How Can You Benefit From Solar Energy?

Solar power is said to be green since, in contrast to other sources of energy, it does not emit any pollutant into the atmosphere, whether it is produced or consumed. Nowadays, more and more people are switching to solar power not only because it is a green source of energy, but also because it is becoming less expensive and more efficient than it originally was. Thanks to technological developments we are now able to convert solar energy into heating or electricity.

Whether you are considering installing solar panelsor a solar thermal collector in your own house or as a business, or if you are just interested in solar energy – here are a few things you need to learn.

Benefits of Solar Energy

• It is clean. When active, solar power releases no harmful substances or noise into the atmosphere. For each megawatt hour of electricity, solar energy produces about 0.75 to one tonne of CO2.
• It is free. Once the mechanism for generating solar power is installed, heating or electricity from the solar system is totally free. This will help you reduce your bills and at the same time lower your household’s’ carbon footprint.
• It works everywhere. Although solar panels’ efficiency increase proportionally to the amount of sunshine they receive, they can work everywhere, even when it is cloudy. Moreover, adding a solar battery storage system to your solar system can enable you to enjoy free energy anytime, even at night and other low-functioning days.
• No need to apply for a permit. Due to the fact that solar panels are considered “permitted development”, you don’t need to obtain a permit before installing them on the roof of your household. There are, however, a few limitations and obligations you need to consider when switching to solar energy.

How Does Solar Energy Work?

Solar energy is energy provided by the Sun. When converted into solar power, it can be used for heating or electricity by private households as well as businesses. Solar power is generated by a) a surface that collects solar energy and b) a method of converting the captured energy into electricity or heat. There are two main methods of converting solar energy into solar power:

1. Direct or photovoltaic (PV) conversion. In this case, you would use solar panels (or solar PV) for generating electricity. 
2. Indirect or solar thermal conversion. In this case, you would use a solar thermal collector to generate heat. This is also known as solar water heating.

As previously mentioned, there are two main uses that can be given to solar energy regarding solar power. Depending on the method chosen to transform the energy, you can use it for electricity or for heating. In the first case, the method is called direct or photovoltaic (PV) conversion, and you need solar panels (solar PV). In the latter case, the method is called indirect or solar thermal conversion, where you use solar energy for heating.

Solar Energy for Electricity

Solar energy can be converted into electricity with the use of solar panels. This technique of harnessing solar energy works similarly to solar energy used for heating.

The light hitting the solar panel installed on the roof of the building is caught, converted, and used instantly.

You can choose whether you want to install a stand-alone PV system, or a grid-connected PV system. The main difference is that a stand-alone system stores solar energy for your personal use. Grid-connected PV systems will send generated power to the public power grid, providing the possibility of selling your solar energy to anyone (i.e. neighbours).

How Do Solar Panels Work?

Solar cells or photovoltaic cells (PV) (comes from the Greek; photo meaning “light” and voltaic meaning “electricity”), convert sunlight directly into electricity. A solar panel is a group of cells connected electrically and grouped into a frame. Many solar panels put together will form a solar array.

PV cells are made of special materials called semiconductors (usually silicon). When light hits the solar cell, part of the energy absorbed and electrons from the atoms in the semiconductor material are released. When electrical conductors are attached to the positive and negative sides, thus forming an electrical circuit, the electrons can be captured in the form or electric current (electricity). This current, together with the cell’s voltage (which is a result of its built-in electric field or fields), defines the power (or wattage) that the solar cell can produce.

FAQs—Solar Panels

Are solar panels very expensive? While the use of solar energy has been growing exponentially in the last twenty years, the prices of PV cells have been dropping. Currently, the price of each PV cell is 99% lower than it was in 1976. Moreover, because solar energy is such an environmentally friendly solution, many governments are offering grants and incentives for the installation of panels. Based on current average electricity costs, and assuming modest inflation of energy prices, the payback period should be between 8 and 10 years.

Do solar panels work in bad weather? Solar PV panels can collect solar energy all throughout the year, whether it is spring, summer, autumn or even winter. However, the conversion of solar energy from solar panels is reduced when there is no direct sun exposure. This means that during cloudy days, solar panels work at 50% of their total capacity and on extremely cloudy days, this number may drop to 10%.

How much roof space do I need? On average, you need 100 square feet of space to generate 1 kW of solar energy. Considering that a typical household uses around 40-50 kilowatts of electricity per day, it is safe to assume that to supply all of your electricity or heating needs with solar energy, you may need up to 500 square feet of roof space. However, already harnessing 20 kW a day from solar energy systems cuts the energy bill in half.

What other types of solar panels are there? Nowadays, there is a big variety of solar panels such as solar blinds for your windows, solar tiles for your roof, and even portable solar panels. All of them help you convert solar energy into electricity. However, there are also other types of systems. For example, you can use solar thermal systems for water heating. 

What is the average lifespan of a solar panel? Solar panels installed today will produce a reasonable amount of solar energy for about 30 to 40 years, without the need for replacing them.

Can I store the electricity generated by my PV system? Yes, you can use solar batteries to store your solar energy produced by your PV system. By doing so, you can save even more on your electricity bill, as you can charge your solar battery during off-peak hours and discharge it when you need electricity.

Solar Energy for Heating

In this case, solar energy is converted to heated water which is then available for household purposes. In a solar water heating system or solar thermal collector system, the energy of the sun is attracted by collectors (either flat plate collectors or evacuated tubes) that are fitted on the rooftop of a household. Hot water is then transported through the tubes for household purposes. Typically, a solar water heating system would meet approximately a third of the hot water demand of a family of four.

Alternatively, thermodynamic panels can be used which are slightly pricier but can supply 90% or more of the water needs of a family. That is possible because thermodynamic heating systems use a different technology than solar thermal, as they are exploiting the heat from the ambient air rather than relying solely on solar energy.

This image reveals the two types of solar thermal systems: flat plate collector and evacuated tubes.

Costs and Savings

It is hard to give an exact price because this will depend on the size and type of technology chosen, on the weather and on different other factors. A very rough estimate is that a solar panel system can cost between £6,000 to £9,000 and solar thermal systems, between £3,000 and £5,000. These numbers taken in isolation could be misleading, as one needs to consider the savings when assessing the cost of a solar panel system. 

Maintenance

Good news! Solar panels require very little maintenance. You should always make sure they are not blocked with dirt from trees or any other substances that could keep the sun away from them. As panels are generally positioned with some angling, the rain will always help to wash the dirt away. Moreover, solar panels should last for around 25 years, but the inverter might need to be changed before (approx. £800).