Solar Powered Amateur Radio

Information about setting up a

Solar Powered Amateur Radio Station

These days, many types of Batteries are available. In my opinion, Lithium Ion and AGM are particularly useful and they don't need upkeep, although I have been told that if connected in parallel, then every 6 months or so, they need to be 'balanced.' If interested, it would pay You to google that. Apparently, Lithium Ion batteries can be discharged way down and still maintain their voltage but they can be very expensive. I don't know much about solar systems, but hopefully this short article may be of help.

This article only gives an overview of using Solar Power to run Your Amateur Radio Station.. -

There's an interest nowadays in alternative forms of power but the most popular for Amateur Radio Operators would have to be Solar Power...

Although I don't know much about solar systems, I can share with you what I do know...

There are basically 3 components to a Solar Installation... The Battery, the Solar Panel and the Controller to regulate the current and voltage sent to the battery from the solar panel...

The sizes of these depend on the amount of current you need to draw from the battery and the duration... Once you work out these 2 requirements, you're able to figure out the capacities of the 3 components... In my case for example, I operate CW on HF so the current draw on the battery would be about 20 Amps... By the way, for a 100 watt radio, using Ohm's Law, you would expect the current drawn using a 12 volt supply to be about 8 amps or so ( 100W = 12V x 8.3A ) but because most modern solid state radios are only about 50 or 60% efficient on CW and a little more efficient on SSB, the current drawn is nearly double that... That's why most 100 watt radios which have 13.8 volt dc power supplies are rated at around about 20 amps or more...

To illustrate, let's say the transmitter was run key down drawing 20 amps for 1 hour. This means that the battery has used 20 Amp Hours in that period (20A x 1H)... Batteries are rated in terms of their voltage and the number of Amp Hours they can supply... However, batteries used with solar panels need to be of the ' Deep Cycle ' type. I think that it pays not to discharge them by too much.

2007 - CW using a Yaesu FT-1000MP Field.

The battery shown in these images has a rating of 670 Amp Hours... 20% of that is approximately 130 Amp Hours which would enable operating for a long time. A battery this size can power a small house but you would need a number of panels to recharge the battery quickly due to the regular current drain by house hold appliances etc... The expected life span is 10 years or more if looked after properly... ie. not run down too far and also topped up with distilled water... (This battery is still in use after 12 years).

BPSK31 using an Icom IC-7600.

The voltage at the battery fluctuates depending on its charging cycle... It may swing from 12 volts or so of a night to about 14.5 volts or so in the daytime... I have 3 different radios that I've used with this battery and the voltage swing doesn't seem to affect them... The amount of current coming from the solar panel is dependent on the size of the panel, it's direction towards the Sun and the availability of sunshine... Since we're not at the Radio QTH all the time and drawing current, the battery doesn't need to be charged quickly on a regular basis... One 80 watt panel is sufficient for my needs ie. to keep the battery charged... The direction that the panel faces is important to maximise the exposure to the Sun... Also, the angle to the horizon should be optimized to ensure that the Sun hits the panel as near as perpendicular as possible throughout the year, especially in the winter... High tech panel installations track the Sun... When mounting solar panels (usually framed in Aluminium) on sections of dissimilar metal, insulators should be used to prevent corrosion at the point of contact. I used sections of black plastic irrigation pipe with a hole drilled through the sides of it... The plastic pipe is compressed when the nuts are tightened...Stainless steel nuts, bolts and spring washers are also recommended...

The ' Charge Controller ' or ' Regulator ' sends the right amount of current and voltage from the panel to the battery... It's job is to ensure that the battery is not overcharged, thereby extending the life of the battery... The panel shown, can deliver in the order of 20 volts or so depending on the availability of sunshine. The controller regulates the voltage down to a charging voltage of around 13.8 to 14.4 volts for 'boost' charging and about 13.5 volts for 'float' charging... These are approximate values... When there is a large current drain from the battery, the regulator will allow maximum regulated current to flow into the battery from the solar panel... When it is fully charged, little current is sent to the battery... With the polycrystalline panel shown, a maximum current of nearly 5 Amps can be produced with a cloudless sky... The maximum Amp Hours this panel can manage at this QTH seems to be about 35 AH or so a day... When buying the battery and panel, the sales people will sell you the appropriate controller as well... A solar controller like this one, with an LCD screen, is able to tell you a lot of information... eg. the voltage at the battery terminals at present, the amount of current going into the battery at the moment, the number of Amp Hours already gone into the battery so far today, the total Amp Hours sent to the battery each day etc... To reduce the risk of sparking when connecting the panel to the controller, I have either done it of a night time or thrown a thick blanket over the panel during daylight. Also, some controllers cause interference to Radios, so if purchasing, ask relevant people about Your particular controller.

The other consideration is the wires connecting components... To reduce voltage drop, ensure that you use heavy gauge wires and also use fuses in the main lines... Ask the sales people questions, they want your business... By the way, it pays to clean your solar panels regularly. Rainwater does not do the job very well as a film of grime builds up on solar panels over time...

Many deep cycle batteries can last a long time depending on usage. If you do not demand too much current from them, the life expectancy of some can be ten years or more. Although deep cycle batteries are not cheap, once you have a solar system up and running, there are no ongoing power bills...

I hope this article is helpful in building your own Solar Powered Amateur Radio Station.

May 2021.

The large 670AH Lead Acid Battery has been in use for 12 years but never the less I decided to replace it with 800AH of Lithium Ion Batteries.

The Lead Acid Battery has performed faultlessly for the entire time. It needed to be topped up with distilled water every month or so but the Lithium Ion

Batteries, 4 x 200AH need no attention paid to them but expensive though. The supplier told me that they can be depleted by 100% and bounce back easily.

Also, they retain their voltage til way down low. Now using a new Controller with no RFI.

www.WIA.org.au

CLICK HERE TO VIEW AN ARTICLE BY THE AMERICAN RADIO RELAY LEAGUE DESCRIBING HOW HF RADIO SIGNALS TRAVEL AROUND THE EARTH.

Australian, 'Paul Hogan' as 'Crocodile Dundee.' click above.

Click Below.

2023...

2022...

If you would like to see my 4 solar shacks, Click Here.

If interested in an article I wrote some time ago about my Solar Powered Caravan Shack which was printed in the Australian 'Amateur Radio' magazine, Click Here.