Skip to main content

4 climate tech startups to watch this year

May's editions of Climate Tech Rundown featured Sesame Solar, Sealed, Carbon Chain and Urban Machine.

A graphic with the words 'startup corner' highlighted in colors including blue, yellow, and pink

Image by Sophia Davirro/GreenBiz

The circular economy and industrial waste

By Leah Garden

Urban Machine Logo

Image courtesy of Urban Machine

Did you know that more than 75 percent of all U.S. construction waste — including wood, drywall, asphalt shingles, bricks and clay tiles — ends up in landfills? And in 2018 alone, 37 million tons of that waste was from wood? Robotics startup Urban Machine does, and its goal is to decrease that number by employing circular climate technology.

Urban Machine, located in Oakland, California, reclaims wood waste from construction and demolition sites and repurposes it into sturdy lumber products. The company claims that it takes 90 percent less energy to reclaim lumber than to create virgin lumber. The startup uses a specially designed machine — fittingly titled "The Machine" — that can remove signs of the wood’s previous wear: bulk fasteners; nails; screws; and industrial strength staples.

"The Machine" uses artificial intelligence (AI) to map and identify any fasteners that must be removed to upcycle the wood. Urban Machine’s software team fed thousands of images of wood into the software, teaching "The Machine" precisely what to look for and where. The 80-foot-long machine sits on two 40-foot-long trailers, enabling Urban Machine to reclaim wood on-site. 

Urban Machine’s last funding round closed at $5.6 million in December, led by Lowercarbon Capital.


Revolutionizing energy efficiency: The story of Sealed

By Sherrie Totoki

Logo for Sealed, black type

Image courtesy of Sealed

Did you know approximately 20 percent of U.S. greenhouse gas emissions come from residential buildings? Energy-saving company Sealed does, and is intent on mitigating emissions from home usage of air conditioning, refrigeration and other sources.  

What makes Sealed unique is its new way of packaging a service of home efficiency upgrades and the affordability it provides for homeowners. This creates a new economic model that makes Sealed a climate tech startup in the form of adaptation, specifically related to the built environment. 

Sealed’s service begins with a home energy assessment to identify where energy is being wasted. Based on the assessment, Sealed develops a customized plan for energy efficiency upgrades that provides the greatest energy savings for the homeowner through insulation upgrades, air sealing, smart thermostats and more. These fixes can reduce energy use by as much as 50 percent. After the assessment, Sealed matches homeowners with a certified contractor, coordinates the upgrades and begins billing for the work through an energy provider partnership.

Sealed covers the upfront cost of upgrades, and receives payments from partner utilities and energy retailers through savings on users’ energy bills. This makes the energy efficiency upgrades more accessible for homeowners. 

Sealed raised a $29.5 million round from investors such as Fifth Wall and Footprint Coalition to further build out their offerings and expand their geographic reach. Since raising the round, Sealed bought InfiSense, a sensor and software company, to track energy on a more granular level and make more accurate recommendations.


Open Sesame

By Jake Mitchell

Logo for Sesame Solar, orange, red, and blue

Image courtesy of Sesame Solar

Natural disasters — hurricanes, wildfires, floods and more — happen five times more often than they did 50 years ago. These disasters pose significant threats to critical infrastructure and human health and safety, which cost the U.S. $145 billion in 2021.

When severe weather events damage or destroy electrical grids, they are traditionally replaced by fossil fuel-powered generators which provide energy, but are problematic. First, these generators are heavy emitters (over 100 megatons of carbon dioxide released annually) and secondly, they’re dangerous for humans as they release toxic pollutants close to homes and businesses. 

Enter Sesame Solar’s "Nanogrid" — an off-grid, 100 percent renewable energy-powered mobile system. The Nanogrid, which resembles a construction trailer, uses solar arrays and green hydrogen to produce up to 20 kilowatts per hour — enough to power four to six houses for weeks at a time — and has battery storage up to 150 kWh. The Nanogrid can deliver up to 500 liters of potable water daily (enough for 250 people) through its water filtration system. Once the unit makes it to the emergency site (hauled by a truck), it’s operational within 15 minutes.  

The startup aims to pioneer a new subscription business model called Mobile, Renewable Power as a Service (MRPaaS), which allows customers to have the system on a need-only basis. Depending on the Nanogrid model, the cost per system ranges between $100,000 to $400,000. However, the Nanogrids qualify for 30 percent tax credits/direct payments per the Inflation Reduction Act and up to 50 percent if deployed in disadvantaged communities or tribal nations. 

The startup was founded in 2017 and has raised $2 million in seed funding. Current customers include the U.S. Air Force and the Ministry of Public Health for Dominica.


The startup linking up to carbon accounting

By Leah Garden

Logo of Carbon Chain in light red

Image courtesy of Carbon Chain

Did you know that just 10 percent of companies comprehensively measure their greenhouse gas emissions? The process, known as carbon accounting, requires a business to quantify the amount of GHGs produced in Scopes 1, 2 and 3 of production. Enter startup CarbonChain, a company whose goal is to make carbon accounting an accessible and integral part of business models within the transport, mining and heavy industry sectors.

CarbonChain worked directly with commodities traders, producers and banks that finance commodities products to build out a database of emissions, which organizes supply chain impacts by sector. For example, the startup compiled the global routes and goods transported by 135,000 ships, which it can then use to calculate associated GHG emissions. 

CarbonChain then advises firms and institutions, providing them insight into the impact of their activities. According to co-founder and CEO Adam Hearne, the database covers up to 80 percent of the world’s current emissions, with its customers accounting for 2 percent of emissions. Aside from the lowered environmental impact from CarbonChain’s services, a 2022 Boston Consulting Group report stated that companies that track, and substantially act to mitigate their emissions, have earned an average of $1 million in annual benefits.  

Originally a member of the 2020 Spring Y Combinator cohort, the London-based startup recently closed out its Series A round at $10 million, led by Union Square Ventures and Voyager Ventures. The capital will go toward expanding operations at its London headquarters and establishing a New York City office.

[Do you know of a startup that should be featured in upcoming editions of Climate Tech Rundown? Send your suggestions to]

More on this topic