Powering Change
Installing since 2010 · 0118 951 4490 · info@spiritenergy.co.uk
Traditionally, an inverter is the component in a solar system that converts the DC power from the panels into AC power suitable for home appliances and the national grid. A hybrid inverter fulfils this purpose, while also managing the flow of DC power to and from a battery, storing surplus solar energy and releasing it when needed.
Most modern hybrid inverters are designed to work with high-voltage DC-coupled batteries. Some manufacturers, such as Tesla and SigenEnergy, integrate the inverter directly into the battery unit itself, simplifying installation and monitoring.
There are several benefits to using a hybrid inverter with a DC-coupled battery:
Many of us are out during the daytime, when solar panels produce the majority of their power. Some of that will be used by background loads (fridges, standby appliances, and so on), but any surplus is typically exported to the grid, unless you can store it.
With battery storage, you can save the energy generated throughout the day and use it in the evenings. On average, a battery increases the proportion of your demand covered by solar by around 20%. Beyond self-consumption, batteries also offer power cut backup and the ability to charge overnight on cheap off-peak tariffs for use during peak hours.
No — but for most new installations, it is the recommended approach. If you are installing solar and battery storage together from scratch, a hybrid inverter with a DC-coupled battery (such as the Tesla Powerwall 3 or a SigenEnergy system) is the most efficient and cost-effective setup.
If you already have an existing solar system and want to add a battery, the right answer depends on your situation. In some cases, an AC-coupled retrofit battery is the simpler and more economical route. In others, particularly where the existing inverter is old or due for replacement, it may make sense to switch to a hybrid. We assess this on a case-by-case basis and will advise on the best option for your system.
If all this talk of AC and DC has got you confused, here is a quick explanation.
DC (direct current) is the form of power generated by solar panels and stored in batteries.
AC (alternating current) is the form of power used by appliances in our homes and transmitted across the national grid.
Every conversion between AC and DC involves some power loss. Here is how the two approaches compare:
DC-coupled system with a hybrid inverter:
AC-coupled system with separate solar and battery inverters:
As the diagrams show, energy flowing to and from the battery in an AC-coupled system has to be converted multiple times, DC to AC, then AC to DC to store it, then DC to AC again when you use it. A DC-coupled system avoids the intermediate conversions, resulting in less energy lost overall.
For most new solar and battery installations, yes. A hybrid inverter is the most efficient setup and is increasingly the default for both new-build properties and homeowners installing solar with storage for the first time.
If you already have solar panels and are looking to add a battery, the answer is less straightforward. Replacing a working inverter is an added cost that does not always make financial sense, in many cases an AC-coupled battery retrofit is the right call. We will always give you an honest recommendation based on your existing setup.
Find out more in our guide to residential battery storage.
Find out more in our guide to residential battery storage:
