How does an Off Grid Power System Work?
From Inverters to Maximum Power Point Trackers, lets look at the key components used to create a Victron Energy, Off Grid power solution
At off grid power systems, we design, build and install high quality, reliable, off grid power solutions throughout the North of England.
Click the link below to find out more about Victron energy and their journey over the last 50 years.
An example of an Off Grid Electrical system
Solar panels
Solar Photovoltaic (PV) panels generate DC electricity when exposed to daylight, the brighter the sun the more current the panels generate. However this power is too high voltage and needs to be regulated to just above the battery voltage, in this example 48volts. To reduce the voltage and maximize the available power, an MPPT (maximum power point tracker) some times known as a Smart Solar charger is used. Correctly regulating the voltage and current in order to charge the battery in the most efficient way.
Lynxs power in
The centre of the illustration shows a Lynx power in unit. Think of this as fused connection unit, that brings together the separate components safely.
Multiplus inverter
The Multiplus 2 is an inverter charger, its the smaller brother to the Quattro (similar but with an extra AC input). The Multiplus converts the 48 volt DC battery power to 230 volt AC for use in your home. But it can also take in 230 volt AC from a generator and charge the battery.
BYD Battery
This illustration uses a BYD battery from the same well known car manufacturer. Its 48 volts and is easily expandable if your needs grow. Lithium batteries have a depth of discharge down to 10% and are often warranted to 6000 cycles. The battery has a BMU battery management unit to communicate with the Cerbo GX.
Generator
Essential in an off grid system, see below for more details.
Cerbo GX & touchscreen
The Cerbo is the brains of the system, it communicates with all the major components and makes the system run reliably and safely. Connected to the internet it shares the data with VRM, a powerful monitoring tool. The battery also sends important data to the Cerbo such as charge or not to charge, and this is relayed to the other components.
VRM
Victron Remote management, online or on the APP, VRM puts you in total control of your system. At a glance your up to date with battery levels, household power usage and solar generation to name but a few. Historical data is there to be viewed, and you can make system changes and even start your generator remotely. Possibly one of the most important features is that we also monitor your installation and can carry out updates or changes remotely.
Generators
All off grid power systems require a back up energy source, usually a generator. A reliable Generator is a must and its something that you should not skimp on.
For smaller off grid power systems, if you have an LPG boiler, then its possible to get LPG generators, but don’t expect to power a large system with one. For most systems we recommend a Diesel generating set.
They come in all sorts of sizes and the specifications can be quite complicated, but dont worry, were here to help. We don’t usually supply the generator, but we will point you to a recommended supplier when we have worked out the requirements.
Quality generators are usually liquid cooled with 3 or 4 cylinder, 1500rpm diesel engines, they are usually very quiet if placed around 10 meters away. A large fuel tank capacity is a benefit as this reduces the fill up frequency. Most of our systems are single phase so a single phase generator is usually the best bet.
The output is dependent upon the battery capacity and the power system size, but often a generator of around 10kVa is OK for smaller systems, 20kVa is suitable for medium and some larger systems. Correct sizing is important, too small and the generator may not deliver clean power and connection issues can some times occur.
Too large a generator and then it can be running at low output and this can mean increased fuel consumption as its running outside of its most economical range. Also we don’t want to charge the batteries too quickly as this may, in the long term reduce their useful life.
A used genset is an option but only if its been properly maintained. Our power systems are very reliable, but for the few occasions that we have a site visit, then its nearly always the generator at fault, so don’t skimp on yours, consider it an investment and buy the best you can.
Get in touch.
If you have any questions or comments, please contact us via email or phone, or send us a message using the contact form.
Telephone: 07500 932951
Email: info@offgridpowersystems.co.uk