100% Renewables—Rapid, Deep and Cheap Emissions Reductions

Rapid deep and cheap greenhouse emissions reductions are possible using solar PV and wind. Together, they comprise 3/4 of global net generation capacity additions, because they are cheap and getting cheaper. They must do the heavy lifting to eliminate global emissions well before 2050.<br/>About 4 terawatts of solar and wind must be deployed each year to do the whole job of eliminating fossil fuels, with a value of ~$4 trillion per year (including storage & transmission). Overall, energy costs will fall because solar and wind are so cheap. We will eliminate greenhouse emissions, oil spills, oil related warfare, urban smog, gas fracking, open cut coal mines, power station smoke plumes, ash dumps, and other unpleasant consequences of burning fossil fuels.<br/>The emissions profile of a country typically comprises 70-80% from energy-related activities, 10-20% from the land sector and 5-15% from other activities. Electrification of nearly all energy-related activities entails a doubling of electricity demand and allows solar & wind to eliminate most emissions.<br/>Balancing of 50-100% solar and wind in an electricity network is straightforward using off the shelf technology from vast production runs, namely storage (pumped hydro and batteries), strong inter-regional transmission connections (to smooth out local weather and demand) and demand management in all of its myriad forms.<br/>Decarbonized electricity from solar & wind can be used to eliminate oil from land transport (via electric vehicles) and eliminate gas from heating (via electric heat pumps and electric furnaces). These three steps typically eliminate 60-80% of the greenhouse emissions of a country. Since the required technology is off the shelf from vast production runs, rapid progress is possible.<br/>Elimination of 60-80% of “easy” emissions by the mid-2030s buys time to develop low-cost techniques to eliminate emissions from the harder sectors: aviation, shipping, metals, chemicals and the land sector.<br/>Australia is a global pathfinder for rapid per capita deployment of solar and wind - deploying solar and wind 3-5 times faster per capita then the EU, USA, Japan or China.<br/>Currently, the Australian National Electricity Market derives 36% of its energy from renewables, mostly solar & wind, and is tracking towards 50% in 2025. Australia is the only non-European country in the top 10 in terms of installed solar and wind power (Watts per person). Of course, Australia's solar resource is better than in Europe, and more typical of the 3/4 of the global population who live at low latitudes. Unlike other countries with high levels of solar & wind per capita, Australia has no grid connection to neighbors, which means that it is not possible to balance the grid when there is an excess or deficit of solar & wind generation by trading with neighbors.<br/>Australia has only a small amount of hydro (7% of generation) and is learning to cope with high levels of variable solar & wind. The key lessons so far are that (i) balancing is neither difficult nor expensive and (ii) the more solar & wind that is deployed, the lower is the wholesale spot price in the market.<br/>So, what is required to accelerate the elimination of emissions?<br/>- Continued development of higher efficiency and cheaper photovoltaics is of prime importance, because solar PV will be responsible for the elimination of about 60% of global emissions.<br/>- Improved batteries for electric vehicles are needed; in particular, removal of rare battery metals such as lithium and cobalt.<br/>- Substantial work is required to bring down the cost of electrolyzers for the production of hydrogen for the metals and chemical industry, and for synthetic jet and shipping fuel.<br/>- Post 2050 it may well be necessary to capture carbon dioxide from the atmosphere and sequester it permanently in the deep earth in order to stabilize the climate. This requires vast amounts of solar & wind energy coupled with highly efficient and recyclable carbon capture chemicals and materials.