable electricity. 

The first is big batteries which have evolved over the last eight years. Initially for frequency control and auxiliary services, then two-hours storage, followed by four hours and now eight hours are starting to emerge. 

Some argue that with grid forming inverters, big batteries no longer need synchronous generation – usually provided by fossil fuel – to provide inertia, the beating heart of an electricity system. Also, consumer batteries can be networked as virtual power plants to achieve similar outcomes. 

The second is smart meters which allow price signals for consumers. Providing cheap electricity when the sun is shining to encourage use and increasing rates overnight or during periods of high demand and constrained supply to discourage electricity use.  Smart meters also provide essential voltage information on the distribution network.

The third is demand response, typically industry but increasingly smart devices like air conditioners, electric vehicles, hot water systems or pool pumps which can be dialled down during periods of constrained supply. 

But what about an island grid with no international connections to enable electricity imports and exports?

Australian mine sites, offshore islands and remote communities are also showing that it is possible to achieve 100% renewable energy at times with the balance provided by gas or diesel. 

Communities like the opal mining town of Coober Pedy now have an abundance of electricity, with an average of 70% renewable energy – and fresh water from reverse osmosis – provide an illustration of what can be achieved.

While possible, engineers currently say that there is a delta in battery costs that currently makes it uneconomic.

This could change in the future as battery costs continue to decline and new technologies replace relatively expensive lithium, nickel and cobalt with sodium or even vanadium flow batteries which have the advantages of long duration and are ideal to operate in exposed hot and salty environments.

There’s also another variable that comes into play – batteries on wheels – electric vehicles.  With vehicle to grid technology now being deployed in Australia for select electric vehicles, electric vehicles can provide a key role in managing supply and demand in island electricity networks, charging when the sun is shining and discharging during evening peaks or even powering homes and businesses during disruptions to supply.

Similarly, charging infrastructure can be designed to support the grid, particularly with fast chargers backed by battery energy storage solutions that can also support the grid when required. 

So the challenge is to design an energy system for the island that considers both electricity and transport and provides flexibility around pricing and demand response. 

Thinking outside the box, what if renewable energy capacity was built to provide shore power for ships so they don’t need to burn marine oil to power themselves in port. At other times this abundance of electricity could be used between visits, to charge batteries and create new business opportunities that could power down when ships are in dock.

So it is possible to get to 100% renewable energy, if not a little uneconomic until transport is electrified and the suite of smart devices is fully deployed. In the meantime, it is important to ensure the grid is flexible enough to incorporate renewable energy and demand management.

Barbara Elliston is a director of Elliston Power Consultants, Unison Networks, Easy Warm and the Smart Energy Council. Richard Neumann is chair of the Smart Energy Council Pacific Working Group and a member of the Advisory Council of the Franco-Australian Centre for Energy Transition at Swinburne University.