Future Renewable Smart Efficient

Solar PV 10kW -1MW installations - What is Large?

Large Solar PV installations can range in size relative the electrical consumption onsite.  What some consider "a big system" others would considerer a minimum as their usage and space available is much larger.  This is fairly obvious but understanding system sizing and managing expectations is key when considering Solar PV. 

Below is an initial guide to understanding the range of system sizes.

*Worth noting virtually all the system sizes below require prior agreement from local DNO.

Contact us or request a callback to discuss your project.

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5 - 10kW system

Above 4kW installations are vey common and provide very usable amounts or power for the home or small business premises. 

  • Much of the Solar PV industry in the UK is geared up to this size installation.  
  • Components are easily available and priced to suit. 
  • A 4-9kW inverter costs do not dramatically increase with capacity. 
  • An installation should take no more than a day to complete. 
  • These size installations are perfectly suited to Battery Storage and power diverter for self consumption (immersion controllers etc.).
  • With SunPower, a 6kW system is only 17 panels covering less than 30sqm!   "Average" amount of space available on a small commercial unit or 3 bed house.

A large home's electrical consumption may require as much as 8kWp solar PV to properly match the consumption and future proof the family from any future inflation in energy costs or usages (electric cars, smart meters, hot tubs etc. all add up on the bills in the end!). 

An example 8kW system using Sunpower X345w panels with SolarEdge optimisers and inverter for above would be approx. £12K fully installed and generating.  Facing roughly south with minimal shading we would expect 7-8000 kWh per year from the system.

Flat roof Solar PV.JPG

10 - 75kW system

10+kW installations are often for small industrial/commercial premises or as multiples within a larger site with multiple meter positions are available.  Our common 10+kW installations are with small business owners looking to future proof and improve their margins by reducing overheads.

  • Most commonly 3 phase installation
  • Good economies of scale
  • Large energy production and still affordable for small-medium businesses
  • Often very agreeable for the DNO and so can be installed in rural areas
  • <30kW requires export metering so 50% export FIT payment still available.
  • Installation generally completed in 2-3 days 
  • Still a large enough installation for a marketing tool or PR event.

A light industrial/commercial unit (1000+sqft) may require as much as 50kW to significantly reduce the electricity company's bills and therefore reduce overheads dramatically.  With the usage from offices and machinery adding up quickly.

An example 25kW SunPower and SolarEdge installation on a single roof area facing east/west would cover approx. 110sqm of roof or ground area, generate roughly 23,000kWh per year.  Saving hundreds if not thousands of £££ in electricity costs per year.  Rough costs of £28,000.

Case study

75 - 250kW system

Widely regarded as the largest of the onsite consumption installations.  Most commonly installed for larger industrial premises, food storage warehouses, multiple occupancy offices/commercial premises.

  • Can provide very good returns.
  • Require good relations with the local DNO from a reputable installer
  • Can be used upstream from private metering and therefore be sold on to tenants for additional financial returns
  • Great for company CSR programmes or carbon footprint reduction
  • Can be installed for free (or reduced overheads) using a PPA agreement (contact us to discuss) with an electricity provider

The is a wide range of variables to a 75-250kW installation and would therefore be misleading to suggest any performance figures or costs etc. 

Even in using a "standard panel"  vs a SunPower Panel - a 100kW system using 250W panels, in the same area a SunPower system would be as much 140kW.  With higher performance, better warranties, better durability and Cradle to Cradle accredited. 

Installation Procedure


Installations larger the 250kW are not particularly common in the UK, unless done through a utility provider for the purpose of grid feed in rather than self consumption.  If you have a electrical consumption, and space available, that you believe would be suited to this size of installation, we have experience in offering a package that would need to bespoke to the company situation so we could offer a highly valuable system. 


If you are considering a system please contact us today or request a callback.

We would happy to work through the requirements and design a system to suit.

Contact us