Ireland-Spain Interconnector: Should You Wait or Install Solar Now?

On 24 April 2026, Ireland and Spain signed a memorandum of understanding (MoU) to explore building a subsea electricity interconnector linking the two countries. Ireland's first direct connection to continental Europe outside the UK. The proposed cable would have approximately 1 gigawatt (GW) capacity, running roughly 700 to 800 kilometres across the Atlantic from the south coast of Ireland to northwest Spain.

For Irish homeowners watching energy infrastructure news, this raises an important question: Should you wait for the interconnector before installing solar panels?

The short answer is no. Here's why.

What Is the Ireland-Spain Interconnector?

The interconnector would be a high-voltage direct current (HVDC) subsea electricity cable allowing Ireland and Spain to trade power. Similar to the existing Celtic Interconnector between Ireland and France (due for completion in 2028), the cable would:

• Import solar-rich Spanish electricity during Irish winter – Spain receives approximately twice Ireland's solar irradiance, meaning Spanish solar farms generate far more electricity during darker Irish months (November to February)
• Export Irish wind power to Spain – Ireland has some of Europe's best wind resources; during high-wind periods, Ireland could export surplus generation to Spain
• Strengthen energy security – diversifies Ireland beyond existing UK interconnectors (Moyle, East-West, Greenlink) and reduces dependence on fossil fuel imports
• Support renewable integration – helps Ireland reach its 80% renewable electricity target by 2030 by balancing variable wind and solar generation across wider geography

Cathal Marley, EirGrid's CEO, said: "The commitment to study the potential for an Irish-Spanish Interconnector is a significant step for the development of our systems and has the potential to play a key role in helping us to move towards greater European energy independence. Strengthening Ireland's interconnection with our neighbours is essential to delivering a secure, low-carbon energy system."

Roberto García Merino, CEO at Redeia (Spain's grid operator), added: "By connecting our electricity systems, we can support the energy transition and contribute to a more resilient and sustainable power system for Spain, Ireland, and Europe."

It sounds promising. But there is a critical timeline reality homeowners need to understand.

The Timeline Reality: 2035 at Earliest

The April 2026 MoU is just the beginning of a decade-long process. Here is the realistic timeline for the Ireland-Spain interconnector:

Phase 1: Feasibility Studies (2026-2028)

The MoU commits both countries to conducting early-stage feasibility studies. This involves:

• Route surveying (identifying optimal undersea path, avoiding shipping lanes, marine protected areas, existing infrastructure)
• Technical design (cable specifications, converter stations, grid connection points)
• Environmental impact assessments
• Economic viability analysis

Duration: 2 to 3 years minimum

Phase 2: Planning and Approvals (2029-2032)

If feasibility studies are positive, the project moves to formal planning:

• Irish planning permission (An Bord Pleanála)
• Spanish planning permission
• EU Projects of Common Interest (PCI) designation and funding applications
• Marine licensing
• Land acquisition for converter stations

Duration: 3 to 4 years minimum (planning challenges frequently cause delays)

Phase 3: Construction (2032-2036)

Actual construction includes:

• Building onshore converter stations in Ireland and Spain
• Manufacturing subsea cables (700-800 km of specialist HVDC cable)
• Marine cable laying (weather-dependent, often taking 2-3 years for long routes)
• Grid connection and testing
• Commissioning

Duration: 4 to 5 years minimum

Realistic Operational Date: 2035-2037

The earliest the interconnector could be operational is 2035, with 2037 more realistic given typical infrastructure project delays. For comparison:

The Celtic Interconnector—announced in 2016, originally scheduled for 2026, now delayed to 2028—took 12 years from announcement to commissioning. The Ireland-Spain interconnector is more complex (longer distance, deeper waters, more challenging route), suggesting a similar or longer timeline.

Bottom line: Irish homeowners waiting for the interconnector will wait at least 10 years, possibly 15.

Why Waiting Costs You Thousands

Let us calculate the real cost of waiting for a typical Irish household:

Scenario: 7 kWp Solar System

At the time of writing, a 7 kWp system costs approximately €7,450 after the €1,800 SEAI grant. Over 10 years, this system will:

• Generate approximately 60,000 kWh of electricity (6,000 kWh per year × 10 years)
• Save approximately €9,000 to €12,000 in electricity bills over 10 years (assuming 70% self-consumption at €0.38-€0.42 per kWh average)
• Earn approximately €1,200 to €1,500 in export income over 10 years (30% exported at €0.15-€0.20 per kWh)
• Total 10-year benefit: €10,200 to €13,500

If you wait 10 years for the interconnector before installing solar:

• Lost savings: €10,200 to €13,500
• Electricity costs paid during wait: €18,000 to €24,000 (assuming 4,200 kWh/year at €0.38-€0.42/kWh, with 3% annual increases)

Even after the interconnector is operational, you still face the same electricity rates homeowners pay today. The interconnector stabilises wholesale markets and helps grid operators balance supply and demand, but retail electricity prices for homeowners remain subject to supplier pricing, VAT, PSO levy, and network charges.

The interconnector does not make home solar obsolete, it complements it.

Grid-Scale vs Home-Scale: Why Both Are Needed

Interconnectors and home solar panels serve different purposes. Here is how they compare:

Think of it this way: the interconnector is like building motorways between countries to improve trade. Home solar is like owning your own car so you do not have to rely on public transport. Both are valuable, but they solve different problems.

What the Interconnector Actually Does for Homeowners

The Ireland-Spain interconnector will deliver some indirect benefits to Irish homeowners:

1. Wholesale Price Stabilisation (Modest Impact)

By connecting Ireland to Spain's solar-rich grid, wholesale electricity prices may become slightly more stable. During Irish winter, cheap Spanish solar electricity could reduce wholesale price spikes. However:

• Wholesale prices are only one component of your retail bill
• Network charges, PSO levy, VAT, and supplier margins remain
• Historical data shows Irish retail prices rose 32.7% between July and December 2025 despite stable wholesale markets in some periods

Impact on your bill: Potentially €50 to €150 per year in reduced volatility—but no guarantee, and far smaller than solar savings (€800-€1,200/year).

2. Energy Security (National, Not Personal)

The interconnector diversifies Ireland's energy supply at a national level, reducing reliance on UK interconnectors and imported fossil fuels. This is strategically important for Ireland's energy security.

But for individual homeowners, personal energy security comes from generating your own electricity. Solar panels (especially with battery storage) provide household-level resilience during:

• Grid failures or blackouts
• Price spikes
• Supply shortages
• International energy crises

The interconnector strengthens Ireland's grid; solar + battery strengthens your home.

3. Renewable Integration Support (Helps the System, Not Your Bill)

The interconnector helps Ireland integrate more wind and solar onto the national grid by exporting surplus renewable generation and importing power during low-wind/low-solar periods. This supports Ireland's 80% renewable electricity target by 2030.

However, this does not change the fact that homeowners still pay retail electricity prices. Whether Ireland hits 50%, 80%, or 100% renewable electricity, your bill is determined by retail pricing, not the generation mix.

The Opportunity Cost: What You Lose by Waiting

Let us compare two homeowners:

Homeowner A: Installs Solar in 2026

• System cost: €7,450 (after SEAI grant)
• Year 1-10 electricity savings: €10,500
• Year 1-10 export income: €1,350
• Total 10-year net benefit: €4,400 (€11,850 savings - €7,450 cost)
• By 2035 (when interconnector goes live), solar system has generated €16,000 to €20,000 in cumulative savings and is still producing for another 15-16 years

Homeowner B: Waits for Interconnector (2035-2037)

• Electricity bills 2026-2035: €21,600 (assuming 4,200 kWh/year at average €0.40/kWh with 3% annual increases)
• Installs solar in 2036: €7,000-€8,000 (cost may drop slightly, but SEAI grant may be reduced or removed by then)
• Total 10-year net loss: €21,600 in electricity costs paid
• Solar system operational for only 15 years remaining before 2050 (vs 25 years for Homeowner A)

Opportunity cost of waiting: €18,000 to €26,000 over the period.

Even if the interconnector delivers some modest retail price benefits (€50-€100/year), it does not come close to offsetting the lost solar savings.

The SEAI Grant Is Guaranteed Until 2029.  But Not Forever

At the time of writing, the SEAI €1,800 solar grant is confirmed safe until at least early 2029 (the current government's term). However:

• There is no guarantee the grant will remain at €1,800 beyond 2029
• Previous reductions: The EV charger grant dropped from €600 to €300 in January 2024
• International trend: Many European countries reduced solar grants after initial uptake targets were met

If you wait 10 years for the interconnector, the SEAI grant may be significantly reduced or removed, increasing your upfront cost by €1,800 or more.

What Irish Homeowners Should Do Now

The Ireland-Spain interconnector is a positive development for Ireland's energy system. It strengthens national energy security, supports renewable integration, and diversifies supply. These are good things.

But interconnectors do not replace the need for home solar panels.

If you are an Irish homeowner:

• Install solar now if your roof is suitable and you can afford the upfront cost (or access financing)
• Benefit from 10+ years of free daytime electricity while the interconnector is being planned and built
• Lock in the €1,800 SEAI grant while it is guaranteed
• Enjoy the interconnector's modest benefits when it goes live in the 2030s, on top of your existing solar savings

Solar panels pay for themselves in 5 to 7 years in Ireland. Waiting 10 to 15 years for a grid infrastructure project means forfeiting €10,000 to €20,000 in savings that could have been yours.

The interconnector is Ireland's energy future. Solar panels are your energy future.

Final Thoughts

The Ireland-Spain interconnector MoU signed in April 2026 is a milestone for Irish energy policy. It positions Ireland as a key player in European grid integration and demonstrates commitment to renewable energy and energy security. These are strategic wins for the country.

But for Irish homeowners, the interconnector's benefits are indirect, modest, and at least a decade away. Meanwhile, solar panels deliver immediate, substantial, and guaranteed savings from the day they are switched on.

Grid-scale infrastructure projects like interconnectors are essential for national energy strategy. Home solar panels are essential for household energy strategy. Both are needed, and they are complementary, not competitive.

Do not wait for the government to build the interconnector. Install solar panels now, lock in €0.12/kWh generation costs for 25 years, and enjoy the interconnector's benefits in the 2030s as a bonus. Not as a replacement for personal energy independence.

Ready to Take Control of Your Energy Costs?

WattCharger offers free solar assessments for Irish homeowners who want to stop waiting and start saving. Our SEAI-registered installers will calculate your potential savings, design a system tailored to your roof and consumption, and handle all grant applications and paperwork.

Get in touch for a free consultation and personalised quote. While Ireland plans its interconnector, you can be generating your own electricity and banking thousands in savings.

Related reading:

• Ireland's Grid Under Pressure 2026-2028: Why Solar + Battery Is Your Best Defence
• €13.8 Billion Grid Investment Approved: Should You Wait or Install Solar Now?
• SEAI Solar Grant Confirmed Safe Until 2029: What This Means for You
• Understanding SEAI Grants for Solar in Ireland: 2025 Update