Solar Panel Installation in London

Solar Panels for London Homes

Solar photovoltaic (PV) panels have become increasingly popular in London as energy prices rise and technology improves. Modern panels work efficiently even in Britain's cloudy climate, and with battery storage, homeowners can significantly reduce electricity bills while cutting carbon emissions.

Hampstead Renovations installs solar PV systems across North London. This comprehensive guide covers how solar works, suitability assessment, planning permission, costs, grants, savings, and battery storage options for your property.

How Solar Panels Work

The Basics

• Photovoltaic cells: Convert sunlight into DC electricity
• Inverter: Converts DC to AC electricity for home use
• Export: Excess electricity sent to grid (you get paid)
• Import: Buy from grid when sun not shining
• Works in daylight: Doesn't need direct sun (works on cloudy days)

System Components

• Solar panels: Mounted on roof or ground
• Inverter: Usually in loft or garage
• Generation meter: Monitors production
• Battery (optional): Stores excess for later use
• Monitoring: App or display showing production

Is Your Property Suitable?

Ideal Properties

• South-facing roof: Best production (SW to SE also good)
• Unshaded: No trees, chimneys, or buildings casting shadows
• Roof angle: 30-40° optimal (but 15-60° acceptable)
• Strong roof: Can support 10-15 kg per m²
• Large roof: Space for 10+ panels (6-10m²)
• Not listed: Easier planning if not listed building

Challenging but Possible

• East/West-facing: 80-90% of south-facing performance
• Flat roof: Panels mounted on frames (extra cost)
• Partial shading: Optimisers can help
• Small roof: Fewer panels = less generation (but still worth it)
• Conservation area: May need planning permission

Not Suitable

• North-facing roof: Very poor generation
• Heavy shading: Most of day in shade
• Weak roof structure: Can't support weight
• Asbestos roof: Must remove first (expensive)

System Sizing

Typical Household Electricity Usage

• 1-2 people: 2,000-2,700 kWh per year
• 3-4 people: 2,900-4,300 kWh per year
• 5+ people: 4,600+ kWh per year

System Sizes

Small System (2-3 kW)

• Panels: 6-8 panels
• Roof space: 10-12m²
• Annual generation: 1,700-2,500 kWh
• Suitable for: Small households, limited roof space
• Cost: £4,000-£6,000 installed

Medium System (4-5 kW)

• Panels: 10-14 panels
• Roof space: 18-25m²
• Annual generation: 3,400-4,250 kWh
• Suitable for: Average family home
• Cost: £6,000-£8,000 installed

Large System (6-10 kW)

• Panels: 16-26 panels
• Roof space: 30-50m²
• Annual generation: 5,100-8,500 kWh
• Suitable for: Large households, heat pumps, EV charging
• Cost: £8,000-£13,000 installed

Generation and Savings

London Solar Generation

London receives decent solar radiation despite perception:

• Annual sunshine: 1,500-1,600 hours per year
• Generation rate: 850-900 kWh per kW installed
• Best months: April-September (70% of annual generation)
• Winter: November-February (minimal generation)
• Example: 4 kW system generates ~3,400-3,600 kWh/year

Financial Savings Example

Scenario: 4 kW system, family using 3,500 kWh/year, electricity at 30p/kWh

Without Battery

• Annual generation: 3,400 kWh
• Self-consumption: 30% (1,020 kWh) - used immediately
• Export to grid: 70% (2,380 kWh) - at 15p/kWh
• Savings on bills: 1,020 kWh × 30p = £306
• Export income: 2,380 kWh × 15p = £357
• Total annual benefit: £663
• System cost: £6,500
• Payback: ~10 years

With Battery (5 kWh)

• Self-consumption: 60% (2,040 kWh) - stored and used later
• Export: 40% (1,360 kWh)
• Savings on bills: 2,040 kWh × 30p = £612
• Export income: 1,360 kWh × 15p = £204
• Total annual benefit: £816
• System cost (with battery): £10,500
• Payback: ~13 years

Factors Affecting Savings

• Electricity prices: Higher prices = better savings
• Usage patterns: Home during day = higher self-consumption
• System size: Bigger system = more generation
• Export tariff: Better rate = higher income
• Battery: Increases self-consumption from 30% to 60-80%

Planning Permission

Permitted Development

Usually no planning needed if:

• Panels don't protrude more than 200mm from roof
• Installed on house (not outbuilding)
• Not on front roof slope (if fronting road)
• Property not in conservation area or national park
• Not on listed building

When Planning Required

• Conservation areas: Front or side roofs visible from street
• Listed buildings: All installations (Grade I, II*, II)
• Flats: Require permission
• Ground-mounted: Large arrays in gardens
• World Heritage Sites: Additional restrictions

Conservation Area Strategies

• Rear roof slopes: Usually acceptable
• Non-reflective panels: Black panels and frames
• In-roof panels: Flush with roof tiles (more expensive)
• Pre-application advice: £50-£200, clarifies likelihood

Installation Process

Timeline

• Week 1: Site survey, system design, quote
• Week 2-3: Accept quote, finalise design
• Week 4-6: Order equipment, plan installation
• Week 7: Installation (1-2 days)
• Week 8-10: Grid connection approval (DNO)
• Total: 8-12 weeks from survey to operation

Installation Steps

1. Scaffolding: Erected for roof access (Day 1)
2. Mounting: Brackets attached to rafters (Day 1)
3. Panels: Mounted and wired (Day 1-2)
4. Inverter: Installed in loft/garage (Day 1-2)
5. Connection: Wired to consumer unit (Day 2)
6. Testing: System tested and commissioned (Day 2)
7. Scaffolding removal: Taken down (Day 2-3)
8. DNO notification: Installer notifies grid operator
9. Approval: Grid approval (2-4 weeks)
10. Live: System operational

Battery Storage

Why Add a Battery?

• Store excess solar for evening use
• Increase self-consumption from 30% to 60-80%
• Greater bill savings
• Energy independence
• Backup power (some systems)
• Charge overnight on cheap rate tariffs

Battery Sizes

• 5 kWh: Small household, 3 kW solar (£3,000-£4,500)
• 10 kWh: Average family, 4-5 kW solar (£5,000-£7,000)
• 13-15 kWh: Large household, 6+ kW solar (£7,000-£10,000)

Popular Battery Brands

• Tesla Powerwall: 13.5 kWh, sleek design (£7,000-£9,000)
• GivEnergy: 5-13.5 kWh, modular, good value (£4,000-£7,000)
• Sonnen: Premium, eco-friendly (£6,000-£10,000)
• Enphase: Modular design (£4,500-£8,000)

Battery Economics

Batteries have longer payback than panels alone:

• Add £3,000-£7,000 to system cost
• Increase savings by £150-£350 per year
• Payback: 10-20 years
• But: electricity prices rising, batteries falling in price
• Future-proofing for time-of-use tariffs

Grants and Incentives

Current Incentives (2024)

0% VAT on Solar and Batteries

• Installations on residential properties VAT-free
• Applies to panels, batteries, installation
• Saves £1,300 on £6,500 system

Smart Export Guarantee (SEG)

• Energy suppliers pay for exported electricity
• Rates: 4p-25p per kWh depending on supplier
• Best rates: Octopus (15p), British Gas (15p), EDF (variable up to 25p)
• Must have smart meter
• MCS-certified installation required

No Longer Available

• Feed-in Tariff (FIT): Closed to new applicants March 2019
• Properties with FIT still receive payments (up to 25 years)

Costs Breakdown

4 kW System (Typical)

• Solar panels: £2,000-£3,000
• Inverter: £800-£1,200
• Mounting system: £400-£600
• Cabling and electrics: £300-£500
• Labour and installation: £1,500-£2,000
• Scaffolding: £500-£800
• Certification and paperwork: £200-£400
• Total: £6,000-£8,000 (0% VAT)

Cost Per kW

• Small systems (2-3 kW): £2,000-£2,200 per kW
• Medium systems (4-6 kW): £1,500-£1,800 per kW
• Large systems (8-10 kW): £1,300-£1,600 per kW

Maintenance and Lifespan

Ongoing Maintenance

• Minimal required: Panels self-cleaning from rain
• Annual check: Visual inspection of panels and wiring (£100-£200)
• Inverter replacement: After 10-15 years (£800-£1,500)
• Monitoring: Check app regularly for faults

Lifespan

• Solar panels: 25-30 years (degradation ~0.5% per year)
• Inverter: 10-15 years
• Battery: 10-15 years (or 4,000-6,000 cycles)
• Warranty: Panels 25 years, inverter 5-10 years, battery 10 years

Choosing an Installer

Essential Criteria

• MCS certification: Mandatory for SEG payments (check register)
• Insurance: Public liability £5m+, product liability
• Experience: Track record, years in business
• References: Recent installations you can view
• Warranty: Installation warranty 5-10 years
• Transparent quote: Detailed breakdown, no hidden costs

Red Flags

• Not MCS certified
• Pressure sales tactics
• Unusually cheap (cutting corners)
• Can't provide references
• Vague contracts
• Requesting full payment upfront

Get Multiple Quotes

• Minimum 3 quotes recommended
• Compare like-for-like (panel brands, warranties)
• Don't automatically choose cheapest
• Consider quality, service, warranty

Solar with Other Technologies

Solar + Heat Pump

• Perfect combination (both electric)
• Solar offsets heat pump running costs
• Size system larger (6-10 kW) for heat pump demand
• Battery helps run heat pump overnight

Solar + EV Charging

• Charge electric vehicle from solar (free motoring)
• 7 kW charger needs large system to fully offset
• Battery stores solar for evening charging
• Smart chargers prioritise solar charging

Solar + Economy Tariffs

• Octopus Flux: Variable export rates (up to 25p/kWh peak)
• Octopus Go: Cheap overnight rate (7.5p/kWh) to charge battery
• Intelligent Octopus: Cheaper EV charging rates

Contact Hampstead Renovations