Frequently Asked Questions

Yes. Green Hat Renewables is fully MCS certified (Microgeneration Certification Scheme), which is required for customers to access the Smart Export Guarantee, Boiler Upgrade Scheme, and other government incentives. MCS certification ensures our installations meet the highest industry standards.

We cover Cambridgeshire, Norfolk, and Suffolk from our base in Isleham. Our core service area includes Cambridge, Ely, Newmarket, Bury St Edmunds, Mildenhall, Thetford, King's Lynn, and all surrounding towns and villages. We also serve Norwich, Ipswich, and Peterborough for larger projects.

Yes. Every project begins with a free, no-obligation site survey. We assess your property, discuss your requirements, and provide a detailed quotation with expected generation or savings figures. There is no pressure to proceed.

A typical residential solar panel system costs between £5,000 and £10,500 including VAT at 0%. A 4kW system (10-12 panels) averages £4,700-£6,700, while a larger 6kW system costs £6,400-£8,700. Prices have dropped approximately 19% since 2023. We provide exact pricing in your free survey.

Residential solar panel installations currently benefit from 0% VAT, saving you approximately 20% compared to standard rates. This zero-rate applies to solar panels, battery storage, heat pumps, and other energy-saving materials. The 0% rate is confirmed until at least 31 March 2027.

The Smart Export Guarantee (SEG) pays you for surplus solar electricity you export to the grid. Rates vary by supplier — the best current rates reach 25-27p/kWh with smart tariffs like Octopus Flux. We help you sign up for the best available rate as part of our commissioning service.

A typical residential solar installation saves £700-£1,300 per year on electricity bills, depending on system size and your energy usage. With battery storage and a smart export tariff, total financial benefits can exceed £1,800 per year. Most systems pay for themselves within 5-7 years.

The Boiler Upgrade Scheme (BUS) provides a £7,500 grant towards air source heat pump installation for homeowners in England. The grant is deducted from your installation cost — you never handle the money. As MCS certified installers, we handle the entire application process for you. The scheme runs until at least March 2028.

Modern air source heat pumps operate efficiently down to -20°C. In East Anglia, where winter temperatures rarely drop below -5°C, heat pumps work comfortably year-round. At 0°C outside, a typical heat pump still delivers 3 units of heat for every 1 unit of electricity consumed.

The ECO4 scheme (extended to December 2026) can fund external wall insulation, loft insulation, and other energy efficiency measures for eligible households. Eligibility is based on property type and household income. We can check your eligibility during your free survey.

All our installations come with comprehensive warranties. Solar panels carry 25-30 year manufacturer performance warranties. Inverters and batteries typically have 10-15 year warranties. Heat pumps come with 5-12 year manufacturer warranties. Our workmanship is guaranteed for a minimum of 10 years through our MCS registration.

Residential solar panels typically take 1-2 days. Battery storage takes half a day (or is included in solar installation time). Heat pumps take 2-4 days. EV chargers take 3-4 hours. External wall insulation takes 2-4 weeks depending on property size. We provide an exact timeline with your quotation.

Yes. We install commercial solar systems on offices, warehouses, factories, schools, and agricultural buildings. Commercial systems benefit from Annual Investment Allowance (100% tax deduction up to £1 million), business rates exemption until 2035, and typical payback periods of 3-6 years.

Standard grid-tied solar systems shut down during power cuts for safety reasons. However, if you have battery storage with Emergency Power Supply (EPS) functionality, your battery can provide backup power during outages. We can recommend and install systems with this capability.

From October 2030, all private rental properties in England must achieve a minimum EPC rating of C, with a cost cap of £10,000 per property. Currently, 52% of rental properties are below this standard. Solar panels, heat pumps, and insulation are the most effective routes to achieving EPC C compliance.

East Anglia receives some of the best solar irradiance in the UK at approximately 1,000-1,050 kWh/m² annually. Cambridge averages 1,024 kWh/m², with coastal areas like Felixstowe reaching 1,067 kWh/m². This above-average sunshine makes East Anglia ideal for solar investment.

System size depends on your electricity usage and roof space. A 3kW system (7-8 panels) suits smaller homes, generating 2,850-3,150 kWh annually. A 4kW system (10-12 panels) is ideal for average 3-4 bed homes at 3,800-4,200 kWh. Larger homes benefit from 5-6kW systems generating 4,750-6,300 kWh.

We install premium panels from JA Solar, Trina Solar, Canadian Solar, and Longi. For inverters and hybrid systems, we use Fox ESS, SolarEdge, and Huawei. All products are Tier 1 rated with manufacturer warranties of 12-25 years for panels and 10-12 years for inverters.

Battery storage costs £4,000-£12,000 depending on capacity and brand. A Fox ESS EVO 9.6kWh costs £4,500-£5,500 installed. Tesla Powerwall 3 (13.5kWh) costs £7,000-£11,500 installed. SolarEdge Home Battery (10kWh) runs £4,200-£5,000. All prices include 0% VAT.

With smart tariffs offering cheap overnight rates (7p/kWh) and export rates of 15-27p/kWh, batteries typically save £400-£800 annually on top of solar savings. Combined with backup power during outages, payback periods are 5-8 years. Batteries also maximise self-consumption from 50% to 80%.

Air source heat pump installations cost £10,000-£18,000 before the grant. After the £7,500 BUS grant, your net cost is typically £3,500-£10,500. An 8kW system for a typical 3-bed home costs £10,000-£13,000, so £2,500-£5,500 after the grant. Costs include cylinder upgrade and any radiator changes.

We install heat pumps from Daikin (Altherma 3), Mitsubishi (Ecodan), Vaillant (Arotherm Plus), Samsung, and Grant. Daikin and Mitsubishi offer the best SCOP efficiency ratings (3.8-4.5). All brands come with 5-7 year manufacturer warranties, extendable to 10+ years.

Underfloor heating is ideal but not essential. Heat pumps work at lower flow temperatures (35-45°C vs 55-65°C for boilers), so larger radiators may be needed for some rooms. We calculate heat loss for every room during our assessment and advise which radiators, if any, need upgrading.

Home EV chargers cost £799-£1,299 installed. Basic 7kW smart chargers start at £799-£999, while premium units like the Zappi (with solar integration) cost £999-£1,299. Prices include installation, electrical connections, and all certifications. Solar-integrated charging maximises free motoring.

Yes. With a solar-compatible charger like the Zappi, excess solar generation automatically diverts to your EV. A 4kW solar system generates enough to drive 8,000-10,000 free miles per year. Combined with overnight charging at 7p/kWh, EV running costs can be as low as 2-3p per mile.

Maximise savings by using electricity during peak generation (10am-4pm), adding battery storage to capture surplus, choosing a high export tariff (Octopus Flux pays 15p/kWh), and switching high-consumption appliances to daytime. Battery storage increases self-consumption from 50% to 80%.

Most residential installations are permitted development. Exceptions include listed buildings, conservation areas, flat roofs where panels project above the highest ridge, and ground-mounted arrays over 9m². We check planning requirements during your free survey and handle applications if needed.

At current rates (electricity 22p/kWh, gas 6p/kWh), heat pumps cost approximately the same as gas boilers to run due to their 300-400% efficiency. With solar panels generating free electricity, heat pumps become significantly cheaper. Future gas price rises will widen this gap further.

We work with finance partners offering 0% APR options on solar installations (subject to credit approval). Heat pumps benefit from the £7,500 BUS grant. Some installations qualify for ECO4 funding. We discuss all available options during your free survey to find the most cost-effective solution.

Research shows solar panels increase property value by 4-14%. With EPC regulations tightening (minimum C rating by 2030 for rentals), properties with solar, battery, and heat pump installations will command premiums. The improvements also make properties easier to sell and more attractive to eco-conscious buyers.

A 3-bedroom house typically needs a 4kW solar panel system (10-14 panels), costing £5,500-£8,000 installed with 0% VAT. This generates 3,400-3,600 kWh per year in East Anglia, saving £650-£1,200 annually. Payback is typically 6-10 years. Adding battery storage (£3,800-£6,200) increases self-consumption from 35-50% to 70-85%.

North-facing roofs generate approximately 50-60% of a south-facing roof's output, making them less economic but not impossible. East and west-facing roofs generate 80-90% of optimum. We assess your roof during the free survey and provide honest generation estimates. In some cases, we may recommend fewer panels on a north roof and maximising other elevations.

System size depends on your annual electricity consumption and available roof space. A typical UK household uses 3,500-4,500 kWh per year, matched by a 4-5kW system (10-16 panels). Homes with EV chargers or heat pumps should consider 6-8kW. We calculate the optimal size during the free survey based on your actual electricity bills and future plans.

Yes. Retrofitting a battery to an existing solar system is straightforward. AC-coupled batteries (like Tesla Powerwall) connect alongside your existing inverter without replacing it. DC-coupled batteries require an inverter upgrade. Costs range from £4,500-£6,500 for a 9-14kWh battery. We survey your existing system and recommend the most cost-effective retrofit approach.

Solar panels have a lifespan of 25-30+ years. Modern panels degrade at approximately 0.3-0.5% per year, meaning a panel still produces 87-92% of its original output after 25 years. Inverters typically last 12-15 years and may need one replacement during the panel lifetime. There are no moving parts to maintain, making solar one of the most reliable energy technologies available.

An air source heat pump costs £7,000-£18,000 installed before the £7,500 BUS grant. After the grant: 1-2 bed homes pay £0-£2,500, 3-bed semis £500-£5,500, and 4-bed detached homes £3,500-£10,500. The BUS grant budget was doubled to £295 million and extended through at least 2028. We handle the entire grant application.

Modern heat pumps are very quiet. The Daikin Altherma 3 operates at just 38 dB (equivalent to a library). The Vaillant aroTHERM Plus is Quiet Mark certified. Most units operate at 40-45 dB — quieter than a typical household conversation. Permitted development rules require the unit to be at least 1 metre from the boundary and not exceed 42 dB at the nearest neighbour's window.

Not necessarily. Heat pumps run at lower flow temperatures (35-55°C) than boilers (60-80°C). Radiators fitted since 2000 are often oversized and work well. Older or smaller radiators in key rooms may need upsizing. We carry out a room-by-room heat loss calculation during the survey and specify any radiator changes needed. Underfloor heating is the ideal pairing, operating at 30-40°C and achieving COP 3.5-4.0.

On standard tariffs, a heat pump at SCOP 3.6 costs roughly £610-£720/year — comparable to gas at £650-£750. On smart tariffs like Cosy Octopus (11.7p/kWh off-peak), heat pumps save £250-£400/year over gas. Against oil boilers, savings reach 30-50%. Against electric storage heaters, 60-70%. Heat pumps also eliminate gas standing charges (£120-£180/year).

Some existing cylinders can be reused if they have a suitable coil for low-temperature heat pump operation. However, most heat pump installations include a new, larger cylinder (200-300 litres) with an oversized coil designed for heat pump flow temperatures. The cylinder is sized during the survey based on your household hot water demand. Upgrading the cylinder typically adds £500-£1,000 to the project cost.

Battery storage is increasingly worthwhile, particularly when combined with solar panels and time-of-use tariffs. A battery increases solar self-consumption from 35-50% to 70-85%, saving 10-20p per kWh stored versus exporting. Time-of-use tariff arbitrage (charging at 7p/kWh overnight, exporting at 26-30p/kWh peak) adds £300-£600/year. Payback on a battery alone is typically 7-10 years; as part of a solar-plus-battery system, the combined payback improves to 6-8 years.

Modern LiFePO4 batteries (Fox ESS, Pylontech, BYD) last 6,000-15,000 cycles — equivalent to 16-40 years of daily cycling. Warranties are typically 10 years. NMC batteries (Tesla Powerwall) have slightly shorter cycle life but still last well beyond their 10-year warranty. Battery degradation is slower than solar panel degradation, making them a reliable long-term investment.

Full off-grid operation is technically possible but not practical or cost-effective for most UK homes. A typical house needs 40-60kWh of battery storage and 10-15kW of solar to cover winter demand — costing £30,000-£60,000 in batteries alone. A grid-connected system with battery provides 70-85% self-sufficiency at a fraction of the cost, with the grid as backup. Off-grid makes more sense for remote agricultural buildings without grid connection.

Home EV charger installation costs £750-£1,400 depending on the brand. The myenergi Zappi costs £1,000-£1,400 (best for solar divert). The Ohme Home Pro costs £850-£1,300 (best for smart tariff integration). The Easee One costs £900-£1,200 (best design). The Workplace Charging Scheme provides £350 per socket for businesses. The residential EVHS grant (£350) is available only to renters and flat owners.

Yes. The myenergi Zappi charger has dedicated ECO and ECO+ modes for solar charging. ECO+ mode charges 100% from surplus solar generation — truly free motoring. ECO mode prioritises solar with grid top-up as needed. A 4kW solar system generates enough surplus on a sunny day to add 20-30 miles of range. Over a year, solar-charged EV driving can save £400-£800 compared to standard grid charging.

External wall insulation costs £90-£150 per m² installed. Total costs by property type: mid-terrace £6,000-£10,000, semi-detached £8,000-£15,000, detached £18,000-£30,000. ECO4 funding (ending December 2026) can cover the full cost for eligible households. The Warm Homes Local Grant (up to £15,000) replaces ECO4 from 2027. Uninsulated solid walls improve from U-value 2.1 to approximately 0.29 W/m²K — an 86% improvement.

Yes, through the ECO4 scheme (ending 31 December 2026). Eligible households receiving qualifying benefits or with income under £31,000 can receive EWI at zero upfront cost. Towns with high eligibility include Wisbech, Great Yarmouth, Lowestoft, and March. From 2027, the Warm Homes Local Grant provides up to £15,000 for eligible properties. Contact us for a free eligibility check.

MVHR (Mechanical Ventilation with Heat Recovery) continuously extracts stale air and supplies fresh filtered air while recovering 90-95% of the heat. Running costs are just £40-£160/year while saving £300-£500/year in recovered heat. MVHR is essential for well-insulated homes (air permeability below 5 m³/m²·h), Passivhaus builds, and whole-house retrofits. It works synergistically with heat pumps by reducing the heating load.

With a heat pump, yes. Underfloor heating operates at 30-40°C flow temperature versus 45-55°C for radiators. Heat pumps achieve COP 3.5-4.0 with UFH versus 2.0-2.5 with older radiators. Every 5°C reduction in flow temperature improves COP by 0.3-0.4. UFH with heat pumps delivers 40-50% lower running costs than radiators with heat pumps. Wet UFH costs £70-£100/m² new-build or £95-£190/m² retrofit.

A standard home EV charger installation takes 3-4 hours. This includes mounting the unit, running cable from your consumer unit, and testing. If your consumer unit needs upgrading or the cable route is unusually long, it may take a full day. We survey your property first to identify the optimal installation route and confirm timescales.

The myenergi Zappi is the best EV charger for solar integration. Its ECO+ mode charges entirely from surplus solar generation, while ECO mode blends solar with grid power. No other charger matches Zappi's solar divert capability. The Ohme Home Pro is best for smart tariff integration, automatically charging at the cheapest overnight rates. Both are 7kW and OZEV-approved.

No. All home EV chargers we install (Zappi, Ohme, Easee, Hypervolt, Pod Point, Tesla) operate on a standard single-phase supply at 7kW (32A). This adds approximately 30 miles of range per hour of charging — more than enough for overnight charging. Three-phase is only needed for 22kW chargers, typically commercial settings.

A tethered charger has a permanently attached cable — simply grab it and plug in. An untethered charger has a socket where you connect your own cable. Tethered is more convenient for home use with one car. Untethered suits households with different EV brands requiring different connectors. Most of our chargers (Zappi, Ohme, Easee) are available in both options.

Yes, though it's more involved than new-build installation. Retrofit wet UFH costs £95-£190/m² (versus £70-£100/m² new-build) due to floor height adjustments. Low-profile systems reduce floor build-up to 15-25mm. Rooms are done individually, making phased installation possible. Downstairs rooms with solid floors are easiest to retrofit. We survey each room and advise on feasibility.

Cavity wall insulation fills the gap between inner and outer walls with insulating material. Most UK homes built 1930-1990 have unfilled cavities. Filling them costs £500-£1,500 and saves £100-£300/year on heating bills — one of the cheapest energy efficiency improvements. ECO4 can fund the cost for eligible households. We assess your wall type during the survey.

Standard extractor fans remove stale air but waste all the heat energy. MVHR recovers 90-95% of that heat, filtering and warming incoming fresh air. MVHR runs continuously at low speed, providing whole-house ventilation rather than localised extraction. It eliminates condensation, reduces dust and allergens, and lowers heating demand. Running costs are £40-£160/year with heat savings of £300-£500/year.

Most air source heat pumps are permitted development and do not require planning permission, provided: the unit is at least 1 metre from the boundary, noise does not exceed 42 dB at the nearest neighbouring window, and the volume is no more than 0.6m³. Listed buildings and conservation areas may need consent. Ground source heat pumps are also permitted development. We check all planning requirements during the survey.

Smart tariffs like Octopus Flux, Intelligent Octopus, and Cosy Octopus offer different electricity rates throughout the day. The strategy: charge your battery from the grid at 7-12p/kWh overnight, use solar during the day, and export surplus at 15-30p/kWh during peak hours. This tariff arbitrage — buying low, selling high — can earn £300-£600/year on top of solar savings. A battery and smart meter are required.