It might be difficult to definitively say what energy source is ‘the best’
It depends on how you define ‘best’, and there’s also a range of different factors and variables that might be difficult to measure or account for
So, what we’ve done in the guide below, is outline how some of the main energy sources might rate across several major energy indicators or measures, such as resource management and environmental impact, economic considerations, social impact, and practical considerations.
Summary – Which Energy Source Is The Best?
What might be concluded from the information below is that each energy source has it’s unique pros and cons to consider
As a few examples …
Renewable energy sources might rate well across some sustainability indicators, but they may have some practical drawbacks to consider
Nuclear energy may have some practical benefits, but some aspects of sustainability, as well as capital or operating costs can be a question
Fossil fuels may have some practical benefits, but there may be some sustainability issues to consider
Inclusions & Exclusions In This Guide
Firstly, it’s important to outline what we’ve completely or partially included and excluded in this guide.
The main inclusions in this guide are:
– Energy sources used for electricity generation
We’ve either partially or completely excluded a full analysis of the following factors in this guide:
– Energy sources used for transport (such as fuels), and also for heating and cooling (such as gases)
Ways To Measure Or Assess Which Energy Source Is ‘Best’
There could be many ways to measure or assess which energy source is ‘best’.
Below, we consider resource management and environmental impact, economics, social, and practical considerations.
But, one or all of the following factors could also be considered:
The cost of each energy source
The impact each energy source has on electricity prices
The quality or reliability of power supply/electricity supply each energy source delivers
The energy source that is used the most, has the highest production and consumption totals, or has the most potential for future growth
The energy source that is the most practical to use, and has the least technical limitations
The sustainability impact of each energy source
The social impact of each energy source
And, other factors – several of which we list in a separate guide
Resource Management, & Environmental Impact
We’ve put together a separate guide about which energy sources might be the most sustainable, specifically when it comes to resource management, and also environmental impact.
A very brief summary of what we outlined in that guide might include:
May have several sustainability benefits
Some examples are that they use renewable resources, they may emit little to no greenhouse gases and air pollutants at the operation stage, and conversion of energy to electricity may result in no waste by-products
However, there are also a range of potential sustainability drawbacks to consider with different renewable energy sources too
Some types of bioenergy in particular may have several sustainability concerns
Comes from uranium, which is considered a non-renewable resource. And, spent nuclear fuel is a waste by-product that needs to be managed
However, the use of nuclear fuel at nuclear reactors might emit little to no greenhouse gases and air pollutants
Come from non-renewable resources, and might emit greenhouse gases and air pollutants during the combustion of fossil fuels
Fossil fuels like coal also have waste by-products like fly ash that need to be managed
However, new power plants might have devices and systems installed that capture or manage carbon and also air pollutants to varying degrees of effectiveness
Economic considerations include things such as:
Cost Of Capital
On a capital cost per kW basis …
Fuel cells, offshore wind, advanced nuclear, and coal with air pollutant controls may be most expensive
Gas/oil combined plants, solar PV, and onshore wind may be the cheapest
New fossil fuel power plants with environmental control measures, and air pollution and carbon capture devices and systems may make coal and other energy sources more costly. Regulations imposed on fossil fuels may also make it more costly.
Fossil fuel plants (for oil, coal, natural gas), and also nuclear reactors may have fuel costs to consider during operation
Renewables like solar and wind don’t have these fuel costs
Research & Development Costs
It might be hard to accurately quantify research and development costs
LCOE (Localised Cost Of Electricity) – Capital, Plus Operation Costs
Coal, biomass and nuclear may have some of the most expensive LCOE
Renewables like hydro, solar, and onshore wind may have some of the cheapest LCOE
But, LCOE can differ between countries, with different technology used, and with different types of setups
Cost To Provide Electricity As A Service
There may be some additional costs to consider when using renewable energy sources to provide electricity to the local power grid – particularly for variable/intermittent renewable energy sources
For example, some variable renewable energy sources require one or both of backup energy sources, and/or energy storage in the form of batteries.
There can also be costs to integrate the new energy source to the existing power grid.
Subsidies is not something we’ve mentioned here, but, subsidies, taxes, and other direct and indirect costs might be considered in the overall cost of each energy source.
Profitability For Investors
Something we haven’t considered in this guide is the profitability of different energy sources for investors
Price Of Electricity For End Consumers
There might be a range of factors that impact the price of electricity for consumers between different cities and towns, with the type of energy source used being just one factor impacting that price
In some cases, taxes and levies for renewable energy can increase electricity prices in some places, but taxes aren’t always the main cause of electricity price increases
New fossil fuel power plants with carbon capture/storage technology, or air pollutant management technology, may also increase the price of electricity (where additional costs for this technology are passed onto end consumers)
Creation Of Jobs, & Employment
The number of people currently employed in fossil fuel related industries is significant
However, because of the labor intensity of renewable energy sources like Solar PV (compared to the capital intensity of some fossil fuel energy sources), and bioenergy, these energy sources may employ more people on a per unit basis (such as per dollar invested in the energy source)
Some renewable energy sources like some types of hydro might be less labor intensive during operation though
Some reports also indicate that the quality or type of the employment may also be better
Total Economic Value Of Different Energy Source Industries
Something we haven’t specifically examined in this guide is the total economic value that different industries are worth to the global economy, and also the national economy of different countries
Seeing as though fossil fuels make up the majority of primary energy use in many countries worldwide, it might be reasonable to assume that fossil fuels still contribute a significant amount of economic value to national economies and also the global economy
These guides contain more information on economic considerations for some of the different energy sources:
Cost Of Renewable Energy vs Fossil Fuels vs Nuclear Energy
Factors That Impact The Price Of Electricity
Do Renewables Create More Jobs Than Fossil Fuels?
Some social considerations might include:
Impact On Public Health & Safety
There may be various ways that the safety of different energy sources for humans and society can be measured
Air pollution (potentially impacting air quality and human health), emissions, and industry related workplace accidents for the different energy sources are examples
According to some sets of data, nuclear energy and some types of renewable energy might be some of the safest energy sources, whilst some fossil fuels can be some of the most harmful
This guide contains more social, and publish health and safety considerations for some of the different energy sources:
Which Energy Sources Are The Safest, & Which Ones Are The Most Harmful?
Some practical considerations might include:
Nuclear and fossil fuels might have some of the best power density of all energy sources
Nuclear, geothermal energy, and natural gas might have some of the highest capacity factors of all energy sources
Variability & Intermittency
Variable energy sources can deliver power intermittently at certain times
Solar and wind energy might be examples of variable energy sources, as the consistency of their power delivery might fluctuate with weather conditions (such as whether the sun is out, or whether the wind is blowing)
In comparison, fossil fuels and nuclear energy might be reasonably stable energy sources, delivering more consistent power.
Other renewable energy sources like hydro energy and geothermal energy might deliver reasonably consistent power too, and have the potential to provide baseload power.
Variability and intermittency can impact other aspects of power supply too.
One example is how intermittency can be bad for grid stability (overloading the grid for example), and can impact the overall reliability or quality of the power supply.
As another example, variable energy sources like solar or wind might also need backup energy sources, or energy storage (such as batteries) – to meet base load and peak energy demand
Several reports indicate that conventional power sources like coal, natural gas, and nuclear are all dispatchable energy sources i.e. they can be turned on or off to to match realtime demand
Some data sets show renewables and nuclear being much more efficient at energy to electricity conversion than most fossil fuels
However, there’s also some data sets that show fossil fuels being more efficient than solar energy specifically
Most Commonly Used Energy Sources
Fossil fuels are still the predominant energy sources worldwide for primary energy use and electricity generation
Renewable energy currently only makes up about 26% of global electricity
Most Commonly Used Renewable Energy Sources
Hydropower currently provides around 50% of global electricity provided by renewables – so, it’s a proven and established renewable energy source
Solar PV and wind energy (onshore might be more commonly used than offshore) are behind hydro energy, with bioenergy behind them
Energy sources like tidal energy and wave energy might be some of the least commonly used and more speculative renewable energy sources right now
Solar and wind energy might be two of the renewable energy sources projected to grow the most in the future
These energy sources may also get cheaper and see improvements in technology and performance over time
Some studies indicate that hydro, solar and wind are three of the key renewable energy sources going into the future
Potential To Scale Up
There might be questions over whether some energy sources can be scaled up beyond where they are at right now (in terms of new projects or additional energy production)
Hydro energy might be an example of an energy source with questionable potential to scale up
Other Miscellaneous Practical Considerations
Beyond what’s listed here, there can be other practical considerations to take into account, both generally, and for individual energy sources.
A few examples of practical considerations for individual energy sources might be:
Pumped storage hydro might have the ability to store surplus renewable energy
Solar energy might be one of the more versatile energy source in terms of how it can be used
More Information On Practical Considerations
This guide contains more practical considerations for some of the different energy sources:
Fossil Fuels vs Renewables vs Nuclear Energy: A General Comparison
Efficiency Of Different Energy Sources
Other Variables In Assessing The ‘Best’ Energy Source
Some other potential variables in assessing the ‘best’ energy source might be:
– Energy mixes, energy sectors, and energy projects differ between different cities and towns worldwide
A specific energy source may be better for some cities or towns than others
Just one example of this is how nuclear energy might be far more expensive in some countries than others, and therefore might be priced out of these countries
– Future developments (such as improvements in technology or other energy related factors) may change the performance, or set of pros and cons of each energy source over time
– Other variables
Other factors that may pay a role in determining the best energy sources are the budget/financial capacity of individual cities and countries, subsidies, exporting and importing between regions, the existing power grid and energy infrastructure (like transmission lines), and more
We list some of those other variables in this guide
1. Various ‘Better Meets Reality’ guides