Solar Battery » Is a smaller battery better for your pocket?

Is a smaller battery better for your pocket?

By Guste May 01, 2018

In the case of domestic batteries, is less more? Here at Moixa we certainly believe it is; let us tell you why.

Smaller is better

The idea that smaller solar batteries give more power to UK households sounds counterintuitive, but it really is the case. Many batteries offer very high charge and discharge rates, as well as enormous capacities to store all that excess solar, but most UK homes won’t be able to produce that much spare solar and even fewer homes will be able to discharge the entire capacity throughout the evening.

Combined with the subtle challenges of selecting an appropriately sized solar battery, the seasonality factor even further highlights the importance for UK homeowners to shop around for a tailored solution. Although a bigger battery would allow households to store the electricity for longer, it would cost more in the long run and simply isn’t the best solution for the British market.

Given that the average UK home consumes around 4000 kWh/year, you would need to invest around £10,000 to get a home battery large enough to store that amount of solar energy. At Moixa, we have engineered a smart solar battery that is tailored to UK households and runs in the most efficient manner. Instead of aiming to store as much solar energy as possible, our battery is designed to charge during the day even with a small amount of PV available. The charge rate of our batteries is lower in comparison to most other batteries on the market. There is still plenty of time to fill the battery throughout the day but limiting the battery to just one cycle per day is excellent for battery efficiency and lifetime. That, plus a lower discharge rate, provide a real chance for homeowners to make consistent savings throughout the year.

Charge & Discharge Rates of The Smart Moixa Battery

  • The battery charges at a rate of approximately 350w/h and discharges at a rate of approximately 430w/h.
  • The 2kWh battery can charge itself in approximately 5-6 hours and discharge itself in 3-5 hours.
  • The 3kWh battery can charge itself in approximately 8 hours and discharge itself in 6-7 hours.

It simply means our battery is designed to perform at an optimal level even without you having to make any lifestyle adjustments.

 Let’s look at a quick example.

In the UK, most residential solar installs will be restricted to 3.68kWp, and as we don’t enjoy the highest levels of daylight throughout the year, it would be impossible to fill up an oversized battery, with a likely exception of July and August. For instance, a 3.68kWp system may generate 29 Kw on a sunny day in July, but it will probably only generate 3.68Kw throughout the winter months, and around 7-8 kW in spring and autumn. Your household will likely be consuming electricity during the day, even when you’re not at home, so not all of the electricity generated would be spare and available to fill the battery. In such case, an oversized battery wouldn’t stand a chance to get charged and cycled (except, perhaps, in the summer months), whereas our smart battery, with a low charge rate and smaller storage capacity, would work even with a minor amount of spare PV available.

The summer months, the only time of the year when you could potentially fill a larger battery, is also the time when we consume the least amount of electricity, since there’s little to no need for heating and we spend most of the time away from the house.

This brings us back to the key question: is a smaller battery really better for your pocket? We believe that it is far more economical to opt for a smaller and reasonably priced battery, like our 2-3kWh models, that will continue to deliver the benefits of solar power all year round, rather than paying a premium for a larger capacity, which you will be able to use to its full potential only a few months per year.

Calculate how much you can save by generating your own renewable energy here.

Information accurate at the time of publishing.