Beyond Wind and Solar: Unveiling the Next Frontier in Clean Tech Investment

What lies beyond wind and solar for renewable energy? Decarbonizing the world urgently requires going further. My brother-in-law, an idealistic climate PhD, left his faculty job last year disillusioned by the lack of political action despite technological potential.

Our family witnessed his spirit crushed firsthand seeing environmental harm outpacing response. He felt propagating more solar panels and wind turbines wasn’t enough progress to deliver needed emission cuts.

I promised him passionate voices like his must ignite society to demand bolder societal change. After much reflection and research into promising renewable alternatives, this article unveils innovations like floating offshore wind, geothermal, tidal power and biofuels essential to actualize cleaner energy systems at the pace and scale climate science compels.

Transformative change remains possible, but only by exploring beyond wind and solar to diversify our renewable solutions portfolio even further.

Overview: Beyond Wind and Solar

Renewable energy has come a long way in recent decades. Thanks to massive growth in wind and solar power, clean sources now generate over 26% of electricity globally, according to the International Energy Agency (IEA).

But as climate targets get more ambitious, many experts argue that renewables need to expand beyond just wind and solar.

What other technologies show promise? And why look beyond the renewable darlings of wind and PV panels in the first place? This article tackles those questions while unveiling promising clean tech options on the horizon.

Why Wind and Solar Aren’t Enough

First, let’s review the incredible expansion of wind and solar power. These two renewable electricity sources have seen average annual growth exceeding 20% over the past decade. What’s enabled such impressive growth?

• Plunging costs – thanks to economies of scale and technology improvements, levelized costs for utility-scale solar fell 88% between 2009 and 2020, while wind dropped 60%.
• Supportive policies – like renewable portfolio standards requiring utilities to source a % of power from renewables. Plus tax credits.
• Corporate procurement – over 300 companies have pledged to power global operations with 100% renewable energy through the RE100 initiative.

But despite the gains, wind and solar are not silver bullets. Here are some constraints:

Intermittency Challenges

• The sun isn’t always shining and wind can be inconsistent. That makes integrating high levels of wind/solar more complex for grid management.
• Solutions like combining wind/solar with battery storage or transmission lines for moving power help, but add costs.

Land Usage Constraints

• Both wind/solar farms require lots of land. For solar that can mean clearing trees/vegetation.
• Suitable areas are limited based on factors like regional sunlight/wind levels and proximity to transmission infrastructure.

Future Energy Demand Growth

• Even if wind/solar expand at past-decade rates, projections suggest they may meet only 30-40% of global electricity demand in 2050.
• With electric vehicles and electric heating poised to grow, overall energy needs will balloon – meaning more solutions are essential.

For those reasons, diversifying beyond wind turbines and solar photovoltaic (PV) panels is key. What are some emerging options? Read on!

Geothermal – A Continuous Renewable Baseline

Volcanic Iceland generates over 25% of its electricity from geothermal energy – far more than any other nation. But enhanced geothermal system (EGS) technology can expand this continuous renewable resource globally. Here’s how it works:

• Wells are drilled miles deep to access hot, dry underground rock.
• Water is pumped down, heated up, and returns to the surface as steam to turn turbine generators.
• EGS uses hydraulic fracturing to boost subsurface heat exchange.

The United States has over 16,000 MW of geothermal technical potential, mostly in the West. With ample natural reservoirs and innovations like EGS, the International Renewable Energy Agency (IRENA) estimates global geothermal power capacity could grow 14-fold by 2050.

Key pros?

• Produces reliable baseload electricity 24/7, regardless of weather changes.
• Small land footprint; can be sited where transmission already exists.
• 96-97% lower lifecycle greenhouse gas (GHG) emissions than coal power.

Yes, upfront costs are high and some locations lack adequate subsurface heat. But with supportive policies and R&D funding, geothermal remains an intriguing option vs. solely wind/solar as countries like the U.S., Indonesia, Kenya and Philippines target increased clean electricity.

Harnessing the Power of Waves and Tides

Another way to diversify renewables? Look to the motions of the ocean – tides and waves.

Tidal power harnesses predictable coastal tidal flows via submerged turbines or tidal barrage dams/gates. Wave power devices capture mechanical energy from ocean surface motion using floating or sea floor-based equipment.

Let’s compare pros and cons:

Generation Type	Pros	Cons
Tidal Stream	– More predictable than waves – Mature turbine techs	– Limited suitable sites – Eco impacts
Wave Power	– More resource abundance – Lower visual impact	– Complex, costly designs – Intermittent

Globally over 500 MW of tidal stream and a couple dozen MW of wave energy are installed so far, with Britain and France leading tidal and Portugal driving wave.

But global wave/tidal electricity potential is forecast to be over 400 TWh annually – greater than all Africa’s power output today.

Yes, surviving harsh ocean conditions has caused setbacks like Scotland’s canceled 400 MW Swansea Tidal Lagoon. But new materials and devices, plus policy support like feed-in tariffs, can assist commercialization.

If challenges get solved, oceans could deliver a sizeable chunk of future renewable electricity.

Floating Turbines Unlock New Offshore Wind Potential

While turbines spinning away on dry land are now commonplace, offshore wind farms are a newer innovation. But their wind yield potential is immense. Winds tend to blow stronger and more uniformly at sea.

The snag? Installing foundations and towers in deep coastal waters over 60 meters deep gets exorbitantly expensive.

Enter floating wind turbines. Rather than fixing towers directly into the seafloor, these let the whole platform float while tethered to anchors. Global floating wind development jumped from under 50 MW in 2020 to almost 500 MW by late 2022. Pilot projects are scattered from Norway to Portugal to South Korea.

And more gigantic projects are queued up. For example:

• The proposed California Redwood Coast offshore wind farm aims to have up to 1,500 MW of floating capacity online by 2030.
• South Korea granted approval for an eye-popping 8.2 GW offshore wind complex – including both fixed and floating turbines – off the coast of Ulsan.
• Oil major Equinor is developing a mega 3.6 GW Korean floating wind farm to help power offshore oil platforms, leveraging existing infrastructure.

Floating designs still require validation, but analysts ID this as a top emerging renewable trend that taps more consistent offshore gusts.

Concentrated Solar Power: Solar on Demand 24/7

Most folks think “solar panel” when they hear solar power. But concentrated solar thermal plants take a different approach – one that could fill gaps left by PV panels.

Rather than converting sunlight directly to electricity, concentrated solar thermal uses swiveling mirrors to concentrate intense heat energy. Molten salt storage tanks retain that thermal juice. The stored heat creates steam on demand to drive turbines, including at night!

That gives this solar thermal tech two huge perks:

1. Storage capability – Unlike PV needing separate battery systems to stash power, concentrated solar thermal is inherently designed for storage.
2. 24/7 renewable power – By tapping storage whenever needed, concentrated solar can provide reliable, predictable electricity around the clock – rain or shine!

Another plus? Siting flexibility in sun-drenched deserts since less water is needed for cooling than fossil plants.

However, scale remains small – just 7 GW installed globally in 2022 out of 3,000+ GW of total solar capacity. Upfront build costs also exceed photovoltaics. Still, panels can’t run at night, meaning solar thermal fills a unique niche.

As nations like China, South Africa, Morocco, and Chile expand projects backed by incentives like renewable portfolio standards and feed-in tariffs, concentrated solar’s future is bright.

Bioenergy: Leveraging Waste to Create Renewable Fuels

When you think “renewables,” wind turbines or hydro dams may spring to mind before bioenergy. But organic matter already produces 10% of global energy – often from wood burning.

Can modern bioenergy uses supplement wind/solar while curbing emissions? Potential sources range from:

• Agricultural residues like corn stalks
• Forestry byproducts like sawdust
• Organic waste from landfills or industrial processes

The IPCC flags bioenergy crops combined with carbon capture (BECCS) as perhaps our best shot at negative emissions. Some lifecycle analyses also show waste-based biofuels like renewable natural gas (RNG) reducing GHG impacts by up to 125% relative to natural gas!

And uses for biogas or liquids range from grid power generation to clean transport fuel to industrial process heating. Leading states producing bioenergy include California, Washington, and Minnesota.

Sure, concerns like land usage, soil health impacts from intensive agriculture, and upfront facility costs pose barriers. Still, bioenergy constitutes a sizeable wedge of our current energy budget while keeping waste out of landfills.

With supportive incentives and deployment of best practices, sustainable bioenergy could grow its footprint and integrate well with rising wind/solar contributions.

Game-Changing Storage: From Batteries to Gravity

My earlier sections touched on storage challenges with variable renewable sources like wind/solar. While geothermal and concentrated solar thermal boast built-in storage, adding big batteries or advanced technologies can also help manage intermittency.

Lithium-Ion Dominance…For Now

Currently, lithium-ion batteries lead the storage race. Prices have plummeted by 85% over the past decade, supporting small-scale rooftop solar+storage systems and massive utility-scale projects alike. Australia’s Victorian Big Battery claims the world’s largest lithium-ion storage system crown today – though bigger ones are coming.

However, lithium-ion batteries typically offer just 2-4 hours of storage. Alternatives able to retain huge amounts of energy for longer durations can better smooth multi-day wind and solar fluctuations.

Pumped Storage: Using Gravity for Renewable Energy Storage

One such solution? Pumped hydroelectric storage (PHS). Here’s how it works:

1. Excess electricity from the grid powers pumps to haul water uphill into an upper reservoir
2. When extra energy is needed, that water gets released downhill through turbines to regenerate electricity

The U.S. and China harbor most of the world’s pumped storage capacity currently. However, suitable terrain limits site choices.

Compressed Air Storage

Rather than water, compressed air energy storage (CAES) leverages air pressure differentials over massive underground storage caverns to act like a giant spring. Off-peak wind energy gets used to compress air injected into the cavern. When electricity demand rebounds, high-pressure air escapes through special turbo generators.

While only a few CAES plants operate globally today, analysts ID air storage in porous rock or lined caverns as an intriguing grid balancing option.

Electrify Everything – Then Store It!

Beyond direct storage techs, digitally managing flexible distributed loads also buffers variability. For example, electric vehicle (EV) batteries plugged into vehicle-to-grid (V2G) systems can absorb midday solar surplus and feed power back overnight.

Likewise, automated intelligent charging of battery-powered e-buses, e-bikes, home appliances and more via smart controls balances supply and demand.

So between expanding storage systems and harnessing electric loads for flexibility, solutions exist to ease renewable intermittency concerns.

Policy Pull Needed to Actualize Alternatives

While all sections above profile exciting renewable alternatives, most remain early stage or constitute minor shares of electricity production currently.

Achieving exponential growth akin to wind/solar may require similar policy pull. Governments play a powerful role incentivizing energy transitions through mechanisms like:

• Renewable portfolio standards – Requiring utilities to source set %s of power from renewables
• Feed-in tariffs – Long-term guaranteed above-market rates for renewable electricity fed into grids
• Capital subsidies – Upfront grants and tax credits easing project development burdens
• Carbon pricing – Making CO2 emissions more expensive tilts scales towards clean competitors
• Public R&D funding – Like ARPA-E grants for pre-commercial energy technologies

Already, increased policy support through initiatives like the Inflation Reduction Act expanding U.S. tax credits for technologies like green hydrogen is catalyzing new investments.

But more sustained, ambitious commitments will likely be essential to diversify our energy economy beyond the wind/solar duopoly. Even oil supermajor Shell concedes we need to quintuple clean electricity sources by 2050 in pursuit of climate goals.

FAQs

What Are The 5 Sources Of Energy?

The five primary sources of energy that modern human civilization relies upon are:

1. Fossil fuels: Oil, coal, and natural gas that were formed from ancient organic matter over long geological timescales. Fossil fuels currently still make up about 84% of world energy use according to the International Energy Agency.
2. Nuclear energy: Energy released from nuclear reactions, primarily nuclear fission of radioactive elements like uranium or plutonium. Nuclear provides around 10% of global electricity, according to the IEA.
3. Hydroelectricity: Electricity generated from flowing water – usually stored behind dams and released through turbines. Hydropower generates 16% of world electricity supply.
4. Wind energy: Harnessing kinetic energy from air currents, mainly via rows of large three-bladed wind turbines that turn generators. Global wind power capacity exceeded 740 gigawatts (GW) by 2019.
5. Solar energy: Collecting radiation energy from the Sun and converting it to electricity in photovoltaic solar cells made of semiconducting materials. Solar is the world’s fastest growing energy source.

Can You Have Solar And Wind?

Yes, solar and wind power complement each other quite well! Installing the two technologies together provides greater electricity reliability than either one alone would offer. The reason being that solar energy peaks at midday and is weather-dependent, while wind patterns shift across seasons and times of day.

So combining solar photovoltaic (PV) arrays with adjacent rows of wind turbines creates a hybrid system where one can potentially pick up slack for the other. This helps continuity of renewable power supply in instances like low wind periods or cloudy days. Research across U.S. states found using both does lower the risk of brownouts. Hybrid solar PV plus wind could be connected via smart inverters to national grids or local microgrids. Ghana, China and several parts of India and Bangladesh have already piloted integrated solar-wind facilities.

Is Solar Power Better Than Wind?

Both renewable sources have unique advantages and downsides. In comparing solar vs. wind, neither definitively beat the other across the board. However, on average current utility-scale solar pricing is somewhat lower at around $30-60 per MW-h vs $40-70+ for wind. But wind maintains an edge in capacity factor – averaging 35-45% worldwide over a typical year, compared to 15-25% from big PV solar plants. And solar’s output fluctuates far more predictably with daylight cycles, while wind speeds fluctuate more erratically minute-by-minute. For regions with the land and weather to harness both, combining solar and wind together often proves optimal to balance their individual strengths and weaknesses.

How Do You Combine Solar And Wind Energy?

Joint solar-wind hybrid power facilities intertwine rows of wind turbines amidst expansive fields populated with solar photovoltaic (PV) panel arrays tilted to follow the sun. This leverages overlapping vacant spacing while allowing each technology to capture its distinct energy flows from the sky (solar radiation) and air (wind gusts) independently. The separate DC electricity outputs get aggregated and connected to a joint inverter station for converting to usable AC. Control software continually optimizes the ratio of wind to solar components dispatched based on weather and demand.

India pioneered this model with a 13 MW hybrid park in 2018 combining ground solar with 32 V-shaped wind turbines. China boasts the largest in Zhangjiakou at 200 MW! These “solar-wind parks” generally distribute power locally or link to regional grid connections depending on scale.

What Is The Combination Of Solar And Wind Energy?

The integration of solar and wind energy leverages how solar panels harness the radiant heat and light from the sun while wind turbines channel the kinetic energy of moving air. Combining these two intermittent but complementary renewable sources together, connected to grid infrastructure like giant interconnected batteries, allows for stabler continuous electrical output not reliant on either wind OR sun alone.

Research suggests pairing large-scale solar + wind plants could supply reliable off-grid power at lower prices than centralized fossil fuel plants for local communities throughout Africa and Asia. Pilot microgrid trials are ongoing. The variability remains an issue for very large systems. But pooling outputs seems a promising tactic where both wind and solar resources exist.

How Long Do Solar Panels Last?

The typical lifespan of quality solar panels falls anywhere between 20-30 years these days thanks to technology improvements. Most manufacturers provide 25-year power performance warranties guaranteeing at least 80% of the original maximum electrical output at the end of that period. While a few issues like thermal cycling fatigue and corrosion can degrade longevity over decades of operation, periodic cleaning and maintenance help minimize wear over time. Newer solar cells boast better encapsulation protecting cells from water/oxygen and utilize robust silicon or thin flexible materials. These enhance durability against vibrations as well as weather extremes like hail or snow loads. Assuming proper installation inappropriate climate conditions, homeowners today can reasonably expect well-made photovoltaic systems to maintain strong functionality for 25-30 years with appropriate upkeep.

What Is The Biggest Disadvantage Of Solar And Wind Power?

The most persistent downsides of solar and wind pertain to intermittency and reliability issues balancing electrical loads. Firstly, solar panels only generate energy when sufficient daylight exists. Output diminishes on cloudier days and obviously disappears at night. Meanwhile wind speeds vary unpredictably hour by hour, producing inconsistent electrical flows. These reliability issues create challenges matching inflexible generation with fickle demand cycles. Subsequently, backup generation or costly large-scale grid storage systems become essential for managing variability at high renewable penetrations. However smart microgrids with local storage/generation assets and robust transmission interconnections can help mitigate these problems.

Unfortunately no silver bullet resolves intermittency yet besides diversifying complementary green sources like geothermal and hydropower for round-the-clock climate-friendly electricity. But technological progress expanding distributed storage options offers promising paths ahead.

What’s Better Than Solar Panels?

Arguably the most effective carbon-free energy solutions moving forward are using solar power together with wind, geothermal, and hydroelectric generation assets plus storage systems like pumped hydro and batteries. By combining multiple complementary technologies, renewable electricity reliability improves through aggregated load diversity while also avoiding land usage and storage discharge duration limitations inherent in any single approach. This “all of the above” strategy harnessing several intermittent sources appears more viable and affordable long term compared to say relying predominantly on solar panels or wind turbines alone at massive scales. We require a diversified, smart renewable grid with many contributors.

Conclusion: An “All of the Above” Clean Energy Future

With climate change accelerating, renewable energy from more diverse sources is urgently needed alongside efforts like energy efficiency and conservation.

While vital expansions of wind power and solar PV should absolutely continue, adding alternatives like geothermal, tidal, floating offshore wind, solar thermal and bioenergy into the mix fosters reliability and flexibility.

Meanwhile, unlocked storage potential from improved batteries to pumped hydropower storage better aligns clean supply and demand hourly.

A recent joint report by the The Intergovernmental Panel on Climate Change (IPCC) and the International Renewable Energy Agency (IRENA) synthesizes reams of research affirming renewables can deliver 90% of needed electricity sector decarbonization this decade if we rapidly scale deployment of available technologies while ramping vital power systems integration solutions.

But realizing such a transition rests upon political will and policies like incentivizing emerging technologies until they mature and market dynamics shift farther in renewables’ favor.

So rather than a single silver bullet like fusion power, combining existing commercial renewables with targeted scaling of new options and storage looks more feasible. While challenges exist, the technical potential is proven.

Unlocking this cleaner mix ultimately requires public and private capital flowing more aggressively into renewables development, infrastructure modernization and complementary solutions. That’s why clean energy received record investment exceeding $1 trillion last year.

Yet still more policy leadership and investment is essential to actualize a resilient, diversified renewable energy system able to sustainably satisfy surging NET demand in a decarbonized global economy.

The promising technologies and solutions highlighted above demonstrate pathways exist to thrive beyond reliance solely on wind and solar generation.

Now bold execution and sustained commitment are vital to convert that potential into widespread reality while empowering cleaner electrification of buildings, mobility and industry. The political will and capital appear to be accelerating. The next frontier in renewables awaits.