Batteria Domestica vs Heat Pump Boiler: Which is Smarter?

Two ways to store energia solare

A scaldacqua a pompa di calore and a batteria domestica solve the same problem: they store surplus energia solare during the day for use when the sun isn't shining. But they do so in a fundamentally different way, with different advantages and disadvantages.

In this article, we compare both technologies fairly and help you make the best choice for your situation.

How does a scaldacqua a pompa di calore work?

A scaldacqua a pompa di calore uses surplus solar elettricità to heat water (up to 65°C) with an efficienza of 300-400% (COP 3-4). The stored thermal energy is used later for showering and heating. A scaldacqua a pompa di calore is relatively affordable (€1,500 to €3,000 including installazione) and has a short periodo di ammortamento.

The disadvantage of a scaldacqua a pompa di calore is that the stored energy is esclusivamente available as heat. You cannot power electrical elettrodomestici with it, charge a car, or absorb elettricità peaks.

Direct comparison: batteria domestica vs scaldacqua a pompa di calore

A direct comparison on the most important criteria.

After the comparison, it's clear: a batteria domestica is more versatile but more expensive, while a scaldacqua a pompa di calore is cheaper but limited in application.

When should you choose a batteria domestica?

A batteria domestica is the better choice if you want to reduce high elettricità costs, have little or no hot water consumption, want to charge an auto elettrica with energia solare, want alimentazione di riserva during outages, or want maximum flexibility for future applications.

• You have high elettricità costs beyond hot water
• You want to charge an auto elettrica with your own energia solare
• You want alimentazione di riserva during outages
• You already have a modern central heating boiler or district heating for hot water

When should you choose a scaldacqua a pompa di calore?

Choose a scaldacqua a pompa di calore if you primarily want to save on hot water costs, have a limited budget, use more hot water than average (large family), and if your nucleo familiare has relatively low elettricità consumption.

• Your primary cost is hot water (showers, baths)
• Your budget is limited and periodo di ammortamento is a priority
• You have a large family with high hot water consumption
• You have relatively low elettricità consumption (no EV, no pompa di calore)

The best choice: combine both

The optimal solution is a combination of both: a scaldacqua a pompa di calore takes care of thermal storage (hot water), while the batteria domestica stores the electrical surplus. Together, you maximise autoconsumo and minimise the bolletta energetica.

The cost of the combination is higher, but the periodo di ammortamento can still be attractive thanks to the ISDE incentivo that applies to scaldacqua a pompa di calores in combination with pannelli solari.