Solar Panels
Solar panels has become one of the main ways for many people to save money in the face of rising electricity prices and bills for the second year in a row. Our country is currently seeing over 100 new solar power panels plants a week. The price of the main component of a solar power plant, the photovoltaic solar cell (PV cell), has fallen 300 times in the last 40 years and is falling further. It therefore looks like we will see more and more solar power plants every day.In this article we will help those who are just starting to get interested in solar panels plants and want to know the answers to these questions:- How does a solar power plant work? What is the difference between solar cells, solar modules, solar panels and batteries?
- Why are people installing solar power plants in United Kingdom? What incentive model works?
- What is the cost of a solar power plant?
- How much electricity does a solar power plant produce in United Kingdom?
- Does a solar power plant really pay? What is the payback time for a solar power plant?
- Does it pay to install a solar power plant now or wait?
The working principle of a solar panels plant.
Solar power plants are based on semiconductors. Photons in the sun's rays "excite" the electrons in the solar cells and make them move, which generates direct current (DC) electricity. DC current is not suitable for our home grid and needs to be "replaced" by alternating current (AC). This is done by a current converter also known as an inverter. From the inverter, the electricity travels to power our home electrical appliances. And when it has nowhere else to go, for example when there is very little electricity consumption in the home, the current travels to the external power grid.
Solar panels, modules, collectors and batteries. What's the difference?
Solar cells are the photovoltaic cells that make up a solar module. It is the solar cells that are the heart of the solar module, converting sunlight into electricity. The most common solar modules on the market are the 60 and 72 solar cell PV modules (or 120 and 144 sliced solar cell modules respectively).Solar modules are made by combining solar cells in series to form larger electricity generating devices. Solar modules are usually made up of 60 or 72 cells or 120 and 144 cut cells respectively.A solar power plant is a collection of components - solar modules, an inverter, fasteners, wires and other materials.A solar collector is a completely different technology component whose main purpose is to convert the sun's rays into thermal energy. This technology is commonly used for water heating. It is not a component of a typical solar power plant and is not connected to it in any way.
Batteries are electricity storage devices that store the excess electricity produced by the sun, instead of feeding it into the grid. Energy storage devices (batteries) are becoming increasingly popular in the US, United Kingdom and Western Europe.
Solar power plant technology
Many people fear that the technology of solar panels is constantly changing and that the plant they have installed will be technologically "obsolete" in just a few years. The vast majority of solar power plants on the market consist of crystalline silicon solar modules (both monocrystalline and polycrystalline). It is this technology that accounts for more than 80% of all modules sold worldwide. This technology has been mainstream for more than 25 years and all improvements are based on this technology, with efficiency improvements of a few percent rather than tens of percent every year. There are three main differences to be aware of between polycrystalline and monocrystalline modules: the difference in efficiency, the difference in price and the difference in appearance. Monocrystalline modules are more efficient than polycrystalline modules, i.e. the same module area can produce more kilowatt-hours. The colour of monocrystalline modules is dark and solid. Polycrystalline modules are a lighter shade of blue. You can read more about the difference between solar modules in our separate article.What is the incentive model for solar power plants in United Kingdom?
There are two main incentive instruments in United Kingdom - two-way accounting and direct support.Many people are still confused about the fact that electricity in United Kingdom is "bought" at a certain tariff. This scheme has not been in place in United Kingdom since 2013. The solar electricity produced is not bought in and the main benefit is not the extra income but the savings from not paying for electricity.In United Kingdom, two-way billing allows electricity to be "stored" on the grid. In this way, everyone who installs a solar power plant becomes a producer as well as a consumer of electricity. The concept of a 'producer' applies to those who install solar panels plants.As most of the electricity generated by a solar power plant is produced in spring and summer, any electricity not consumed goes to the grid, where it is metered by a two-way metering system. In this way, this electricity is stored and can be used in the autumn and winter months. The generating consumer must use his or her reserve of electricity from the solar plant by 31 March of the following year. So you will have to use the electricity you generate in 2023 by 31 March 2024.While many people resent this model because of the storage charges, grid storage still pays more than battery storage.However, the generation consumer and two-way metering model alone would not be enough to generate the increase in the number of people installing solar PV, as the payback period would still be 10-12 years. It is the additional support that is driving this rapid increase in the number of generating consumers.A £323 support per installed kilowatt for an upfront purchase or a £381 support for an instalment purchase of a solar power plant covers around 30-35% of the cost of installing a solar power plant and reduces the payback period to 6-8 years.Solar panels plant cost
Preliminary estimates for the cost of a solar power plant per installed kilowatt in United Kingdom range from around £800 to £1,100 per installed kilowatt. You can find out the preliminary cost of your solar power plant using the calculator. The core of the cost of a solar power plant consists of the photovoltaic solar modules and the inverter, which together can account for 70-75% of the total cost of a solar panels power plant.How much electricity does a solar panels plant in United Kingdom generate?
In 2012-2013, due to very favourable electricity purchase prices, a large number of 30 kW solar power plants were installed in United Kingdom. Below, we share the production data of one of the solar power plants installed on the roof of a flat building in the London district, which should help you to estimate how much electricity the plant produces in real conditions.Calculating a six-year average of the electricity produced by the solar plant, the 30 kW solar plant produced an average of 30528 kWh per year. One installed kilowatt produced on average 1018 kWh of electricity.
We share generation data for the same solar panels power plant in different months.
As we can see, the lowest generation is in November, December, January and February. The amount of electricity generated in these months is only about 6% of the total annual amount. Most of the electricity is generated in the spring, summer and autumn months. More than 90% of electricity is generated between March and September.Solar panels power plant payback
Let's calculate the payback time of a solar panels power plant in the specific case of a 5 kW solar power plant.Let's use the following assumptions:- As we have already shared in one of our posts on solar power plant prices, the average price of a 5 kW solar power plant in the mid-price segment in this particular case is £5180.
- The exact capacity of this solar power plant is 5.2 kWp. It is eligible for a GRANT of 5.2*323 = £1679.6.
- The investment after the grant will therefore be £ 5180 - 1679,6 = 3500,4.
- Installed on a suitable roof on the southern slope of the roof, such a plant can produce 5000-5200 kWh per year. Let us take an average value of 5100 kWh.
- Buying 5100 kWh from 1 July 2020 at the updated electricity tariff, the rates of which you can see below, and taking a fairly standard scenario that 60% of the electricity is consumed during the day, and 40% at nights and at weekends, we get an average kilowatt-hour price of (0.6*0.155)+(0.4*0.099)=0.1326 £/kWh. This means that we will pay a total of 5100*0.1326=676.26 £ per year for electricity.
- Any equipment can fail. Let's take the pessimistic scenario that the inverter will need to be replaced immediately after the end of the 10 year warranty. This will cost £1100. This means that we would have to put aside £110 per year.
- The price of electricity in 2019 and 2020 has risen for two consecutive years. Taking into account that the final price of electricity in United Kingdom for residential customers is one of the lowest in the EU, let's take a more conservative scenario of 3% electricity price growth every year.