100% renewable by 2050? Yes, we can

Can Australia meet all its energy demands from renewable energy sources by 2050? Could the world? Not if you believe the coal industry, the nuclear lobby or the gas industry. But many in the renewable energy industry and green groups think they can, and WWF today releases a major new study, compiled with the help of European energy consultancy firm Ecofys, that finds that the world's energy needs can be met “cleanly, renewably and economically” within 40 years.

The 300-page global study finds that such an effort would require an extraordinary amount of investment, and the securing of significant gains through energy efficiency. The energy supply would be sourced from solar, wind, geothermal and hydro, and facilitated by the introduction of smart grids, international networks that balance renewable power sources, electrification of transport, major efficiencies in buildings, and the increased use of solar, geothermal and heat pumps for heating and cooling.

It doesn't quite get to 100 per cent though – at least not by 2050. WWF thinks it can, but the scenario painted by Ecofys suggests that 5 per cent of the power, mostly for industrial fuel use, will need to come from gas or nuclear sources by 2050, although this could be phased out in subsequent years. The Australian scenario, painted by another consultancy group – Climate Risk, suggests a lingering role (just over 5 per cent) for fossil fuel (albeit with CCS) by 2050.

Ecofys says the investments required to get to its target would be between $1.4 and $4.7 trillion a year (or 1-2 per cent of GP) over the next 25 years. It says the savings from energy efficiency and reduced fuel costs from the business-as-usual scenario would start to pay off between 2035 and 2040, and by 2050 it would be delivering annual savings of $5.4 trillion. It says the pay-off is greater, and earlier, if the costs of climate change, the impact of fossil fuels on public health are factored in, and if oil prices rise faster than predicted.

Ecofys argues that there is more than enough of the main renewable sources, particularly in solar, geothermal, wind and marine, although there are constraints in hydro. It says solar could provide 46 per cent of electricity (as opposed to total energy) needs (from effectively zero now), with onshore wind going from 2 to 20 per cent, offshore from zero to 5 per cent, geothermal taking 4 per cent, marine energy 1 per cent, and hydro declining from 19 to 12 per cent. The bulk of industry fuels and heat comes from biomass (59 per cent), but fossil fuels still play a role here, with 21 per cent. Most of the building fuels and heat comes from solar thermal and geothermal, and biomass accounts for all of the non-electric transport fuels.

“In this report we are very deliberately not making extravagant assumptions about the benefits of technologies yet to come,” Ecofys director Kees van der Leun said. “This inherently means that this is a moderate estimate of the renewable energy future we could enjoy by 2050.”

WWF says it wanted to demonstrate that a renewable energy future is not an “unattainable utopia”, and was in fact technically and economically possible. However, there are immense difficulties, and some of these revolve around the social and lifestyle changes that may be required.

Indeed, one of the most contentious points in the scenario is the suggestion that the widespread use of biofuels in the transport sector means that farm land and forests would need to be carefully managed, particularly in the face of population growth and emerging economies. It suggests that lifestyle choices may have to be made, such as eating less meat – a scenario that was also painted in the Garnaut report.

It notes that 1.6 billion people need access to electricity and a further 2.6 billion people need to replace their “dirty” power sources with cleaner cooking and heating fuels; and, as economies expand, emerging countries will want to eat more meat, meaning reductions of up to half for those in the OECD. “We will live differently, but we will live well,” WWF Director General Jim Leape said in a statement. “We must provide energy for all without imperiling our planet. This report shows that we can.”

An accompanying report, prepared by the consultancy group Climate Risk, suggests that Australia could source all its energy needs from renewables and occupy a “highly competitive position as a supplier of large volumes of low-cost, low-carbon energy to energy intensive industry, with the potential to attract greater investment.”

Climate Risk says Australia could meet this target through energy efficiency measures that reduce demand by 24 per cent compared to business-as-usual, and a massive rollout of renewable energy sources. Its scenario proposes 110 utility-scale solar farms of 500MW each, 74 geothermal power stations of 500MW, the equivalent of 203 wind farms of 500MW each, 101 small hydro power stations of 10MW each, 23 marine energy installations of 250MW each, the use of 50 per cent of available roof space for building integrated solar PV, and 100 per cent of available solar thermal roof space for heating and cooling. It also estimates 23,000GL of bio-hydrocarbons – but envisages a small role for fossil fuels with carbon capture and storage.

Climate Risk says this scenario would involve “additional” costs of $2.5 billion a year on average, assuming no carbon price, but it says that by 2045, all of the renewable energy resources will be producing energy at, or below, the cost of fossil fuel generation. With a carbon price such as that envisaged by Treasury – starting at $28/tonne of C02e and rising to 158/t by 2050 – the crossover in costs will occur more quickly (by 2030) and at additional costs of $1.5 billion a year.

“In practice, Australia, like other countries, will need a number of policies to drive the simultaneous delivery of each of the renewable resources including tailored feed-in-tariffs for specific resources and/or a renewable energy target which specifies quotas from each resource,” the report says. “The higher the carbon price underpinning the economy to begin with, the less specific resources and development time will be required from complementary measures."