Solar energy, in plain English.
- 43 articles
- Updated about every 6 days
- Latest 2 days ago
Long-form technical articles on solar panels, photovoltaic pergolas, batteries, EV chargers and the Spanish solar market — written by the team at A Todo Sol.
For beginners
The questions everyone asks
Start here: signing, bifacials, tax deductions, and why a 600 W panel does not deliver 600 W.
All articles
The red-tile myth: why bifacial panels always win, even on a cloudy day
Bifacial always wins: more on a sunny day, fewer losses under cloud. Neither red tiles nor €3–4 per module justify a monofacial over 30 years.
Solar panels on your warehouse with no money down? It exists — and it is not a PPA
Install PV on your warehouse with zero deposit and own the system from day one. Finance with instalments covered by savings. Real numbers for a 100 kWp site.
12 questions to ask any solar installer before you sign (2026)
Objective checklist: own support, string monitoring, fixed price, weekend and holiday sales/support, whole-home backup, batteries and what happens if the company closes.
The great self-consumption PPA scam: why your business should not give its roof away for fifteen years
Solar PPAs are being signed in Spain at €32.50/MWh. Over 30 years, handing over your roof for fifteen costs €138,000 to €388,000 on a €75,000 system.
The year the midday kWh stopped being worth money: why 2026 is about batteries
Spain curtailed 2.5 TWh of renewables in the first half of 2026 and has passed 500 hours of negative prices. What that means for your roof and for a battery.
One third of the owners was always enough: what really changed in March for solar panels on your building
RDL 7/2026 did not cut the majority to one third: it was already there. What changed is which systems it covers, the 5 km rule and the IRPF deduction.
Your system can be perfect… and still fail: why monitoring matters more than installation day
Even a perfect solar installation develops faults. We monitor your plant, detect blown fuses and dead strings, and compensate the production lost.
Shared self-consumption between two homes within 5 km: paperwork, batteries and Iberdrola (vs virtual battery)
How hourly kWh sharing works between two CUPS within 5 km: customers choose β coefficients (not i-DE or Iberdrola), DSO paperwork, host battery effects, economics, and why retailer virtual battery is not collective self-consumption.
Real technical support: 12 minutes, 32 minutes, 4:57 a.m.
Three real Atodosol after-sales cases: Huawei inverter WiFi in 12 minutes, attic noise in Elche in 32 minutes, and a tripped RCD at 4:55 fixed on WhatsApp. Solutions — not more problems.
Genergy: how not to run technical support (and why Atodosol defends the customer)
After-sales lessons with Genergy and the Mulhacén Sol: consumer warranty, pickups, installer channel and privacy. How not to leave the end customer stranded.
Why saving €800 on solar can cost you the next 30 years — history, bankrupt installers and real monitoring
Choosing a solar installer is not today's price: it is 30 years of service. SolarProfit, Svea, Social Energy, Google vs Trustpilot, hidden costs of cheap quotes and free lifetime monitoring.
Single-phase vs three-phase at home — and why whole-house Deye backup beats Huawei + Backup Box
Why Spanish homes should stay single-phase (neutral safety, simplicity, EV charging at 7.4 kW) and why a Deye hybrid with whole-house critical loads is stronger backup than Huawei + Backup Box.
Off-grid solar: if your installer closes at 15:00, you do not have real support
Companies that install and maintain off-grid PV but do not answer after 15:00, nor on weekends or holidays. Why continuous support off-grid is not an extra: it is the difference between light and darkness.
Deye EVSE charger: what is still green (Peak Shaving, contracted power and Solar-only)
Deye SUN-EVSE22K01-EU-AC in our catalogue with transparency: Peak Shaving and Solar-only still green (Deye is working on inverter and charger firmware). Site gotcha: if the inverter’s only RS485 is used by the battery, you need external power and more complexity.
How brand SAT can break the brand: the V2C Trydan case (and why A Todo Sol controls it)
How defensive brand SAT — with V2C Trydan as the mirror — destroys installer and end-customer trust and ends up killing the manufacturer. Why A Todo Sol controls support and always defends the customer on warranties.
Why we don't process IBI council-tax rebates (and why anyone who says they do is lying)
No council lets a third party handle the IBI rebate. Real cases: illegal BBQ, a €5,000 fine, and why A Todo Sol won't sell you a false promise.
We stopped installing V2C Trydan chargers
We cut Trydan (V2C) on new builds: burned terminals and boards, protections that fail, and a SAT/channel that, in four cases, threw the installer under the bus in front of the customer — even trying to void warranties. No anaesthetic.
Hacienda catches you via the cadastre if you deduct and collect Next Generation
Real limited tax checks: if you claim 100% deduction and later collect NextGen, you repay tax + interest + penalty. Worked example with tables (€8,800 / €6,500).
We stopped processing Next Generation: the paperwork is sometimes impossible
Why A Todo Sol stopped filing Next Generation in the Valencian Community: impossible documentation packs, ten-day remediation letters, and a grant that can clash with the tax deduction.
You have just had solar panels fitted: why the app shows a few watts from the grid (and it is not a fault)
New solar system: how to read the inverter diagram, why 10–25 W from the grid is normal, why Solarman-Deye Cloud lags 5 minutes and the display is live. In summer the residual at the neutral point can rise a little because hot copper has higher resistance.
The call that changed everything: what Social Energy's collapse teaches us about choosing a solar installer
A customer who wasn't ours called for help with her subsidy: her installer had gone bankrupt. Why who installs your panels matters more than you think.
40% or 60%? Spain’s solar income-tax deduction, the Valencian 40%, and whether you need a heat pump
State 60% is building energy renovation (certificate), not windows or a heat pump. In the Valencian Community the regional 40% caps at an €8,800 base.
When the grid is not the answer: peak shaving, off-grid and hybrid in three real cases
Three real cases where the grid was not the answer: a house with no power, a factory facing a €140,000 bill, and a home on construction power.
How much do you really save with solar panels at home?
Discover how much you really save with solar panels in a home. Real data, practical examples and payback calculation.
Solar panels in a second home: is it worth it if I only go at weekends?
Does it pay off to install solar panels in a second home if you only use it at weekends? Find out when it is profitable and calculate your real savings.
Solar panels vs diesel generator: which is better and more profitable?
Solar panels or generator: which is better? Discover the differences, costs and real benefits before deciding your energy investment.
Why KNX isn’t always the answer for industrial automation
KNX should be Europe’s open building automation standard. In practice, each manufacturer implements their own version. A real case from a shoe factory in Elche.
Bioclimatic vs solar pergola: everything you need to know before deciding
Bioclimatic or solar pergola? Find out which suits your case, with a comparison of costs, subsidies and real profitability.
How to recover 60% of your photovoltaic investment for your residents' association
The 60% IRPF deduction for solar panels in residential buildings is extended to 2027. Turnkey service so your residents' association recovers the investment.
10% VAT on solar panels in Spain: the sales trick competitors still use (and the real risk for you)
10% vs 21% VAT on solar in Spain: sector tricks, penalties up to 150%, and how a dirty invoice risks the 60% state and 40% regional income-tax deductions.
Solar pergola FAQ: what you should know before installing
Frequent questions about solar pergolas: where to install them, cost, financing and batteries. Clear answers for Spain.
Clean solar panels? On monocrystalline, it almost never pays (and can do harm)
After a calima panels look dirty (~15% for a day) and rain usually resets them. Cleaning badly can microcrack glass; professional cleans start ~€80. We prefer daily string/fuse monitoring (see /en/technology/) over selling mops.
Why your solar system shut down during the blackout — and how to avoid it
Why did so many solar installations go offline during the national blackout, and how the Backup Box keeps your home running through power cuts.
Why your 600 W solar panel only produces 531 W: a guide to compatibility in photovoltaic systems
Your panel may produce less than its rated capacity: mismatch between the panel's max current and your inverter costs you energy and money.
Energy advice: optimise your consumption and cut costs on your electricity bill
Did you know you can optimise your electricity bill at no cost? At Atodosol we offer free energy advice to help you pay only for the energy you really need.
Solar energy at home: essential guide before taking the leap
Essential guide before installing solar panels: prepare your roof, know your consumption and choose a good installer.
ATODOSOL offers free help to those affected by the DANA in the Valencian Community
Free advice on electricity and photovoltaics for those affected by the DANA in the Valencian Community and across Spain.
The SunPower bankruptcy: lessons for the Spanish solar market
The SunPower bankruptcy shakes the solar market. Discover the implications for Spanish consumers and how to choose reliable solar providers.
Hail warranty for solar panels: what it is and why you need it
Hail warranty from A Todo Sol: we replace any hail-damaged panel at no cost, ensuring your solar system's durability in extreme weather.
Solar pergolas: the best alternative for your photovoltaic installation
Solar pergolas combine aesthetics and function: shade and clean energy for your home. Advantages, technical operation and success stories.
A Todo Sol: certified Tesla Powerwall installer in Spain
A Todo Sol, certified Tesla Powerwall installer in Alicante. Get your Powerwall solar battery with Tesla's quality guarantee and A Todo Sol's experience.
Cost vs return: understanding the solar panel investment in the Valencian Community
Cost and return of solar panels in the Valencian Community: prices, subsidies and financing for an informed decision.
The Backup Box for photovoltaic systems: an energy backup solution
Backup Box from A Todo Sol and Toscano: a backup device that keeps critical devices running during blackouts.
And once it is installed, somebody is watching it.
We check every string of panels every night and alert you if one drops — something the manufacturer's app does not do. Included for life, at no cost.