Home Battery Storage
Home battery storage installation in Ireland. Double your solar self-consumption from 35% to 75%. LiFePO4 batteries, backup power, night rate arbitrage. GoodWe ESA, Sigenergy SigenStor, Tesla Powerwall.
Key Features
- Double self-consumption — 35% to 75%
- Additional €400–€800/year savings
- LiFePO4 chemistry — safest available
- Backup power in under 4 milliseconds
- Night rate arbitrage — charge at 6c, use at 42c
- 10–15+ year battery lifespan
Store Your Solar. Use It When You Need It.
Double your savings. Keep the lights on during outages. Charge at 6c, use at 42c.
75%
self-consumption with battery
€800
extra savings per year
36c
arbitrage spread per kWh
15yr+
LiFePO4 battery life
Why You Need a Battery — The Simple Maths
Without a battery, you use only 30–40% of your solar generation. The rest goes back to the grid at 18.5–25c/kWh — less than you’d save by using it yourself at 42c/kWh. That’s money leaving your roof every sunny day.
Add a battery and self-consumption jumps to 70–80%. Your solar charges the battery during the day, then powers your home in the evening and overnight. The additional saving: €400–€800 per year.
We only install LiFePO4 (Lithium Iron Phosphate) batteries.
It’s the safest lithium battery chemistry available — no thermal runaway risk, longest cycle life, and 100% depth of discharge. We don’t install NMC (Nickel Manganese Cobalt) — older chemistry with fire risk we’re not willing to take.
Self-Consumption: With vs Without Battery
35%
Without battery
75%
With battery
€600
Saved without battery
€1,300
Saved WITH battery
Based on 4kW system, 3,800 kWh/year, 42c/kWh import rate. Battery adds €400–€800/year in additional savings.
LiFePO4 vs NMC — Why Battery Chemistry Matters
| Feature | LiFePO4 (What We Install) | NMC (What We Don’t) |
|---|---|---|
| Thermal Runaway Risk | No — inherently stable | Yes — can catch fire |
| Cycle Life | 4,000–6,000 cycles | 1,500–3,000 cycles |
| Expected Lifespan | 10–15+ years | 7–10 years |
| Depth of Discharge | 100% usable | 80–90% recommended |
| Round-Trip Efficiency | 95–98% | 90–95% |
| Operating Temperature | Wider stable range | More sensitive to heat |
| Our Recommendation | ✓ Install this | ✗ Avoid |
How Big a Battery Do You Need?
For a typical 3-bed Irish home with a 4kW solar system, 10–16kWh is the sweet spot. Here’s why:
5kWh
Budget option
- • Covers evening usage
- • Not enough for overnight
- • ~60% self-consumption
- • Fills quickly in summer
10–16kWh ★
Recommended
- • Covers evening + overnight
- • 70–80% self-consumption
- • Night rate arbitrage possible
- • Full home backup for 6–10 hrs
20kWh+
Maximum independence
- • Near-complete self-sufficiency
- • Extended backup (12+ hrs)
- • 80–90% self-consumption
- • Premium cost, premium returns
Battery Systems We Install — Compared
We work with the best battery systems available. Here’s how they compare.
| Feature | GoodWe ESA | Sigenergy SigenStor | Tesla Powerwall 3 | BYD / GivEnergy |
|---|---|---|---|---|
| Battery Capacity | 5–48kWh (stackable) | 8–40kWh per tower | 13.5kWh | 5–16kWh |
| Inverter Power | 3–10kW | 5-in-1 integrated | 11.5kW | 3.6–6kW |
| Chemistry | LiFePO4 | LiFePO4 (314Ah cells) | LiFePO4 | LiFePO4 |
| Depth of Discharge | 100% | 100% | 100% | 100% |
| Backup Switchover | <4ms | <0ms claimed | <20ms | <20ms |
| Backup Type | 63A full-home | Full-home | Full-home | Essential load |
| EV Charging | Via AC charger | 25kW DC built-in | Via AC charger | Via AC charger |
| V2X (Vehicle-to-Home) | No | V2H/V2G ready | No | No |
| IP Rating | IP65 | IP66 | IP67 | IP65 |
| Phases | Single + Three | Single + Three | Single + Three | Single |
| Safety Voltage | Standard | <36V (human-safe) | Standard | Standard |
GoodWe ESA — Our Most Popular System
The GoodWe ESA is a compact all-in-one hybrid inverter and battery system. Stack up to 6 battery modules for 48kWh total. The 63A bypass means full-home backup — not just essential loads. Available in single-phase and three-phase configurations.
3–10kW
Inverter range
5–48kWh
Battery capacity
<4ms
Backup switchover
63A
Full-home backup
Sigenergy SigenStor — The 5-in-1 Powerhouse
Sigenergy combines five systems into one: Solar Inverter + EV DC Charger + Battery PCS + Battery Pack + Energy Management System. The 25kW bi-directional DC EV charger is built in — no separate unit needed. V2X ready means your car battery can power your home.
5-in-1
Integrated system
8–40kWh
Per tower
25kW DC
EV charging built-in
0ms
Load disruption
5-layer safety protection, 314Ah cells, <36V human-safe battery voltage, IP66 rated for outdoor installation.
Hybrid Inverter vs AC-Coupled — Which Do You Need?
Hybrid Inverter ★ Recommended
Best for: new installs or full system replacement
- • One unit handles solar + battery + grid
- • Fewer components = less to go wrong
- • Higher efficiency (one conversion step)
- • Backup power built in
- • Add battery now or later
AC-Coupled Battery
Best for: adding to an existing solar system
- • Keep your existing solar inverter
- • Separate battery inverter added
- • Slightly lower efficiency (extra conversion)
- • More components on the wall
- • Good option when existing inverter is fine
Night Rate Arbitrage — The Battery’s Secret Weapon
Even when the sun isn’t shining, your battery makes money. On Pinergy’s Lifestyle EV Drive tariff, electricity costs just 5.99c/kWh between 2am and 5am. Your battery charges from the grid at this rock-bottom rate, then discharges during the day when you’d otherwise pay 42c/kWh. That’s a 36c/kWh profit on every kWh.
| Scenario | Charge Cost | Use Saves | Profit per kWh | 10kWh Battery per Night |
|---|---|---|---|---|
| Pinergy night rate | 5.99c | 42c | 36c | €3.60/night |
| SSE/Energia night rate | ~9c | 42c | 33c | €3.30/night |
| Annual arbitrage (Pinergy) | 365 nights × €3.60 | €1,314/year | ||
This works even without solar panels. A battery on a smart night rate tariff pays for itself through arbitrage alone. Add solar and the savings stack even higher.
Backup Power — When the Grid Goes Down
Every battery system we install includes backup power capability. When the grid fails, your battery kicks in automatically.
<4ms
GoodWe ESA
0ms
Sigenergy (claimed)
<20ms
Standard hybrid
63A
GoodWe full-home
Essential Load vs Whole-Home Backup
Essential Load Backup
Selected circuits only — lights, fridge, router, sockets
- • Pre-selected circuits backed up
- • Battery lasts longer (smaller load)
- • Lower cost — simpler wiring
- • Heavy loads (cooker, shower) not backed up
- • Typical for budget installs
Whole-Home Backup ★
Everything keeps running — GoodWe ESA, Sigenergy
- • Every circuit in the house backed up
- • No need to choose what stays on
- • Higher capacity needed (10kWh+)
- • GoodWe ESA: 63A, 80A internal bypass
- • Our recommendation for new installs
How a Home Battery System Works
It’s simpler than you might think:
- 1. Morning: Solar panels start generating. Your home uses what it needs first.
- 2. Midday: Surplus solar charges the battery. Once full, excess is exported to the grid (earning you 18.5–25c/kWh).
- 3. Evening: Sun sets, battery takes over. Powers your home through the evening peak.
- 4. Overnight: Battery continues to discharge. If empty, switches to grid. On a smart tariff, it recharges at 2–5am for 6c/kWh.
- 5. Repeat.
Technical Details — For the Numbers People
Cycle Life
4,000–6,000 cycles at 80% DoD. At 1 cycle per day = 10–15+ years of daily use.
Depth of Discharge
100% — use every kWh you’ve stored. No need to keep a buffer.
Round-Trip Efficiency
95–98% for modern LiFePO4. Put in 10kWh, get 9.5–9.8kWh back.
Operating Temperature
-10°C to 50°C. Irish garages and utility rooms are well within range.
Warranty
10 years standard, some brands offer 15. Covers capacity retention above 60–80%.
Monitoring
All systems include app monitoring — see charge/discharge, state of charge, and daily savings in real time.
Frequently Asked Questions
Can I add a battery to my existing solar system?
Yes. If you have a standard string inverter, we add an AC-coupled battery alongside it. If your inverter needs replacing anyway (10–15 year lifespan), we’d recommend upgrading to a hybrid inverter at the same time — more efficient and fewer components.
How much does a home battery cost?
Expect €4,000–€8,000 for a 10kWh system installed, or €6,000–€12,000 for 15–20kWh. Costs vary by brand, capacity, and whether you need a new inverter. The additional savings of €400–€800/year mean payback of 6–10 years for the battery alone. Combined with solar, the whole system payback is 5–8 years.
Is there a grant for battery storage?
Not separately, no. However, if you’re installing solar PV with a battery, the SEAI solar grant of up to €1,800 helps reduce the overall system cost. The battery adds to the total cost but significantly improves the return on investment through higher self-consumption and arbitrage savings.
Do I need solar panels to get a battery?
No. A battery works without solar by charging from the grid at cheap night rates (6c/kWh) and discharging during peak hours (42c/kWh). The arbitrage alone can save €1,000+/year. Solar makes it even better — free charging during the day — but isn’t strictly necessary.
Will a battery power my whole house during an outage?
With a GoodWe ESA (63A bypass) or Sigenergy SigenStor — yes, your whole house stays on. With some other systems, you’ll need to pre-select which circuits to back up (essential load backup). Duration depends on battery size and what you’re running. A 10kWh battery runs essential loads for 8–12 hours.
How long do home batteries last?
LiFePO4 batteries: 10–15+ years with daily cycling. They’re rated for 4,000–6,000 cycles at 80% depth of discharge. At one cycle per day, that’s over 10 years before you reach the rated cycle limit — and the battery doesn’t die at that point, it just has slightly reduced capacity (still 60–80% of original).
Where is the battery installed?
Typically in your garage, utility room, or a sheltered external location. The GoodWe ESA and Sigenergy SigenStor are IP65/IP66 rated, meaning they can be installed outdoors if needed. We’ll recommend the best location during our survey. The battery is wall-mounted and takes up roughly the space of a small fridge.
Are home batteries safe?
LiFePO4 batteries are extremely safe — they cannot undergo thermal runaway (the chain reaction that causes battery fires in NMC batteries). That’s specifically why we only install LiFePO4 chemistry. The Sigenergy system operates at <36V, which is below the threshold for electric shock — human-safe voltage.
What’s the difference between kW and kWh for batteries?
kWh is the size of the tank — how much energy the battery stores. kW is how fast it can fill or empty — the power rate. A 10kWh battery with a 5kW inverter can power 5kW of loads for 2 hours, or 1kW of loads for 10 hours. You need enough kWh for capacity and enough kW for your peak demand.
Ready to Double Your Solar Savings?
Free consultation. LiFePO4 batteries only. Backup power included.
Get a Free Quote
Ready to Switch to Solar?
Get a free, no-obligation quote today. We'll design the perfect system for your home or business.