Company lists · Data refreshed September 2026

Top 25 Sustainable development firms based in Johannesburg, South Africa

Name: Sustainable development firms based in Johannesburg, South Africa
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 22, 2026 91 companies tracked

RevenueBase identified 91 sustainable development firms headquartered in Johannesburg, South Africa as of September 2026 and tracks 783 professional contacts across them, including 302 with verified work emails. Johannesburg is the largest hub.

This list covers sustainable development firms headquartered in Johannesburg, South Africa, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 22, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 22, 2026 86% judged on-target in blind review

91Companies

783Contacts tracked

302Verified emails

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The 25 largest sustainable development firms based in Johannesburg, South Africa

Ranked by team size

Top 25 of 91 sustainable development firms based in Johannesburg, South Africa, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to sustainable development firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Siyakha Consulting	Strong evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	51-200	90 contacts →
	Strong evidence “We are a niche firm that drives investment, commercial excellence, developmental strategies, and sustainability.” Source: RevenueBase Database · checked Sep 22, 2026
2	Pele Energy Group	Strong evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	51-200	68 contacts →
	Strong evidence “A sustainable development company.” Source: RevenueBase Database · checked Sep 22, 2026
3	Pele Green Energy	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	51-200	51 contacts →
	Indirect evidence “Founded in 2009, Pele Green Energy (PGE) is a leading independent power producer dedicated to transforming Africa’s energy landscape through innovative renewable energy solutions.” Source: RevenueBase Database · checked Sep 22, 2026
4	Synergy Global Consulting LTD	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	37 contacts →
	Indirect evidence “Synergy Global Consulting Ltd (Synergy) is an independent international consulting company that works with natural resource and infrastructure sectors operating in challenging…” Source: RevenueBase Database · checked Sep 22, 2026
5	Solid Green	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	36 contacts →
	Partial evidence “Solid Green Consulting is a young and energetic company enthusiastic about advancing sustainability in the built environment.” Source: RevenueBase Database · checked Sep 22, 2026
6	Harmattan Renewables	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	35 contacts →
	Indirect evidence “Harmattan Renewables brings together a team of experienced renewables consultants who have been at the forefront of developing Africa’s renewables sector.” Source: RevenueBase Database · checked Sep 22, 2026
7	Journey2green	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	22 contacts →
	Indirect evidence “Journey2Green see the decision to go Renewable Energy as a Journey and like any journey you plan for it with a start date, an end-destination and a route plan to get you there…” Source: RevenueBase Database · checked Sep 22, 2026
8	Savannah Environmental PTY LTD	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	21 contacts →
	Indirect evidence “Through undertaking a broad range of environmental studies, Savannah Environmental has gained extensive experience with regards to environmental legislation requirements and…” Source: RevenueBase Database · checked Sep 22, 2026
9	Brundtland Consulting	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	19 contacts →
	Indirect evidence “Brundtland Consulting is a South African management consulting firm specialized in climate change, green economy and renewable energy.” Source: RevenueBase Database · checked Sep 22, 2026
10	Umsizi Sustainable Social Solutions	Strong evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	16 contacts →
	Strong evidence “Umsizi Sustainable Social Solutions (Umsizi) specialises in designing customised solutions and implementing effective programmes to promote sustainable socio-economic development.” Source: RevenueBase Database · checked Sep 22, 2026
11	Dhahabu Consulting	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	15 contacts →
	Indirect evidence “Dhahabu Consulting (Pty) continuously works to being the partner, service provider and employer of choice offering customised project management, project controls (quantity…” Source: RevenueBase Database · checked Sep 22, 2026
12	Nsovo Environmental Consulting	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	13 contacts →
	Partial evidence “Our specialist area of focus is the assessment of multifaceted projects, including the establishment of linear developments, bulk infrastructure, power generation and…” Source: RevenueBase Database · checked Sep 22, 2026
13	Ep3 Environmental	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	12 contacts →
	Partial evidence “EP3 Environmental (Pty) Ltd was established by Eben van Schalkwyk in 2013 and is a multi-disciplinary consulting firm that provides Environmental and Sustainability consulting…” Source: RevenueBase Database · checked Sep 22, 2026
14	Delta Carbon	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	9 contacts →
	Indirect evidence “Delta Carbon is an integrated energy services and decarbonisation advisory company.” Source: RevenueBase Database · checked Sep 22, 2026
15	TCH Group	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	9 contacts →
	Partial evidence “At TCH Group, we're on a mission to create a brighter, more sustainable future through innovative solutions.” Source: RevenueBase Database · checked Sep 22, 2026
16	Mamadi And Company SA	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	5 contacts →
	Indirect evidence “Mamadi and Company is a leading professional services firm offering superlative consulting services in planning, design, engineering, project management, construction management…” Source: RevenueBase Database · checked Sep 22, 2026
17	Elizabeth Kent Consulting	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	5 contacts →
	Partial evidence “Elizabeth Kent Consulting is a writing, communications and reporting firm with a sustainability specialism.” Source: RevenueBase Database · checked Sep 22, 2026
18	Greenfield Sustainable Group	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	11-50	5 contacts →
	Indirect evidence “Greenfield denotes pristine resources with untapped potential, operating at peak capacity.” Source: RevenueBase Database · checked Sep 22, 2026
19	Citycon Africa	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	5 contacts →
	Partial evidence “CityCon.Africa is a boutique project development and preparation advisory consultancy focusing on African infrastructure and cities.” Source: RevenueBase Database · checked Sep 22, 2026
20	NSI Consultants	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	4 contacts →
	Partial evidence “We pride ourselves in assisting businesses to drive sustainable growth through Impact Investing and helping NGOs carry out the phenomenal work they do to strengthen our…” Source: RevenueBase Database · checked Sep 22, 2026
21	Solar Deity PTY LTD	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	4 contacts →
	Indirect evidence “At Solar Deity (Pty) Ltd, we're on a mission to revolutionize South Africa's renewable energy landscape.” Source: RevenueBase Database · checked Sep 22, 2026
22	Energidrop	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	3 contacts →
	Partial evidence “Energidrop is growing a team to address some of the most pressing needs in the quest to solve the sustainability puzzle in the 21st century.” Source: RevenueBase Database · checked Sep 22, 2026
23	Cominergy Africa Group	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	3 contacts →
	Indirect evidence “At Cominergy, we are united and fueled by the power of purposeful projects within strategic economic sectors.” Source: RevenueBase Database · checked Sep 22, 2026
24	Alpenglow Consulting	Partial evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	3 contacts →
	Partial evidence “Alpenglow Consulting is a leading energy project development and advisory firm based in Johannesburg, South Africa.” Source: RevenueBase Database · checked Sep 22, 2026
25	NIA Impact Invest	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 22, 2026	1-10	3 contacts →
	Indirect evidence “We design rigorous, data-driven frameworks that help investors, funds, and enterprises strike the right balance between financial performance and measurable impact.” Source: RevenueBase Database · checked Sep 22, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: sustainable development firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names sustainable development firms.
Partial evidence: Its own public description names part of sustainable development firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name sustainable development firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 91 sustainable development firms based in Johannesburg, South Africa

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Sustainable development firms based in Johannesburg, South Africa at a glance

As of Sep 22, 2026

38.6%Verified-email coverage

8.6Average contacts per company

1-10Median size (employees)

100.0%Largest-city concentration · Johannesburg

Sep 22, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

Email recency for this list is measured across the whole South Africa list rather than for Johannesburg, so it is reported there. Company counts and contact totals on this page are exact for Johannesburg, over 91 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among sustainable development firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in Johannesburg, South Africa whose own description of what they do matches “sustainable development firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names sustainable development firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among sustainable development firms, and records with no verified work email. Companies headquartered outside Johannesburg are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 302 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 22, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Sustainable development firms by metro in South Africa

Sustainable development firms in Johannesburg91
Sustainable development firms in Cape Town78
Sustainable development firms in Pretoria42

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names sustainable development firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many sustainable development firms are there based in Johannesburg, South Africa?

RevenueBase identified 91 sustainable development firms headquartered in Johannesburg, South Africa as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Siyakha Consulting, headquartered in Johannesburg, tops this list with the largest team on record.

Which city has the most sustainable development firms?

Johannesburg leads with 91 headquartered companies, followed by Cape Town (78) and Pretoria (42).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 302 verified decision-maker contacts tracked across these 91 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 22, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.