In today’s post, PowerFilm Ambassador Julian White explores the role power plays in portable communications looking at the different aspects of a portable ham radio setup.
Benefits of solar for portable ham radio operations
Traditionally, operators deploying with lead-acid batteries would carry “enough” battery storage to last them the day. Unfortunately, there wasn’t a man-portable way to recharge that pack in the field if there was a greater demand for their energy supply.
Lightweight thin-film solar panels allow the operator to choose smaller batteries, reducing his/her weight without reducing operating time.
With lithium technologies and thin-film panels, we start the deployment with a full battery pack. The solar panel’s job is to keep the battery topped up. We go back to using our battery storage during darkness, augmenting our solar panels when there’s no sun.
Before we dig into the different aspects of a portable solar solution for ham radio, it’s vital to understand our power budget clearly. A well thought out power budget informs the batteries we take and the solar panel we select.
Developing your power budget
How much power you use is variable depending on how often you transmit vs. receive.
This number can be determined using an inline amp meter. Measure for a day how much power you are consuming. Remember to consider what kind of communicating you are doing (narrowband/wideband).
Know what the weather will be like when you are in the field.
Weather plays a critical role in our remote power solution. Look for past statistics on weather in a given area and analyze short term weather data.
Understand your operating environment.
Your operating environment will dictate what kind of solar panels you need to take with you.
Here is a video discussing when to choose a foldable solar panel versus a rollable solar panel.
Parts of a total power solution for field communication
The radio is the heart of the system but not the only thing we need to power. In many cases, we have lights, tablets, mobile phones, or other gear that supports the station. These items are also included in our overall power strategy. I created a video called “How to Ham radio Off Grid,” which may give a better understanding of choosing a radio, estimating power requirements, how much power to run, powering the stations, etc.
Battery storage has traditionally been AGM or deep cycle batteries. Today it is more common to find lightweight Lithium Iron Phosphate (LiFePO4) batteries used for field applications. Their higher energy density and lower weight make them an attractive choice for deployments with weight and space limitations.
Charge controllers are the first line of defense for battery storage. The charge controller manages power coming from our solar panels, ensuring we do not overcharge the battery. The charge controller also ensures the operator does not create an under-voltage state, which is also harmful to our battery storage system.
Power distribution acts as a multi-output splitter for DC voltage coming out of battery storage. It can be integrated with the charge controller or a stand-alone piece of equipment with fuses and DC output ports to feed station equipment. DC power distribution usually has a combination of fused DC ports and USB ports for mobile devices. Power distribution is another line of defense protecting battery storage and connected gear from one another.
Here is a video showing battery storage and charge controller, with integrated power distribution. There are some obvious benefits for cable management and the simplicity of the system.
Different ways to charge batteries
My ultimate goal is to use solar power, which almost always works well in keeping batteries topped up. The caveat is solar performance is based on having done a good solar survey of our energy deficits before deployment. In reality, there is often a back-up strategy. In my case, the back-up plan is a hand crank generator. I call it a back-up system because it is unsustainable in caloric expenditure over the long run. Some operators, teams, and organizations use small generators to charge batteries. From a communications perspective, I have found that generators create far too much interference for reliable radio operations in the field.
There are different levels of need for portable communications deployment. From an individual perspective, we can think about a single amateur radio operator, running a QRP (low transmit power) station, activating a SOTA mountaintop for Summits On The Air. These operators' requirements are more modest and can be met by systems like the LightSaver Max.
This video highlights how I can use the LightSaver Max to power my QRP radio.
There are other scenarios, such as interoperability training, where large numbers of operators participate in training exercises to improve emergency response and build the core skills of operators who participate in these types of events.
In recent times, teams of operators are deploying solar power and battery storage as their primary and secondary means (augmenting other sources of power) of station power. Renewable energies such as solar power are often encouraged in rapid deployment scenarios over traditional generator-driven power delivery.
The benefits of lightweight solar power and battery storage make rapid deployment of disaster relief teams a reality since team equipment, and logistics can be better managed using lithium battery technologies combined with thin-film solar panels.
Now that we know the different parts of a portable ham radio setup and various deployment scenarios, you are ready to set up an off-grid basecamp where you can broadcast in perpetuity.
Building an off-grid basecamp
This video highlights the gear I use to set up my basecamp beyond my lightweight solar panels.
Basecamps maintain communications capabilities with the remote teams it services. Often a basecamp is little more than an off-grid tent city.
Here again, we have an opportunity to deploy lightweight solar panels and lithium-based battery storage. We can see how large, heavy batteries and solar panels were expensive and logistically impossible to deploy from the deployment after-action reports.
A basecamp doesn't need to be at the base of the Himalayan mountain range. It can be a single person set up in a remote area, first responders, or aid workers deployed after a tsunami or hurricane. In each case, communications specialists provide critical communications that wouldn’t exist without lightweight, portable power.
Designing and executing a portable power solution for remotely operating your ham radio is no small task. With careful planning, analysis, and the right gear, you can create a sustainable solution that will keep you operating as long as you wish.
I sat down with Julian to hear more about how he started using solar in the field and the lessons he learned through the years. Listen to the full interview below.