NFE

Author: Aaron Tushabe

  • Open Energy Hackathon 2.0

    Open Energy Hackathon 2.0

    It is hard to overstate the energy in the startup Hub that is San Franscisco. In April 2026, Nearly Free Energy took part in the second iteration of the Open Energy Hackathon at SF Climate Week organized by Energy IoT Open Source.

    The challenges

    This hackathon attracted about 20 participants and about 6 different challenges, 3 of those challenges were motivated by the work we are doing at NFE. And I was humbled to see more than 50% of the participants sign up for the NFE challenges

    Challenge #1 : Manual Recurring Billing

    Our business is selling (reliable) electricity. A key process is that we bill our customers at end of the month for the electricity they used the previous month. However our current process constitutes manual creation of invoices, manual compliance reporting and payment collection via mobile money. This requires about 2 to 3 hours of human time every month for our 10 pilot microgrid customers. Needless to say, this is not scalable not just because of the time it takes but frequency and cost of errors involved with human’s doing repetitive work. In March 2026 alone, invoices for 2 of our customers had human errors costing us about 5% of our monthly revenue and of course hurting our reputation with our customers.

    Solution: Automated payments; during the hackthon, the team built and deployed to production an API integration between a new open source invoicing system (MBE) and local payment provider Pesapal. This service went live during the hackthon and we were able to use to for April billing cycle reducing the human effort by over 50% for that cycle.

    All this was made possible by the dedicated work of Open Energy advocates Alejandro M and Redwan H.

    Next steps: MBE continues to evolve as we add more capabilities. You can follow the project on github.

    Challenge #2 : No Real time Metering

    If there’s a capability that’s absolutely core to community microgrids, it’s metering. And we have come a long way with our metering capability since inception. For example we recently found a local supplier for smart meters who’s data is accessible openly. This is huge but our current process still required us to read the data from those meters manually which is very human error prone as well and huge risk to the business because of it’s impact on revenue and customer experience.

    Solution: During the hackathon, we prototyped using OpenEMS to read data remotely in real-time from our newly installed DDSU666 chint smart meters. We were able to successfully demo this integration and a few days ago, we managed to get the change merged into OpenEMS!!! This is our first major contribution to the project we hope to continue contributing to as NFE.

    Next steps: We are working on deploying OpenEMS to our pilot microgrid by the end of the month. Look out for a more detailed post on our Metering 2.0 stack later next month.

    Huge thank you for our Open Energy advocates Guru Prakash, Matthew G and Nicolas F Nunez-Sahr for their work on making this happen in less than 2 days.

    Challenge #3: Onsite only on/off relay control

    One of the reasons NFE using postpaid by default is because it was just so much easier to set up technically, just measure usage and send a customer a bill at the end of the month. However, in the event of non-payment, we turn off the power and currently, this is done manually by the on-site microgrid manager or a technician. And the same process is repeated to turn the power back on when the customer makes a payment. All this movement of humans is no cheap and is error prone. Meters that come with in-built relays were too expensive to procure for our business size and already require expensive propriertary software to communicate with them

    Solution: Let me introduce you to Open AMI with meshEMS hardware: It’s a project with an audacious vision of enabling microgrid operators to design metering and grid control open source hardware, firmware and software. And train them to assemble the hardware in country to bring other cost of purchase and maintenance down by more than 50%.

    During the hackathon, we designed a prototype for a simple relay we can control remotely to turn. Demo-ed with this visual simulation the team made.

    Next Steps: The brilliant people at NESL have donated some meshEMS hardware to NFE so we can test out the relay in production later this year and their founder Glenn will be coming to the Power Africa Conference in September 2026 to offer a training workshop to help us continue to leverage Open AMI ecosystem and meshEMS hardware.

    Huge thank you to Adam S, Kyle B for leading the team that crushed this challenge.

    All 3 challenges and the entire hackathon were made possible by the support of mentors Liam O, Glenn A and the amazing Arila B from Energy IoT Open Source. And of course hosted at Informal Spaces in Oakland run by Kyle V.


    A million thanks everyone for contributing your ideas, skills, time and heart to this theme.

    Community Microgrids need a community owned and supported software/hardware foundation to deliver on their promise of reliable, resilient and abundant energy for everyone.

    Thank you all for helping lay that foundation!

    Onward.. Upward.. ⚡

    As always, if this work sounds relevant to you or your community. Get involved! 👇🏾

    Energy IoT on Zulip
    Energy IoT Open Source LinkedIn
    Nearly Free Energy Matrix Room
    NFE on LinkedIn

  • Go-live: Pilot at Sezibwa Rental Homes, Phase 1.0

    “Even a journey of 1000 miles begins with a single step”
    ~ Ancient Chinese Proverb

    Location

    In September 2025, we deployed our first microgrid to a small community of 10 customers in a small densely populated town called Nansana, right outside the Ugandan capital of Kampala.

    The goal

    To demonstrate that a grid connected microgrid can provide a sustainable way for a community to provide power at a lower cost through bulk billing and allow the community to monitor their energy usage for solar and battery backup sizing.

    The problem

    We have 10 residential energy consumers connected to the main grid. They consume about 1 to 3 kWh a day each which costs them about 80,000 UGX per month for each household. However they get 6 to 12 hours of unscheduled and indeterminant power outages every week for all the reasons shared here.

    From what they shared, the closest transformer they are connected to may be overloaded causing phase to phase voltage to significantly drop occasionally but we didn’t have the data to verify this before deployment.

    The technical details

    We deployed extended a 3 phase main grid connection and reconnected the homes to the grid via this connection. The connection to the grid is metered with a large commercial 3 phase meter controlled by UEDCL. The connection is sized to deliver 415V, 100A (240V phase to phase) for up to 30 kWh load. That meter is mirrored by another 3 phase meter we control.

    Single phase connections to each household are metered by smart meters connected to an AMI provided by the meter supplier.

    Tech Stack

    Metering: Din rail Calin Smart Meter with inbuilt relays and LoraWAN modules

    Connectivity: Central LoraWAN gatway that is 4G enabled with SIM card.

    AMI: CalinAMI for hourly meter readings and remote on/off.

    Communication: Whatsapp for customer support and a Microgrid Manager who resides in the community.

    Billing: Monthly postpaid payments via Pesapal (Mobile Money, Visa/Mastercard). Invoicing managed via EFRIS.

    Finances: We are tracking our spending and inflows (contributions and income) via Open Collective here.

    Documentation: Most information about this microgrid is available on our public Wiki here.

    Present Challenges

    Metering: We are seeing anomalous behavior with the smart meter connections getting dropped. It maybe coming from clustering LoraWAN enabled meters in a meter box but we don’t know at this point. We do get enough connectivity to collect and view high fidelity data on daily usage patterns on most days.

    Next Release: Phase 2 goals

    Backup: The primary goal is to deploy batteries and or solar capacity to handle at least 6 hours of a power outage during peak demand windows (6pm to 12 midnight).

    Metering 2.0: Secondarily we’d like to move to an Open Source AMI we can modify ourselves instead of the proprietary one we currently use. And since our meters are clustered, we’d like to connect to them directly via RS485/Modbus to a raspberry-pi running OpenEMS edge. We think hard wiring to the meters locally will be a more stable solution than the wireless connectivity via LoraWAN.

    CRM: We would like to switch to MicroPowerManager for our CRM. We need to add invoicing and postpaid capabilities to it and integrate it with EFRIS which we must continue using for easier tax compliance.

    For more on this project, you can connect with the NFE team via our public channel on Matrix or receive our quarterly progress updates via our community mailing list.

    You can also make contributions to the project to support phase 2 via Open Collective here.

  • Our Microgrid Cultivation Blueprint

    Our goal to build community owned microgrids and teach others to do the same.

    This means our initiatives are not considered “Complete” till we exit and empower the community to energy independence. I’d like to talk a little about how we intend to achieve this.

    Why Community Ownership matters

    • Sustainability: when the community owns the energy resources, they have incentive to make the product better because they stand to benefit as customers and owners. This drives down cost of energy for them long term and leads to a sustainable (self-funding) model.
    • Agency: ownership helps guard against perverse incentives that could benefit owners at the risk of hurting customers. The community can take a driving seat in the decisions on future of their microgrid.
    • Efficiency: In our experience, there’s a organic desire to conserve and use energy responsibly that is cultivated when the community can think of the energy resources as “our own power”. So it turns out, ownership is a brilliant way to address energy waste and encourage responsible use.

    Building community owned microgrids

    Our conviction is that people should live in communities and we want to help cultivate that. So our primary target customers are residentials first (and adjuscent businesses like schools, hospitals, saloons, shopping centers, restaurants) that already have a sense of community around them. This can take on different shapes like a rental apartment complex or a set of homes under the same home owners association.

    We build a community owned microgrid for such communities through a 4 phase journey.

    Phase 1: Data Ownership with a Microgrid Operating System

    We deploy a microgrid OS for that community with smart metering capabilities. This microgrid OS is powered by free/open source software to protect the community’s freedom and start them on their energy independence journey by giving them ownership of the data generated by their energy use. The microgrid OS also enables usage data analysis which informs load sizing in the next phase. The smart metering capability enables bulk purchase of power from the grid which can generate income to fund the next phases. The microgrid resells energy as a service to the community.

    Phase 2: Backup

    Our communities deal with frequent macrogrid power outages. For most of them, having a reliable electricity is the main value proposition for setting up a microgrid. In phase 2, we deploy right sized solar and or battery capacity to provide backup power during macrogrid outages and increase energy reliability for the community

    Phase 3: Backbone

    After achieving nearly 100% power reliability, we now invest in reducing the community’s reliance on the macrogrid. We increase battery capacity and add onsite renewable generation capacity like solar to grow our backup into the main source and then rely on the macrogrid as a backup. This further drives down the cost of energy for the community and stimulates growth in new businesses and quality of life for people living there.

    Phase 4: Energy Independence

    NFE exists as co-owner of the microgrid by transfering the operational microgrid to an entity (another co-op) representing the community. This can be started during phases 1 to 3 by baking in lease-to-own economics into the energy as a service contract NFE has with the community.

    Teaching others to do the same

    Along the way, we are sharing everything about how and who we work with. How things work and offer training for those who want to learn so that others (especially the communities we serve) can run with the same vision. All these are documented on our website here or in our Community Library here.

    And that’s all. Community Owned Microgrids in 4 Phases.