Financing your home solar solution in Wales

If you have the cash available for a solar-and-battery system, life is simple: you buy it, install it, and start saving (and exporting) straight away.

But plenty of households want the benefits of solar without a large lump-sum payment. The good news is that the market has matured to the point where there are now multiple routes to fund a home solar solution—some sensible, some best avoided.

This guide sets out the main financing options, how they typically work, and what to watch for so you can choose a structure that fits your budget without compromising on installation quality.

Options to treat with caution

Before we get into the practical funding routes, it’s worth calling out three models that often look attractive on the surface but can create long-term problems.

1) Rent-a-roof schemes

How it works: a company installs panels on your roof at their cost. You use the electricity generated “for free”, and they earn money by exporting surplus energy and (where applicable) incentives.

Why it can be a problem:

• Long commitments (often 20+ years).

• Home sale complications: the lease transfers to the buyer, and some mortgage providers may require it to be terminated—sometimes with punitive fees.

• Restrictions on renovations: roof works may require compensating the scheme provider for lost generation.

  
  

Bottom line: the contract can limit your flexibility for decades. If you ever consider one, scrutinise the terms as if you were signing a commercial property lease—because you effectively are.

2) Subscription / buyback schemes

These are often positioned as “different” from rent-a-roof because you may own the system from day one and keep export income. In practice, they can behave like a long-term finance agreement plus an ongoing service fee.

Key watch-outs:

• Monitoring/support fees that sound small monthly but can add up to thousands over the term.

• Total cost creep: fees plus interest can materially inflate what you pay versus buying outright.

• Sale friction: you may need to settle the loan on sale, or persuade a buyer to take it on.

• Installer choice can be limited or opaque, and “lowest bid wins” dynamics often reduce quality.

  
  

Bottom line: if a scheme ties you into a long repayment period and you don’t control the installer, the risk profile goes up.

3) Energy provider finance offers

Some energy suppliers bundle finance with installation packages offering an all-inclusive experience for some households.

Why it can be a problem:

• You may have limited choice of installer.

• Service quality can vary if work is subcontracted through competitive tendering.

  
  

Bottom line: a finance offer should not dictate your installer choice. Vet the installer and system design first; then decide how to fund it.

The better routes: practical ways to fund solar and battery

1) Government-backed schemes

1.1) Not Means-tested

Homeowners in Wales benefit from the Green Homes Wales scheme, a government-backed initiative designed to help households improve energy efficiency and adopt renewable technologies.

Delivered in partnership with local authorities, the scheme offers free advice, home energy assessments, and, for eligible households, grants and interest-free loans towards measures such as solar PV and battery storage. The level of support depends on household income, property type, and existing energy performance, but for qualifying applicants it can significantly reduce—or even eliminate—the upfront cost of installing solar:

• Flexible financing:

  • Interest free loans ranging from £1,000 to £25,000 with repayment terms up to 10 years. For larger projects, terms may be extended.

  • A 6-month upfront repayment holiday while your new energy efficiency measures begin delivering results.

• Grant funding (for projects which also include installation of a heat pump):

  • Access to grant funding alongside loans.

    
    

As with any publicly funded programme, availability and eligibility criteria can vary, so it’s important to engage early.

For more information about the Scheme and to apply, homeowners should register their interest at https://developmentbank.wales/green-homes-wales

1.2) Means-tested

Means-tested government initiatives which can cover the cost of solar panels in Wales include Nest, ECO4 and ECO4 Flex. If you receive means-tested benefits or have a low-income, we cover these Scheme here.

2) Bank “green” home improvement loans and cashback

A standard personal loan can fund solar, but many lenders now offer green loans with better terms for eligible upgrades (solar PV, batteries, heat pumps, insulation).

Why this route works:

• Fixed monthly payments and defined term.

• Often quicker and simpler than mortgage change.

• Green products may offer preferential rates or incentives.

  
  

For example: Nationwide customers can get 0% interest green improvements loans borrowing £5000 to £20,000 for the first 2 to 5 years.

Some lenders provide cashback linked to installing renewable tech (often where you hold a qualifying current account or mortgage product).

For example: If you have or are in the process of setting up a mortgage with Lloyds and you have a Lloyds Club account, you can receive a £1,000 cashback for a new solar panel or battery installation.

3) Extend your mortgage (where appropriate)

If you already have a mortgage, one of the most straightforward approaches is to borrow against the property—because the solar and battery system becomes part of the home.

Why homeowners like this option:

• Rates can be relatively competitive versus unsecured lending.

• Repayments can be spread over longer terms.

• The borrowing aligns with an asset that improves the home’s running costs.

  
  

Practical step: speak to your mortgage provider and ask specifically about borrowing for energy efficiency / renewable improvements and any loan-to-value limits that apply.

For example: If you are with Santander you can borrow £5000 or more for a minimum of 5 years at your current mortgage rate providing your new mortgage total is less than 85% of your home’s value.

4) Local authority loan schemes

Depending on where you live, your local authority or council may offer low-interest or even 0% finance for home energy improvements.

Why it can be attractive:

• Favourable terms designed to accelerate retrofit adoption.

• Often more forgiving underwriting than mainstream finance.

  
  

What to watch:

• Eligibility criteria (postcode, property type, income bands, EPC rating).

• Approved contractor requirements—if you’re forced into a limited installer pool, do extra diligence on quality.

  
  

Conclusion

Solar and battery systems are no longer an “exclusive club” purchase. As finance options expand—from mortgages and green loans to council schemes and installer-led credit—more households can access the benefits: lower bills, greater energy resilience, and a measure of independence from volatility.

The most important rule: choose the installer first. Do not let a finance deal choose your installer. Poor installation quality can erase the value of even the best finance offer—through underperformance, roof issues, warranty disputes, and expensive remedial work.

At Ulex Energy we specialise in bespoke solar PV and battery storage solutions. Founded by chartered engineer Ian Mach, the business designs and installs high-performing systems tailored to each customer’s property, budget and energy needs. Ulex Energy is MCS certified, carries out all installations using its own team and provides a 10-year insurance-backed guarantee on workmanship.