Bug-Out Electrics

19-Mar-2020

In these uncertain times it is nice to know that we have independent or “off-grid” options for electrical power.
In our highly connected age we often assume that we would not be able to do anything at all without electricity? It is certainly true that electricity is the vital life-blood of our modern age. However, the essentials of lighting, heating and cooking can be adequately maintained without a supply of electrical power, we only need access to fire, fuels and various kinds of containment’s to supply all the light and heat we need.

In our hypothetical bug-out scenario electricity is essentially only required for communications and IT equipment and we don’t really need all that much of it, as these native electrical devices also tend to be relatively low energy systems that use electricity efficiently. Certainly low energy compared to washing machines, electric heaters and cookers etc.

So in this “bug-out” situation we no longer have access to mains electrical power but need to maintain communications and IT including Laptops and possibly even PC’s; then we will typically need roughly 160 – 200 Watts of power.

A Basic Power System

This comprises of a 180W 12V solar panel, 12V charge regulator and a 12V 125Ah lithium battery.

The charge regulator is a “smart” device that goes between the solar panel and battery (lithium batteries require careful charge management) and controls the amount of energy flowing into the battery as a function of the charge demand. The charge regulator also has terminals for a 12V load.

We will use this system to provide charging power for a range of small electronic items such as phones or ipads. It will be necessary to connect these devices via a buck converter providing the standard 5V of a typical USB power bus.

Buck / Boost Converters

The buck converter or adjustable voltage regulator could be connected to the load terminals of the charge regulator or directly to the output of the battery or solar panel.

Diode

In this case we need to protect the connected devices with a blocking diode (a bit like an electrical one-way valve) and after this we can also connect a high value capacitor across the supply to smooth out any voltage fluctuations caused by transient shading of the panel.

Capacitors

Large and more demanding loads such as laptops are easily powered directly or charged with this system. In this case we may need to use a boost converter to provide higher voltage from our 12V, typically around 18 or 19 volts for many laptops.

We need to have a basic multi-meter simply for setting output voltages of our buck or boost converters; but it is generally a useful thing for monitoring and measuring on our system.

Just a little handy hint for those wishing to maintain IT and comms in what ever may be around the next corner. Or those who simply want to experience the satisfaction of capturing a useful amount of electrical power from sunlight.

NB Images are examples used for illustrative purposes. Prestburyweb does not own the copyright on these images which are freely available on Google.

More info on solar power systems from Victron