This is an FAQ guide answering some of the most common questions that start with ‘Which Renewable Energy Source’.
*Note – this guide mostly refers to modern renewables solar, wind, hydropower, geothermal, and tidal/wave energy. Bioenergy may have been omitted in some of the stats and figures below.
Which Renewable Energy Source Produces The Most Energy, & Electricity?
There are global, but also country or city specific renewable energy stats for energy and electricity production, and these stats can differ.
It should also be noted that total energy production is different to electricity production (as energy involves other sectors like transport, heating etc., whilst electricity is just the power sector). But, hydropower tends to be the prominent renewable energy source in terms of production and consumption:
- Globally, hydropower was responsible for 7% of total primary energy consumption in 2015 (wikipedia.org)
- Globally, hydropower was responsible for 15.8% of total electricity produced in 2018 (bettermeetsreality.com)
Which Renewable Energy Source Is The Most Used Worldwide?
As mentioned above, hydropower has the highest installed capacity, production and consumption totals and shares worldwide. But, the most used renewable energy source can vary country to country, and city to city.
Which Renewable Energy Source Is The Most Efficient?
But, efficiency can sometimes be dependent on the technology available, and also the specific type of renewable energy source e.g. offshore vs onshore wind, large hydro dams vs run of river vs pumped storage hydro, and so on.
Which Renewable Energy Source Is The Cheapest?
‘Cheapest’ can refer to a few different things:
- How costly capital and set up/building costs are for a renewable energy project – onshore wind and solar PV might be some of the cheapest renewable energy sources in terms of capital cost
- Operating costs
- Entire energy production lifecycle costs
- Cost to deliver one unit of electricity to the customer – hydro and wind might be some of the cheapest renewable energy sources to deliver 1MWh of electricity
- Wholesale price that the consumer pays for electricity – this can depend on the energy mix in a particular State or city, but in South Australia for example, wind and solar have contributed to more competitive electricity prices
Overall though …
- Historically, hydropower has been the cheapest way to source renewable electricity. But that’s changing. Wind and solar (also called photovoltaic solar, or PV) have become the most economic forms of electricity. They are the renewables of tomorrow. (cnet.com)
Which Renewable Energy Source Has The Greatest Environmental Footprint?
Solar and wind can have a large land footprint for the utility sized wind and solar farms.
But, large hydroelectric dams, geothermal energy, and tidal/wave energy might have some of the most negative environmental side effects. Bioenergy with the use of resource intensive bio crops can also be environmentally damaging.
Despite the environmental side effects of renewable energy, it’s often mentioned that these environmental side effects are nowhere near as bad as fossil fuels like coal, oil, and natural gas.
Which Renewable Energy Source Is The Worst?
There are a number of ways you can measure the worst renewable energy source:
- Which source is the most expensive
- Which source is the most unreliable
- Which source provides the least energy and electricity
- Which source has the least long term potential
- Which source is the most environmentally damaging
- Which source is the most socially damaging
- Or, you could combine all factors
Out of wind, solar, hydropower, geothermal, and tidal/wave energy … tidal and wave energy are probably the ‘worst’ at this point in time because they are costly, speculative and produce almost no electricity as a share of total renewable electricity (but, both might have much better long term potential than what they produce right now).
Bioenergy can be good in some applications and not so much in others. Bioenergy that requires the growth of biocrops can be resource intensive and environmentally damaging/unsustainable in some aspects.
Which Renewable Energy Source Is The Most Plentiful?
This can be country or city specific.
Based on global stats, you might say that hydropower in most plentiful because it has the highest installed capacity and generation.
But, in reality, each country or location with populations of people has different natural resources available.
Just as one example, Iceland gets most of it’s electricity from hydropower (about 87%), with a smaller amount from geothermal (about 13%) (reuk.co.uk)
On the other hand, different States in Australia have different renewable energy mixes, and Australia overall, because of it’s masses of available land, is seen as having tremendous potential for solar and wind energy (because solar and wind farms use up a lot of land).
Which Renewable Energy Source Is The Most Reliable?
In this instance, we define reliable as the consistency of the power supply.
Solar and wind can be reliable when part of a flexible and diverse energy system. But, right now, on their own or when used solely/primarily together, they are seen as variable and intermittent sources of energy. They usually need other complementary sources of energy to help meet energy demand at certain points (when sun and wind conditions are poor or when energy demand is high), or they need expensive battery energy storage, or both. This of course could change in the future with technological breakthroughs.
Hydropower is probably the most reliable renewable energy source right now along with geothermal (neither are seen as intermittent sources).
Which Renewable Energy Source Is The Best?
There is no clear objective way to classify the ‘best’.
But, if we had to pick, we would say that solar, wind and hydropower are the best renewable energy sources because:
- Hydropower already has proven energy and electricity generation capability in the present day, and pumped storage hydro has the capability to store energy
- Solar and wind have been expanding rapidly the last decade or two, receive most of the investment money, are getting cheaper, are performing better, and are overall seeing the most development and real life results of the modern renewable energy sources. Specifically, solar PV and onshore wind.
- Most of the studies and reports about a 100% renewable energy future specify solar, wind and hydro as key parts of that future
If you are interested in reading about other considerations such as cost, efficiency, power density etc., we have put together a guide discussing some of these things, and comparing renewable energy to fossil fuels and nuclear energy in some of the same areas.