On the weekend, an area 20km off the Illawarra coast south of Sydney became Australia's fourth offshore wind energy zone. It's the most controversial zone to date, with consultation attracting a record 14,211 submissions—of which 65% were opposed.

The zone's declaration has inflamed fierce debate over the pathway to decarbonization, particularly in industrial regions. The Illawarra hosts heavy industries such as Australia's largest steel manufacturer, BlueScope Steel.

In response to the announcement, National Party Leader David Littleproud declared Australia doesn't need "large-scale industrial windfarms." He argues the focus should instead be on household solar and battery storage.

So what is the role of offshore wind in our future energy mix? Here we argue offshore wind energy has three main advantages: scale, availability and proximity. It's just what Australia needs.

1. Scale

Offshore wind has substantial energy-production potential. A single 100-turbine project is capable of generating up to 1.5 gigawatts (GW) of energy and the Illawarra zone could contain two projects (2.9GW).

To put this in perspective, Eraring, Australia's largest coal-fired power station near Lake Macquarie in New South Wales, also produces 2.9GW.

Because offshore wind is more consistent than either onshore wind or rooftop solar, it is the most practical way to provide time-sensitive renewable energy grid security for large energy users.

This high-capacity, consistent energy source is particularly crucial for Australia's industrial decarbonization efforts. BlueScope Steel, for example, estimates it will need approximately 15 times its current energy consumption to transition to green steel-making operations in the Illawarra region.

2. Availability

Offshore wind blows more consistently than onshore wind. We can quantify this by comparing so-called "capacity factors."

The capacity factor is the actual output of a power station over a given period of time, divided by the theoretical power that could be generated if the plant operated at full output for the same period of time.

Onshore wind has a capacity factor of 30%, meaning 1GW of onshore wind farms can be relied upon to deliver 0.3GW of output at any time.

Offshore wind has a capacity factor of at least 50%.

For reference, coal plants in Australia, due to their age and condition, have a capacity factor of 60% and this falls further every year.

It is a common myth that coal is reliable. The reliability of Australian coal fired generators is currently at an all time low and falling.

The Coalition's plan for nuclear power plants announced on Wednesday might look like an alternative answer to the energy availability challenge. But the plan relies on coal in the meantime and coal-fired power plants have a limited lifespan. It's highly unlikely those nuclear power stations could be built in time to take over from coal.

The International Atomic Energy Agency publishes a step-by-step guide to going nuclear. This internationally recognized manual says it takes 10–15 years for a country to go from initial consideration of the nuclear power option to operation of its first nuclear power plant.

So the first big problem with nuclear in Australia is, how do we ensure we have reliable power for the five to ten year gap between when most of the coal exits and the first nuclear power plant could possibly be commissioned?

This article is republished from The Conversation under a Creative Commons license. Read the original article.