A quick introduction and guidance into having a Photovoltaic (PV) system installed based around a 1kwp (the peak output) system:-
1. A 1kwp system will cost around £5,200
2. Additional1kwp’s will add about £3,000 to a system eg, 2kwp will be about £8,000.
3. 1kwp will cover about 7 square meters of roof area.
4. 1kwp system in Gloucestershire will deliver about 850kwhrs of electricity in a year.
5. A typical system will take 2 to 3 days to install
6. A typical house will use 3-3500kwhrs/year ofelectrical energy
7. The system should ideally face South but SE to SW will be OK – see tilt and orientation guide.
8. The ideal roof pitch is 30-35deg, traditional pitches of 45º and 55º make only a few % difference – see tilt and orientation guide.
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>9. Space is needed in the house for the inverter and the total generation meter – see picture.
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10. The total generation meter is the reading that gives you your payment for the energy generated – see picture.
11. The system is fully automatic and will generate electricity when the sun shines.
12. When electricity supply fails generation stops, so your system does not electrocute the man on the wire repairing the supply! Then it automatically starts working again after the grid supply returns and becomes stable.
13. Installing a solar PV system on a roof is a “Permitted Development” (excluding Listed Buildings) provided it is less than 200mm above the roof and complies with the General Permitted Development Order. AONB’s are not “Conservation Areas” in “planning terms” so even in AONB's solar panels on the roof are a permitted development. In “Conservation Areas” solar systems do not need planning permission if they are on the roof, however if they are on the walls and can be seen from the highway Planning Permission will be required.
14. The price guidance does not take into account scaffolding, any building specific problems or any electrical wiring changes that may be required to your particular building.
15. The Feed in Tariff (FiT) started in April and a typical 2.5kwp system facing south will earn about £942 per year under the scheme, plus a further 3.1p/kwhr for everything that is exported, PLUS some of the electricity generated will be used by the building at the time of generation which avoids paying for imported mains supply - saving further money. Considering only the FiT (not the electricity used) as a return on capital this represents approximately 9-10%. This guide income considers a system of 2.5kwp which attracts a total generation payment rate of 43.3p/kwhr and this rate is guaranteed by the government for 25 years.
Payment is index linked and TAX FREE under current legislation.
Each kwhr of electricity generated saves 0.526kgs of CO2. This CO2 figure varies daily depending on the generation mix in the grid supply.
Quick Solar guidance of prices on a 2.1kwp system using different panel manufacturers.
Some information to get you started based on approximately 2kw peak output system. We use panels of differing makes, sizes prices and efficiencies, a small roof requiring maximum output will require a high efficiency (expensive) panels but a large roof will often facilitate the use of a lower efficiency (cheaper) panel whilst still achieving the same output. Often roof features (hips or Veluxes) will dictate the physical size of the panels used to make up the array. For example on a roof with features on it may be better to use 15 small 135 watt panels rather than 8 much larger 250 watt panels.
Therefore below you will see a range of Greenshop Solar installed prices from three different panel manufacturers for an approximately 2.1 kw peak system:-
- 2.155kwp (9 x 235watt panels) in Sanyo panels will cover 11.35m2 and the module efficiency is 19.1% and a system would cost £9536 including Vat@5% Cost = £4.51/watt peak. Return on investment 8.4%
- 2.15kwp (10 x215 watt panels) in Kyocera panels will cover 14.85m2 and the module efficiency is 16.5% and a system would cost £8,605 including Vat @5% Cost = £4.00/watt peak. Return on investment 9.45%
- 2.20kwp (10 x220 watt panels) in Yingly panels will cover 16.34m2 and the module efficiency is 14.4% and a system would cost £7979 including Vat @5% Cost = £3.63/watt peak. Return on investment 10.43%
A 215 watt panel will product a peak output of 215 watts but the more efficient panels will produce a higher output at lower light levels so they will average a higher annual return. The generation figures we quote are based on SAP (Standard Assessment Procedure) and do not consider panel efficiencies.
These parameters change as other panel manufacturers are considered. We use a variety of different panel sizes and manufacturers as required by the specification.
These prices include installation, scaffolding, commissioning and MCS Registration. They are one off single building prices. Rows or larger numbers of houses would be cheaper, as would larger commercial buildings.
2.15kwp systems would expect to produce 1855 kwhrs/year on a south facing 45 deg pitch roof and give an annual income of £803 (@43.3p/kwhr) + Free electricity if you use what it is being generating and 3.1p/kwhr for what is exported.The 2.2kwp system would produce 1855 kwhrs/year. These figures are obtained using SAP are proving to be conservative on our on going monitoring. The more efficient panels are likely to give a higher annual output.
Under the 4kwp level you will receive 43.3p/kwhr payment.
The maximum size allowable under Regulation G83 is 16amp/phase and on a single phase connection this allows 3.67kwp, larger systems than that we are governed by G59 which has other implications. Over G83 size we need to apply to the DNO before we connect, this is not usually a problem but depends on many things including the supply size and proximity to the substation.
These guide prices use a mid-priced solar panel, do not include scaffolding and only include for a straight forward electrical connection, a survey would required for any specific installation.
- 3.87kwp - Cost -£13,863 including VAT @ 5% , covers 29m2 and this will generate (according to SAP in Gloucestershire) 3263 kwhrs/year which will give an income of £1413/year (@43.3p) + Free electricity if you are using what it generates + The export rate of 3.1p for what you export, for 25 years. 10.56% return on capital. Cost = £3.58/wp (inc VAT)
- 9.675kwp - Cost -£27,578.53 + VAT @ 5%, covers 69m2 and this will generate (according to SAP in Glos) 8158 kwhrs/year which will give an income of £3084/year (@37.3p) + Free electricity if you are using what it generates + The export rate of 3.1p for what you export, for 25 years. 11.18% return on capital. Cost = £2.85/wp
- 14.19kwp - Cost -£37,081.11 + VAT @ 5%, covers 106m2 and this will generate (according to SAP in Glos) 11965 kwhrs/year which will give an income of £4523/year (@32.9p) + Free electricity if you are using what it generates + The export rate of 3.1p for what you export, for 25 years. 12.2% return on capital. Cost = £2.61/wp
Commercial Systems
Systems larger than 20kwp are treated differently and often need to include grid connection study. These will typically cover 7.5m2/kwp and cost will be typically £2.50/wp or less, + site electrical specifics and Grid connection extras. A 140kwp project in Wales is currently costing £308,000 which is £2.20 per watt peak.
Large systems - please contact us to talk through your project.
