Guide To 5kW Solar Panel Systems

Our 5kW solar panel system guide covers the likes of: 

• Property suitability
• Costs (with and without a storage battery)
• The amount of electricity a 5kW solar panel system will generate
• How much you should expect to save
• Roof space needed
• Whether a DIY system is suitable

What You Need To Know About 5kW Solar Panel Systems

This page is a 10-minute read, so if you’re short on time, bookmark this guide for later and read this overview instead…

A 5kW solar panel system is going to be suited to a 3-4 bedroom property that’s using less than 4,000 kWh of electricity per year.

Costs are likely to be around £10,000 for a standalone system. They’ll quickly jump to £15,000-£20,000 when incorporating a solar storage battery; the bigger the battery the higher the price.

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Using this system, expect to save anywhere from £500-£1200 per year. With finance packages available, these monthly savings could pay for your solar panels, with a full return on investment within 7-15 years.

For installation, expect to need around 30m² of roof space, as well as a roof that has the structural integrity to support 300 kg+.

And finally, whilst there are 5kW DIY kits available, they tend to be less efficient and have a shorter warranty than kits a MCS registered engineer would install.

A DIY project of this kind is a huge undertaking and if you're not MCS registered, you won't be eligible for the Smart Export Guarantee (SEG), so won't be able to sell excess electricity back to the grid. 

Take the hassle out of deciding which system you need and get it fitted by an MCS certified engineer. You can get quotes on your 5kW solar panels using our clickable tool here. 

Our Guide To 5kW Solar Panel Systems

Property Suitability

The first thing you’ll need to decide is whether a 5kW solar panel system is the right size for your property. 

The easiest way to determine what size solar panel system you need is to first, check your electricity consumption. 

Remember, you want to check every single month's electricity consumption. Some months you'll consume much more than others and your system needs to be able to handle this spike in demand.

For an average 2-3 bedroom household in the UK, consumption is going to be somewhere in the region of 2,700kWh per year. 

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A typical solar panel system will produce around 800x its output per year. So, in the case of the 5kW system you’d expect it to produce at least 4,000kWh per year of electricity. 

Properties consuming 4,000kWh of electricity are likely to be 3-4 bedroom homes, so this is what a 5kW solar system is most suited to.

This is a ballpark figure. Some 3-4 bedroom households might use as little as 3,000kWh and get away with a 4kW system. However, high consumption households may be using 5,000kWh or higher and be better suited to a 6kW system or bigger. 

Another thing to consider, is can you actually use the electricity as it’s generated? 

The most productive times for solar panels is during the daytime, when most people are at work, as you can see from the chart below: 

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So, for the typical household, not only will they need the correct sized system, they’ll also need a storage battery. The system then stores the electricity produced in the day time, so it can be used in the evenings.

Still confused? Use our solar panel tool here. That will calculate everything from available roof space to potential electricity production and determine what size solar panel system you need. 

Costs

We’d expect an average 5kW solar panel system to cost £10,000. However, the majority of households would benefit from using a solar storage battery.

Storage batteries can be incredibly expensive, with large storage units costing up to £10,000 (meaning a total installation cost of £20,000).

5kW Solar Panel System Installation Costs

Expect your 5kW solar panel system to cost around £10,000. However, the price can fluctuate by £1000 or more (either way) depending on: 

• Labour rates in your local area
• The quality of the components use 
• Ease of access to your property’s roof
• How easy it is to secure your solar panel mounts to the roof joists

We’ve written a detailed guide to solar panel costs here. Or, if you want to get fixed prices on-screen for the most suitably sized system, use our clickable solar panel tool here. 

Cost of Solar Panels With a Battery

It’s not essential to have a solar storage battery fitted with your panels. However, for the majority of households it’s a good idea. 

Take the time to decide if you want a storage battery fitted before paying for solar panels to be installed, as it’s likely to be cheaper as a package deal. 

The cost of 5kW solar panels with a basic battery is likely to start at around £15,000; £10,000 for the solar panel system and £5,000 for the battery. 

However, this will get you a 5kWh battery which for many households, isn’t enough. Having a battery that’s up to 10kWh, could cost up to £10,000 for a total installation cost of £20,000.

Your solar panel installer will be able to determine exactly what sized solar battery you need by checking: 

• Average electricity consumption
• Times of the day where electricity is being generated but not used (this would be stored in your battery)

Whilst you can sell excess electricity back to the grid via the Smart Export Guarantee, it’s likely battery storage is the better solution. What you’ll get paid per kWh you export, is a lot less than what you’ll pay per kWh if you need to buy electricity back from the grid. 

Use our solar panel and battery configuration tool here. It’ll determine the most cost effective setup for your property based on electricity consumption. 

How Much Electricity Will 5kW Solar Panels Produce?

On average, you can expect a 5kW solar panel system to produce approximately 4,000kWh of electricity per year, or, just over 300kWh per month. 

The majority of electricity production will take place between 10am-4pm daily, so you need to either use it as it’s produced, or store it via a battery.

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Whilst this is an average, there are plenty of variables that affect just how much electricity your 5kW system will generate, including: 

• Efficiency of your panels, with solar panel efficiency range from 18%-24%
• Any panels that are affected by shading (buildings, trees etc)
• The type of inverter your system uses (using a string inverter would mean 1 low efficiency panel affects the whole “string”)
• Degradation rate of your solar panels (they lose efficiency over time)
• Roof pitch and orientation

We’ve written a detailed guide to solar panel efficiency here that’s worth a read. 

Or, use our solar panel quotation tool to determine what system you need, and how efficient it’s likely to be. 

How Much Money Will You Save?

With a 5kW system generating approximately 4,000kWh per year, you could expect to save around £1,200 if you’re paying 30p per kWh for electricity. 

Obviously the exact amount you save depends on: 

• The exact price you pay per kWh of electricity
• If you’re able to use all of the electricity you produce (by storing excess in a solar battery)
• Exactly how many kWh of electricity your solar panels produce (this varies from property per property)

Even if we take a more pessimistic view, you can see that using the Smart Export Guarantee, the Energy Saving Trust expects the average property using solar panels to save up to £520 per year:

With finance available, you’ll be able to spread the cost of your 5kW solar panel system and essentially, pay for it via savings you make on a monthly basis.

And depending on your setup, your payback period could be as low as 7-years. 

To get exact prices on a 5kW solar system with a suitable storage battery, check out our clickable solar panel tool here. 

How Much Roof Space Do 5kW Solar Panels Need?

Depending on the brand and particular model, roof space needed to fit solar panels will vary. 

However, using a top solar panel brand such as LONGi, expect to need approximately 30m² of roof space to fit solar panels.

It’s worth referencing our guide covering roof suitability here, as you won’t just need plenty of space, but a roof that has structural integrity. A 5kW system could weigh over 300 kg including roof mounts and anchors, and your roof needs to support that weight. 

5kW DIY Solar Panel Systems

A question we get asked a lot is: can you fit solar panels on a DIY basis?

Whilst you can, there are a few things to consider: 

• A lot of DIY solar panel kits use sub-par components, they won’t last as long, nor be as efficient as products from leading brands
• Labour from a professional (MCS installer) makes up a big chunk of the cost, and isn’t included in a DIY kit

A 5kW DIY solar panel system is still likely to cost around £5,000. As DIY projects go this is a huge undertaking, not to mention the fact that if you don’t have solar panels fitted by an MCS registered installer, you won’t qualify for the Smart Export Guarantee. 

Looking to install a small 1kW system to power small outdoor appliances (in a workshop, for instance)? A DIY installation is perfect.

However, for anything bigger, we’d recommend using a professional.

Get quotes on your 5kW solar panel system fitted by an MCS professional by using our solar panel tool here. 

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