Question 1

How much roof do I need for a solar system?

Accepted Answer

Roughly 5 m² per kilowatt-peak. A typical 8 kWp home system occupies about 40 m² of usable, unshaded roof. Roof orientation and inclination change yield more than they change area.

Question 2

Does my roof have to face south?

Accepted Answer

No. In southern Europe an east–west split array typically produces 85–92 % of an equivalent south-facing array, and it matches consumption better because production is spread across morning and evening.

Question 3

Will panels work on a cloudy day?

Accepted Answer

Yes, at reduced output — typically 10–30 % of clear-sky production. Annual yield modelling already accounts for the local cloud climatology.

Question 4

How long does a solar installation take?

Accepted Answer

Most residential installations are completed in one to three days on site. The full process, including design, permits and grid registration, usually runs three to six weeks.

Question 5

Do panels need cleaning?

Accepted Answer

Only where measured soiling loss justifies it. We monitor performance and recommend cleaning when the loss exceeds the cost of the visit — usually annually in dusty regions, less often elsewhere.

Question 6

What happens to production in summer heat?

Accepted Answer

Output per module falls slightly as cell temperature rises. We select modules with strong temperature coefficients for hot climates and design mounting for airflow behind the array.

Question 7

What is the lifespan of a solar panel?

Accepted Answer

Modules are warranted for 25 years at 85–92 % of rated output, and generally continue producing well beyond 30 years at gradually reduced capacity.

Question 8

Can I add panels later?

Accepted Answer

Yes, if the inverter and board are sized with headroom. We design every array with a defined expansion path and note it in the handover documentation.

Question 9

What is a P50 yield?

Accepted Answer

The production figure that has a 50 % probability of being exceeded in any given year — the honest central estimate, as opposed to a best-case number.

Question 10

Are bifacial panels worth it on a pitched roof?

Accepted Answer

Usually not. Bifacial gain requires reflected light behind the module, which a tiled roof does not provide. On flat roofs and canopies the gain is real.

Question 11

How many Powerwalls do I need?

Accepted Answer

It depends on evening consumption and backup ambition. One unit (13.5 kWh) covers a typical home's evening and overnight load; whole-home backup with air conditioning and EV charging usually calls for two or more.

Question 12

Can Powerwall power my whole house?

Accepted Answer

With a Backup Gateway and adequate power capacity, yes. Powerwall 3 delivers 11.5 kW continuous, which is sufficient for most homes; larger properties use multiple units.

Question 13

How fast does backup engage?

Accepted Answer

Within milliseconds. Lights do not flicker and computers do not restart.

Question 14

Does the battery work without solar?

Accepted Answer

Yes. On a dynamic tariff it charges during the cheapest hours and discharges during the most expensive, which alone can justify the investment.

Question 15

How long does a Powerwall last?

Accepted Answer

Warranted for 10 years. Field data suggests useful life well beyond that, at gradually reduced capacity.

Question 16

What is Storm Watch?

Accepted Answer

The system monitors severe weather alerts and automatically charges the battery to full before the event arrives, maximising backup duration.

Question 17

Can I run an EV charger from the battery?

Accepted Answer

Yes, though it will drain quickly. We normally configure charging to pause during outages so backup energy goes to the house.

Question 18

Powerwall 2 or Powerwall 3?

Accepted Answer

Powerwall 3 for new solar installations — it integrates the solar inverter and delivers more power. Powerwall 2 for retrofits to healthy existing PV systems.

Question 19

Is the battery safe indoors?

Accepted Answer

Yes. It is rated for indoor and outdoor installation, uses a thermally stable chemistry and includes multiple layers of protection. We follow manufacturer and local fire-authority separation requirements.

Question 20

Does the battery make noise?

Accepted Answer

There is a quiet cooling fan under heavy load. In a garage or plant space it is inaudible from living areas.

Question 21

How fast will my car charge at home?

Accepted Answer

A single-phase 7.4 kW connection adds roughly 35–40 km of range per hour. A three-phase 22 kW connection adds around 100 km per hour, if the vehicle accepts it.

Question 22

Does my car support 22 kW AC?

Accepted Answer

Many do not. Most electric vehicles accept 11 kW AC; some accept only 7.4 kW. We check your vehicle before specifying.

Question 23

Do I need to upgrade my supply for a charger?

Accepted Answer

Usually not. Dynamic load management measures total household draw and reduces charging current in real time so the main fuse is never exceeded.

Question 24

Can I charge only from solar surplus?

Accepted Answer

Yes. Solar-only or solar-priority charging modes are standard when the charger is integrated with the energy system.

Question 25

Can non-Tesla vehicles use a Tesla Wall Connector?

Accepted Answer

The Universal Wall Connector charges all electric vehicles. The standard Wall Connector is designed for Tesla vehicles.

Question 26

What is OCPP and do I need it?

Accepted Answer

OCPP is the open protocol between chargers and management platforms. Any site with billing, multiple users or reporting requirements needs it.

Question 27

How do I bill guests or tenants for charging?

Accepted Answer

Through an OCPP back-end with per-user tariffs, RFID or app authorisation, and automated invoicing. We configure this as part of commercial installations.

Question 28

Can chargers be installed in an underground car park?

Accepted Answer

Yes, subject to ventilation, fire strategy and cable containment requirements, which we address in the design.

Question 29

What is dynamic load balancing?

Accepted Answer

Real-time allocation of available current across multiple chargers so a site can serve far more bays than the raw supply capacity suggests.

Question 30

How much does public fast charging cost to install?

Accepted Answer

Site dependent, dominated by the grid connection. A small DC site starts in the low six figures; a large hub with a transformer station runs into the millions.

Question 31

Do you provide electrical certificates?

Accepted Answer

Yes. Every installation is delivered with full test results, certificates and, where required, the regulatory dossier for the competent authority.

Question 32

What standards do you work to?

Accepted Answer

IEC and EN standards, national wiring regulations including the Spanish REBT, and the applicable network operator requirements for each connection.

Question 33

Can you upgrade my distribution board?

Accepted Answer

Yes. Board upgrades, supply upgrades and full rewiring are core work, and often a prerequisite for solar, storage or charging.

Question 34

Do you handle medium voltage?

Accepted Answer

Yes, up to 36 kV, including transformer station design, construction and commissioning.

Question 35

What is protection discrimination?

Accepted Answer

Coordinating protective devices so that only the device nearest the fault operates, keeping the rest of the installation live.

Question 36

Do you carry out thermographic inspections?

Accepted Answer

Yes, as part of our maintenance programme and as a standalone service for existing installations.

Question 37

Can you work on occupied buildings?

Accepted Answer

Routinely. Phased works, temporary supplies and out-of-hours execution are standard on our commercial projects.

Question 38

Do you offer engineering-only services?

Accepted Answer

Yes. Design, calculations, studies and documentation can be commissioned without installation.

Question 39

How much does a complete home system cost?

Accepted Answer

A typical 8 kWp array with one Powerwall and a Wall Connector sits in the range of €18,000–28,000 installed, before incentives, depending on roof complexity and electrical works.

Question 40

Do you offer financing?

Accepted Answer

Yes, including leasing and power purchase agreements for commercial clients, and financing partners for residential projects.

Question 41

What incentives are available?

Accepted Answer

These vary by region and change frequently. We identify and process every applicable subsidy, tax deduction and grant as part of the proposal.

Question 42

How long is your warranty?

Accepted Answer

Manufacturer warranties apply to equipment (typically 10–25 years). Our installation workmanship is warranted for 10 years.

Question 43

What happens if the system underperforms?

Accepted Answer

Our performance guarantee is written against the modelled P50 yield. If the system underperforms materially, we investigate and remedy at our cost.

Question 44

Do you work outside Spain?

Accepted Answer

Yes. We deliver projects across southern and western Europe, and engineering services more widely.

Question 45

How do I get started?

Accepted Answer

Book a free consultation. We review a year of bills, model the site remotely and return a full engineering proposal with modelled yield and savings.

Question 46

What response time do maintenance contracts guarantee?

Accepted Answer

24 hours for critical faults and 72 hours for standard service calls, with 24/7 automated monitoring on all connected systems.

Answers, in engineering terms.

Solar

Powerwall & Storage

EV Charging

Electrical Engineering

Process, Pricing & Warranty

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