What Are the Limitations of Solar Energy?

Solar is quickly becoming a panacea to some of our greatest problems, but what are solar energy limitations?

The climate crisis is no longer a debate but an agreed problem that must be solved.

Fossil Fuels are a large part of the climate problem and are depleting quickly, meaning they are no longer a viable energy solution. 

A new solution is needed and solar leads the charge (no apologies for the pun).

While solar has many benefits, it does have drawbacks. 

Today we will explore solar energy limitations.

The world is being forced to move away from traditional fuel sources.

Not only have they been shown to be bad for the environment but they are quickly running out. 

While man has been slow to change due to environmental pressure, the lack of traditional resources will soon force migration to alternative solutions.

Fossil fuels have provided energy and other benefits to mankind for thousands of years.

These fuels date back as far as the ancient Babylonians and Egyptians who used oil for an abundance of reasons.

Indeed, the Egyptians are now known to have used oil to keep the pyramids held together.

However, the era of fossil fuels is coming to an end and it can no longer hold together the needs of modern life.

These finite resources are diminishing, with some estimates suggesting that oil and gas will be exhausted in 50 years and coal in 150 years.

A new solution must come to the fore.

While many renewable and non-renewable options have been tipped to succeed (nuclear, solar, wind, wave, etc.), solar continues to lead the pack as the solution favored to become the new number one.

Today solar contributes just over 7% of total electricity generation but will grow to 50% by 2050. 

While there are many reasons to choose solar, we must better understand the energy resource in detail as well as its limitations before committing. 

The future relies on society making the right decisions now and while solar can be a fantastic resource, we need to understand any issues with it to better inform what next steps to make.

Taming the Weather

A key issue with solar power is the unpredictable nature of weather.

Solar relies on harnessing the power of the sun.

At night and during poor weather conditions, it becomes impossible to harness energy from the sun, limiting the window of opportunity of creating energy and making this window somewhat unpredictable.

Solar power relies on direct sunlight. 

Most places (in the US) have on average seven hours of sunlight a day, but only have between three to five direct hours of sunlight, varying due to time of the year, location and other factors.

If we only have three to five hours of direct sunlight a day to generate energy our window of time is small. 

A cloudy afternoon from twelve o’clock to three o’clock could ruin the generating capacity of that day.

This combined with factors such as tree coverage and geographical location all present a small window and a small coverage area for solar generation.

All in all, it means that not everywhere is suited to solar generation and certainly not all the time.

While California may be well suited, Boston is far less. 

Does that matter? 

If California can have direct sunlight for five hours a day and Boston can have direct sunlight for one hour a day, aren’t they both better off?

Lowering their energy bill and saving the world?

Not necessarily!

This brings us to the second important limitation; cost.

Paying For The Sun

Solar installations are an expensive investment.

While some would argue that utilizing just one-hour of direct sunlight a day for energy helps to move away from using fossil fuels, there are costs involved.

However, it is not possible to expect people and businesses to invest in large solar investments for a low pay off. 

One estimate suggests it would cost the US $4.5 trillion to make the United States 100% renewable energy-based (and therefore even higher to be 100% solar renewable). 

The key cost arises from the storage and transportation of solar power and an inherent contradiction of solar energy. 

The issue or contradiction of solar energy is that it generates power when there is sunlight but it is at this time that we need the least power.

Most electricity is needed in the evening and night to provide heat and lighting in homes.

Therefore there is a clear gap between when energy is being created and used. 

This is why solar requires a large scale investment in storage facilities to house energy created for long periods (not only night and day but particularly over lengthy cold periods).

Although US$4.5 trillion is a lot of money (approximately 25% of US annual GDP) there are already large subsidies provided to fossil fuels today, with fossil fuels globally receiving over $US5 trillion in subsidies each year.

While solar is still expensive there are evidently some funds available to offset the cost of solar from savings made by abandoning fossil fuels for large businesses and governments.

What about the average home?

Solar is still an expensive investment for the average homeowner but it has decreased a significant amount in recent years.

In 2022 the average cost of a national solar panel in the US is US$2.99/watt, with the average system around 6 kilowatts.

This means the average system costs roughly US$13,000 after tax credits.

The good news is that the cost is declining rapidly. 

A decade ago a similar 6-kilowatt system would have cost over US$50,000.

As solar demand grows it will continue to fall in price but the environment doesn’t have time to wait.

Governments must accelerate their investment in solar energy to increase technology development and lower the associated price for the average homeowner. 

Otherwise, we will have this conversation for 50 more years until the last drop of oil and gas finally disappears.

Efficiency Is The Key

Solar is expensive.

Due to the technology and raw materials involved the base cost is high and is a key obstacle.

Another issue related to this cost is efficiency of solar panels.

Today solar panels are inefficient.

If a panel receives only three hours of direct sunlight a day then it is best if it can maximize this time and create as much energy as possible.

Unfortunately, a lot of direct sunlight is not utilized.

The efficiency of the average panel is about 20%, with some systems recording higher % figures (although at a higher cost) and some recording lower % scores (at lower cost). 

Energysage has ranked numerous solar providers based on its efficiency with the highest topping out at 22.8% in 2022.

This is a leading example and still, almost 80% is lost with the rest of the sunlight that strikes the panel being wasted as heat. 

This means that we are not utilizing the sun to its full potential and is a key limitation of the technology.

Dust particles that rest on the panel greatly reduce the % of sunlight utilized meaning that if your panel begins at 20% efficiency it will soon drop after the dust settles.

This dust means that maintenance costs are an ongoing pain as we must ensure solar panels remain clean to absorb as much sunlight as possible.

Work is being done to improve the efficiency of solar panels but this is driving costs higher.

A Mountain To Climb

As already mentioned, geographical location has a direct impact on how much sun exposure there is and therefore how much direct sunlight can be relied on to provide solar energy to a home or business. 

The geographical problem goes further still.

When we picture the ideal solar solution it is a wide-open space with large solar panels in a field or even a detached home in an open area with solar panels on the roof. 

It is not always possible to build these systems.

The world is increasingly urban.

Today some estimates suggest that the world is now 50% urban and increasing at a steady rate. 

For those living in apartment buildings or the shadow of apartment buildings, solar does not offer a clear solution.

It would be difficult to place solar on the side of your home (assuming it is sun-facing) to receive any meaningful benefit. 

Even if panels were placed on top of an apartment building, by the time the resource was divided amongst all the dwellers the benefit would be minuscule. 

Solar is a solution for low density urban and rural areas where residents have space to install a solution. 

Unfortunately, modern living is moving further away from the idea of everyone having their own home, front garden, and individual space. 

The world is increasingly overpopulated and while we are slowly coming to terms with what that means for modern living, with more and more people living in apartments, we must understand how it impacts our energy generating abilities.

Solutions are possible.

Those in lower-density areas may be able to offset the demands of those in higher density areas.

If a farmer can produce 200% of his energy needs he could potentially sell some back to the energy company and make a profit in providing energy for other people.

This type of solution has already shown dividends in a number of places.

These types of entrepreneurial activities will incentivize people to invest in solutions that can not only benefit them but benefit those not in a position to create energy themselves.

While those living in apartments may only be able to generate a small amount of solar power, this combined with the additional generation of others could offset their usage.

Work must be down for those in apartments to successfully lobby other dwellers in their building for solar panels on apartment roofs.

If one resident wants solar panels on the roof, legislation must be put in place to lower the barriers of achieving such a feat without them taking all of the cost.

Already in other markets, such as fiber broadband rollouts, a lot of work has been done to minimize the obstacles of apartment living in installing a solution that benefits the whole building.

Keeping it Clean

Why is solar tipped to become the leading energy solution before 2050?

Why is investment increasing in this technology?

Why is there so much hype?

The answer to all three questions is simple.

It is because it is perceived to be an environmentally friendly renewable solution utilizing a resource that is in abundance, the sun.

We have already addressed the sun aspect of this belief but what about the environmentally friendly part?

How good for the environment is solar really? 

According to KubyEnergy, when solar solutions are installed they produce emission-free energy for more than 30 years however the manufacturing process is far less positive.

Installation and manufacturing have a negative environmental impact.

The energy it takes to manufacture solar panels is greater than any other form of energy to produce as it requires raw materials to transform into photovoltaics.

In essence, there is far more precision required with the transformation of raw materials for solar compared to something like coal.

Quartz is just one material used that must be mined, processed, cleaned, heated and combined with multiple other materials to produce panels.

Nitrogen trifluoride is used to manufacture solar cells and is a greenhouse gas 17,000 times more potent than carbon dioxide

The energy required upfront is high and there are dangerous chemicals at play.

However,  KubyEnergy estimates that the payoff period is short, only 2 – 4 years before the solar panel has overcome these front-loaded problems. 

So while there are some manufacturing environmental issues, we should not be dissuaded as in time the net result remains positive.

Ready To Recycle?

A tougher issue that is only coming to the fore now, is that of recycling.

While solar panels have a long lifespan the materials used to create them include hazardous chemicals and other materials that should not be left in a landfill.

Today, in many cases that is what is happening.

Lu Fang, of the China Renewable Energy Society, highlighted the issue in 2017.

By 2050, China alone will have created retired solar panels of up to 20 million tonnes. 

That equates to almost 900 Statue ́s of Liberty (the heaviest monument in the world by the way – sorry old girl) and highlights the sheer scale of this issue.

The issue is that solar panels are not easy to recycle.

They contain lead, copper, aluminum and crystallized silicon. 

These can not be simply left in a landfill.

While some companies are creating sophisticated methods to recycle these panels, at present the money and effort required to offset the materials are higher than the amount recouped so it is not taking place to a large degree.

When solar panels reach a higher number the cost to properly recycle may come down due to economies of scale.

Until then it poses a significant problem.

While it has already been pointed out that a large issue for solar panels is the cost, it appears the only solution to the recycling problem today is to include some of the recycling cost in the initial purchase for consumers.

While this will increase the price and as a result, lower demand, it will at least offset the huge environmental burden facing solar panels at their end of life.

Time Is Running Out

While the limitations of solar have been laid out, the largest obstacle facing solar is time, or a lack thereof.

All of the problems listed have potential solutions but they must be worked on quickly to solve the energy and environmental crisis that is taking place.

Today, nuclear plants are actively being shut down and coal plants are being phased out. 

Many now think there will be an electricity shortfall in the near future unless solar can solve its problems and quickly. 

One estimate suggests that photovoltaic systems must be significantly expanded from 2021 onwards and have sufficient storage capacity to address the energy shortage that is on the horizon.

Final Thoughts

I started this post noting that many claim solar energy can be the panacea of all environmental and energy problems.

Solar does have a huge amount of benefits that have been discussed previously. 

While solar is in a fantastic position to solve many of the energy and environmental problems a lot of work is required.

Solar is far from a perfect solution.

Those who are incentivized to lobby against solar have plenty of ammunition giving the limitations it faces, meaning that politically it could still face some challenges.

While none of the limitations are without solutions, the issue is that the myriad of problems creates an uncertain future for solar energy.

Uncertainty is bad for businesses as companies will refrain from investing large amounts in the technology. 

Uncertainty is bad for the consumer as they will be anxious about investing large amounts in their homes if it is not guaranteed to work.

Uncertainty is bad for the environment because solutions are required now and the world can not afford to wait.

This uncertainty must be resolved.

While little can be done about the weather, other factors can be addressed.

The cost factor requires support from both private and public organizations.

As fossil fuels are in decline and phasing-out plans are already in place, finding a renewable source of energy to fill the divide is now a leading problem for many governments.

Government funding, subsidies, and other incentives must be introduced to support the development of renewable energy solutions and solar must take a key role.

The materials used to create solar panels are one of the key issues so work must be done to increase the economies of scale associated with these technologies or look at alternative technology solutions that can bring down the cost.

The uncertainty of recycling has faced many new industries in the past, as a sort of chicken and egg problem. 

There is unlikely to be suitable recycling plants in place for these materials when solar is only beginning to grow as a solution but the time is now for these recycling plants to come to the fore as demand is increasing. 

Private companies have a role to play and must find a way to recycle these parts in a profitable manner.

Geographical issues will always be prevalent as some areas are not suited to solar solutions while others require support.

Urban landscapes, for example, will be difficult to cover in solar panels but most apartment buildings have roofs that go unused and so there is still prime real estate available for solar solutions.

Policies must be introduced to remove bureaucratic issues such as rights of way and access as buildings must be covered in solar on a large scale.

While there are environmental issues with solar these are largely net positive for the environment so solar must still be pursued while trying to lower any environmental costs and concerns.

The low efficiency of solar panels must be addressed.

This largely comes from the inability of solar panels to move to capture direct rays of sunlight.

The ongoing innovation in artificial intelligence and small site communication means that there will be cognitive technologies available in a short amount of time that allow these panels to move to capture sunlight at a low cost, making them more efficient.

The most important obstacle that must be overcome is time.

Those in government and private industry must stop discussing what is needed and must start doing what is required.

Otherwise, we risk leaving it too late to act, resulting in electricity shortfalls or worse, environmental disaster.

If you have read this blog, then you are an interested party, I ask you to continue to show an interest in solar energy as despite its limitations it has the potential to deliver meaningful benefits.