The honest guide to solar PV, battery storage & whole home backup prices.
If one company says you’ll save £40,000 and another says £22,000, don’t ask who promises more. Ask who can prove it.
If you’re researching the cost of solar panels in Sussex, you’ve probably already discovered that prices vary enormously. One installer may quote £6,000 while another quotes £12,000 for what appears to be a similar system.
The reality is that not every solar installation is designed or installed to the same standard.
At Bright Spark Energy, we’ve installed hundreds of systems across Sussex, Hampshire and Surrey – from family homes and listed buildings to schools, hospitals and commercial premises. We believe customers deserve transparent pricing and honest advice rather than pressure selling and unrealistic promises.
Typical installed costs (2026)
As a general guide for quality residential installations:
| Item | Typical cost |
|---|---|
| Solar PV | Around £1,000 per installed kWp |
| Battery storage | Around £500 per usable kWh |
| Whole home backup | Typically from £2,000 |
| Panel optimisation | Around £50 per panel |
These figures are intended as useful benchmarks rather than fixed prices. Roof type, scaffolding, electrical upgrades and equipment specification will all affect the final cost.
Typical Sussex system prices
Small home
- 3 kWp (6–8 panels)
- No battery
£4,500–£6,000
Average family home
- 4.5–5 kWp
- 10–12 panels
- 5–10 kWh battery
£9,500–£13,000
Larger home
- 6–8 kWp
- 14–20 panels
- 10–20 kWh battery
- Whole home backup
£13,000–£20,000+
Ideal for homes with EVs, air conditioning, swimming pools, heat pumps or high electricity demand. Our guides to how many panels you need and the right battery size explain how we arrive at these figures.
What are you actually paying for?
A higher quotation doesn’t necessarily mean higher profit.
Often it reflects:
- Better panels
- Better inverter technology
- Higher quality battery storage
- Better mounting systems
- Fire safety measures
- Qualified installation teams
- Better warranties
- Ongoing support
Solar is a 30-year investment, so installation quality matters just as much as the equipment.
When cheap is too cheap
If you’re being quoted significantly below £1,000 per installed kWp, ask why.
Very low quotations often involve compromises such as:
- Unknown manufacturers
- Budget inverters
- Undersized batteries
- Poor cable routes
- No panel optimisation
- Minimal commissioning
- Limited after-sales support
- Short warranties
The cheapest quote often becomes the most expensive over the lifetime of the system. We’ve covered this in detail in why cheap solar quotes often cost more.
Buy cheap. Buy twice.
Beware the shiny-suited salesman
One of the biggest changes in the solar industry has been the rise of aggressive sales techniques.
Be cautious if you’re told:
- “This offer ends today.”
- “Our manager has authorised a special discount.”
- “Government funding finishes tomorrow.”
- “Sign today to secure this price.”
- “We’ve only got one installation slot left.”
A reputable installer should encourage you to compare quotations and take time to make an informed decision.
Beware the YouTube experts
There are many excellent technical reviewers online.
There are also influencers who receive sponsorship, affiliate income or review products they have never installed themselves.
Ask your installer:
- How many of these systems have you actually installed?
- How long have they been in service?
- Who supports the warranty?
- Can you service the products you recommend?
At Bright Spark Energy we only recommend products we would install in our own homes.
Don’t believe every saving you see
If somebody promises:
- Zero electricity bills
- A three-year payback
- £3,000 annual savings
- Guaranteed returns for 25 years
…ask one question:
“Can I see the MCS performance calculations?”
Every MCS-certified installer should be able to provide the predicted annual generation and explain the assumptions behind the figures.
Ask to see the assumptions
Your savings depend upon:
- Annual electricity consumption
- Roof orientation
- Shading
- Battery size
- Electricity tariff
- Export tariff
- Future energy prices
- Future usage
Nobody can accurately predict electricity prices or export rates over the next 25–30 years.
If the numbers sound too good to be true, they probably are.
Remember: SEG rates can change
Many quotations assume today’s Smart Export Guarantee rates continue forever.
They won’t necessarily.
SEG tariffs are commercial products offered by electricity suppliers and may increase, reduce or disappear.
Any payback calculation should explain exactly which tariff assumptions have been used.
Compare like for like
Always ask every installer for:
- MCS predicted generation (kWh/year)
- Self-consumption assumptions
- Export assumptions
- Electricity price used
- Export tariff used
- Battery assumptions
- Payback calculation
- Installation warranty
- Manufacturer warranties
Only then can you compare quotations fairly.
Is battery storage worth it?
For many Sussex households, yes.
Battery storage can:
- Increase self-consumption
- Charge on cheap overnight tariffs
- Reduce peak electricity costs
- Provide backup power (with the correct gateway)
- Future-proof your home
Whole home backup
Whole home backup has become increasingly popular for:
- Rural properties
- Home workers
- Medical equipment
- Smart homes
- Security systems
- Internet connectivity
Budget around £2,000 depending on the system and installation requirements.
Are optimisers worth it?
At around £50 per panel, optimisers can:
- Improve generation on shaded roofs
- Monitor every panel individually
- Improve fault finding
- Enhance DC safety
- Improve long-term performance on complex roofs
Hidden costs
Ensure quotations include:
- Scaffolding
- DNO application
- MCS certification
- Building Regulations notification
- Bird protection (if required)
- Monitoring
- Commissioning
- Warranty registration
Why choose Bright Spark Energy?
We don’t chase the newest brand every six months.
We invest in products we trust, manufacturer training and long-term support.
Every system is designed with safety, performance and future expansion in mind.
We install systems exactly as we would in our own homes.
Frequently asked questions
What do solar panels cost in Sussex?
Quality residential systems typically start around £5,000 and rise depending on size, battery storage and roof complexity.
How much should solar cost per kWp?
Around £1,000 per installed kWp is a useful benchmark for a professionally installed system.
How much should battery storage cost?
Around £500 per usable kWh installed.
Is the cheapest quote the best value?
Usually not. Compare quality, design, warranties, fire safety and aftercare – not simply the headline price.
Ready to compare quotes?
If you’re comparing solar quotations in Sussex, we’d be happy to provide a clear, transparent proposal based on realistic assumptions – not sales tactics.
Bright Spark Energy – Designed properly. Installed properly. Supported properly.
