As concerns about increasing populations and the environmental impacts of fossil fuels grow, the energy industry is looking for ways to evolve. Renewable energy and nuclear power both have the potential to be significant players in the next era of electricity generation. Each type of energy resource has its benefits and challenges, and both have their proponents.
Will nuclear or renewables be the answer to our energy woes? The issue isn’t quite so straightforward. We already use both, and comparing these two very different types of energy can get a bit messy. Circumstances vary from facility to facility, and opinions vary widely. However, we’ll do our best to break the differences down for you in this article.
In 2016, the world used about 592 million tons of oil equivalent (MTOE) of nuclear power and 1330 MTOE of renewables, 910 of which was hydroelectricity, according to BP’s 2017 Statistical Review of World Energy. REN21’s 2017 Renewables Global Status Report estimates nuclear makes up 2.3 percent of energy consumption, while renewables — including biomass, hydropower, solar, wind and geothermal — make up 19.3 percent.
It wasn’t until relatively recently, though, that renewables surpassed nuclear in terms of production and consumption. Renewable markets have been growing fast, while nuclear plants are struggling to remain economical.
Nevertheless, the U.S. Energy Information Administration (EIA) predicts global demand for nuclear power will increase by 1.5 percent per year from 2015 to 2040. Renewables, according to the agency’s forecasts, will be the fastest-growing energy source at 2.3 percent per year over that period. Total world energy consumption is expected to increase by 28 percent during that time.
Nuclear plants and renewable energy resources generate power in very different ways. Even among renewables, generation attributes vary substantially.
One of the most frequently cited differences between the two types of energy, especially by nuclear advocates, has to do with baseload power. This term refers to energy from plants that can generate electricity continuously and have a certain amount of fuel stored on site.
Nuclear power plants have such a fuel supply, while solar and wind farms depend on input from variable natural processes — sunlight and wind. Some say we need baseload power to have a reliable electric grid, and that nuclear plants are necessary because of this need.
However, others point out hydropower is already a baseload power source, and batteries give solar and wind the ability to store fuel onsite. Battery technologies are quickly becoming more efficient and more affordable.
Still others say we don’t even need baseload facilities, or at least not many, that store fuel onsite. With enough renewable plants, they argue, we could reliably meet all our energy demand.
One of the most persuasive arguments for both renewables and nuclear is their zero-emissions attributes. Generating power with nuclear and renewable resources does not release any emissions that pollute the air or contribute to the greenhouse effect.
To get a full understanding of each technology’s environmental impact, we have to look at the whole lifecycle, which includes everything from mining fuel to building facilities to generating electricity.
Estimates of lifecycle emissions vary according to the parts of the lifecycle analyzed. Actual lifecycle emissions can also differ substantially depending on the specifics of each project. On average, though, nuclear has slightly higher lifecycle emissions than most renewables. Solar PV has slightly higher emissions than nuclear. Both nuclear and renewables, though, have far fewer emissions than fossil fuels.
Another concern with nuclear power generation is the waste it produces. This radioactive waste is currently in interim storage sites. Permanent underground storage facilities are under construction in Finland and Sweden, but plans to build a repository in the U.S. have stalled due primarily to opposition from politicians and citizens.
While hydroelectric power causes very few emissions, it does present other environmental concerns, such as the disturbance of aquatic ecosystems.
In terms of technological advancement, renewables have beaten out nuclear power in recent years. Renewable technologies have become more efficient and cost-effective, while nuclear has remained relatively static. Innovations in renewables continue to come about, with battery technologies being a prime example.
There is a lot of research and development underway in the nuclear field as well, though, and there’s always a chance new technology will emerge and flip everything on its head. Areas of study include molten-salt reactors and nuclear fusion, as opposed to fission, which is the technology in use today.
Emerging renewable technologies include concentrated solar photovoltaics, marine energy and artificial photosynthesis.
Another ever-present concern is cost. You can describe the expenses associated with an energy resource in terms of its levelized cost of energy (LCOE), which represents the cost per megawatt-hour of a plant over its lifetime. It incorporates capital costs, financing costs, assumed usage rate and expenses associated with fuel, operation and maintenance.
The costs of wind and solar energy have fallen dramatically in the past decade, which has contributed substantially to their increasing prevalence. The LCOE for large-scale solar projects built by utilities is between about $46 and $61 without subsidies, according to asset management firm Lazard. For residential rooftop solar, it’s about $138 to $222. Wind has an LCOE of $32 to $62, which is one of the lowest compared to other renewables and all other energy sources.
Nuclear’s LCOE is between $60 and $143, putting it ahead of residential rooftop solar, but behind utility-scale solar and wind.
In recent years, though, nuclear plants have been struggling to compete with natural gas, as well as utility-scale wind and solar. One reason for this is that it takes a long time to build nuclear plants and to see a return on the investment. With technology moving as fast as it is, you risk never seeing a return at all.
According to EIA forecasts, the LCOE for resources entering the market in 2022 will be:
- Nuclear: $93
- Solar PV: $63
- Onshore wind: $59
- Offshore wind: $138
- Hydroelectric: $62
Safety and Security
Safety and security are some of the most often-cited concerns when it comes to nuclear power. There have been three high-profile accidents in the nuclear energy industry: Three Mile Island, Chernobyl and Fukushima. These incidents have soured the public’s view on nuclear, but proponents argue it’s as safe as any other energy source overall.
The routine operation of nuclear plants doesn’t cause a safety concern. The potential for accidents, however, causes apprehension. Percentage-wise, these incidents are extremely rare. An increased focus on safety in recent years has reduced the rate of incidents requiring plant shutdown in a year to 0.1. Still, many are apprehensive about what could happen in the event of another disaster.
In fact, nuclear waste is more of a safety and security issue. There still isn’t a good solution in place for storing it. While in interim storage, it must be protected to prevent it from falling into the wrong hands. Establishing a permanent storage solution would reduce these risks.
Renewable energy resources don’t inspire the same fear nuclear plants do. One concern some cite is the security implications of an unreliable electric grid caused by too many intermittent energy sources. As of now, though, there’s no evidence renewables are threatening the reliability of our power system.
The energy industry is somewhat complicated, especially considering its environmental impacts and quickly advancing technologies. Nuclear and renewable energy are two technologies that have the potential to help us address our energy-related challenges. Only time will tell exactly how we choose to progress.