Specialist solar panels for schools in Portsmouth
Scottish and Southern Electricity Networks runs the network around Portsmouth, and on a school site their answer on export shapes the design as much as the roof pitch does. We look at the roof, the switchboard and the timetable in that order, then set the array size against what the site draws in term time.
987 kWh per kWp a year at this latitude, so a 350 kWp array, the size applied for at the nearest school scheme on record, models at about 345,500 kWh. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.
Book a roof survey in Portsmouth- 1 teaching block
- 2 hall and kitchen
- 3 sports hall
- 4 1960s block, no array
- first phase
- later phase
Illustrative layout for an estate of this size. The array is drawn at about 345 kWp, roughly 53 percent of the 650 kWp these three roofs would hold, because a school sizes to the load it can use in term time rather than to the roof it has: generation it cannot use is exported at a much lower rate than it pays to import. The hatched block carries no array because its structure has not been assessed, which on a school of that era is the usual starting point rather than an exception. Your own figures, and which of your blocks can take an array, come from the roof survey.
School rooftop solar across Hampshire
A one kilowatt-peak array on a shallow pitched roof in Portsmouth models at 987 kWh a year, from modelled irradiation of 1,265 kWh per square metre in the plane of the array (EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss). At 11 percent above our mean, Portsmouth is at the strong end of the range, and a roof here earns more for every square metre than the same roof would further north.
Scaled up, a 350 kWp array, sized to what the nearest school scheme on record applied for, 13 miles away at Chichester, models at about 345,500 kWh a year before shading, and needs roughly 1,040 square metres of clear roof. We take the size from the nearest real application rather than a round number, so the example is anchored to something a planning officer has already seen.
Spread across the year that is about 88,800 kWh landing in July and August and roughly 17,300 kWh across December and January. Scottish and Southern Electricity Networks sets what may go back onto the network here, so the July figure is the one worth putting in front of a governing body first.
Portsmouth ranks 1 of 10 towns we cover in Hampshire on modelled yield, against a national mean of 886 kWh per kWp. The county runs from 903 to 987, a spread of 84 kWh per kWp. On a 500 kWp array that is about 42,000 kWh a year between the strongest and weakest town in the county.
What the planning record shows around Portsmouth
Search the Renewable Energy Planning Database for the PO2 postcode district and nothing comes back under education. That is worth stating plainly and then setting aside: the register is built around generating stations, a school array is a fraction of the size it captures reliably, and plenty of school roofs never appear in any national record at all.
The nearest education scheme on the record is 13 miles from Portsmouth, at Chichester: 350 kWp at Chichester College, Westgate Fields, applicant Green Nation Solar Energy, which holds consent and is awaiting construction. That is someone else's application, not ours, and it is here because it shows what Sussex planning has already accepted at an education site. Source: Renewable Energy Planning Database, Q1 2026.
The summer holiday problem for a Portsmouth school
25.7 percent of the annual output modelled for Portsmouth arrives in the two months a school uses least (EU PVGIS v5.2). Term ends in the third week of July and the buildings stay largely empty until September. June is the strongest single month here at 14.2 percent of the annual total, which is still term time, and that works slightly in your favour against towns whose curve peaks in July.
The inverse holds at the other end. December and January together return only 5 percent of the year, and those are the months with the heating, the lighting and the full timetable all running at once. The roof makes 6.1 times as much in June as it does in December, and August alone outproduces December by about 5 to one. 74 percent of the year arrives between April and September, and the point of that figure is not that the summer half goes unused, because April, May and June are full teaching months that draw hard. It is that the concentration peaks in the few weeks at the end of it when the building is shut.
Across the country the arithmetic settles at roughly 49 percent of output on a session day, against about 71 percent for a weekday business. That figure hardly varies by location, which is why the local numbers that matter here are the yield, the roofs and what has already cleared planning nearby.
And the week has the same hole in it. Two days in seven the site is closed altogether, at no cost to the generation, which is part of why the session day share sits where it does. Weekend lettings are the one lever a Portsmouth school has over that, and they are worth counting properly.
That argues for a particular shape of scheme rather than against one. Size to the load that does not stop at the end of term, count in lettings, holiday clubs and summer works honestly rather than optimistically, and then decide whether storage or an export arrangement with Scottish and Southern Electricity Networks pays for the surplus that is left.
We set out the complete version of the term time arithmetic on the home page, and what it does to a payback figure under costs.
- generated while the school is open
- generated at a weekend or in the holidays
The same figures as a table
| Month | Session days | Output, kWh per kWp | School open | School closed |
|---|---|---|---|---|
| Jan | 20 | 26 | 17 | 9 |
| Feb | 15 | 42 | 23 | 20 |
| Mar | 21 | 80 | 54 | 26 |
| Apr | 12 | 115 | 46 | 69 |
| May | 17 | 132 | 72 | 60 |
| Jun | 21 | 140 | 98 | 42 |
| Jul | 11 | 139 | 49 | 90 |
| Aug | 0 | 114 | 0 | 114 |
| Sep | 20 | 88 | 59 | 29 |
| Oct | 17 | 54 | 30 | 24 |
| Nov | 21 | 32 | 22 | 10 |
| Dec | 15 | 23 | 11 | 12 |
| Year | 190 | 985 | 481 | 504 |
Grid connection through Scottish and Southern Electricity Networks
Scottish and Southern Electricity Networks is the network operator here, and their answer on export capacity shapes the design. Any commercial array above 3.68 kW per phase connects under G99 rather than G98, and the application fixes what you are allowed to push back onto the network. If the local network is tight, limiting export rarely breaks the case here: most of the generation is consumed on site while the building is working.
Across Hampshire the planning database records 237 solar schemes totalling 1634 MW, of which 51 are operational (REPD Q1 2026).
How many schools Portsmouth has
Portsmouth has 62 open state-funded schools and colleges on the DfE register teaching 27,696 pupils between them. Source: DfE Get Information About Schools.
The split is 45 primary, 11 secondary, 5 special and 1 further education, at an average of 447 pupils a site. 4.1 primaries per secondary is a mix weighted towards small sites. The roof area, and therefore most of the generation, sits with the 11 secondaries and the 1 further education site.
Across an estate of that size the roofs will not be in the same condition, and that is the point of surveying them together: the block with the best orientation is often not the block whose covering has twenty years left in it.
Start with the Portsmouth roof
The first survey answers three questions at once: what the roofs carry, what they generate against your own timetable, and how a Portsmouth school pays for it. Send the postcode, an approximate roof area per block and half hourly meter data if the school can get it from its supplier.
Lenzie Consulting Ltd arranges the survey and passes your details to an MCS-certified installation partner so they can quote. We do not carry out the installation ourselves.
Questions governors ask us about Portsmouth schools
- Is there enough sun around Portsmouth for this to be worth doing?
- The model gives 987 kWh a year for every kWp installed at this latitude, so a 350 kWp array comes out at roughly 345,500 kWh a year before shading. It needs about 1,040 square metres of clear roof once walkways and rooflight setbacks are allowed for. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.
- Does a Portsmouth school waste its generation in August?
- 25.7 percent of the modelled annual output for Portsmouth falls in July and August, when the buildings are closed for most of six weeks (EU PVGIS v5.2). It does not go to waste, but it only has three places to go: the base load that runs regardless, such as servers, catering refrigeration and ventilation; storage; or export under an agreement with Scottish and Southern Electricity Networks. We model all three against your half hourly data before an array is sized.
- Will the network around Portsmouth accept the export?
- Scottish and Southern Electricity Networks is the distribution network operator for Hampshire. Anything above 3.68 kW per phase connects under G99, and the application fixes the export limit. On a school site the incoming supply is often the binding constraint rather than the roof, so we ask that question before anyone sizes an array.
- Is planning permission needed for panels on a school in Portsmouth?
- Usually permitted development covers a roof array on a school, with prior approval from Portsmouth needed above a capacity threshold. A ground mounted array in the grounds is a different question and much more likely to need a full application. We check both before design sign-off.
- How many schools are there around Portsmouth?
- Portsmouth has 62 open state-funded schools and colleges on the DfE register, with 27,696 pupils on roll. Source: DfE Get Information About Schools. We survey across the whole of that area, and where a trust holds several sites we look at them in one pass.