Energy Startups

RayGen develops concentrated solar systems integrated with thermal energy storage that deliver dispatchable renewable power for 8-48+ hours. The technology serves utilities and energy companies seeking firm, grid-scale clean energy with long-duration storage capabilities.

2 investors

Re-Twin provides simulation software that models battery energy storage system (BESS) projects in real power markets to produce revenue forecasts. It targets energy storage developers and operators evaluating project earnings potential.

2 investors

Reel is an electricity supplier that offers businesses fixed-price power purchase agreements sourced from solar, wind and battery storage, along with tools to optimize on-site solar and battery assets and track the source of every MWh purchased. It serves companies in sectors such as real estate, manufacturing, and logistics to help them manage energy costs, hedge risk, and meet renewable energy targets.

2 investors

ReJoule develops battery diagnostic and testing solutions based on electrochemical impedance spectroscopy, a non-invasive method that works across battery chemistries, form factors, and voltages. Its technology serves automakers, battery repurposers, and energy storage operators for end-of-line quality control, remanufacturing, and qualifying batteries for second-life use.

2 investors

Relion offers an end-to-end, hardware-agnostic operations and maintenance (O&M) platform for EV charging infrastructure, letting operators monitor charging stations, detect and diagnose issues, and manage work orders across equipment from different vendors. It serves charging network operators, EV fleets, service providers, EVSE manufacturers, and residential and workplace charging sites, primarily across North America and Canada.

2 investors

Ren Energy runs supply chain decarbonization programs across the Asia-Pacific region, connecting global brands and their suppliers with renewable energy projects. It combines on-the-ground local teams with a platform to map supply chains, organize supplier cohorts, run RFPs for clean energy procurement, and measure carbon reductions.

2 investors

Pexapark provides market-based price benchmarks and data for battery energy storage systems (BESS) and renewable energy offtake, covering markets in Europe (France, Germany, Spain, Italy) and the US (ERCOT, PJM). It also offers risk management software and renewable advisory services to help energy companies with FPA and PPA pricing, benchmarking, risk analysis, and investment planning.

2 investors

Renew Home operates a residential energy management platform that embeds energy-smart features into connected home devices, starting with smart thermostats, to automatically shift energy usage to cheaper, cleaner, or lower-demand times. It serves both homeowners looking to save on energy and energy providers seeking scalable, reliable grid capacity (virtual power plants) in the US.

2 investors

Renovate America provides financing for home improvement projects focused on energy-saving and water-saving upgrades, working with homeowners and contractors. The company positions its programs around reducing homeowners' electric bills and water usage while supporting local contractor jobs.

2 investors

Resolv is a back-office platform for contractors, especially HVAC installers, that finds and files energy rebates, files building and mechanical permits, and registers equipment warranties automatically. It also offers AI playbooks that handle pipeline tasks such as estimate follow-ups, invoice chasing, and install photo checklists, and integrates with tools like Housecall Pro and ServiceTitan.

2 investors

Resonant Link Inc. developed wireless power technology and is no longer operating as an active business, now managing and licensing its patent portfolio for non-medical wireless power. Its medical device wireless power work continues through a related entity, Resonant Link Medical.

2 investors

ReVibe Energy manufactures wireless, self-powered vibration sensors for monitoring industrial vibratory equipment in mining, aggregates, cement, waste management, food processing, and pharmaceutical applications. The sensors harvest energy from machine motion to enable continuous monitoring without batteries or cables.

2 investors

Revterra develops industrial-scale flywheel energy storage systems that store and discharge electrical energy using rotating rotors and magnetic bearings, serving grid stabilization and renewable energy integration applications. The company's modular kinetic stabilizers offer 20+ year lifespans and 90% energy efficiency for both high-power and long-duration applications.

2 investors

RGREEN INVEST is an asset manager that finances renewable energy and clean technology infrastructure projects across Europe and OECD countries. Since 2010, it has built partnerships with energy transition entrepreneurs and invested in solar, wind, energy storage, and other green technologies.

2 investors

Provides satellite-based offshore communications services revolutionizing connectivity for marine and offshore industries.

2 investors

Rise Reforming converts stranded biogas from wastewater plants, farms, and landfills into valuable chemicals including dimethyl ether (DME), methanol, and dimethyl carbonate (DMC) using modular, containerized technology. The company serves the chemical industry, offering a low-carbon alternative to fossil fuel-dependent chemical production with domestic feedstock security.

2 investors

Roble is a software platform that helps real estate owners capture energy incentives and utility rebates, forecast CapEx ROI, quantify equipment lifecycle risk, and manage regulatory compliance across property types such as office, retail, industrial, multifamily, hospitality, and self-storage. It serves commercial real estate owners across multiple asset classes.

2 investors

RoboDock builds autonomous robotics systems for electric and autonomous vehicle depot operations, automating charging, plug insertion, and vehicle inspections. The company serves fleet operators managing mixed EV and AV fleets in ports, logistics yards, and urban charging facilities.

2 investors

Rock Zero is a technology company with chemistry, materials, and process engineering teams working on chemical and materials science-based technology. The page does not describe a specific product or target market beyond its technical focus.

2 investors

Rogue 7 Inc. builds machine learning software (Rogue Intuition) for industrial automation, offered on a Machine Learning as a Service (MLaaS) subscription model. Its products, Oil Intuition and Water Intuition, help pipeline and water distribution operators optimize pump schedules to lower power usage, costs, and carbon footprint.

2 investors

Rovco (operating as Beam) develops autonomous subsea robotic systems and AI-powered technologies for offshore and subsea engineering applications. The company serves the energy and critical infrastructure sectors in complex subsea environments.

2 investors

Rubio is an impact venture fund providing early-stage growth capital to founders building companies that combine profit and purpose. It focuses on two thematic areas: social cohesion through wellbeing, education, and inclusion, and net-zero transitions in energy, industry, and agrifood.

2 investors

Rune Energy develops solar power systems using an integrated approach spanning PV arrays, DC power delivery, integration architecture, and software and controls. The company focuses on full-stack hardware and software for solar energy generation and load management.

2 investors

Saltworks designs, builds, and delivers modular systems for treating industrial wastewater and refining lithium, including desalination, evaporation, and zero liquid discharge processes. It serves industrial clients needing water recovery, wastewater treatment, and lithium brine-to-battery-grade refining.

2 investors