Solar electricity technologies

Solar panel and batteries

Conventional power plants use only one third of the primary energy used to generate electricity. Thus, about two-thirds of the energy generated in central power plants and distributed throughout the grid is wasted. Electricity generation traditionally has a significant negative impact on the environment. Therefore, it is important to generate electricity decentralized and close to consumers using renewable energy sources such as solar, wind, water and biomass.

By using a rooftop solar panel system, every homeowner becomes an electricity producer. Everything is very simple - the modules are installed, the connecting wires and the inverter are connected, and everything is ready to go. If necessary, a battery power system is added. Today, more and more customers are showing interest in this type of electricity generation.

Electricity from Solar

What is solar energy?
Solar energy is the radiation from the Sun capable of producing heat, causing chemical reactions, or generating electricity. The total amount of solar energy received on Earth is vastly more than the world's current and anticipated energy requirements. If suitably harnessed, solar energy has the potential to satisfy all future energy needs.
What are the common uses of solar energy?
Solar energy is commonly used for solar water heaters and house heating. The heat from solar ponds enables the production of chemicals, food, textiles, warm greenhouses, swimming pools, and livestock buildings. Cooking and providing a power source for electronic devices can also be achieved by using solar energy.
How is solar energy collected?
The most common devices used to collect solar energy and convert it to thermal energy are flat-plate collectors. Another method of thermal energy conversion is found in solar ponds, which are bodies of salt water designed to collect and store solar energy. Solar radiation may also be converted directly into electricity by solar cells, or photovoltaic cells, or harnessed to cook food in specially designed solar ovens, which typically concentrate sunlight from over a wide area to a central point.
Read a brief summary of this topic
solar energy, Radiation from the Sun that can produce heat, generate electricity, or cause chemical reactions. Solar collectors, such as those used for solar water heating, collect solar radiation and transfer it as heat to a carrier fluid. It can then be used for heating. Solar cells convert solar radiation directly into electricity by means of the photovoltaic effect. Solar energy is inexhaustible and nonpolluting, but there is inherent inefficiency in converting light to electricity. In the 21st century solar energy is expected to become increasingly attractive as a renewable energy source and as a useful tool in the fight against anthropogenic global warming.
Thermal energy
Among the most common devices used to capture solar energy and convert it to thermal energy are flat-plate collectors, which are used for solar heating applications. Because the intensity of solar radiation at Earth’s surface is so low, these collectors must be large in area. Even in sunny parts of the world’s temperate regions, for instance, a collector must have a surface area of about 40 square metres (430 square feet) to gather enough energy to serve the energy needs of one person.

Solar-powered transportation

An innovative practice to effectively make use of the sunshine is with transportation powered by photovoltaic (PV) energy.

Railroads, subways, buses, planes, cars and even roads can all be powered by solar, and solar transit is becoming a popular offering in the renewable energy sector.

Recently, the solar powered-aircraft Solar Impulse 2 made its way around the world, soaring across the Pacific and making big splashes in iconic photographs.

Meanwhile, solar buses are helping China reduce its carbon footprint while simultaneously maintaining efficient mass transit in densely populated cities like Beijing.

Finally, solar cars are starting to play a role in racing competitions around the world, especially in Australia where the SolarSpirit model has gained major recognition.

With these advances and more, there’s no question that solar power is the transforming transportation sector around the world.

How much energy does a solar panel produce?

While there are many factors that affect the amount of energy a solar panel can produce, you can expect a typical single solar panel in the United States to generate about 1- 2 kWh per day, which saves an average of about 0,36 EUR on electricity costs per day.

Now, 0,36 EUR doesn’t seem like a lot, but that’s just the energy savings for one panel over the course of one day. Installing a whole solar panel system, on the other hand, would save you more like 132 EUR a month (or more!).

Most residential solar panels used today have a power rating of somewhere between 300 and 420 watts in size. The higher the wattage of a panel, the more electricity it can produce.

The wattage of a panel has to do with the way the panel is constructed. The type of solar cells used, for example, influences the wattage of a panel. This is why most solar panels today use something called monocrystalline solar cells, because they’re able to generate more electricity than older solar cell technologies (namely polycrystalline solar cells).

Frequently asked Questions

How can I maximise the amount of solar electricity generated that I use?

The simplest way to use a higher percentage of the electricity generated is to design the PV system to meet the average daily electricity demand of the house, although this may mean a very small PV system is installed if demand is low during the daytime.

Another simple measure is to install a ‘diverter switch’ which diverts any unused electricity to heat your hot water in your immersion tank. In this way some of the energy generated is stored as hot water, which you can use later.

Finally, a more complicated option is to install a PV system which does not face south, but faces west or east. This will provide more energy in the morning or the evening when you have a greater demand to use it. However, an east- or west-facing PV system will generate less energy over the year than a south-facing system

What about a battery storage system?

Adding a battery to your solar PV system means the battery will charge when the PV system is generating electricity which isn’t being used, and then discharge when you need it next (normally that evening/night). A battery can increase the percentage of solar PV electricity you use in your house. Adding a battery to the system will increase the cost of the PV system and some energy will be lost in the battery during the charge and discharge cycle.

Is there a ‘feed-in tariff’ payment for excess solar electricity fed into the grid by owners of solar PV systems?

There is currently no obligation for energy suppliers to pay their customers for the electricity they generate with their solar panels (sometimes known as a ‘feed-in-tariff’). It is up to energy suppliers to decide whether they wish to offer such a scheme to customers.

Does a rooftop PV system require maintenance?

PV systems are low-maintenance, but not zero maintenance. The most important aspect is to monitor the performance of your system regularly. This could simply be a routine check of your inverter to see that the system is operational and that the energy meter is increasing each day.

You should get an idea from your installer about how much the PV system should generate each year, and see that your system is generating close to that amount. Some suppliers will provide you with access to this information via your smartphone. The most common point of failure is the inverter, which may need to be replaced at some point in the PV system’s lifetime.

The solar panels themselves are extremely robust, but consideration should be given to cleaning them every few years to maintain their performance. If you live near the sea or a main road more regular cleaning may be necessary.

What information is available regarding solar farms?

Consult the FAQs on solar PV(opens in a new tab) for more information on planning and other consideration related to solar farms.

Common Types of Solar Panels

The most common photovoltaic modules, or solar panels, on the residential solar market contain monocrystalline or polycrystalline (also called multicrystalline) solar cells. Both types of PV cells produce electricity when exposed to sunlight, however there are some differences between the two.

There are many panel manufacturers that build panels containing both mono and polycrystalline wafers to form solar cells, capable of harvesting energy from a wider spectrum of light. If space is limited on your roof or project site, a higher-efficiency, a monocrystalline panel may be preferred and could result in a better return on investment (ROI).

On the other hand, it’s possible a lower-cost, slightly less efficient, the polycrystalline panel might fit your needs best. Be sure to ask what type of cell (“mono or poly”) your solar system design contains – this distinction may affect the aesthetics and economics of your project.

It’s important that your solar panel array(s) are installed in areas that receive good insolation (sun exposure) throughout the day, free from as much shading from trees or neighboring obstructions as possible. This will ensure your system is as productive as possible, given the site conditions.