As the global climate crisis continues to rise up nowadays, the need to find solutions to combat this problem has become more crucial than ever. One recommended solution that has been going around these days is to utilize alternative sources of energy. Fossil fuels, such as coal, petroleum, and natural gas, do a relatively okay job of providing us energy, but they are very limited and highly dangerous to the environment. So, finding alternative sources is a must. Luckily, there are quite a ton of them out there, and two of the most popular ones are solar power and nuclear power.
What Is Solar Power?
As the name suggests, solar power is the conversion of energy from sunlight into electricity. There are three main ways to harness solar energy. The first method, photovoltaics, is arguably the most commonly used, and it involves generating electricity directly from sunlight via an electronic process that occurs naturally in certain types of material, called semiconductors. The other two methods, solar heating and cooling (SHC) and concentrating solar power (CSP), both use the heat generated by the sun to provide space or water heating (in the case of SHC systems) or to run traditional electricity-generating turbines (in the case of CSP plants).
Solar technologies can harness the sun’s energy for a variety of uses. Some of these uses include generating electricity, providing light or a comfortable interior environment, and heating water for domestic, commercial, or industrial use.
What Is Nuclear Power?
Simply put, nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which is most frequently used in steam turbines to produce electricity in a nuclear power plant. Nuclear power can be obtained from nuclear fission (nucleus splits into two smaller, lighter nuclei), nuclear decay (unstable atomic nucleus loses energy by emitting radiation), and nuclear fusion (two or more nuclei are combined to form one or different nuclei and subatomic particles).
Nuclear power has one of the lowest levels of fatalities per unit of energy generated compared to other energy sources. Coal, petroleum, natural gas, and hydroelectricity each have caused a greater number of fatalities per unit of energy, due to air pollution and accidents. Since its commercialization in the 1970s, nuclear power has prevented about 1,84 million air pollution-related deaths and emission of about 64 billion tonnes of carbon dioxide equivalent that would have otherwise resulted from the burning of fossil fuels.
However, despite that, there is still an ongoing debate about nuclear power. Proponents, such as the World Nuclear Association and Environmentalists for Nuclear Energy, argue that nuclear power is a safe and sustainable energy source that reduces carbon emissions. However, nuclear opponents, such as Greenpeace and NIRS, assert that nuclear power actually poses many threats to people and the environment. In particular, the opponents point to nuclear accidents, such as the death of Louis Slotin, the Windscale fire, the Three Mile Island accident, the Chernobyl disaster, and the Fukushima Daiichi nuclear disaster, combined with escalating acts of global terrorism, to argue against the continuing use of this particular technology.
Comparing and Contrasting
Time to Build Solar Power vs. Nuclear Power
One of the most noticeable differences between solar power and nuclear power is the time it takes to build each type of generating facility. Long story short, nuclear power is the one that takes much longer to bring online.
To elaborate further, it is helpful to look at the recent history of nuclear power construction in the U.S. since it provides a useful point of comparison. In the last 30 years, only a single nuclear power plant has been completed in the U.S. — the two-unit Watts Bar Nuclear Plant in Tennessee, which required 23 years for one reactor to be operational and 33 years for the other. Additionally, the two most recent nuclear projects under construction — the Vogtle Electric Generating Plant and the V.C. Summer Nuclear Station — received approval in 2012 from the Nuclear Regulatory Committee (NRC), and they are both over budget and far from completing construction.
Meanwhile, in the six years since the approval of the Vogtle plant and V.C. Summer station, the Solar Energy Industries Association has listed 57 utility-scale projects of at least 100 megawatts (MW) that have come online. In addition to that, there are 14 more 100+ MW projects that are currently under construction.
Moreover, Lazard, a leading financial advisory and asset management firm, forecasts the construction time required to build the different facilities. And the firm has discovered that utility-scale solar takes nine months to complete while nuclear may take 69 months to build. Considering the recent experience of building nuclear power in the U.S., 69 months — or about 6 years — is actually not so bad. In fact, the revised estimated operational dates for the two units of the Vogtle plant are now 2021 and 2022, which is a full decade after the plant received approval from the NRC.
Cost to Build Solar Power vs. Nuclear Power
Somewhat an extension to the previous point, another noteworthy difference between the two is the cost it takes to build the facilities. And very much like the previous point as well, nuclear power is the more expensive route.
A perfect example to highlight this is the revised cost forecast for the Vogtle Electric Generating Plant, a nuclear power project. In this revised cost forecast, it is projected that the plant will have a total project cost of $25 billion, which is a 75% increase over its original estimate of $14.3 billion. Meanwhile, one solar project that is under construction, the 250 MW Phoebe Solar Project in Texas, is projected to cost $397 million and to take less than one year to bring online.
These stark differences are echoed in a recent Levelized Cost of Energy Analysis by Lazard. Their findings suggest that the cost per kilowatt (KW) for utility-scale solar is less than $1,000 while the comparable cost per KW for nuclear power is between $6,500 and $12,250. At present estimates, the Vogtle nuclear plant will cost about $10,030 per KW. This then means that nuclear power is almost 10 times more expensive to build than utility-scale solar on a cost per KW basis.
Yearly Energy Generation
Another important factor to consider in the comparison of solar power vs. nuclear power is how much energy each produces on a yearly basis.
Power sources have two key characteristics. The first is capacity, which is a measure of the power that a source can output in megawatts. And the second is generation, which is a summation of the amount of energy that a power source can supply to an electric grid in a given time period (measured in megawatt-hours or MWh). For example, an incandescent light bulb requires 60 watts of power, and keeping that light on for an hour requires 60 watt-hours of energy.
A measure of how much energy a certain power source puts onto the grid is its “capacity factor,” which calculates how close to the maximum amount of possible annual generation a source might produce.
As such, a nuclear power plant will run at its maximum until it needs new fuel, which may be six or twelve months later. In other words, nuclear has a capacity factor of close to 100% because it usually produces as much generation as possible during every hour of the year. On the other hand, solar power can only produce electricity when the sun is out. This means that over the course of the year, solar power plants will produce their maximum amount of generation in just 17% to 20% of total hours, on average.
To illustrate this point, the 2,430 MW Vogtle nuclear plant could be expected to generate 21 million MWh per year. That is enough to power about 1.75 million residential households. Meanwhile, a hypothetical 3,500 MW solar power plant would be able to produce just under 6 million MWh of electricity per year. This number is enough to power only 500,000 homes, which is considerably less than nuclear power.
For solar to produce as much electricity as is generated by a nuclear power plant, it would require about 13,000 MW of utility-scale solar capacity, which about four times as much as built in the existing plants. However, the cost to build this 13,000 MW facility would be $12.1 billion, which is still just 50% of the cost of the $25 billion Vogtle nuclear plant.
Conclusion: Which Is Better — Solar Power or Nuclear Power?
From all these comparisons, one can say that the clear winner is solar power. This is because, as what the comparisons have shown us, solar projects can be built in substantially less time and at a much lower cost than a single nuclear project. Even when accounting for capacity built and energy produced from a nuclear facility, large-scale solar farms remain much less expensive and quicker to bring online than nuclear power plants. And so, it is safe to assume that as governments are planning for the next century of power generation, utility-scale solar easily beats nuclear as the leading source of carbon-free power.
But this is not to say that nuclear should be cast aside forever. This power source still has the potential to become an ideal alternative energy source. It already is capable of producing so much power on a yearly basis. Its primary problem is really the cost. If by some miracle, the cost of building a nuclear power plant will go down in the future, nuclear will definitely skyrocket to the top. But as of right now, the cost weighs it down, and so solar power remains the winner in this competition.
Related article: The Falling Cost of Solar Energy: Reasons and Implications