Exploring the new frontier of renewables beyond solar and wind

TL;DR

• Solar and wind power have led the energy transition, offering a relatively cheap, quick to deploy and low carbon-intensive source of power.  

• However, they are not perfect solutions: both are subject to fluctuations in capacity, negatively impact the environment with their construction and operation, and limit the economic and carbon reduction potential of renewable energy.  

• Diversification can mitigate these issues, making the energy transition less vulnerable to sudden market shifts, diminishing reliance on specific technologies and resources, and curbing environmental vulnerabilities. 

• Complementary energy sources include hydropower, biofuels, geothermal and wave and tidal energy, which are all currently being successfully deployed worldwide.  

• To create a balanced renewables energy sector, these lower profile energy sources need investment, an improved infrastructure and co-ordinated knowledge sharing to succeed.   

The detail

As we continue to pursue the goal of net zero by 2050 via the global energy transition, much of the world’s focus has been on solar and wind power. There are many valid reasons why these two energy sources have attracted attention and investment: they are relatively cheap, quick to deploy and among the cleanest and least carbon-intensive power sources available. Adoption of these renewables is already having a profound impact on global emissions – in 2022, experts say that the world’s power sector emissions would have been 20% higher if all the electricity generated by wind and solar had come from fossil fuels instead. 

They are also prolific. The Intergovernmental Panel on Climate Change (IPCC) estimates that wind and solar alone can deliver more than a third of the emissions reductions needed to deliver the 1.5-degree pathway across all sectors by 2030. The latter is on course to account for two-thirds of the world’s annual increase in renewable power capacity. Indeed, it’s predicted that the world will have enough solar PV manufacturing capacity by 2030 to meet the level of demand required by net-zero.  

Cost is another important factor that favours solar and wind. From 1990 to 2020, the price of wind and solar power fell by 55% and 85% respectively, meaning that the cost of producing a unit of electricity from onshore wind or solar is generally below that of gas and coal in many countries. This affordability, and the speed at which solar and wind farms can be assembled, has led to rapid growth in this area, with large-scale projects in China, the US, India and Europe. 

However, solely relying on wind and solar comes with risks. Both are intermittent, have impacts during their construction and operation, and limit the potential economic benefits and carbon emission reductions of renewable energy by restricting the market to just two sources.  

Diversifying the market 

Diversification has myriad benefits and is in line with the International Energy Agency (IEA)’s ideal Net Zero Scenario, which is a balanced blend of solar, wind, hydro, geothermal, ocean and modern bioenergy technologies. With a diverse renewables market, the energy transition becomes less vulnerable to sudden market shifts, diminishes its reliance on specific technologies and resources and curbs environmental vulnerabilities. The economic impact of diversification is equally positive, with a potential global GDP increase of $1.3 trillion and the creation of 38.2 million jobs by 2030.  

The first step in broadening the renewables energy market could be to exploit emerging technologies that are helping to optimise existing solar and wind production. An alternative to solar PV, concentrated solar power is one opportunity to exploit low light conditions as it uses mirrors or lenses to focus sunlight onto a receiver, generating heat that drives a turbine to create electricity.  

Improvements in renewable energy storage are also yielding positive results with technologies such as lithium-ion batteries, flow batteries, hydrogen fuel cells and electrolysis diversifying that market. Finally, investing in smart grid technologies can bridge the gap between renewable energy and fossil fuels by integrating sustainable sources into existing power grids more effectively.  

Exploring alternative energy sources 

Looking beyond wind and solar, there are several alternative renewable energy sources worthy of consideration – these include hydropower, biofuels, geothermal and wave and tidal energy.  

Hydropower is one of the world’s oldest and largest sources of renewable energy and has been influential for many countries for over a century. It currently provides over 15% of the world’s electricity and works by using the natural flow of moving water to generate electricity. There’s no set size of stream or river required to take advantage of this kinetic energy, but an elevation difference is often needed, usually created by installing a dam or a diversion structure. While the construction of a dam does require an initial investment, hydropower is generally considered affordable and low cost during its lifetime in terms of maintenance, operation and fuel.  

Hydropower can also provide environmental benefits as it can mitigate droughts due to the water storage function of its reservoirs. Such is its impact, it is estimated that $130 billion in drought related losses are saved each year. Hydropower currently makes up around a third of the US renewable energy market, with states such as Washington generating 66% of its electricity from this resource. Even so, the world’s capacity for hydropower needs to double if net-zero is to be achieved by 2050, demanding a cumulative investment of $3.7 trillion.  

Building on the principles of hydropower, wave and tidal energy are generated from the movement of the seas and oceans. It is most effective when leveraging underwater turbines with short, strong blades, which turn a generator to create electricity. Promising potential has been seen in narrow passages of water such as the Severn estuary and the straits between mainland Scotland and the island of Stroma, which capture tides moving out to the Atlantic and the North Sea.  

Wave and tidal energy are renewable energy sources that could play a significant role in the UK’s energy transition. It’s estimated that the UK has approximately 50% of Europe’s tidal energy resource which could meet up to 20% of the UK’s current electricity through an installed capacity of 30 to 50 GW. The UK’s tidal range alone may be enough to supply up to 12% of the country’s electricity. It’s also a more predictable alternative to wind and has a higher production rate in the winter months when electricity demand is at its highest.  

Harnessing heat and fuels from sustainable sources 

A similarly low-cost and year-round alternative to solar and wind power is geothermal energy. This is energy stored in the form of heat beneath the surface of the earth, meaning it’s not dependent on weather conditions and is a reliable and constant source of low-carbon heat. Its low spatial footprint and scalability also make it a good choice for heating both individual homes and larger areas.  

When it comes to cost, the levelized cost of electricity (LCOE) from geothermal power projects averaged between $0.049 and $0.085 per kWh from 2010 to 2022. Geothermal power has already been adopted in many countries around the world – for instance, it currently meets 90% of heating demand in Iceland and owns a significant share of the electricity market in El Salvador, New Zealand, Kenya and the Philippines.  

Biofuels are liquid or gaseous transport fuels, such as biodiesel and bioethanol, made from biomass. There is huge global demand for oil, which biofuels can help satisfy; 77 million barrels are pumped worldwide each day and the US alone uses 19 million barrels daily. Derived from biological materials, biofuels can bolster energy security, improve environmental conditions and provide additional income for the agricultural sector. When it comes to emissions, sulphur oxides are practically eliminated, while carbon is reduced by 10% compared to standard fuels. Furthermore, 98% of biodiesel degrades in less than three weeks.  

Despite this, growth in the biofuel industry is being hampered by high prices and land use concerns. Global demand is set to grow by 28% or 41 billion litres between 2021 and 2026, in part thanks to favourable legislation in the US and Europe. However, there are concerns that biofuel’s use of cropland may lead to the extension of agricultural land into more fragile ecosystems such as forests and wetlands.  

Inspiring strategic investment  

These alternative renewable energy sources prove there are several options beyond solar and wind worthy of exploration. However, there are steps that need to be taken to ensure these opportunities are realised and the process of energy transition is diverse, robust and reliable.  

Knowledge sharing, government strategy and investment are arguably the three most influential factors. It is essential that a globally co-ordinated approach is taken to expand and diversify global manufacturing to improve the supply of renewable energy components and raw materials. This development in infrastructure must also coincide with incentives to promote and accelerate renewable energy projects and inspire private sector investment. However, these practical measures need to be considered alongside investment in winning hearts and minds. By eliminating roadblocks to knowledge sharing and investing in people’s skill training, research and innovation, the renewable energy sector can grow exponentially.  

Raw finance is also crucial. The United Nations advises energy subsidies are moved away from fossil fuels to renewables – this is because an investment of at least $4 trillion a year until 2030 is required if the world is to achieve net zero by 2050. The payoff isn’t just a more sustainable energy system that reduces environmental harm and preserves the planet for future generations. Indeed, by reducing pollution and the impact of climate change, the world could also save up to $4.2 trillion a year by 2030.  

Diversifying the renewable energy mix and inspiring optimism in industries beyond solar and wind will not be an easy task, but it is an essential one. As the UN Secretary-General put it, “renewables are the only path to real energy security, stable power prices, and sustainable employment opportunities.”  

— Lew 👋

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The Transition’s work is provided for informational purposes only and should not be construed as advice in any capacity. Always do your own research.