Top Cleantech Marketing Agencies That Help Green Startups Grow

Growth-stage climate tech companies face a specific set of challenges: long and multi-stakeholder sales cycles, technically demanding buyers, a regulatory context that shifts faster than most content calendars, and the constant pressure to communicate complex value propositions to audiences that have heard every clean energy pitch. These are not challenges that generalist agencies are built to navigate without a steep ramp-up period.

The agencies that operate in this environment combine cleantech sector knowledge with operational flexibility suited to early- and growth-stage companies. They understand how to translate technical differentiation into B2B stakeholder engagement that holds up across procurement, investment, and policy contexts. And they tend to work lean enough to adapt quickly when market conditions change, as they do in this sector with regularity.

This guide profiles seven cleantech marketing agencies with public evidence of climate tech work and the capabilities that B2B green startups actually need.

Quick Look at the Companies in Our List

How These Agencies Were Selected

Every agency in this guide was assessed against four criteria before inclusion:

• Public evidence of cleantech work. Each agency maintains a dedicated cleantech or clean energy industry page, named case studies involving cleantech clients, or a documented client roster that includes companies operating in climate tech, renewable energy, or adjacent sectors.
• Multi-sector positioning. Agencies whose entire business is focused on renewables or climate tech were excluded. The agencies here serve cleantech as one of several industries, which means they bring broader communications discipline alongside sector knowledge.
• B2B marketing and communications capability. This guide focuses on startups and growth-stage companies with complex B2B sales cycles. Agencies without documented B2B capability were not considered.
• Operational fit for growth-stage companies. Large holding company agencies with minimum engagement models incompatible with early-stage budgets were deprioritized unless they have a documented track record with growth-stage cleantech clients.

1. twentytwo & brand

Value proposition twentytwo & brand is a full-service cleantech marketing agency built for B2B climate tech companies with lean marketing teams under real operating pressure. The agency provides integrated storytelling, communications strategy, and design under one roof, a combination that most agencies require multiple vendors to replicate. That integration reduces the coordination overhead that often consumes marketing bandwidth at growth-stage companies.

Key clients FranklinWH, Castillo Engineering, and more than 100 cleantech and renewable energy brands across clean energy storage, utility-scale solar, and climate tech sectors.

Recognized work For Castillo Engineering, the twentytwo & brand led a branding and media relations campaign that ultimately helped secure Castillo’s first 100+ MW utility-scale solar project win. For Burnham, the agency developed a new value proposition, website, and investor presentations, and secured earned media coverage that helped position the company for an acquisition by Ares Management. For GameChange Energy, the agency's SEO and content work has kept the company ranked between positions 1 and 3 on page one for "solar tracker companies," one of the most competitive keyword categories in the sector.

Services Public relations and earned media for cleantech brands. Brand strategy, visual identity, and creative. Content marketing, social media, and thought leadership. Paid advertising and digital marketing. Web design and lead generation infrastructure.

2. M studio (mdidit)

Value proposition M studio is a New York-based multi-sector B2B agency with documented work in cleantech alongside fintech, consumer, and art sector clients. Founded in 2004, the agency combines brand strategy, web development, and integrated marketing with a track record in community solar and clean energy brands. M studio positions itself as a senior-led engagement model, which aligns with growth-stage cleantech companies that need direct access to experienced practitioners rather than junior account teams.

Key clients Solar Landscape, a New Jersey-based community solar developer, is among the agency's publicly named cleantech engagements.

Recognized work M studio's work with Solar Landscape included brand development and digital marketing support for a community solar platform operating in a complex regulatory and consumer education environment. The engagement reflects the agency's capacity to support cleantech brands communicating to multiple stakeholder audiences simultaneously, including residential customers, municipalities, and commercial offtakers.

Services Brand strategy and identity development. Web design and digital experience. Integrated B2B marketing across earned, owned, and paid channels. Content strategy and production. Account-based marketing and lead generation.

3. V2 Communications

Value proposition V2 Communications is a Boston-based agency serving B2B companies across AI, climate tech, healthcare, and emerging technology sectors. Founded in 1997, the agency has a long track record with growth-stage technology companies and combines PR, content, and integrated communications programs designed for companies navigating complex B2B buyer environments. V2 is positioned as a mid-sized agency that can provide senior counsel without the overhead of a large holding company structure.

Key clients Electric Hydrogen, Uplight, and E Ink are among the publicly documented clients in the climate and clean energy space. Electric Hydrogen is a developer of industrial-scale green hydrogen production systems. Uplight is a B2B SaaS platform serving utilities in demand-side energy management.

Recognized work V2's work with Electric Hydrogen supported the company's communications programs during a period of significant commercial and fundraising activity in the green hydrogen sector. The Uplight engagement spans utility-focused B2B communications, where messaging must address both enterprise software buyers and regulated utility procurement processes. These engagements reflect V2's capacity to handle technically demanding, multi-stakeholder communications in the energy transition space.

Services Public relations and media strategy. Executive and thought leadership positioning. Content marketing and editorial programs. Integrated communications strategy for B2B technology companies. Analyst relations and stakeholder engagement.

4. Bolder Agency

Value proposition Bolder Agency is a Berlin-based multi-sector agency serving technology, sustainability, and brand clients with a dedicated Energy Tech and Cleantech branding practice. Founded in 2008, the agency provides brand positioning, identity, and communications strategy with documented work in the cleantech sector. For growth-stage cleantech startups with European operations or investors, Bolder offers geographic and market-entry context that North American agencies may not provide with comparable depth.

Key clients Attero, a waste-to-energy and resource recovery company, is among the named clients in the agency's cleantech and energy tech portfolio.

Recognized work Bolder's work with Attero engaged the agency's dedicated Energy Tech and Cleantech branding practice, which applies brand development and communications strategy to companies operating at the intersection of resource management and clean technology. The agency has also published editorial content on cleantech startup positioning, reflecting ongoing engagement with the sector's communications challenges beyond individual client work.

Services Brand strategy and identity for cleantech and energy tech companies. Communications strategy and positioning. Content development and editorial programs. Digital presence and campaign development. Market entry and growth communications for European markets.

5. Martal Group

Value proposition Martal Group is a B2B lead generation and sales-as-a-service agency headquartered in Mississauga, Canada. The agency operates across technology, SaaS, and cleantech verticals with documented cleantech content and outbound lead generation capability. For cleantech startups that need pipeline development alongside marketing support, Martal provides a commercial-facing model that connects marketing execution directly to qualified sales conversations. The agency's outsourced sales model is relevant for early-stage cleantech companies that need pipeline growth before building out internal sales infrastructure.

Key clients Martal Group has published cleantech-specific playbooks and maintains documented engagement with B2B cleantech and SaaS companies across North America and Europe. Named clients are available through direct agency engagement.

Recognized work Martal's cleantech vertical capability includes outbound campaign strategy, content development for technical buyer audiences, and appointment-setting services tailored to cleantech sales cycles. The agency has produced publicly available resources on cleantech lead generation that reflect its operational engagement with the sector's specific go-to-market challenges, including long sales cycles, procurement committee dynamics, and the role of verifiable case studies in building buyer confidence.

Services B2B outbound lead generation and appointment setting. Sales-as-a-service for early and growth-stage cleantech companies. Content development for technical buyer audiences. Account-based marketing and pipeline development. CRM integration and sales infrastructure support.

6. Hawthorn Advisors

Value proposition Hawthorn Advisors is an independent multi-sector strategic communications consultancy with offices in London and New York, operating with more than 70 staff across both locations and serving clients in 18 cities globally. The agency has a dedicated Sustainability and Purpose practice providing ESG strategy, sustainability communications, and stakeholder engagement counsel. For growth-stage cleantech companies preparing for institutional investment rounds, regulatory engagements, or international market entry, Hawthorn's financial PR and corporate communications depth is a material differentiator from pure marketing agencies.

Key clients Hawthorn serves clients across energy, financial services, technology, and sustainability sectors. The agency has been recognized as Highly Commended at the PR Week Awards for Mid-sized Consultancy of the Year. Named cleantech client details are available directly from the agency.

Recognized work Hawthorn's Sustainability and Purpose practice provides clients with strategic communications counsel on ESG positioning, impact narrative development, and stakeholder engagement. The practice operates at the intersection of regulatory disclosure requirements, investor relations, and brand communications, which is a critical space for cleantech companies managing multiple audiences with different information needs. Hawthorn has documented work across energy and infrastructure sectors alongside its corporate and financial communications core.

Services Corporate and financial communications for growth companies and capital markets. Sustainability and Purpose practice: ESG strategy, impact communications, and stakeholder engagement. Media relations and reputation management. Executive and CEO advisory. Investor relations and public affairs.

7. Trefoil Group

Value proposition Trefoil Group is a Milwaukee-based integrated B2B marketing agency serving mid-market and PE-backed companies across manufacturing, packaging, logistics, and cleantech. Founded in 1992, the agency maintains a dedicated B2B Marketing Services for Cleantech Companies practice, with stated capabilities across battery innovation, solar efficiency, carbon capture technologies, and other advanced cleantech applications. For cleantech companies with technical products and complex B2B sales cycles, Trefoil offers sector-informed go-to-market strategy and execution that does not require an extended orientation period.

Key clients Trefoil's cleantech practice page documents client engagements across clean energy and industrial sustainability. The agency's broader client portfolio includes Hoffer Plastics, C&W DustTech, and MGS, reflecting the manufacturing and industrial B2B depth that translates to cleantech contexts.

Recognized work Trefoil's cleantech marketing practice addresses the challenge of communicating complex technical value propositions to diverse cleantech decision-makers, including investors, enterprise buyers, utilities, and policy stakeholders. The agency uses thought leadership, executive visibility programs, and targeted digital campaigns designed for the procurement and regulatory audiences that matter most in B2B cleantech sales cycles. Their cleantech content explicitly addresses battery innovation, solar, and carbon capture, indicating a practice with direct technical engagement rather than surface-level sector positioning.

Services B2B marketing strategy and execution for cleantech companies. Thought leadership, PR, and executive visibility programs. Content development and technical storytelling. Digital campaigns and demand generation. Brand development and go-to-market strategy.

How to Choose a Cleantech Marketing Agency

The following four considerations apply regardless of which agencies a growth-stage cleantech company is evaluating.

1. Capabilities vs. Your Actual Needs

Start by mapping what your company needs in the next 12 months: brand positioning, earned media, content for technical buyer audiences, pipeline development, or market entry communications. Not every agency in this guide covers all of these equally. twentytwo & brand integrates PR and creative. Martal Group is built for pipeline and outbound lead generation. Hawthorn Advisors offers financial and investor communications depth. V2 Communications focuses on technology PR. Match capability to your near-term priority before evaluating everything else.

2. Sector Knowledge and Ramp-Up Time

Cleantech communications requires familiarity with regulatory dynamics, utility procurement processes, investor expectations for climate tech, and the technical vocabulary of the products being marketed. An agency that does not already hold this context will acquire it on your budget and timeline. Ask agencies directly: who on your team has worked on cleantech accounts, and what was the specific scope? Request verifiable case studies rather than general capability claims. The difference between an agency that understands BESS market dynamics and one that has heard of the term will be visible in the first month of engagement.

3. Resource Fit and Operational Model

Growth-stage cleantech companies typically have lean internal marketing teams, sometimes one person, sometimes none. Some agencies are built to function as an extension of an internal team; others expect the client to manage day-to-day coordination. Martal Group operates as an outsourced sales and lead generation function. twentytwo & brand is structured to serve as the primary marketing partner for companies without large in-house teams. Hawthorn Advisors is a retained strategic communications model. These are meaningfully different operational relationships, and understanding which you are evaluating matters before a decision is made.

4. Proof of Outcomes, Not Activity

The cleantech market has high tolerance for agencies that measure their own work in outputs: placements secured, content pieces delivered, posts published. What actually matters to a growth-stage company is whether marketing is contributing to pipeline, shortening sales cycles, supporting fundraising credibility, or accelerating market entry. Ask prospective agencies how they have measured outcomes for cleantech clients in the past, and request verifiable case studies that connect their work to a commercial result. Activity-based reporting is not an acceptable substitute for that conversation.

Final Thoughts

The cleantech companies that scale effectively in 2026 are those that match their marketing investment to their actual growth stage and choose agencies with the sector knowledge to shorten the ramp-up period. The seven agencies in this guide all bring documented cleantech credentials alongside multi-sector B2B capability. None of them are identical in what they do best.

twentytwo & brand is the only agency in this guide built exclusively around the cleantech and renewable energy sector, integrating communications strategy, creative, and PR under a single model designed for companies with lean internal teams. The others bring cleantech knowledge within a broader B2B practice that may offer advantages depending on a company's specific stage, geographic market, or communications priority.

The right evaluation process starts with clarity about what outcomes marketing needs to produce in the next 12 months, then works backward to which agency has the sector knowledge, operational model, and documented track record to deliver them.