SOLAR SID'S NO-BS GUIDE: 36 SOLAR TERMS YOU NEED TO KNOW
If a salesman says it, it's in here.
Lads, I'm sick of the jargon. If you're getting solar in Ireland, you need to know these - save this post!
☕ Help keep Solar Sid independent
Hi, I'm Dale McWilliams (Solar Sid). This site has no ads and no installer sponsors — it's 100% independent. If the guides helped you, you can buy me a coffee to help cover domain and hosting and keep it free for everyone.
THE BASICS:
- kW = HOW FAST (power) - How much muscle your system has at any one second. Your kettle is 3kW.
- kWh = HOW MUCH (energy) - What you're billed for, what fills your battery. If your 5kW system runs full whack for 1 hour, you made 5kWh.
- kWp = max power in perfect lab conditions. Never happens in Ireland!
THE GEAR:
- Solar Panel - turns sun into DC.
- String Inverter - one big brain for all panels. One shaded = all sulk.
- Hybrid Inverter - solar + battery in one. Get this if you EVER want a battery.
- Microinverter - one tiny inverter per panel. Great for shade but more to go wrong.
- Battery Storage - your bucket of kWh for nighttime (10 kWh min but 15kWh needed for most Irish homes to get the full benefit).
- DoD - Depth of Discharge - how much battery you can actually use.
- Charge/Discharge Rate - how fast it fills/empties.
THE ROOF BIT:
- MPPT - Maximum Power Point Tracker - squeezes max power every second (this is in the inverter).
- String - panels wired like Christmas lights.
- Azimuth - which way the roof faces. South is king. 180 = South, 90 = East, 270 = West.
- Tilt - angle. 30-35° is sweet spot for Ireland.
- Shading - Enemy No.1. Chimneys, aerials, Mick's tree (also see optimisers).
THE PAPERWORK (Irish bit):
- BER Cert - needed AFTER install, no BER, NO GRANT.
- SEAI Grant - €1,800 back.
- NC6 Form - to ESB Networks to get PAID for export. No NC6 = No cash.
- Export - leccy you sell back. 13-19c/kWh.
- Self-Consumption - how much of your own solar you use. Aim for 45-55%.
THE SAFETY & DETAILS:
- MC4 Connector - joins panels. Cheap ones MELT. Staubli is the original and the best.
- Bird Mesh - stops pigeons setting up an Airbnb under your panels.
- Isolation Switches - big red (AC) & a big grey (DC) off switch. Mandatory.
- Fireman Switch / Rapid Shutdown - safety switch so fire brigade can kill DC on the roof in an emergency. Mandatory.
- Generation App - addictive, you'll check it 20 times a day.
- Degradation - -0.5%/yr. Still 88% after 25 years.
- Grid-Tied - normal system, off when ESB goes off.
- EPS/Backup - Emergency Power Supply - keeps lights on when ESB is down.
- Shunt - See Fireman Switch / Rapid Shutdown
- ESB Smart Meter - what ESB bills you from. Import + Export.
- Solar Meter - measures ONLY what solar made.
- CT Clamp - little clip in fuse board that tells inverter what house is using. Fitted backwards = chaos.
- Battery Breaker / DC Fuse - big fuse that stops a fire. Non-negotiable.
- Optimiser (Tigo / SolarEdge) - panel-level box so you can see each panel in app, needed if you have shading.
- CCA - little box that collects all optimiser data and sends it to your router. No CCA = no Tigo monitoring.
Sid ☀
If a salesman baffles you with jargon, send him this page.
☕ Solar Sid's Tip: Got your head around the terms? Now run your real numbers in my Irish Solar Calculator.