Two ways to store your surplus

On the Costa del Sol a solar system usually produces more than the house uses between 11:00 and 17:00. You can store that surplus in two very different ways:

A physical solar battery in your home, storing kWh you use the same evening.

A virtual battery (*bateria virtual*), where your supplier banks the value of exported kWh as credit against future bills.

Physical battery: costs and payback

Capacity	Suits	Price installed (excl. VAT)
5 kWh	Apartment, light evening use	from EUR 3,600
10 kWh	Family home, A/C at night	from EUR 5,900
15 kWh	Villa with pool and EV	from EUR 8,400

A 10 kWh battery shifts roughly 2,500-3,000 kWh a year from day to evening. At current tariffs that is EUR 500-700 saved annually, so eight to eleven years for payback - faster if you also want backup during power cuts, which several Axarquia and inland municipalities still see in summer storms.

Virtual battery: how it works

Your surplus is compensated at the contracted export price and, instead of being capped at your monthly electricity bill, the remaining value is stored as credit. That credit can offset later bills and, with some suppliers, the standing charge, gas or even the bill of a second property.

There is no hardware, no installation and no wear. The downside: you depend on your supplier's terms, the credit is worth less per kWh than self-consumption, and it gives no protection during a blackout.

Which one pays off for you?

You are home in the evening, run A/C at night or charge an EV after work - a physical battery wins.

Your house is empty on weekdays or you rent it out seasonally - the virtual battery is usually the better return.

You want backup power - only a physical battery with a backup-capable inverter does that.

Large summer surplus, low winter use - the virtual battery carries value across the seasons.

Many of our clients combine both: a modest 5-10 kWh battery for evening use, and a virtual battery contract for what is still left over.

Frequently asked questions

How long does a solar battery last?

Lithium iron phosphate batteries are warranted for 10 years or around 6,000 cycles and keep about 80% of their capacity at the end.

Can I add a battery to an existing system?

Yes. With a hybrid inverter it is straightforward; with a string inverter we add an AC-coupled battery.

Does a battery need maintenance?

Only a yearly check of the connections and firmware, which is part of our maintenance contract.

Is the virtual battery credit refundable in cash?

No. It offsets bills; it is not paid out.

Send us your last twelve months of consumption and we will calculate both options for your home, in English.

Source: MiTechoSolar.com, Premium solar energy on the Costa del Sol

Installed by Mi Techo Solar · Professional solar panels, batteries & EV chargers · mitechosolar.com

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