100kW Solar Panel System UK | Output, Suitability & Install

The right fit

Why a 100kW solar panel system could be the right fit

A 100kW commercial solar system marks the entry point of our larger commercial range. It uses 200 to 225 panels across 450 to 550 square metres of roof and suits businesses with annual electricity demand of 85,000 to 125,000 kWh, typically larger industrial units, mid-size warehouses, supermarkets and hotel-chain properties.

At this scale, three-phase supply is standard and the economics improve per kW, because labour, scaffolding and infrastructure costs are largely fixed. The system is eligible for the Annual Investment Allowance, business rates exemption to April 2035 and 20% reclaimable VAT, and often leaves roof capacity for future expansion.

The datasheet

100kW spec sheet

Indicative figures for a 100kW commercial system on a typical UK site. Your exact output depends on your roof, orientation, shading and usage, confirmed in a site visit.

System size100 kW DC

Solar panels200-225

Roof space450-550 m²

Site demand85,000-125,000

Annual output85,000

Self-consumption80-95%

VAT20% reclaimable

Capital allowanceAIA-eligible

Business ratesExempt to 2035

Panel warranty25 yrs

Indicative, not a quote · final figures after a free roof assessment.

What is included

200-225 tier-one panels

High-efficiency panels, sized to deliver 100 kW DC across your commercial roof.

Commercial inverter (three-phase)

A quality inverter, three-phase ready, with capacity for battery and peak-shaving.

Mounting, wiring & connection

All roof mounting, cabling and grid connection, done neatly and safely.

Commercial monitoring dashboard

Live generation and consumption data for your facilities team, set up before we leave.

Full MCS install + AIA guidance

Fitted under our own MCS registration, with AIA capital-allowance guidance for your accountant.

25-year panel warranty

Plus a team you can still call after switch-on. Every job certified under our own MCS registration.

On real UK rooftops

Sized for your building, fitted under our own MCS registration

Every 100kW system is designed around your site’s demand profile and usage, then installed by the same MCS-certified team that assessed it. Certified under our own MCS registration, no remote sales centre, 3,000+ UK homes and counting.

Storage

100kW: self-consumption and battery

Panels only

Good if you use power in the day

The panels power the site during working hours and export the surplus for a payment under SEG. Ideal if your demand is daytime: production, refrigeration, machinery or EV charging while the sun is up.

Panels + battery

The most common upgrade

Battery storage shifts daytime solar into evening, out-of-hours and peak-rate periods, lifting self-consumption further and cutting demand charges. Sized to your load profile during the design stage.

The right size?

Is a 100kW solar panel system enough for your site?

For businesses using 85,000 to 125,000 kWh a year, a 100kW system covers a large share of demand at a strong cost-per-kW, with capacity to expand as your load grows.

If your demand is lower an 80kW system may suit; for multi-acre sites, distribution centres or manufacturing plants we design systems up to 150kW and beyond. We size precisely from 12 months of your meter data.

How it works

Go commercial solar in three steps

STEP 01

Site visit + structural assessment

A local engineer visits, assesses your roof for pitch, orientation and shading, and designs a 100kW system around your actual demand profile. No cost, no obligation.

STEP 02

Fixed-price commercial proposal

A clear, itemised commercial proposal with AIA modelling guidance for your accountant. We handle all paperwork and grid approvals as standard.

STEP 03

Installation & commissioning

Our in-house team completes installation in one to three weeks on site. Tested, MCS-certified and the commercial monitoring dashboard set up before we leave.

Why Solar4Good

Engineer-led, in-house, UK-wide

You work with a UK-wide commercial team based in Harrow, not a remote sales centre. The person who assesses your roof is directly involved in designing the system, and once it is in we handle MCS certification, SEG export-tariff setup and your monitoring app, so you are never left navigating the process alone.

3,000+UK installs

50,000+Panels installed

4.9★from 1,000+ reviews

MCSCertified, in-house

Rated 4.9/5 from 1,000+ verified reviews on Trustpilot, TrustATrader and Google

“George the sales chap was straightforward and honest, and the whole installation team were awesome, courteous and professional throughout.”

Jamie Wilson · Verified Trustpilot review

“From start to finish the whole job has been seamless. The install guys were polite, knowledgeable and efficient.”

Timothy Clarke · Verified Trustpilot review

“I wholeheartedly recommend this company for solar and battery storage installation.”

Soham Acharya · Verified Trustpilot review

Read All reviews →

Good to know

The questions businesses actually ask about a 100kW commercial solar system.

Is a 100kW system right for a large industrial site?

A 100kW system suits larger industrial units, warehouses, supermarkets and hotel chains with annual demand of 85,000 to 125,000 kWh. Three-phase supply is standard and the per-kW cost is strong at this scale.

How many panels are needed for 100kW?

200 to 225 panels across roughly 450 to 550 square metres of roof, sized to deliver 100 kW DC, often with capacity for future expansion.

What is the business case for commercial solar?

Commercial solar is eligible for the Annual Investment Allowance, business rates exemption to April 2035, and 20% reclaimable VAT. With high daytime self-consumption, payback is typically faster than an equivalent residential system.

Do you carry out a structural assessment?

Yes. Every commercial project starts with a site visit and structural assessment. A qualified engineer reviews roof type and load capacity and, where available, 12 months of half-hourly meter data to design around your actual demand.

Who installs it, and do you handle the paperwork?

Most installations are carried out under our own MCS registration. Further afield we use installers working under our MCS registration, and the certificate and workmanship warranty remain ours. We handle all paperwork, grid approvals, MCS certification and AIA modelling guidance for your accountant.