No. They are plain-English orientation to get you up to speed before a survey. The specifics that apply to your building, the system size, the grid terms, the cost and the return, are confirmed for your site once we have surveyed the roof and modelled your half-hourly load. Where a guide touches tax or finance, confirm the position with a qualified adviser.
Alectrona
Commercial solar guidesThe commercial solar questions, answered plainly.
Orientation for a finance or facilities director looking at solar over 50 kWp: the grid process, the compliance that replaces MCS at this scale, and how the cost and returns actually work. Guides, not a sales pitch.
- Plain English, not jargon
- Over 50 kWp, outside MCS
- Orientation, not advice
What these guides are, and what they are not.
A commercial solar project runs on engineering and process, not a brochure. These guides explain the parts that decide whether a system gets built, gets connected and earns its place: the grid application, the assurance stack that stands in for MCS above 50 kWp, and the honest version of cost and payback.
They are orientation, written to get a commercial buyer up to speed before the survey, not formal advice for a specific site. Every figure that matters to your building, the system size, the cost and the return, comes from an on-site drone survey and a half-hourly model, not from a guide. Where a guide touches tax or finance, confirm the position with your own adviser.
Guides by topic.
Connecting to the grid
A system over 50 kWp connects through your Distribution Network Operator, not a domestic notification. These guides orient you on the process before the application goes in.
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G99 application
What G99 means for a commercial solar export connection: how the DNO assesses your system, why a larger array needs a full application, and where G100 fits.
Read the guide -
Grid-connection queue
Why a DNO connection offer can take time, what network capacity limits commercial solar, and how an export-limited design can avoid the queue.
Read the guide -
DNO explained
What a Distribution Network Operator is, how the regional DNO model works, and why every commercial solar project needs DNO sign-off before it can connect.
Read the guide -
G100 export limitation
What G100 export limitation means for commercial solar: how an agreed or zero export limit lets a constrained network grant a connection, distinct from G99.
Read the guide -
Network charges (DUoS, TNUoS)
What DUoS and TNUoS network charges are, why self-consumed solar reduces the units you import, and why they grow material on larger commercial systems.
Read the guide -
How long installation takes
A realistic end-to-end timeline for a commercial solar install over 50 kWp: survey, design, the G99 DNO application, procurement, install and commissioning.
Read the guide
Compliance and assurance
MCS is a domestic-scale scheme; commercial systems are assured by a different stack. Planning, fire safety, construction duties and how a system is signed off without MCS.
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Rooftop planning permission
When commercial rooftop solar needs planning permission and when permitted development applies, plus prior approval, Article 4 and listed buildings.
Read the guide -
Quality without MCS
MCS caps at 50 kWp, so it cannot assure commercial solar. Here is the engineering stack that takes its place, and why a finance director can rely on it.
Read the guide -
RC62 fire safety
What RC62, the insurer fire-safety guidance for rooftop solar, asks of a commercial array, why your insurer cares, and how good engineering answers it.
Read the guide -
CDM 2015
How CDM 2015 applies to a commercial solar install: your client duties, the principal designer and contractor roles, and how work at height is planned.
Read the guide -
MEES / EPC for commercial solar
EPC E is the band in force to let; EPC B was reset to 2031 for larger let buildings. How on-site solar feeds the SBEM model, and what is still policy.
Read the guide -
BS 7671 for solar
What BS 7671, the UK wiring regulations, requires of a commercial solar system, why Section 712 covers PV, and how it fits the non-MCS assurance stack.
Read the guide -
Asbestos on older roofs
Why an older roof needs an asbestos survey before solar, what the Control of Asbestos Regulations 2012 require, and why mounting stays non-penetrative.
Read the guide -
Ground-mount planning
Why ground-mount commercial solar generally needs full planning permission, what the application considers, and how its lead time differs from rooftop work.
Read the guide -
Choosing a commercial installer
How to choose a commercial solar installer above 50 kWp: the checks that matter, the documents to ask for, and the red flags that should end a conversation.
Read the guide -
Commercial solar insurance
A finance director's orientation to insuring commercial solar: the contractor's liability cover, the post-50 kWp protection gap and insurer disclosure.
Read the guide -
Commercial solar maintenance
What ongoing O&M a commercial solar system needs, and how to read a contract: scope, preventive and corrective work, reporting and warranty terms.
Read the guide -
Cleaning and bird-proofing
Condition-led commercial solar panel cleaning and perimeter bird-proofing for arrays over 50 kWp. Why shallow-pitch and coastal roofs soil. Book a survey.
Read the guide -
PAS 2038
What PAS 2038, the non-domestic retrofit specification, is, how commercial solar sits inside it, and why it suits a project over 50 kWp outside MCS.
Read the guide -
Structural roof survey
What a structural roof survey checks before a commercial solar array: load cases, purlin and fixing capacity, remaining roof life, and engineer sign-off.
Read the guide
Sizing and metering
The right system size comes from your actual load, not your roof area. How half-hourly data and a roof survey set the figure.
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Half-hourly metering
What half-hourly settlement metering is, why most larger commercial sites are on it, and how that 30-minute data is the best single input for sizing solar.
Read the guide -
How much roof space?
A rule-of-thumb guide to roof area per kWp for commercial rooftop solar, what kWp common roof sizes carry, and why the firm figure needs a survey.
Read the guide
Cost and returns
What drives the capital cost, how payback is actually calculated, and an honest read on when commercial solar is worth it. Indicative only, never a from-price.
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Commercial solar cost
What drives the capital cost of a commercial solar system over 50 kWp, why there is no honest 'from £X' headline, and how we reach a fixed price from a survey.
Read the guide -
ROI and payback
How commercial solar payback and ROI are worked out: capex, annual saving, self-consumption and first-year tax relief, and the mechanics behind any figure.
Read the guide -
Feasibility study
What a commercial solar feasibility study contains and how it replaces a from-price with a real, site-specific number: drone survey, half-hourly load, PV*SOL.
Read the guide
Reporting and ESG
How commercial solar shows up in mandatory energy and carbon reporting, and how the carbon saving is actually calculated. Methodology, not headline numbers.
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ESOS and SECR
How ESOS energy audits and SECR carbon reporting apply to large UK businesses, and how on-site solar reduces reported energy use and Scope 2 emissions.
Read the guide -
Social value and carbon reporting
How metered on-site solar evidences a Scope 2 reduction for SECR and ESG, and how it scores in public-sector social-value and Carbon Reduction Plan bids.
Read the guide
Panels and cell technology
The module on the roof: how we choose the cell technology, the format and bifacial gain, and what bankable and Tier 1 actually mean.
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Bankable Tier 1 panels
What bankable and BloombergNEF Tier 1 mean for commercial solar panels: a financeability heuristic, not a quality guarantee. We name the scheme and quarter.
Read the guide -
TOPCon vs HJT vs PERC
How TOPCon, HJT and PERC cells differ on a commercial roof, what changes kWh/kWp, and why the right choice is modelled for your roof. Get it modelled.
Read the guide -
Bifacial on flat roofs
Where bifacial panels earn real rear-gain on a commercial flat roof: albedo, row spacing and elevation, modelled in PV*SOL for your roof rather than assumed.
Read the guide -
Best commercial solar panels
There is no single best commercial solar panel. Five weighed criteria decide it: bankability, efficiency, warranty, temperature coefficient and roof fit.
Read the guide -
String vs central inverters
How string and central inverters differ on a commercial project: MPPTs, redundancy, serviceability and phasing, chosen for your roof rather than a spec sheet.
Read the guide -
Why we do not specify Huawei
Why Alectrona does not specify Huawei on a commercial system: the LUNA battery line is being withdrawn from the UK, plus long-term support and policy risk.
Read the guide
Commercial solar guides: common questions
MCS is a certification scheme built around domestic-scale installations. Systems over 50 kWp sit above it, so MCS is not the assurance for a commercial project. The assurance comes from a different stack: design and wiring to BS 7671, commissioning to IEC 62446-1, a compliant G99 grid connection, CDM 2015 construction duties and a JCT or NEC contract. The guides on compliance and assurance walk through it.
The G99 application, the DNO correspondence and the CDM 2015 duties are part of delivering the system, not a separate exercise you are left to manage. The design, the protection settings and the export strategy all feed the grid application, and the network operator response feeds back into the design.
The cost and returns guides explain how the numbers are built and what drives them, which is the honest thing a guide can do. The actual figure for your site is not a from-price: it comes from a system sized to your roof and modelled against your real consumption. That is the number worth having.
A dated programme arrives with the proposal, once the survey and model are done. The site survey reaches you quickly from our Yorkshire base, so getting to your roof is rarely the slow part. From there the pace is set by the G99 connection to your DNO, whose timescales drive the date more than travel or panel supply ever do. The installation timeline guide walks through each stage.
Get a commercial quote
Read the guide, then get the numbers for your roof.
We model your half-hourly load against a system sized from an on-site drone survey, so the figure you get is yours, not a from-price. No obligation, and no MCS gatekeeping on systems this size.
- On-site 3D drone survey, fully insured in-house pilot
- Half-hourly load modelled in PV*SOL before anything is specified
- Engineer-led, assured to the non-MCS standard (CDM 2015)