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Aleksander
Jess
Energy
21.06.2024 | 7 min

Answering Your Questions About Solar Energy

Solar energy, together with wind energy are two of the most rapidly growing ways to generate renewable electricity. Solar panels, together with wind turbines are popping up across landscapes of multiple countries (for example Sweden’s solar energy participation in the energy mix is much higher than Norway’s). I am sure your head might be full of questions about these two renewable energy sources. We are here to answer some of the most common questions you could have had, starting with how solar energy is harnessed.

Answering Your Questions About Solar Energy - 2024 56
Table of Contents
  • How Do We Get Electricity From the Sun?
  • How Panel Placement & Solar Power Plant Placement Affects Energy Production?
  • How Does An Inverter Convert AC to DC?
  • What’s the “Energy Payback Time”, and What Are the Limitations of the Metric for Solar Panels?
  • How Is Solar Energy Integrated Into Smart Grids for a More Efficient Electricity Network?
  • What Are the Challenges and Opportunities for Recycling Solar Panels at the End of Their Lifespan?
  • Summary

How Do We Get Electricity From the Sun?

Do you remember your physics classes? Don’t worry, we won’t go too in-depth. What you need to recall is that light is both a wave and a particle. Now think of each wave of light as an endless stream of little particles called photons. To simplify everything, they come “raining” on our panels, and we convert them into electricity. How exactly do these small particles get transformed into the electricity that powers your home? Buckle up, because it's about to get exciting (and surprisingly simple)!

The Solar Cell

A solar panel is made up of many smaller units called solar cells. Each cell is like a mini-power plant, and here's what happens inside:

  1. The key part is a thin layer of silicon, a material found in sand. When sunlight hits the silicon, it knocks loose tiny particles called electrons.
  2. Think of these electrons as cars on a highway. Normally, they wouldn't move freely, but the solar cell is cleverly designed with a special electric field. This field pushes the loose electrons in one direction, creating a flow of electricity. The same as moving cars create a current.
  3. Thin metal fingers collect these moving electrons and channel them out of the cell. Imagine these fingers as toll booths on the electron highway, directing the current towards a wire.
  4. A single solar cell doesn't produce much power, so many cells are wired together in a panel to create a usable amount of electricity. It's like connecting multiple lanes on a highway for a bigger traffic flow!

So there you have it. That’s how solar energy works. Moving on to the panel placement.

How Panel Placement & Solar Power Plant Placement Affects Energy Production?

We all know that solar panel placement plays a role in the efficiency of energy production. Here's the science bit:

  • Optimal Angle: The ideal tilt angle for solar panels is generally considered to be equal to your latitude. For example, if you live at 40 degrees north latitude, a 40-degree tilt would be best. For Oslo, that would be ~59 degrees, and the same for Stockholm. You don’t have to be clinically precise, either.
  • Forgiveness: Solar panels are fairly forgiving. Deviations of 10-15 degrees from the optimal angle won't cause a dramatic decrease in energy production (around a 10% reduction).
  • Flat Roofs? No Problem: Don't worry if your roof isn't perfectly angled. Mounting systems can be used to tilt the panels towards the sun, even on flat rooftops.

When thinking of solar power plants, there is one more aspect to consider. The type of soil underneath your power plant matters. How so? The ground beneath the panels acts as a heat sink. Materials with high thermal conductivity, say, rocks, can help dissipate heat from the panels, maintaining optimal operating temperatures for better efficiency. Poorly conductive soils can trap heat, reducing power output.

Furthermore, solar power plants require stable foundations to withstand strong winds and even earthquakes. Geological surveys are crucial to identify areas with minimal seismic activity to prevent damage and ensure long-term panel performance.

With the multitude of factors, placing a solar power plant must be a tough task, you might think. You’d be correct. That’s why we developed software to do it automatically. Another automatic process is the conversion of AC to DC (yes, the Australian band got its name from that).

How Does An Inverter Convert AC to DC?

Imagine you have a garden hose spraying water in one constant direction (DC) - that's how solar panels work, producing a direct current (DC) of electricity. But your appliances, like lights and TVs, need electricity that flows back and forth (AC), like a sprinkler constantly switching directions. We need to somehow translate one to another.

An inverter acts like a translator between the languages of electricity. Here's the magic:

  1. The inverter receives the DC electricity from your solar panels.
  2. Using super-fast electronic switches, the inverter rapidly turns the DC current on and off hundreds of times per second. This creates a series of quick bursts of electricity, like a rapidly flicked on/off switch.
  3. While the on/off pulses might seem chaotic, the inverter uses clever circuitry to smooth out these bursts. Imagine a dimmer switch gradually turning the light up and down - the inverter does the same for the DC pulses, creating a smooth, wave-like flow of electricity.
  4. This resulting wave is alternating current (AC), the type of electricity your home uses! Now your appliances can party with the sunshine-generated power.

If, after reading this, you’re still not sure how it all works, take a look at the video below.

https://www.youtube.com/watch?v=jsBn2r94BDA

What’s the “Energy Payback Time”, and What Are the Limitations of the Metric for Solar Panels?

Producing solar panels takes loads of electricity. You might be wondering - do these panels then produce more energy than it took to produce them? You aren’t the only one wondering. The energy payback time (EPBT) for solar panels refers to the amount of time it takes for the energy produced by the solar panels to offset the energy used to manufacture, transport, and install them.

A lower EPBT indicates a faster return on investment for your solar panels. It highlights the environmental benefit of solar energy, as the panels become net energy producers after the payback period.

While helpful, EPBT has limitations:

  • Focuses on Initial Energy: It only considers the upfront energy used, not the ongoing environmental impact of traditional energy sources like fossil fuels. Solar panels have minimal emissions during operation.
  • Variations Exist: EPBT can vary depending on factors like panel efficiency, manufacturing location, and local energy sources used for production.
  • Doesn't Consider Lifetime: EPBT doesn't account for the entire lifespan of the panels. Solar panels typically last 25+ years, generating clean energy far exceeding the initial energy investment.

A Broader Look:

While EPBT is a useful metric, it's important to consider the bigger picture. Solar panels offer significant environmental benefits throughout their lifespan by reducing reliance on fossil fuels and their associated greenhouse gas emissions.

How Is Solar Energy Integrated Into Smart Grids for a More Efficient Electricity Network?

Traditional electricity grids were designed for one-way flow of power, from large power plants to consumers. However, solar energy throws a wrench in this system because it's variable and decentralized - homes with rooftop panels can become both producers and consumers of electricity. This is where smart grids come in!

Smart grids are essentially the internet of electricity. They use advanced technology to create a two-way conversation between all the players in the energy game, including:

  • Solar panels: Homes and businesses with solar can feed excess electricity back into the grid during peak sun hours.
  • Smart meters: These intelligent meters track energy use in real-time, allowing for better grid management and potential consumer incentives for using power during off-peak hours.
  • Energy storage: Batteries and other storage solutions can capture extra solar energy during the day and release it back into the grid at night, helping to balance supply and demand.
  • Control centers: With real-time data, grid operators can optimize power flow, integrate renewable sources like solar, and even predict potential issues.

Integrating solar panels into smart grids has three main benefits.

  • Increased Efficiency: Smart grids can help integrate solar energy seamlessly, reducing reliance on traditional power plants and potentially lowering overall energy costs.
  • Improved Reliability: With storage and real-time monitoring, smart grids can handle the variable nature of solar energy, ensuring a more reliable power supply.
  • Consumer Empowerment: Smart meters and time-based pricing can incentivize consumers to shift their energy use to off-peak hours, further optimizing grid efficiency.

It’s still very early in the technology development’s cycle. There are multiple companies aiming to deliver innovative solutions in the area, with one being Zeronest. If you wish to find out more about the technology, follow them for more.

What Are the Challenges and Opportunities for Recycling Solar Panels at the End of Their Lifespan?

Solar panels are a fantastic source of renewable energy, but like any technology, they have an end-of-life cycle.

Firstly, solar panels are made with a variety of materials like silicon, glass, aluminum, and sometimes even trace amounts of rare earth metals and lead. This inconsistency makes it difficult to develop a one-size-fits-all recycling process. Currently, it’s a costly process. So costly, it could be more cost-effective to simply dump them.

Secondly, the global infrastructure for recycling solar panels is still in its early stages. More facilities and collection systems are needed to handle the growing volume of retired panels. To make matters worse, many countries lack clear regulations or mandates for solar panel recycling, making it less of a priority for some players in the industry.

There are also good news, however. Solar panels contain valuable materials like silicon and metals. Recycling these materials reduces reliance on virgin resources and creates a circular economy for the solar industry.

Ongoing research could make the solar panels easier to recycle, and many people are thinking of ways to turn solar panel recycling into a more efficient process. In the future, it may very well turn out to be a profitable venture..

Summary

There you have it, six questions on solar energy, answered. Let us know whether the explanations are clear, and whether you have more questions. We would love to make another post like this, if you feel like we missed something.

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