Every year, TechCrunch’s Startup Battlefield pitch contest draws thousands of applicants. We whittle those applications down to the top 200 contenders, and of them, the top 20 compete on the big stage to become the winner, taking home the Startup Battlefield Cup and a cash prize of $100,000. But the remaining 180 startups all blew us away as well in their respective categories and compete in their own pitch competition.

Here is the full list of the clean tech and energy Startup Battlefield 200 selectees, along with a note on why they landed in the competition. 

AraBat 

What it does: AraBat has developed a recycling technology that recovers critical metals like nickel, cobalt, and others from spent lithium‑ion batteries. 

Why it’s noteworthy: The company’s process is bio-based, using plant waste like citrus peels rather than toxic chemicals.  

Aruna Revolution 

What it does: Aruna Revolution has developed a compostable natural fiber menstrual pad from agricultural by-products. 

Why it’s noteworthy: Aruna has redesigned the menstrual pad into a product that works well yet still decomposes quickly and avoids plastic and harmful chemicals. 

CarbonBridge 

What it does: CarbonBridge builds bioreactors for microbial gas fermentation that transforms waste gases like methane and CO₂ into valuable molecules. 

Why it’s noteworthy: CarbonBridge says its technology is more efficient than other methods to synthesize molecules. 

Carbon Negative Solutions 

What it does: Carbon Negative uses an AI-powered platform to turn industrial wastes and minerals into cement. 

Why it’s noteworthy: The company says its cement can be used with standard equipment, making it affordable, yet its process transforms this major building material to become carbon negative. 

COI Energy 

What it does: COI Energy runs a marketplace where enterprises can buy and sell excess energy capacity, as well as get better, predictive insights into their energy needs. 

Why it’s noteworthy: By letting enterprise campuses share their reserved energy allotments with each other, the company instantly optimizes grid usage. 

Coral 

What it does: Coral offers an AI-powered carbon accounting management platform. 

Why it’s noteworthy: It automates data collection and reporting of the energy footprint and uses the blockchain to trace, and stay accountable for, carbon credits.  

Emobi 

What it does: Emobi offers an AI-powered cloud platform for universal electric vehicle charging. 

Why it’s noteworthy: The company’s service supports secure automatic charging for EV charging networks, even on legacy hardware. 

EnyGy Limited 

What it does: EnyGy has invented a line of higher performance ultracapacitors, an energy storage device that rests somewhere between a conventional capacitor and a battery. 

Why it’s noteworthy: The company makes its ultracapacitors by melding activated carbon electrodes with a state-of-the-art electrolyte and claims this boosts energy densities up to double the capacity of alternatives, while remaining cost-effective. 

Ganiga Innovation 

What it does: Ganiga offers an AI- and robotics-powered garbage bin called Hoooly that recognizes and sorts recyclables.

Why it’s noteworthy: Ganiga is selling Hoooly to enterprise campuses and industrial sites like airports to boost recycling rates, offering analytics that assist with ESG reporting. 

Gemini Energy 

What it does: Gemini has developed a fuel cell technology that can generate power on-site, converting gas into electricity without combustion, it says. 

Why it’s noteworthy: The company is marketing its clean tech power generator at data centers and says its systems can be deployed in months versus the years needed to upgrade a conventional power grid. 

Helix Earth 

What it does: Helix Earth has created products for earth from liquid-gas chemistry designed for spacecraft, including ultra-efficient HVAC and carbon capture systems. 

Why it’s noteworthy: The company says its processes are far more energy-efficient while being more affordable and can be retrofitted to commercial rooftops.  

HKG Energy 

What it does: HKG energy has created a next-generation silicon material for lithium-ion batteries. 

Why it’s noteworthy: HKG says its tech increases battery performances by 80% yet costs up to 40% less than those using conventional materials. 

HomeBoost 

What it does: HomeBoost offers a do-it-yourself energy assessment system that helps homeowners identify leaky windows and find rebate opportunities and other ways to cut their energy bills.

Why it’s noteworthy: It ships to homeowners custom hardware that, coupled with a smartphone app, scans the home and then home energy experts review and produce the report. 

HyWatts

What it does: HyWatts supplies modular systems that generate energy on-site for industrial uses.

Why it’s noteworthy: It calls its system Power-Plant-in-a-Box, which integrates hydrogen storage and reversible fuel cells for, it says, zero-emission, off-grid electricity at far lower costs than battery storage.

Kaio Labs 

What it does: Kaio Labs develops CO₂ conversion technologies to transform waste carbon dioxide into valuable chemicals like carbon monoxide, formic acid, and ethylene. 

Why it’s noteworthy: Kaio uses an AI-powered workflow to automate discovery, with the goal being to extract these chemicals in a cost-competitive way. 

MacroCycle Technologies 

What it does: MacroCycle has invented a patented polyester textiles recycling technology.

Why it’s noteworthy: The company promises to make recycled plastic as inexpensive as virgin material through tech that separates the desirable synthetic fibers from waste textiles. 

Namu Robotics Corporation 

What it does: Namu Robotics provides tree-planting robots geared toward re-forestry projects.

Why it’s noteworthy: The world doesn’t have the resources to replant trees fast enough between the labor involved and the terrain, so Namu’s tech promises to automate the process. 

Naware 

What it does: Naware offers an AI-powered robotic weed killer that attaches to lawn-mowing equipment to kill weeds as the lawn is mowed.

Why it’s noteworthy: Not only does it auto-detect weeds, but it also uses hot steam to kill them, rather than toxic herbicides.  

Segura 

What it does: Segura offers a proprietary method to test water quality that delivers nearly instant results without the need to hire testing experts.

Why it’s noteworthy: Segura has invented a test strip that is reminiscent of those used for diabetes monitoring and is as easy to use. 

ShellVive 

What it does: ShellVive has created a method to filter water by repurposing oyster shells. 

Why it’s noteworthy: ShellVive solutions take an abundant agricultural waste product, discarded oyster shells, and turns them into an affordable, eco-friendly water filtration material. 

Whisper Energy 

What it does: Whisper Energy is developing an AI-native sensor to improve energy efficiency in commercial buildings.

Why it’s noteworthy: The company is targeting small to midsized buildings with its easy-to-install sensors and system as an affordable alternative to large-scale energy automation solutions.

Xatoms 

What it does: Xatoms has created a photocatalyst — a light-activated chemical — that can remove bacteria, viruses, chemicals, and heavy metals from polluted water. 

Why it’s noteworthy: The company is using AI and quantum chemistry to find new water-treatment chemicals.