Energy mix of the future: Looking at the big debate between renewables and nuclear energy

According to the World Energy Outlook 2019, almost 1 billion people in the world today do not have access to reliable electricity. As the world continues to lift people out of poverty and bring access to electricity to deep corners of the world, the global energy requirements, including for electricity and for industry, are going to go up.

At the same time, it is widely accepted that we need to find different energy sources. Carbon intensive sources like fuelwood, coal and natural gas need to be phased out as we build a climate-resilient world. Several authorities have come onboard the need for low-carbon energy generation. (And even if you don’t believe in the CO2-induced theory of climate change, the fact remains that using fuelwood, coal and gas-based energy generation has terrible health consequences.)

Discussing low-carbon energy invariably leads to a big debate: Renewables vs nuclear.

Option 1: Renewable energy (solar and wind)

When we talk of renewables, most people stress on solar and wind energy.

Solar and wind have become increasingly popular in the last two decades. They are being promoted as the energy sources of the future because they do not emit GHGs during electricity production. Even their emissions during manufacturing and decommissioning pale compared to other forms of energy. Energy generation from renewables is expected to grow by 300% by 2040 due to their popularity and advancements in battery storage technology.

Producing energy from wind and solar has become cheaper—costs of generating electricity from wind and solar have fallen by 90% in the last 20 years.

Solar and wind farms are also easier and faster to build compared to most other sources of energy.

They are flexible and can ramp energy production up or down at a moment’s notice, depending on the demand. This is important in today’s energy use scenario. For example, if a popular TV show runs from 9:00 – 9:30 PM, we will see a spike in energy demands at 9 PM followed by a dip in demands at 9:30 PM. We also have situations of negative demand, when people generate more electricity (from their rooftop solar) than they use and supply the surplus to the grid. In such cases, other sources of energy would need to ramp down. Such situations place undue stress on the grids, which renewables can easily handle.

Their independence from the grid is the biggest advantage of solar and wind. Set up panels or windmills on your rooftop and you can produce your own electricity without depending on the grid! This ability makes these options attractive in unelectrified areas and areas very far from electricity generation plants.

Option 2: Nuclear energy

Nuclear energy is not new; nuclear power plants have existed since the 1950s. Nuclear power plants also do not emit GHGs during electricity production and are a good low-carbon energy source. Several features of nuclear energy make it a superb source of energy for the future.

The most impressive by far is its power density: nuclear energy produces more power per unit volume than any other form of electricity source we know. This also makes them space-efficient. Even their waste products can be contained within a small space, compared to the waste generated by decommissioned solar and wind infrastructure.

They are stable and reliable. If the nuclear power plant works properly, we can be guaranteed a given amount of electricity at all times throughout the year (except when it might be shut down for maintenance). This is key in industrial areas and urban centers where the demand for energy rarely fluctuates. Often, these areas are also well-connected to the grid and require large amounts of power, making nuclear a more attractive option than the intermittent, power-thin renewables.

Contrary to popular belief, it is safe. Nuclear disasters have occurred largely due to mismanagement, and primitive technology, both of which are avoidable in today’s world (in case of natural disasters, we can only do so much to minimize risks). Nuclear wastes also need not be dangerous if proper precautions are taken and protocols are diligently followed.

However, solar and wind are far from ideal…

Solar and wind have their fair share of criticisms.

First, they are intermittent: we cannot get reliable electricity throughout the day, month or year from either of these sources. This means we need a back-up—either through battery storage (who’s capacity is still low) or through coal/natural gas plants (kind of beats the purpose)—or we need a combination of different renewable energy sources that can feed support each other. The need for backup, along with the new grid infrastructure we need to interconnect different renewable sources, has increased the cost of electricity for consumers even though the cost of energy has gone down.

Second, they have low power densities; they produce low energy per unit volume compared to fossil fuels and nuclear. This means that if we tried to power the world entirely by a combination of different renewable energy sources, we would need A LOT space. For example, if the entire world was to be powered by solar, we would need a land area the size of South Africa. Not at all efficient.

Third, the infrastructure we create for wind and solar has a lifespan of 25-30 years. What happens at the end of their lifespan? Disposing solar panels and windmills are a huge pain, requiring massive infrastructure to recycle their components. If we didn’t recycle them, we would dump them in landfills and cause an environmental disaster.

When we try to scale solar and wind energy generation through parks or farms, this technology incurs a significant ecological cost. Solar farms displace animals from their homes and create a heat island that is unconducive to most lifeforms. Similarly, wind farms are notorious for their interference with the flight paths of large birds and bats.

Nuclear energy also has problems…

Nuclear energy’s biggest detractor is its construction. It takes a long time and a lot of money to construct a nuclear power plant. This isn’t ideal because we need to cheaply and quickly produce low-carbon forms of electricity to meet the rising demands around the world. Construction of nuclear power plants is also very carbon-intensive.

Nuclear isn’t traditionally flexible, and modern designs offer limited flexibility, which isn’t ideal in places with highly variable energy demands.

Introducing nuclear energy (and wastes) in countries that do not yet have access to this technology creates the risk for weaponization. While the chances of an all-out nuclear war continue to be low, the risk cannot be discounted.

Should we be choosing one or the other?

For the longest time, I felt that this is a binary option. That is how the debate has been structured on the global stage for the last 25 years. But a closer look at the advantages and disadvantages of renewables and nuclear paint a different picture. See for yourself…

This table compares the two forms of energy against several parameters of a future energy grid.

Clearly, nuclear and solar/wind are complimentary: where one falls short, the other can support.

Conclusion: Should we rely on only one form of energy?

Given different needs in different areas of life, it is unwise to depend on any one form of energy. For example, solar/wind is cheaper and faster to electrify rural areas, where the need for electricity remains low and it is expensive to connect them to the grid. Nuclear makes sense in cities and industrial complexes that need reliable, stable and cheap electricity all the time.

Let me ask you the question again:

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The future of energy in a low-carbon world, according to me, does not have to renewable OR nuclear. We need a bit of both (the relative proportions, of course, are debatable). Their features are complimentary and the next generation energy grid should evolve to accommodate both forms of energy.