As we turn towards renewable energy, solar has consistently popped up as an option. Still, solar energy continues to have its critics who maintain that solar has too many problems to be used. In this article, we will touch on some current problems with solar energy.

Low Efficiency Means Lower Output and Higher Costs

One of the biggest problems with solar power is efficiency. The exact efficiency is dependent on the set up and what technology is used but can currently range from 14-35%.

For photovoltaic (PV) cells the highest available conversion rate is around 35%. This is possible only when using the best technology available and comes with a high initial cost – too high for the vast majority of users.

The efficiency that isn’t ridiculously expensive is 22%. This means that only 22% of the energy from the sun is converted into useable energy. Most current household solar panels only covert 14%.

Theoretically, solar set ups could get up to 55% for a system that doesn’t track the sun and even 85% for a concentrated solar system that uses mirrors and tracks the sun. The problem is that this is currently too expensive to be feasible.

At such high costs for even an efficiency of 35% percent, users have to pay a lot of money for not very much energy output. In order for solar to be a major contender, the cost for the higher efficiency needs to be lowered.

Solar is Dependent on Expensive Battery Storage

In some areas, like ones far from the equator, you only get a few hours a day of very weak sunlight. In this case, it just doesn’t make sense to use year-round solar. Other areas, like island nations, are closer to the equator, but deal with a lot of cloud cover.

Even for areas that get enough sunlight, solar energy needs to use batteries, since the sun doesn’t shine all the time. If it’s nighttime or cloudy, the user will depend on the stored energy to get through those periods of no sun.

These batteries are expensive. The current cost is between $8,500 to $10,000 and that doesn’t include the cost to install them. Bringing down this cost would make solar more of an option for households.

Could Solar Energy Make Global Climate Change Worse?

Some speculate that large solar farms could make our climate and environmental problems worse. Since only 14%-22% is converted into electricity, the rest of the solar energy gets released as heat.

This isn’t a huge issue for smaller installations. Some of the large installations – like this proposed one that covers the Sahara Desert – could have regional and even global impacts on the climate.

In fact, a study done in 2018 found that solar panels have a lower albedo than sand. Albedo is how well a surface reflects sunlight. Because solar panels are darker than sand, they absorb more of the heat.

The model developed by the researchers found that when just 20% of the Sahara is covered with solar panels, the local climate changes could be enough to turn the Sahara Desert into a lush oasis.

While a lush oasis might not seem that bad, these kinds of changes could have major consequences for the global temperature.

In a more recent study published in 2020, researchers looked closer at the interaction between a solar farm on the Sahara Desert and the climate. This study found that covering 50% of the desert with solar farms could raise local temperatures by 2.5 °C.

The model also found that this temperature shift likely wouldn’t stay local. Covering 50% percent of the Sahara Desert with solar farms could translate to a 0.39 °C increase in the global temperature. Under the 2015 Paris Agreement, nations have agreed to keep the global temperature increase to under 2 °C.

While solar power does have its problems, it also has its champions who strongly believe in its feasibility as a renewable power source. In a future article, we will go over current innovations that could make solar a better option.