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How Many Solar Panels And Batteries Do I Need?

Are you presently considering adding a solar system to your home? With several homeowners in the UK using solar now, many more are realizing the numerous benefits they stand to derive by getting one. Therefore, if you’re thinking about adding the system to your home but do not know where to start, you’ve come to the right place.

Here, we’ll help you calculate the number of solar panels and batteries you’ll need to power your home. Starting from the panels, you can begin by taken into account everything that makes use of power in your home to get a good idea of how many you’ll need.

• Firstly, you’ll have to determine the number of watts you use. Simply go through your utility bill for kilowatt-hours (kWh). This varies amongst homes and being able to identify your daily average energy usage will assist you in getting your solar needs.

• Secondly, you have to determine the peak sunlight hours - having in mind that the solar panels only work when under direct sunlight. Once determined, you can then multiply the figure in hours by your home’s hourly energy usage and divide by your selected solar panel’s wattage.

Generally for a 1500 square foot house, you might need around 15 to 18 solar panels to cover the house’s electricity.

Meanwhile for batteries, there are also some factors to be considered to determine the number of batteries you’ll need for your house. These factors include your home’s power or electricity usage, the period of time in which the battery will be used as well as the battery’ specifications. Once done, you’ll be able to calculate the number of batteries required by your home.

How Do Solar Panels And Batteries Work Together?

With solar panel system rapidly becoming an ubiquitous phenomenon within the modern society, several homeowners in the UK are just coming to terms with the numerous benefits offered by the system. The solar power’s popularity has even led to the rise of another renewable technology - solar batteries able to store excess solar power that can be used later. Now several companies such as Tesla are now building solar batteries that can be fitted alongside solar panels for your building. So how exactly do solar panels and batteries work together? Let’s have a look!

Solar panels make use of the sun light to generate electricity and as a result, they can’t function when sunlight is absent - giving a big issue of how to power your house when it’s dark. In the event whereby this occurs, you’re afforded two options which is either to contact energy providers to buy electricity or purchase a battery storage system.

So what’s the function of the battery storage system? Basically when your solar panel provides electricity which is not needed right away, a solar battery will work to convert the DC electricity into AC energy which is going to be stored for later use (when you actually need it). in other words, your solar panels charge the batteries when you do not require the energy they’re generating right away.

As a result, when it’s dark and the solar panels are no longer functioning, your system will tap into the energy that’s already been stored by your battery for later use. This way, you can be totally independent of the National Grid, which implies more savings on your electricity bills.

The importance of selecting the right size battery for your home simply cannot be overemphasized. A lot of home and property owners are facing this challenge and understandably so. Selecting the right battery size for your needs depend on a number of factors which includes your motive for adding a battery, your electricity usage, your budget as well as your panel array size, be it new or existing. In this post, we’re going to take you through some of these factors to help you determine the right battery size for your home or property. Let’s take a look!

• Your motive for getting a battery. While most people purchase a battery to wipe out their need to purchase electricity from the grid with the hope of making some savings, others add a battery so as to enjoy backup power. There are also some who just needs it to power their home with solar energy. It’ll not be economical to size a battery to effectively take you off the grid, but if your motive is to make savings, then you’ll should expect to purchase some electricity from the grid during the year.
• Electricity usage. The average household uses about 16kWh of electricity on a daily basis. During the daylight hours, most of these household will use a third of their electricity when the solar panels are still generating electricity, while the remaining two third are purchased from the grid. In other words, you’ll require a minimum of 10kWh battery capacity if you were to use a battery to power the electricity you purchase from the grid.

For a typical British household, you’ll most likely need a 5kWh solar power system which normally generates about 17 to 21 kWh on a daily basis depending on your location in the UK.

It’s important to get the right size solar panel system for your commercial property. Solar panels are usually installed on pitched roofs, although they can be fitted on stands on the ground if you have some unused outdoor space. The more panels you install, the more power you’ll generate, but there’s no point buying more panels than you have space for.

Solar panel system sizes are measured in kW. 4-10kW solar panel systems are usually too big for domestic properties but are ideal for smaller commercial properties. Here’s an idea of how many panels and space you’ll need for a few different system sizes:

System size, Number of panels, Area required (approximate)

4kW, 16, 23m²

6kW, 24, 35m²

8kW, 32, 46m²

10kw, 40, 58m²

Bear in mind that solar panels can’t be less than 30cm away from a roof edge, so you’ll need more space than the area that the panels take up.

Just like other major house improvement projects, some specific requirements must be met to allow for the installation of solar panels on commercial buildings. The main reason why these standards and regulations were established is to minimize the risk of the solar system becoming an issue or potential hazard in the unforeseeable future. So if you’re thinking about buying and fitting new solar panels, you’ll probably want to know whether or not you’ll require to submit a planning permission application for approval before you can proceed.

Fortunately, the installation of solar panels on commercial buildings may be “permitted development which mean you won’t have to apply to the Local Planning Authority for planning permission. There are, however, some important limits and conditions which must be put into consideration in order to benefit from these permitted development rights. Some of the limitations include:

• The solar panels must be installed on a wall or pitched roof that should project at a maximum of 200mm from the surface of the wall or roof slope.
• Equipment placed on a roof should not be within one metre of the external edge of that roof.
• Equipment mounted on a wall must not be within one metre of a junction of that wall with another wall or with the roof of the building
• If the equipment is on the roof of a building, the capacity for generation of electricity across the entire site must not be more than 1 megawatt.
• In the situation whereby the panels are installed on a flat roof, the highest part of the equipment should not exceed one metre above the highest part of the roof.

In general, obtaining a planning permission is very important and as such, you must discuss your position with your chosen installation company before you proceed.

Whether solar panel batteries are worth it depends on how much you’re at home and how big your solar panel system is. If you’re at home most of the day and your solar panels only generate enough electricity for you to use while for that day, then a battery probably isn’t worth investing in. However, if you have a large system that generates more than you can use or you’re out most of the day, then solar panel batteries are definitely worth it.

A solar battery storage system works by storing the electricity that your solar panels generated until you need to use it. That’s why they’re great for people that are out all day – your solar panels generate electricity all day whilst the sun’s out, but no one’s home so you’re using minimal energy except for things like your fridge and any appliances on standby. Most of the electricity charges your solar panel battery. Then, when you get home, your battery will discharge, and you’ll use all the solar electricity that your panels generated during the day.

Solar batteries are also excellent for people with large solar panel systems that generate more than they use in the day. Any electricity that you don’t use during the day will charge the battery, so in the evening when the sun goes down, you’ll just use the excess electricity that’s stored in the battery.

To work out whether solar panel batteries are worth it for you, you’ll need to work out how much of your solar electricity you’re using already. If you’re at home and you’re able to run your appliances all while your solar panels are generating electricity, a battery might not be worth it. Also, if you’re receiving export payments from the Feed-in Tariff Scheme (FITs) or the Smart Export Guarantee (SEG), you might want to look at the rate you’re getting paid. If it’s a good rate, it might be more cost-effective to continue exporting unused electricity to the grid. Speak to an MCS-registered installer that will be able to help you work this out.