Battery Storage Companies in Cardiff: 25 Active Firms (2026)

Battery storage companies in Cardiff develop and operate grid-scale batteries and flexibility services for electricity networks across the city region.

Buying decisions tend to sit with network-facing energy teams, renewable-site owners, commercial landlords, industrial energy users and public-sector estates rather than domestic consumers. Work is usually project-led: connection studies, asset development, operational optimisation, maintenance, trading support and flexibility-service participation. Cardiff firms in this niche appear to cluster around small to mid-market engineering, developer and asset-management models, with engagement sizes shaped by grid constraints, site control and the ability to combine batteries, power electronics and energy-management software into bankable operating cases.

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Cardiff has 25 actively trading battery storage companies, making this a narrow local cohort rather than a broad energy-software market. Reported employment across the cohort is 48 people, which points to a base dominated by compact operators, consultancies and project vehicles rather than labour-intensive manufacturers. The commercial centre of gravity appears to be South Wales power infrastructure: grid connection work, flexibility services, renewable co-location and energy management for public and industrial estates around the city region.

Grid-facing battery storage sits in a market shaped by connection queues, planning consent, network charging, capacity obligations and balancing-service qualification. For Cardiff operators, the practical constraint is often less the battery chemistry than the ability to secure a usable grid position and a contract stack that can support the asset. Public-sector estates and industrial users add procurement and site-risk disciplines, while flexibility revenues depend on operational reliability and eligibility for network and system-balancing services.

Commercial development appears likely to favour firms that can combine development capability with operational discipline, rather than pure project origination. The cohort looks early-commercial in shape, with many businesses likely to remain specialist advisers, project companies or local asset managers. Consolidation may come from operators seeking grid positions and planning progress, while smaller engineering-led firms may continue to sell services into developers and estates. Revenue quality, connection certainty and route-to-market will matter more than broad claims about storage demand.

What’s in the file

One row per company, 50+ columns — everything below plus each company’s verified directors, from Companies House filings.

Company data

Company name
Website
City & address
Companies House no.
Incorporation date
SIC codes & industry tags
What they do / who they sell to
Turnover, profit, cash & net assets
Employees
Growth (YoY & 3-year)
Financial-health score & flags
Sales-readiness score
Detected technologies

Verified directors — included

Director names
Director roles
Appointment dates

25

Active firms

2026

2

Above £5M

Reported revenue

6

Newer firms

Incorporated since 2022

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Key facts

About 8% of the trading cohort reports turnover above £5M (2 of 25 firms) — the rest sits below that revenue band.

24% of the cohort was incorporated since 2022 (6 firms), so a sizeable share is in its first few filing cycles.

Cardiff battery-storage firms sit close to electricity-network constraints, where asset dispatch and route-to-market choices shape project economics.

The local market includes asset-owning and project-finance models, rather than only labour-intensive services businesses.

Flexibility services link battery assets to balancing requirements across the UK electricity market.

Top Cardiff Battery Storage companies

Company
Sales readinessHow strongly each company matches this list’s ideal-customer profile. An AI model assesses what each company does (from its website), its sector and size, and scores its overall fit 0–100. Companies are listed highest score first, so the best-fit prospects appear at the top.
Turnover
Employees
Growth (yoy)Year-on-year change in UK headcount, from filed accounts.
Financial healthComposite 0–100 score from recent XBRL filings (profitability, net assets, liquidity, cash, headcount). Bands: Strong, Healthy, Stable, Weak, Distressed.
Location
WP GRID STORAGE 5 LIMITED
Welsh Power
UtilitiesRenewable Energy
Inc. 2022CardiffCH 14049814
welshpower.com
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Financial sub-scores

Computed from 3 filings
Net assets40 / 100
Cash55 / 100
What does WP GRID STORAGE 5 LIMITED do?

Develops, constructs and manages distributed energy assets including gas‑fired peaking plants, grid stability infrastructure and battery storage projects, providing flexible power generation and…

Who does WP GRID STORAGE 5 LIMITED sell to?

Serves B2B energy asset owners, developers and infrastructure investors with flexible generation, grid stability and battery projects for electricity networks across the UK.

Full details & directors in the file
Company vitals
UK Headcount
0
UK Revenue
£6KEstimate
Founded
4 years ago
Since Apr 2022
HQ
Cardiff
Financial health
46

Financial Health

Stable

Stable

Location

Map of Cardiff
Fourth Floor,, 2 Kingsway
Cardiff, CF10 3FD
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SERO TECHNOLOGIES LIMITED
Sero
Renewable EnergyReal Estate & PropertyStartup
6 employeesInc. 2017CardiffCH 10928834
sero.life
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Financial sub-scores

Computed from 5 filings
Cash100 / 100
Headcount100 / 100
What does SERO TECHNOLOGIES LIMITED do?

Provides retrofit and energy services for social housing, installing technologies such as solar panels and batteries and managing smart energy use. Aggregates homes to purchase electricity and…

Who does SERO TECHNOLOGIES LIMITED sell to?

Serves social housing landlords and their residents, plus institutional investors and funders seeking climate and social impact from retrofit programmes in the UK housing sector.

Key contacts (1)
LS
Laura Sandys
Director
Full details & directors in the file
Company vitals
UK Headcount
6
UK Revenue
£2.3MEstimate
Founded
8 years ago
Since Aug 2017
HQ
Cardiff
Financial health
100

Financial Health

Strong

Strong · Hiring · 19% CAGR over 4y

Hiring

Location

Map of Cardiff
Westgate House, Womanby Street
Cardiff, CF10 1BR
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GREEN FROG POWER LIMITED
Green Frog Power
UtilitiesRenewable Energy
7 employeesInc. 2021Cardiff, South GlamorganCH 13352043
greenfrogpower.co.uk
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Financial sub-scores

Computed from 4 filings
Net assets0 / 100
Headcount90 / 100
What does GREEN FROG POWER LIMITED do?

Builds and operates fast‑start power stations supplying standby and peak electricity to the national grid. Develops and delivers power generation projects including gas‑fuelled peaking plants and…

Who does GREEN FROG POWER LIMITED sell to?

Sells to National Grid and UK wholesale energy-market counterparties, serving grid operators and electricity-market buyers that require standby generation capacity.

Full details & directors in the file
Company vitals
UK Headcount
7
UK Revenue
£707.1KEstimate
Founded
5 years ago
Since Apr 2021
HQ
Cardiff, South Glamorgan
Financial health
34

Financial Health

Weak

Weak · Hiring · 12% CAGR over 3y

HiringFinancial distressTechnical insolvency

Location

Map of Cardiff, South Glamorgan
4th Floor 1 Capital Quarter, Tyndall Street
Cardiff, South Glamorgan, CF10 4BZ
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SMS
UtilitiesRenewable Energy
6 employeesInc. 1996CardiffCH 03197379
smsenergy.com
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What does SMS do?

Provides energy infrastructure, smart metering installation and management, and gas and electricity data services. Also delivers energy management, demand flexibility and project delivery services to…

Who does SMS sell to?

Serves UK energy suppliers, utilities, industrial and commercial organisations, public sector bodies and domestic consumers involved in energy generation, supply and consumption.

Full details & directors in the file
Company vitals
UK Headcount
6
UK Revenue
£76.5KEstimate
Founded
30 years ago
Since May 1996
HQ
Cardiff

Location

Map of Cardiff
Prennau House Copse Walk, Cardiff Gate Business Park, Pontprennau
Cardiff, CF23 8XH
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Nuvolt Ltd
Nuvolt
Renewable EnergyField Services & Trades
16 employeesInc. 2021Cardiff, South GlamorganCH 13454546
nuvolt.co.uk
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Financial sub-scores

Computed from 3 filings
Cash100 / 100
Headcount100 / 100
What does Nuvolt Ltd do?

Designs and installs commercial renewable energy systems including solar PV, battery storage and electric vehicle charging infrastructure. Provides consultancy, system design, installation and…

Who does Nuvolt Ltd sell to?

Serves UK businesses, commercial property operators, EPC contractors, and organisations with commercial, domestic or public charging facilities seeking low-carbon energy infrastructure.

Key contacts (1)
CC
Chandra Chandrappa Gowda Bipin
Director
Full details & directors in the file
Company vitals
UK Headcount
16
UK Revenue
£2MEstimate
Founded
5 years ago
Since Jun 2021
HQ
Cardiff, South Glamorgan
Financial health
100

Financial Health

Strong

Strong · Hiring · 73% CAGR over 2y

Hiring

Location

Map of Cardiff, South Glamorgan
39 Cardiff Road, Llandaff
Cardiff, South Glamorgan, CF5 2DP
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Ecogen Innovations Ltd
Ecogen
Renewable EnergyUtilitiesWaste Management
5 employeesInc. 2023CardiffCH 15355567
ecogentech.io
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What does Ecogen Innovations Ltd do?

Develops renewable energy systems including waste-to-energy plants that convert municipal waste into electricity, hybrid solar‑wind microgrids with battery storage, modular off‑grid power units, and…

Who does Ecogen Innovations Ltd sell to?

Serves government agencies, municipalities, hospitals, community leaders and businesses needing clean energy infrastructure, including towns, industries, remote or off-grid communities, disaster…

Key contacts (1)
AD
Abdul Daiem Mehboob
Director
Full details & directors in the file
Company vitals
UK Headcount
5
UK Revenue
£181.6KEstimate
Founded
2 years ago
Since Dec 2023
HQ
Cardiff
Financial health

Financial Health

N/A

N/A

Location

Map of Cardiff
15355567 - Companies House Default Address
Cardiff, CF14 8LH
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Aldustria Ltd
Aldustria
StartupRenewable Energy
Inc. 2020NewportCH 13042739
aldustria.com
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Financial sub-scores

Computed from 4 filings
Net assets0 / 100
Cash100 / 100
Headcount0 / 100
What does Aldustria Ltd do?

Develops, delivers and operates grid-scale battery energy storage systems (BESS). Procures and manages fast-response storage projects that store electricity and provide grid-balancing services,…

Who does Aldustria Ltd sell to?

Serves UK power-sector stakeholders, infrastructure investors and mixed-use development partners involved in grid-scale battery storage, private-wire, micro-grid and EV charging projects.

Full details & directors in the file
Company vitals
UK Headcount
0
UK Revenue
£369.3KEstimate
Founded
5 years ago
Since Nov 2020
HQ
Newport
Financial health
27

Financial Health

Weak

Weak

Financial distressTechnical insolvency

Location

Map of Newport
Unit A & B Leeway House, Leeway Industrial Estate
Newport, NP19 4SL
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TEWDRIC ENERGY CYMRU LTD
Tewdric Energy
Renewable EnergyField Services & Trades
Inc. 2024BarryCH 15470577
tewdricenergy.com
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What does TEWDRIC ENERGY CYMRU LTD do?

Designs and installs solar photovoltaic (PV) systems, battery energy storage, and electric vehicle charging points for homes, businesses, and community projects, providing on‑site renewable…

Who does TEWDRIC ENERGY CYMRU LTD sell to?

Serves homeowners, businesses, councils, housing associations and local community groups across South Wales seeking solar, battery storage and EV charging solutions.

Full details & directors in the file
Company vitals
UK Headcount
0
UK Revenue
£0Estimate
Founded
2 years ago
Since Feb 2024
HQ
Barry
Financial health

Financial Health

N/A

N/A

Location

Map of Barry
Bay 3 Building 215, Bro Tathan
Barry, CF62 4AF
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Infinite Renewables Wales Ltd
Infinite Renewables
Renewable EnergyUtilities
2 employeesInc. 2023BridgendCH 14615689
infiniterenewables.com
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Financial sub-scores

Computed from 2 filings
Net assets15 / 100
Cash58 / 100
Headcount40 / 100
What does Infinite Renewables Wales Ltd do?

Designs, develops and manages renewable energy projects including wind, solar and battery storage systems. Supplies wind turbines and microgrid solutions, and provides consultancy, asset management,…

Who does Infinite Renewables Wales Ltd sell to?

Serves businesses and organisations seeking renewable energy infrastructure, including industrial sites, sustainability teams, remote or off-grid operators, and international project partners.

Full details & directors in the file
Company vitals
UK Headcount
2
UK Revenue
£171.1KEstimate
Founded
3 years ago
Since Jan 2023
HQ
Bridgend
Financial health
33

Financial Health

Weak

Weak · 0% CAGR over 1y

Location

Map of Bridgend
1000b Central Park, Western Avenue
Bridgend, CF31 3RT
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MODERN ENERGY AND ELECTRICAL SERVICES LTD
Modern Energy and Electrical Services
Renewable EnergyField Services & Trades
Inc. 2014PorthcawlCH 08885321
modernenergyelectricalservices.com
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Financial sub-scores

Computed from 5 filings
Net assets100 / 100
Cash100 / 100
What does MODERN ENERGY AND ELECTRICAL SERVICES LTD do?

Installs and maintains solar energy systems, battery storage and electrical installations for residential, commercial and industrial properties. Provides electrical contracting, renewable energy…

Who does MODERN ENERGY AND ELECTRICAL SERVICES LTD sell to?

Serves homeowners, commercial businesses and industrial clients seeking renewable and electrical project support, with stated coverage across South Wales, the West and nationwide.

Key contacts (1)
JP
John Paul Thomas
Director
Full details & directors in the file
Company vitals
UK Headcount
0
UK Revenue
£326.7KEstimate
Founded
12 years ago
Since Feb 2014
HQ
Porthcawl
Financial health
100

Financial Health

Strong

Strong

Location

Map of Porthcawl
337 New Road
Porthcawl, CF36 5PH
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Off Grid Engineering Ltd
OFF Grid Engineering
Renewable EnergyField Services & Trades
2 employeesInc. 2020Cowbridge, Vale of GlamorganCH 12426283
offgridsolarexperts.co.uk
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Financial sub-scores

Computed from 5 filings
Net assets6 / 100
Cash100 / 100
Headcount40 / 100
What does Off Grid Engineering Ltd do?

Designs and installs off‑grid power systems using solar PV, battery storage and generators. Provides system design, turnkey installation, upgrades, and remote monitoring for homes, businesses and…

Who does Off Grid Engineering Ltd sell to?

Serves homeowners, self-builders and rural property owners, plus businesses with remote sites such as workshops, holiday lodges and commercial premises needing off-grid power systems.

Key contacts (2)
IM
Ian Michael Hewson
Director
DS
David Scott Simpson
Director
Full details & directors in the file
Company vitals
UK Headcount
2
UK Revenue
£651.7KEstimate
Founded
6 years ago
Since Jan 2020
HQ
Cowbridge, Vale of Glamorgan
Financial health
41

Financial Health

Stable

Stable · 0% CAGR over 4y

Location

Map of Cowbridge, Vale of Glamorgan
C/O Bevan Buckland Llp Suite 4 Britannia House, Penny Lane
Cowbridge, Vale Of Glamorgan, CF71 7EG
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How Cardiff Battery Storage companies work and how to sell to them

What they do

Cardiff battery-storage firms usually make money from project development fees, engineering consultancy, asset-management retainers and operating revenue linked to flexibility services. Some take fees for feasibility work, connection strategy, planning support and procurement management; others own or manage storage assets and earn from contracted availability, balancing participation and optimisation of power flows around renewables or high-load sites. Hardware margin may exist where batteries, inverters and metering are supplied, but many small operators sit closer to services and controls than manufacturing. Only 2 have crossed £5M turnover, so pricing is likely to be bespoke, milestone-based and tied to site risk rather than standard subscription bundles.

Who they sell to

Typical buyers are asset owners and energy-intensive organisations: renewable-site developers, commercial landlords, industrial energy users, local authorities and estates teams that need lower exposure to grid constraints or better use of on-site generation. Decision makers tend to include energy managers, estates directors, finance leads, technical directors and procurement teams, with network-facing specialists influencing the specification. Smaller advisory jobs may close through direct relationships, while asset development, public-sector work and long-term operations contracts usually require tendering, due diligence and board-level approval. Sales cycles are often governed by connection milestones and planning risk, so a technically interested buyer may still move slowly until site control and revenue assumptions are clearer.

What they buy

Most Cardiff battery-storage firms tend to spend on grid studies, planning advice, legal support, financial modelling, insurance and metering before they buy general business software. Operating assets then bring demand for monitoring, controls, forecasting, cyber security, maintenance scheduling, incident management and market-settlement workflows. Developer-led firms may also need land and lease support, project finance advice, geospatial tools, document management and bid support for public or industrial customers. Compact teams often outsource accounting, HR, recruitment and specialist engineering rather than building permanent departments, so services providers need a clear link to project milestones, operational availability or financeability.

Why and how to sell to them

Battery storage buyers tend to evaluate vendors when a connection offer changes, a site moves from option to development, an asset starts trading, or an estate owner asks for evidence that storage will reduce cost and risk. Other triggers include new leadership, a capital raise, a public-sector tender, hiring for operations roles or a move from consultancy into asset ownership. Outbound works better when it names the operational constraint: queue delays, uncertain revenue stacking, battery availability, reporting to lenders, fire-risk governance or procurement paperwork. Generic decarbonisation language is less useful than showing where a supplier removes friction between engineering, finance and commercial operation.

How this list is built

Methodology

Data sources

This list is built from UK Companies House filings, XBRL accounts data, and semantic analysis of each company's public website. Revenue and headcount figures come from the most recent filed accounts; where the company has not filed, values are estimated using a model trained on filed history and peer benchmarks and are labelled as estimates.

Classification

Rather than relying solely on SIC codes, Firmbase classifies each company semantically: the company's website is crawled, an AI model reads what the company actually sells, and the company is placed into the relevant industry and subsectors. SIC codes are used as one signal but not the only one. This means a company that registered under a generic SIC code but pivoted into (for example) fintech is correctly identified as fintech, not as its original SIC category.

Freshness

The underlying company data is refreshed from Companies House continuously; filings appear in the list within days of submission. The curated list ordering is regenerated when the underlying data moves meaningfully (company count changes by more than 5%, a new company enters the top-ranked segment, or the filed-revenue numbers for the top firms change). You can see the last-updated timestamp near the top of the page.

Sources

  • July 2024: Battery energy storage research round-up
    • 141 individual battery units make up 4.1 GW of battery energy storage capacity currently operating in Great Britain.
    • Q2 2024 saw 186 MW of new battery energy storage capacity begin commercial operations in Great Britain.
    • The first half of 2024 added 370 MW of new operational battery energy storage capacity, the lowest since 2022.
    • 1.4 GW of non-operational sites hold Capacity Market contracts for 2024/25, with 1.1 GW expected operational in Q3 2024.
    • In the most optimistic case, operational battery energy storage capacity would reach 5.2 GW at the end of 2024, 1.5 GW below pipeline capacity.

Also in Cardiff

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Frequently asked questions

How many battery storage companies are there in Cardiff?
Around 25 actively-trading battery storage companies are registered in Cardiff. Of those, 2 report turnover above £5M in their most recent filed accounts. This Cardiff list covers companies across the wider Cardiff travel-to-work area, including surrounding towns — not just the Cardiff local-authority boundary.
What counts as a battery storage company in this list?
A company is included when its public website and filed activity descriptions indicate it sells battery storage products or services as its primary business — not just because of the SIC code it picked at incorporation. Each company is tagged via semantic analysis of its website content; SIC codes are used as supporting signal, not the sole gate.
Which are the largest battery storage companies in Cardiff?
The list is ranked by a sales-readiness score — built from trading signals, financial health and growth rather than raw turnover — so the most actionable battery storage companies in Cardiff appear at the top of the table. Larger firms often still rank highly, because that score rewards genuine trading scale, but the order reflects sales-readiness, not turnover alone. About 2 of the 25 actively-trading firms report turnover above £5M in their most recent accounts; subsidiaries that file consolidated worldwide accounts are excluded so the figures stay comparable across UK filers.
What do battery storage companies in Cardiff actually do?
Cardiff battery-storage firms usually make money from project development fees, engineering consultancy, asset-management retainers and operating revenue linked to flexibility services. Some take fees for feasibility work, connection strategy, planning support and procurement management; others own or manage storage assets and earn from contracted availability, balancing participation and optimisation of power flows around renewables or high-load sites. Hardware margin may exist where batteries, inverters and metering are supplied, but many small operators sit closer to services and controls than manufacturing. Only 2 have crossed £5M turnover, so pricing is likely to be bespoke, milestone-based and tied to site risk rather than standard subscription bundles.
How does Cardiff battery storage compare internationally?
Cross-border comparisons of battery storage populations are tricky because every country defines the sector slightly differently and reports financials on different cadences. We focus this list on firms that file UK statutory accounts so the figures are comparable; international peer breakdowns aren't bundled here.
How is this list built and how fresh is the data?
The list is rebuilt from Companies House dump data, XBRL filings, and a website analysis pass over each company's public site. Companies with consolidated group accounts (worldwide rather than UK-only revenue) are excluded so the figures stay UK-specific. The page's last-updated date is shown at the top.
How big are the typical battery storage companies in Cardiff?
Company sizes in this list vary widely. The median actively-trading battery storage firm employs around 2 people, and median UK turnover across the list is roughly £331k in the most recent filed accounts.
Are these mostly new or established battery storage companies?
6 of the 25 actively-trading battery storage companies in this list were incorporated since 2022; the remainder were incorporated before then, so the Cardiff list mixes recent entrants with longer-established firms.
What SIC codes does this use?
Rather than relying solely on SIC codes, we build a semantic understanding of what each company actually does by scraping its website and analysing it with AI. This means a company is included based on what it sells, not what SIC code it picked at incorporation. SIC codes are used as a signal but not the primary classification.
What buying signals should I look for?
The strongest signals for B2B outbound are recent leadership changes (new CFO/CRO), rapid headcount growth, revenue-band changes, and web-stack changes. Firmbase tracks all of these automatically.

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