Solar Panel & EV Charger FAQs — Milton Keynes
Answers to the most common questions about solar panels, battery storage, and EV chargers — from a local Milton Keynes installer.
Solar Panels
A typical residential solar panel system costs between £3,500 and £7,000 installed, depending on system size. A 5kWp system (suitable for a 3–4 bed home) typically costs £4,600–£5,800. All residential installations qualify for 0% VAT until at least March 2027.
Most solar systems pay for themselves in 7–9 years. A 4kWp system typically saves £900–£1,200 per year on electricity bills, plus Smart Export Guarantee income for energy exported to the grid. Adding battery storage increases savings to £1,400–£1,800/year and can shorten the combined payback period.
Yes. Solar panels generate electricity from daylight, not direct sunlight. They produce around 10–25% of their peak output on overcast days. The UK averages around 1,100–1,400 peak sun hours per year, and modern panels are efficient enough to make solar worthwhile even in cloudier regions. Milton Keynes actually receives more sunshine than the UK average.
In most cases, no. Solar panel installation on a residential property is permitted development in the UK. Exceptions include listed buildings, properties in conservation areas, and installations that project more than 200mm above the roof plane. We check this during the site assessment at no extra charge.
The Smart Export Guarantee (SEG) requires energy suppliers to pay you for surplus solar electricity you export to the grid. Rates vary by supplier but average 7–15p/kWh. You need an MCS certificate to apply — we issue this with every installation. The income is modest (most homes export 30–50% of what they generate), which is why battery storage is so effective at maximising value.
The right number depends on your roof size, orientation, and electricity usage. As a guide:
- 2–3 bed home: 8–10 panels (3–3.5kWp)
- 3–4 bed home: 10–12 panels (3.5–4kWp)
- 4–5 bed home: 14–18 panels (5–6.5kWp)
We'll calculate the exact system size during the free home survey based on your actual roof dimensions and usage data.
Most residential solar installations are completed in 1–2 days. Larger systems (6kWp+) or those with battery storage may take 2 days. There is minimal disruption — scaffold goes up in the morning, panels go on, inverter is fitted inside, and the system is live before we leave.
Most panels we install come with:
- 25-year performance warranty — guaranteeing minimum output levels
- 12-year product warranty — covering defects and failure
- 10-year workmanship warranty — from Depth of Light on the installation
Inverters typically come with 5–10 year warranties, extendable to 20 years on some brands.
Battery Storage
A standalone battery storage system costs between £3,500 and £6,000 installed, depending on capacity and brand. We install Fox ESS and SigEnergy systems — a 6kWh battery starts from around £3,500; a 10–12kWh system from £4,500. Installing alongside solar panels is more cost-effective than adding a battery later.
Yes — in most cases. We can add AC-coupled battery storage to most existing solar installations regardless of the original inverter brand. In some cases we'll replace the inverter with a hybrid unit for better integration. We'll assess your existing system during the free survey.
It depends on the battery system. Some batteries include a backup power function that automatically switches your home to battery power within milliseconds of a grid outage. Others don't. We'll flag this clearly when recommending a system — backup function is not standard on all models, so ask us specifically if this is important to you.
Modern home batteries typically last 10–15 years before capacity degrades noticeably. Most manufacturers guarantee at least 70% capacity after 10 years. The battery can continue to work beyond this — it just holds slightly less charge. This compares well against the 7–10 year payback period on most solar + battery packages.
EV Charger Installation
Yes. The OZEV EV Chargepoint Grant provides up to £350 off a home EV charger installation for qualifying customers. Eligibility requires: owning or leasing an eligible EV, living in a flat or rental property (or having off-street parking), and using an OZEV-approved installer. We're OZEV-approved and handle the paperwork for you.
A 3-pin socket delivers around 2.3kW / ~8 miles per hour of charging. A dedicated 7kW home charger delivers ~25–30 miles per hour. A full charge from empty takes 30+ hours on a 3-pin vs 6–8 hours on a 7kW charger. A home charger also includes safety features, smart scheduling, and app control that 3-pin sockets lack.
At standard rate (28p/kWh), a full charge for a typical 60kWh battery EV costs around £17. On an off-peak overnight tariff (Octopus Go, EDF GoElectric) at 7–10p/kWh, the same charge costs £4–£6. With solar panels and a solar-compatible smart charger, daytime charging is effectively free.
About Depth of Light
Yes. Depth of Light is MCS certified (Microgeneration Certification Scheme). This certification is required to issue the MCS certificate you need to apply for the Smart Export Guarantee — meaning you get paid for every unit of electricity you export to the grid. Always check your installer is MCS certified before booking.
We're based in Milton Keynes and cover Milton Keynes, Buckinghamshire, Bedfordshire, and Northamptonshire. Our core area includes MK1–MK19, Bedford, Northampton, and all towns in between. If you're unsure whether we cover your area, give us a call.
We work with third-party finance providers who offer 0% interest options on solar and battery installations. Ask us about finance when requesting your quote and we'll provide details of the options available to you.
Submit the free quote form or call us on 07516 762540. We'll arrange a free home survey (no obligation), design a system for your home, and provide a fixed price in writing before any commitment. Most surveys are booked within a week.
Still have a question?
Call us or submit the quote form and we'll get back to you the same day.
MCS certified • Based in Milton Keynes • 16 five-star reviews