Maximise your return and reduce your energy bills faster
When considering solar and battery storage, one of the most common motivations is the financial return. A well-designed system can pay for itself in just a few years and continue saving you thousands over its lifetime. But not all systems are created equal, and the choices you make during the design and installation stages will determine just how fast you break even.
Here are the ten most important factors that can improve your solar payback period - and save you more in the long run.
1. Maximise Your Roof’s Solar Potential
The more photovoltaic (PV) surface area you cover, the more energy you can generate. Since panels themselves are relatively cheap compared to the labour, scaffolding, and inverter costs, squeezing more generation out of your available space dramatically improves return.
At Spirit Energy, we assess every project with this in mind - often trialling multiple panel types and layouts to see which combination delivers the highest kilowatt peak (kWp). Even a 5 - 10% increase in system size can have a massive impact on your payback over 25 years.
2. Consider Larger Panels to Increase Output & Lower Costs
Using fewer, higher-wattage panels can help you get more generation per square metre while also reducing the overall system cost. Jumbo panels (such as 625W modules) tend to have a lower cost per watt and require fewer mounts and fixings, meaning less labour and lower install costs.
We’ve helped many homeowners achieve better returns simply by selecting the right panel size for their roof.
3. Choose a Local Installer Who Prioritises Design
National installers often focus on standardised panel options and layouts to maximise buying power. While this can lower upfront costs, it doesn’t always yield the best long-term return.
A good local specialist will design your system around your specific roof characteristics - adjusting layouts and panel choices to boost output. Paying a little more for a better design can deliver thousands in extra savings over the system’s lifetime.
Watch this video to see how national installers and local specialists stack up:
4. Skip All-Black Panels (If Aesthetics Aren’t a Priority)
All-black solar panels look sleek - but they’re typically less efficient and more expensive than their standard counterparts. If curb appeal isn’t a priority, ask your installer about alternative options that offer better efficiency for a lower price.
5. Don’t Oversize the Battery
It may be tempting to buy the biggest battery you can afford, but batteries only deliver strong returns when they cycle daily. Oversizing a battery system can lead to unused capacity that doesn’t pay for itself.
For most homes, a slightly smaller battery that charges and discharges fully each day provides the best rate of return. Oversizing is only sensible if you anticipate a significant increase in usage - such as getting an EV or heat pump in the near future.
6. Opt for a DC-Coupled System
DC-coupled systems are more efficient than AC-coupled alternatives, as they require fewer energy conversions. With a DC system, solar electricity only needs to be inverted once, while AC systems often invert two or three times, causing round-trip losses.
DC coupling also tends to be cheaper to install, as you only need one inverter rather than two.
DC coupled battery + inverter systems include the Sigenergy SigenStor (left), and Tesla Powerwall 3 (right).
7. Size the Inverter Correctly
A poorly sized inverter can cap your generation or result in inefficiencies. Some inverters perform best when slightly oversized, while others should be undersized depending on MPPT voltage ranges, efficiency curves, and DNO export limits.
Your installer should be able to explain the pros and cons of each approach - and if they can’t, it might be worth seeking a second opinion.
8. Avoid Overcomplicating the System with Add-Ons
Technologies like microinverters, optimisers, or hot water diverters have their place - but not in every install.
For example, if you’re installing a well-sized battery, there may not be enough excess solar to power a diverter. Similarly, the long-term maintenance risk of optimisers and microinverters, particularly when installed on the roof, may outweigh the small gains in generation.
Always weigh up the added complexity and potential replacement costs before including these extras.
9. Work with a Reputable, Experienced Installer
A system is only as good as the people installing it. We regularly receive enquiries from customers who can’t get support from their original installer - or worse, whose installer has gone out of business.
Look for an installer with a strong financial record, years of experience, in-house staff (not subcontractors), and excellent local reviews. Solar is a long-term investment - make sure your installer will be around to support you for the next 25 years.
10. Adjust Your Habits to Match Solar Output
One of the simplest and most effective ways to improve payback is to shift electricity use to match solar generation. Use timers on your washing machine or dishwasher to run during the day, and consider seasonally adjusting your energy tariff.
In summer, export-friendly tariffs like Octopus Flux may deliver the best returns. In winter, switching to a tariff that offers cheap off-peak rates for battery charging - such as Octopus Go or Octopus Cozy - can save even more.
If you have an EV, charging overnight at low rates can make a bigger difference to your savings than almost anything else.
Ready to Get Started?
If you’re within two hours of Reading, get in touch with Spirit Energy for a free, bespoke quote. We’ll run through every option with you in detail and help you design a system that delivers the best possible return - tailored to your roof, your energy usage, and your goals.
And if you're not quite ready yet, check out our video case studies to see what a full Spirit Energy install looks like - from first enquiry to final commissioning.
