What Is The Difference Between Renewable Energy And Alternative Energy?

Renewable energy and alternative energy are two terms that are sometimes used interchangeably, but they refer to slightly different concepts. Renewable energy comes from natural sources that are continuously replenished, such as sunlight, wind, water, plants, and geothermal heat. Alternative energy refers to energy sources that are alternatives to traditional fossil fuels such as coal, oil, and natural gas. Most renewable energy sources are considered alternative energy, but some alternative energy sources are not renewable.

The key difference between renewable and alternative energy is that renewable energy comes from sources that are naturally replenished over time, while alternative energy may or may not come from renewable sources. Renewable energy is considered a sustainable energy solution since the sources regenerate naturally within a human lifespan. Alternative energy encompasses a broader range of energy solutions that can reduce reliance on fossil fuels.

Table of Contents

Renewable Energy Overview

Renewable energy, as defined by the U.S. Energy Information Administration, is energy that is collected from renewable resources that are naturally replenished within a human’s lifespan[1]. Common types of renewable energy include:

Solar energy – Energy from the sun converted into thermal or electrical energy.
Wind energy – Kinetic energy from air converted into electrical energy by wind turbines.

Hydropower – Potential energy from falling or fast-moving water converted into electrical energy.
Geothermal energy – Thermal energy from the earth used to generate electricity or provide heating.
Biomass – Organic material from plants and animals used as fuel.

Renewable energy has several key advantages:

It produces little to no greenhouse gas emissions, supporting cleaner air and mitigating climate change.
The resources replenish naturally, making them sustainable long-term energy solutions.

They reduce reliance on finite fossil fuel reserves that take millions of years to form.

[1] https://www.eia.gov/energyexplained/renewable-sources/

Alternative Energy Overview

Alternative energy refers to energy sources that serve as alternatives to fossil fuels like coal, oil, and natural gas. Some examples of common alternative energy sources include:

Nuclear energy – Energy from nuclear fission or nuclear fusion reactions
Hydrogen – A clean fuel that can be produced from electricity and water
Biofuels – Fuels derived from biomass like plants and agricultural waste

Alternative energy sources have some advantages over traditional fossil fuels:

They can reduce dependence on fossil fuel imports from other countries
Some alternatives like nuclear and biofuels provide constant power output unlike intermittent renewables

They can help diversify a country’s energy mix

However, alternative energy sources also have some challenges:

High upfront capital costs for building power plants and infrastructure

Safety concerns with certain sources like nuclear energy
Less advanced technology and infrastructure compared to fossil fuels in some cases

Key Differences

There are some notable differences between renewable energy and alternative energy sources:

Renewable energy comes from natural sources that are replenished over time. This includes sunlight, wind, water, plants, and geothermal heat. These energy sources are constantly renewed through natural processes and will never run out¹.

Alternative energy refers to power generated from sources that are not fossil fuels. This includes nuclear, biomass, hydroelectric, and geothermal energy. While alternative energy sources are considered more environmentally friendly than fossil fuels, some types like nuclear and biomass do produce waste and are not replenished quickly².

Renewable energy sources like solar, wind, and hydropower do not generate any waste or emissions during operation. On the other hand, some alternative energy sources like biomass and nuclear produce waste and emissions, albeit less than fossil fuels¹².

In summary, all renewable energy sources are alternative energy, but not all alternative energy sources are renewable. Renewable energy is a subset of alternative energy that is replenished naturally and does not produce waste or emissions.

Usage and Statistics

Currently, renewable energy accounts for about 12% of total energy consumption in the United States, while fossil fuels like petroleum, natural gas, and coal make up about 80% of total energy consumption. However, the adoption of renewable energy sources like wind, solar, and hydropower has grown rapidly over the past decade.

According to the U.S. Energy Information Administration, renewable energy consumption in the United States more than doubled from 2000 to 2020, growing from 6.1 quadrillion Btu in 2000 to 12.9 quadrillion Btu in 2020. In comparison, total US energy consumption grew just 25% during that same time period. Renewable energy generation from wind and solar in particular saw enormous growth, with wind power growing over 90 times and utility-scale solar growing over 900 times between 2000 and 2020.

The growth of renewable energy is part of a global trend. As of 2018, renewables accounted for about 11% of total primary energy production worldwide, according to Our World in Data. While fossil fuels still dominate energy production and consumption worldwide, some experts predict renewable energy will become the largest source of global electricity generation by 2025.

Environmental Impact

Renewable energy sources have a much lower environmental impact than traditional fossil fuels or alternative energy sources like nuclear power. Renewable energy produces little to no global warming emissions (UCSUSA, 2021). In contrast, burning fossil fuels like coal, oil and natural gas release greenhouse gases like carbon dioxide that contribute significantly to climate change. Nuclear power also has risks like radioactive waste, meltdown threats and uranium mining impacts (UCSUSA, 2021).

Other environmental benefits of renewable energy include reduced air pollution and ecosystem impacts. Wind, solar and hydro power don’t emit air pollutants or toxic chemicals. They also don’t require mining or drilling that can damage habitats and landscapes. Biofuels like wood do release some air pollution when burned, but much less than coal or oil (DOE, 2019). Overall, renewable energy has a positive environmental impact by mitigating climate change and reducing harmful emissions and ecosystem disruptions.

UCSUSA, 2021: https://www.ucsusa.org/resources/environmental-impacts-renewable-energy-technologies

DOE, 2019: https://www.energy.gov/eere/environmental-impacts-clean-energy

Economic Considerations

The economics of renewable energy have become much more favorable in recent years compared to fossil fuels. According to a 2014 study from Boston University, the costs of renewable energy have declined substantially, making them economically competitive with traditional energy sources.

In terms of upfront capital costs, building new renewable energy capacity can be cheaper than building fossil fuel power plants. For example, constructing a wind farm or solar array requires less infrastructure and materials than a coal or natural gas power station. Operational costs are also lower since renewable sources like wind and sunlight have zero fuel costs.

Government subsidies and incentive programs have accelerated the adoption of renewables. Tax credits, cash rebates, and renewable portfolio standards mandating utilities to obtain a percentage of their power from green sources have all helped drive down costs. Further advances in renewable energy technologies and manufacturing are projected to lower costs even more in the future.

According to projections, renewable energy costs will continue falling while fossil fuel prices are expected to keep rising over the long-term as reserves deplete. The crossover point where green energy becomes unambiguously cheaper than conventional fuels on an unsubsidized basis may occur within 10-20 years. This dynamic creates a strong economic motivation to transition more of the world’s energy infrastructure to renewable sources.

Challenges and Limitations

While renewable energy sources offer many benefits, they also face some key challenges and limitations compared to traditional fossil fuels:

Intermittency is one major challenge, as renewables like solar and wind are weather-dependent and generate power inconsistently compared to the constant output of fossil fuels (source: https://regenpower.com/what-are-the-problems-faced-by-renewable-energy/). This requires storage solutions and backup power to ensure supply when renewable sources are unavailable.

Transmission can also be an issue, as the best renewable energy sites are often located far from major cities and demand centers. Significant investment is needed in transmission infrastructure to transport renewable power over long distances (source: https://sustainablereview.com/challenges-in-renewable-energy/).

Alternatives like biomass and waste energy face limitations in scale and consistent feedstock supply. There are also safety concerns for some technologies like nuclear power (source: https://www.iea.org/reports/renewable-energy-market-update/challenges-and-opportunities-beyond-2021).

Future Outlook

The future growth potential for renewable energy is significant, with most projections showing renewable energy continuing its rapid growth and adoption in the coming decades. According to the International Renewable Energy Agency (IRENA), renewables are on track to supply up to 30% of global power demand by 2030 and 50% by 2050 under an ambitious scenario [1]. Key drivers will include further cost reductions, enabling policies, accelerated growth in developing countries, and increased electrification of energy end-uses like transport and heating.

Renewable energy will play a major role in climate change mitigation efforts. The Intergovernmental Panel on Climate Change (IPCC) scenarios project that renewable energy must supply 70-85% of electricity by 2050 in order to limit global warming to 1.5°C [2]. This will require rapid decarbonization of the power sector and increased electrification of end-use sectors.

Key developments to watch include advancements in energy storage technology, expansion of electric vehicle infrastructure, innovations in offshore wind and solar, policy support mechanisms, grid integration solutions, and progress on new technologies like green hydrogen. While challenges remain, the transition to renewable energy continues to accelerate and will reshape energy systems in the coming decades.

Conclusion

Renewable energy and alternative energy refer to two broad groupings of energy sources, but there are some notable differences between them. Renewable energy comes from naturally replenished sources like sunlight, wind, rain, tides, plants, and geothermal heat. Alternative energy is a broader term that can include renewables but also refers to technologies like nuclear power, hydrogen fuel cells, and others.

While renewable energy currently makes up a small percentage of global energy production, continued adoption of renewables and alternatives is critically important for environmental sustainability and reducing carbon emissions. Renewable energy has far lower environmental impacts than conventional fossil fuels, and can help nations achieve energy independence and security. There are still challenges to the large-scale implementation of some renewables like solar and wind power, but costs are declining rapidly as technology improves.

In summary, renewable energy and alternative energy both serve important roles in transitioning the world away from fossil fuels, but have distinct definitions. Ongoing innovation and investment will be key to unlocking their full potential and building a clean energy future.