If every house had solar...

If every suitable rooftop was converted into a solar power station, solar could supply 134 per cent of Australia's residential power needs, new research shows.

Bill Gates dreamt of a world with a computer on every desk and in every home. Many scoffed at his vision, but the advent of the personal computer changed the world for the better.

As the co-founder of Energy Matters, one of Australia’s leading solar providers, our vision is not too dissimilar; we believe every suitable rooftop in Australia could be turned into a solar power station. Why? Because we feel this is the most cost-effective solution to the crisis currently facing Australian electricity prices.

For years Australian households have been feeling the ever-increasing strain of high electricity prices, but it doesn’t have to be that way.  

We wanted to provide an alternative; so earlier this year, my team and I set out to calculate the reality of our vision. We said goodbye to our loved ones, rolled up our sleeves and the results were, to say the least, remarkable.

We crunched the numbers and discovered that approximately 134 per cent of the country’s residential electricity needs could be met if every suitable rooftop was converted into a solar power station.

You’re probably wondering, how on earth did we come up with this figure? Is it accurate or grossly overstated?

Firstly, I can assure you we’ve based our calculations on robust, up-to-date government data and, secondly, it’s extremely conservative. 

Here’s how the team did it:

-- Using a combination of census data and information provided by the Department of Infrastructure and Transport, we discovered that of the 9.4 million houses in Australia, 7.6 million (84 per cent) are constructed in a way that would accommodate a solar system.

-- Utilising Australian Bureau of Statistics data, we calculated the average Australian floor size is 150 square metres. Considering the average floor size is now 220 square metres, this is a very conservative figure. Prior to 1970, the average Australian floor size was a mere 140 square metres.

-- Of those eligible rooftops, 34 per cent of roof space was available to fit a solar system. This is assuming 70 per cent of homes are single storey, 10 per cent of the available area is inappropriate for solar, 10 per cent have roofs too steep for solar, 10 per cent have chimneys and obstructions, 25 per cent of roof area is facing due south and 10 per cent of the edge zone around the roof borders needs to be kept clear for access.

-- That gives us a total of 394 square kilometres of available roof space in Australia, meaning we could fit more than 246.6 million 250 Watt standard solar panels in this area.

-- These panels could then produce a staggering 277.5 million kWh of electricity per day, based on our equation of: number of panels x rating of each panel x available sunlight per square metre.

-- This equates to a yearly energy production total of 81,047 gigawatt-hours (GWh). When you consider the yearly Australian residential energy consumption is 60,139 GW (according to the Bureau of Resources, Energy and Tourism), this gives you the all-important 134 per cent.

The overarching idea is for eligible houses to produce more electricity than they need, with the excess supply fed back into the grid in order to cope with Australia’s residential and non-residential power needs.

Not only would the installation of solar on this scale be a boon for jobs, financially it is very feasible because solar has never been so affordable.  Even though some benefits have been taken away, new financing plans such as Energy Matters’ Save as You Go Solar make owning a system very reasonable.  Such new offerings include a no-deposit payment plan where the savings from your electricity bill actually pay off your solar loan.

A national rollout would, of course, be a mammoth task and would involve many companies coming together for the good of the country.

So what would this mean for Australia’s current electricity production facilities? Remember, this is an extreme case study, some may say fanciful! 

Baseload power stations could be made essentially redundant on a sunny day, meaning Australia could close down most of its coal-driven power stations overnight, except for those in heavy industrial areas. 

Under-utilised gas-fired peaking plants, which are already in existence, could be called upon to generate Australia’s night time and cloudy day electricity needs. Shutting down Australia’s coal power stations alone would mean our emissions targets would be met almost immediately.

Above all, this study has proven a point; that solar is a viable solution to Australia’s energy challenges and would indelibly change the country’s reliance on expensive, polluting fossil fuels to generate electricity.

Is it worth mentioning that we haven't even considered the available commercial roof space and the impact this would have on total energy availability? That is, if all available roof space was used, we would be in a situation of energy abundance without CO2 issues so electric vehicles, desalination and the hydrogen economy could become more than viable in a realistic timeframe.

This is not about solar, it is about building a resilient Australia, with more jobs, economic growth and internationally relevant exports powered from the sun.

Solar on every suitable rooftop in Australia could easily become reality and the positive impact on our lives would be immediate and long lasting.

Bill Gates changed the world, why can’t we change Australia?

Nick Brass is a Co-Founder of Energy Matters.

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