Imagine a future where all the world’s energy needs are provided by free, inexhaustible sources of energy: the sun, the wind and the waves.

If that were possible, wouldn’t that be better than what we have today?

Many scientists, policy analysts and environmentalists think it’s both possible and affordable. So much so that the calls for a transition away from fossil fuels to a 100% renewable energy economy have become mainstream.

But is 100% renewable energy really practical?  Is it technically feasible and does it make sense financially?

Here’s a review of what a 100% transition to renewable energy means, what the benefits of a transition would be and the major “buts” that are commonly raised as concerns.

What 100% renewable means 

Currently, about 86% of all primary energy used globally comes from oil, coal, gas, nuclear and other assorted biomass fuels like wood, peat and waste.  

A 100% renewable energy system, also referred to as 100% WWS (wind, water and solar),  means that the use of non-renewable energy – coal, gas, oil, nuclear as well as biomass, is phased out in favour of renewably generated electricity from solar as well as onshore and offshore wind turbines.  In some regions, geothermal and tidal electricity could play a role but analysts expect solar and wind generation to dominate.

Hydroelectric installations, even though they generate electricity without emissions, do not expand in 100% WWS models.   Hydro dams have other negative environmental impacts and take too long to build to achieve net zero emissions goals by 2050.

A fully electric world

A major implication of a 100% WWS transition is that all the technologies that run directly on fossil fuels also need to transition to run on electricity.  That means pretty much everything: cars, buses, trains, heating systems, lawnmowers, industrial processes – all need to be able to run on electricity.

Fortunately, analysts say that today we have 95% of the technologies needed to transition to a 100% renewable energy system across all sectors of the economy.  The main gaps that are still in development are solutions for long-distance air travel and long-distance shipping where battery power is not practical.

These gaps are expected to be filled as hydrogen fuel cell-based engines are refined.  Hydrogen is produced by electrolysis – splitting water with electricity.  So long as the electricity to produce hydrogen comes from a WWS source, so-called “green hydrogen”, hydrogen-based energy is free of emissions.

The growing body of evidence

The increasing awareness of the need to transition away from fossil fuels has driven research interest in renewable energy transitions.  Since 2009, there has been a growing body of evidence demonstrating that it is possible and economically feasible to shift to 100% WWS across all sectors, including power, heat, transport, and industry, on a global scale.

The benefits of a 100% renewable energy transition:

1 – Dramatically reduced emissions  

The key argument for a transition to 100% WWS energy is that it will cut greenhouse gas emissions quickly and dramatically. 

Most global emissions come from the use of fossil fuels to produce energy for various applications.   In a 100% WWS world – those would be eliminated. 

Also eliminated would be the emissions that come from all the activity worldwide to explore for, extract, produce, refine, and transport fossil fuels.  In Canada, for instance, the largest source of our emissions stem from the production of oil and gas. This would be eliminated in a 100% WWS transition.  About half of all emissions from international shipping come from the transport of oil and coal – also eliminated in a 100% WWS transition.

In a complete transition to renewable energy sources, 70% to 80% of global emissions would be cut, which would make avoiding the worst impacts of climate change much more likely.

2 – Eliminating Air Pollution

In addition to being the main driver of climate change, fossil fuel combustion is the major source of air pollution worldwide.   

The World Health Organization estimates air pollutants were responsible for an estimated 6.7 million deaths in 2019 – about 12% of all people who died in the world that year – making it the 3^rd leading cause of death globally, after high blood pressure and smoking.   

Shifting entirely to renewable energy sources would lead to better air quality, reducing the prevalence of critical illnesses. This improvement would contribute to longer, healthier lives, and decrease the number of people needing hospitalization and other medical interventions. It would reduce strain on healthcare systems across the globe.  

It’s not just humans who suffer from the effects of air pollution from fossil fuels.  The entire ecosystem, plants, animals, water sources and the soil would all benefit from the elimination of the main source of sulphur dioxide, nitrogen oxides and fine particulate matter.

3 – A solution that is proven to work in the real world

Critically, the core technologies to transition to 100% WWS energy exist today.  We have solar panels and wind turbine generators that are proven to work and are commercially available.  An increasing number of cities, states and countries are generating most of their power from these technologies.  

Some other ideas are being promoted as solutions for the climate crisis – small modular nuclear reactors, carbon capture and storage approaches, nuclear fusion, and even seeding the atmosphere with sun-reflecting aerosols. Such ideas, while potentially promising, can be controversial, are still in development and remain in need of technological breakthroughs to qualify them as practical or economic solutions.

In contrast, WWS technology exists today, is proven to work at scale, is affordable and is available commercially.

4 – A safer geopolitical world. 

Renewable energy advocates encourage us to imagine a world where countries are not motivated to attack each other to secure energy access or funnel billions in oil revenues to despots who fund destabilizing terror organizations.  Countries would enjoy enhanced energy security and reduce geopolitical tensions by virtually eliminating dependence on imported fuels.   They contend there may be a peace dividend attached to a renewable energy transition.

The “Buts”

1- But won’t there be blackouts?

The biggest question people have with a transition concerns the intermittency and reliability of renewable energy: what happens to us if it’s not so windy?  How do we get solar power at night or when it’s cloudy?  How will an energy system, largely based on the weather, supply our needs in heat waves cold snaps or other extreme conditions?  Opponents of renewable energy get a lot of traction when they emphasize the risk of blackouts. 

Researchers agree that keeping a system with variable sources stable is more complex, they point to a range of strategies that will be used to ensure energy needs are always met.  

These include:

• oversizing solar and wind capacities 
• strengthening grid interconnections to move energy from regions of surplus to regions of need
• improving demand management such as having smart electric vehicles delay charging to off-peak hours or even selling  energy back to the grid at times of peak demand
• energy storage systems​ such as battery reserve facilities or pumped hydro reservoirs

Researchers also point to over 660 published, peer-reviewed studies supporting the feasibility of 100% renewable energy transitions at a national or regional level. 

These feasibility studies involve creating national and regional models of wind and solar resources, determining an optimal mix of renewable power generating facilities and storage solutions and testing the ability of these systems to meet power demand continuously over extended periods and under various conditions.

The overall consensus of the body of work is that through a mix of generating, transmission and storage vehicles, adapted to the local renewable energy resources available, energy can be continuously and reliably supplied to meet the demands required in all regions of the world.

2 – But won’t it be expensive?

According to studies, it will be. 

In a pivotal study, a team of researchers at Stanford led by Dr. Mark Z. Jacobson estimated the capital cost of a 145-country WWS transition to be $61 trillion USD.  That would be spread out over 30 years or so – but it’s still a lot of money.  To put it in perspective, the average annual cost of the transition would equal about about 2.4% of the current annual global GDP.

However, aside from the humanitarian benefit of preventing the worst impacts of global warming, studies indicate that a 100% transition to renewable energy will be a sound financial investment. It would cut the costs of energy and health care and would avoid the enormous financial burden of damages associated with climate change.

In terms of energy savings, Jacobson et al estimated that in a 100% WWS transition, the world would save $17.8 trillion dollars per year in energy spending.   That is due to a lowered cost per unit of energy produced by renewable energy and a reduction in the energy required to power a 100% WWS world.

The average per unit cost of energy is expected to decline because the sun, the wind and the waves are free and there is no cost to mine, process and transport them.  Jacobson and his team estimate that the average energy rates could drop by 15%.

The other big factor is that in a 100% WWS transition, the world will use a lot less energy.  In their study, Jacobson et al demonstrate that a 100% renewable energy-powered world would need to generate 56% less power than in a business-as-usual scenario.  

Much of the energy in fossil fuels is lost due to waste heat while electrical-powered technologies tend to be much more energy efficient. 

For example – in transportation, only about 20% of the energy in gasoline goes to propel a car forward – the rest heats the engine block or shoots out the exhaust.  Electric vehicles on the other hand use energy 4 to 5 times more efficiently, requiring less energy to produce the same result. 

In addition to this increased efficiency, the world will also save all the energy and cost that goes into exploring for, extracting, refining and transporting fossil fuels.  

Combining, the lower price per unit of energy with the reduced amount of energy required, Jacobson estimates that based on energy cost savings alone, the transition would pay back in 3.5 years.

The team at Stanford also expects that the reduction in air pollution would result in savings to global health costs of $34 trillion per year. And of course, the whole point of a transition is to avoid the damaging effects and costs of climate change, which they estimate at $32 trillion a year.

Taken together, Jacobson puts the combined savings at ~$82 trillion per year, well beyond the  $61 trillion estimated capital cost for the transition.  

It’s important to be cautious with forecasts that span decades over the scope of the entire planet.  But this work, which is peer-reviewed and corroborated by other research lays out a solid basis for why a 100% WWS transition is likely to be a financial win.

3 – But don’t windmills and solar panels take up a lot of space?

In their 145-country study, Jacobson et al concluded that a transition to a 100% WWS system would need ~0.17% of the world’s land to install renewable energy-generating facilities.  Taking into account that windmills and solar panels need to be spaced out, that number grows to ~0.36% of the world’s land. 

For some, those may seem like big numbers, but the authors contend that the space required is small relative to the land used by the fossil fuel industry.

The fossil fuel industry uses more land than most people realize.  In the US for instance, a 2021 analysis by Bloomberg, concluded that the current energy system uses 81 million acres of land – about 4% of the land mass of the contiguous United States, an area about the size of Iowa and Missouri combined.  About 75% of that footprint goes to producing fossil fuels and biofuels like ethanol which would no longer be necessary in a transition to 100% renewable energy.

3 – But what about jobs?

The other big hitch, of course, is that there are a lot of people, businesses and entire economic sectors who rely on how we do things today.  People legitimately worry about an energy transition that will eliminate large sectors of current economic activity.  But a $61 trillion dollar global investment in new energy systems will also create a lot of jobs and economic spinoffs.  

In their modelling, Jacobson et al estimate that a transition could produce 55.6 million new long-term jobs.  That would offset the 27.2 million jobs that they expect would be lost in the transition away from fossil fuels, resulting in a net gain of 28.4 million long-term, full-time jobs across the 145 nations studied.  While most world regions would expect a net gain in jobs, some regions, like Russia, Canada and parts of Africa, which are particularly reliant on the fossil fuel sector may see net job losses.  The study estimates Canada may lose 275,000 net jobs over the 30-year transition. 

Over a 30-year period, a transition to renewable energy is expected to create millions more long-term, full-time jobs than lost.  It will certainly disrupt the existing fossil fuel sector but it will eliminate greenhouse gasses and air pollution from energy.

The biggest BUT

An energy system that is 100% based on renewables has emerged to become scientific mainstream and researchers agree that the world can reach a 100% renewable energy system by or before 2050.  As of 2020, about 8% of energy came from renewable sources. Because the technology exists today and is relatively quick to implement, Jacobson et al believe that number can reach 80% by 2030, and 100% by 2035.

The barrier for the scientific community is not technical or financial, but political. The pace of the transition depends on whether policymakers can garner sufficient political will.

In the sober, detached tone of academic writing,  Jacobson neatly summarizes the ongoing struggle that will determine the fate of billions in the coming decades: 

“…that political will is adversely affected by lobbyists for conventional energy, other people with a vested interest in the current energy infrastructure, the difficulty in changing some people’s opinions about whether we should move off of fossil fuels, and confusion sown by those against a renewable energy transition.” 

The good news is that despite these headwinds, the transition to renewables is well underway and gaining momentum.  As more and more people realize the climate, health and economic advantages of 100% renewable energy, political leaders will gain confidence to adopt policies and increase investment to speed the transition.    

The journey is likely to be bumpy, but the destination sure seems worth it.