POWERPIGGY BATTERY GUIDES
Is battery storage
worth it for you?
The honest answer: it depends
For some properties a battery is a sensible investment. For others, the savings are too small to justify the cost. Rather than promising a payback period, it’s better to understand the handful of things that decide the answer, so you can judge any quote on its merits.
1. The gap between cheap and expensive electricity
A grid-charged battery earns its keep by buying electricity at a lower rate and using it instead of electricity at a higher rate. The bigger that gap, and the more often you use it, the stronger the case. Check your tariff’s off-peak rate, peak rate, charging window and standing charge, and whether you qualify for it.
2. How much you use at higher-priced times
A battery only saves money on electricity it actually replaces. If most of your use already happens overnight, or your evening use is low, there may be little to shift. A household with high early-evening demand, or a business busy during the day, is usually a better fit. Smart-meter data or a recent bill is the best place to start.
3. Charging losses and degradation
Batteries don’t return every unit you put in: some energy is lost when charging and discharging, and usable capacity gradually reduces over the years. Any realistic estimate should allow for both, as well as any standby consumption.
4. The complete installed cost
Compare the full installed price, including inverter, electrical work and any backup equipment, rather than an equipment-only price. If you’re using finance, include the cost of borrowing. Bigger isn’t automatically better: a battery that is rarely fully used can offer poor value.
5. Warranty and expected life
Look at the warranty length and its conditions, such as limits on cycles or energy throughput and what capacity is guaranteed at the end. The benefit you expect needs to arrive within a realistic working life.
Other reasons people choose a battery
Some people value using more of their own solar electricity, or having automatic backup power during an outage, which comes with every system we install. These can be good reasons, but they should be weighed separately from the financial case.
Further reading: Energy Saving Trust’s battery storage guide.