How much would a school roof near Southampton generate?

Modelled at 950 kWh per kWp a year, a 280 kWp array on a Southampton school models at about 266,000 kWh. What decides whether that is worth doing is how much of it the school uses itself, not the total. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.

How does the school year affect a solar scheme in Southampton?

It goes somewhere, just not into the timetable. 25.4 percent of the Southampton generating year lands in July and August (EU PVGIS v5.2), and a closed school still runs servers, comms, refrigeration and ventilation. What that base load does not absorb is either stored, exported under an agreement with Scottish and Southern Electricity Networks, or a sign the array is too big. We test which before sizing anything.

Which network operator handles the connection at a Southampton school?

Applications go to Scottish and Southern Electricity Networks, who run the network across Hampshire. An export-limited offer usually still works for a school, because the summer surplus is the part you were least likely to be paid much for anyway.

What does Southampton require for solar on a school building?

Roof-mounted solar on a non-domestic building often falls within permitted development under Part 14 of the General Permitted Development Order, subject to limits on how far the panels stand proud of the roof plane and, above a threshold, to prior approval from Southampton on siting and design. Listed buildings and conservation areas are the usual exceptions. We put the position to Southampton before a design is finalised.

How many schools are there around Southampton?

Southampton has 75 open state-funded schools and colleges on the DfE register, with 33,440 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.

Specialist solar panels for schools in Southampton

A kilowatt-peak on a Southampton school roof models at 950 kWh a year, above the mean across the towns we cover, and the roofs it applies to are mostly carrying nothing. The survey records sheet type, remaining life, purlin spacing and the state of the incoming supply, and the model runs off your own meter data rather than an average.

266,000 kWh a year, modelled for a 280 kWp array on roughly 832 sqm of clear roof. That is the median size on the national planning record. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.

Book a roof survey in Southampton

1 teaching block
2 hall and kitchen
3 sports hall
4 1960s block, no array
first phase
later phase

Drawing Illustrative estate, not a Southampton school

Blocks 4, 3 with array

Array about 345 kWp

Yield about 328,000 kWh/yr

Frontage about 90 m / Rev A / SO17

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.

Southampton / Hampshire

A school on the edge of a Home Counties town, solar arrays on its roofs and wooded low hills beyond — School buildings of the kind we survey across South East. Not a named school and not our work.

Solar PV for academy trusts across Hampshire

A one kilowatt-peak array on a shallow pitched roof in Southampton models at 950 kWh a year, from modelled irradiation of 1,221 kWh per square metre in the plane of the array (EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss). That is around 7 percent above the mean across the towns we cover, which is about as strong as a UK school roof gets.

Scaled up, a 280 kWp array, sized to the median array applied for at schools on the national planning record, models at about 266,000 kWh a year before shading, and needs roughly 832 square metres of clear roof. We use the national median from the planning record rather than a round number, so the example stays anchored to what schools have applied for.

Spread across the year that is about 67,600 kWh landing in July and August and roughly 14,100 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.

FIG. 1 Southampton against the rest of Hampshire

Portsmouth987
Fareham980
Southampton950
Eastleigh942
Winchester917
Andover915
Basingstoke906
Fleet904
Farnborough903

Southampton ranks 3 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.

Bars are zero based, so length is proportional to the figure. Where a county is flat, that is the finding: latitude is not the lever, the timetable is. Source: EU PVGIS v5.2, modelled per town

The planning position for Southampton schools

The Renewable Energy Planning Database holds no school scheme for the SO17 postcode district. Read that as a gap in the record, not a gap in the roofs: the database is reliable above one megawatt and thin below it, and a school array is typically a fifth of a megawatt.

The closest recorded one is about 27 miles away at Basingstoke: The Costello School, a 0 kWp roof mounted array applied for by Nero Energy, which holds consent and is awaiting construction. We were not involved in it. We cite it because it is a public record of what has cleared planning in this part of Hampshire. Source: Renewable Energy Planning Database, Q1 2026.

Why demand in Southampton falls as the roof peaks

The generating year and the school year are out of step in Southampton. July and August carry 25.4 percent of the modelled output (EU PVGIS v5.2), and the site is closed for most of those nine weeks. June is the strongest single month here at 14 percent of the annual total, which is still term time, and that works slightly in your favour against towns whose curve peaks in July.

At the other end of the year the mismatch flips. Only 5.3 percent of output falls in December and January, the two months when a Southampton school is fully occupied and its heating and lighting are at their heaviest. The roof makes 5.8 times as much in June as it does in December, and August alone outproduces December by about 4.8 to one. 73 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.

Summed over the year, about 49 percent of what a school roof makes arrives while the school is open. For a business trading every weekday the equivalent is roughly 71 percent. Nothing about Southampton changes that ratio much, but plenty about your own site changes what to do with it.

The weekly pattern repeats the annual one. Saturdays and Sundays generate as well as any other day and consume almost nothing, so before storage or export is even discussed it is worth knowing what the site does at a weekend, which only half hourly data will tell you.

A Southampton governing body should read that as a sizing constraint, not a reason to stop. The base load that runs through the holidays, servers, comms, refrigeration, ventilation and hot water, is the floor the array should be built up from, and everything above it has to be justified by storage, export or summer occupancy.

We set out the whole argument about term dates and the generation curve on the home page, and what it does to a payback figure under costs.

FIG. 2 A Southampton roof against the English school year

generated while the school is open
generated at a weekend or in the holidays

The same figures as a table

Monthly output for a 1 kWp array in Southampton, split by whether the day is a school session day. Across the year 49 percent of generation lands while the school is open.
Month	Session days	Output, kWh per kWp	School open	School closed
Jan	20	27	17	10
Feb	15	41	22	19
Mar	21	77	52	25
Apr	12	111	44	67
May	17	126	69	57
Jun	21	133	93	40
Jul	11	132	47	85
Aug	0	110	0	110
Sep	20	86	57	29
Oct	17	53	29	24
Nov	21	32	22	10
Dec	15	23	11	12
Year	190	951	463	488

Per kWp installed, month by month, separating generation while the school is open from generation at a weekend or in the holidays. 73 percent of the Southampton year sits between April and September, most of which is term time; it is the tail of that period, the last week of July and all of August, that the school is not there for. The daily split is a flat apportionment of each month, not a metered one. Session days follow a typical English school year of 190 days. Your own trust or authority may differ by a few days either way. Source: EU PVGIS v5.2, session days from a typical school calendar

The school estate in Southampton

Southampton has 75 open state-funded schools and colleges on the DfE register teaching 33,440 pupils between them. Source: DfE Get Information About Schools.

The split is 54 primary, 13 secondary, 6 special and 2 further education, at an average of 446 pupils a site. That is 4.2 primaries for every secondary, which is the ratio that matters for a roof: a primary of a few hundred pupils usually offers a hall roof and one teaching block, while a secondary site carries a sports hall, a dining block and several flat roofs.

If your trust holds several of them, the sequencing question comes before the sizing question. Roof age, covering type and the state of the incoming supply vary block by block across an estate, and that is normally what sets the order of works.

Aerial view of a school site with teaching blocks of several different ages, a sports hall and a playing field, solar arrays on two of the flat roofs — A school site with blocks of several ages, which is the usual starting point for a trust estate survey.

Grid connection through Scottish and Southern Electricity Networks

Connections around Southampton are handled by Scottish and Southern Electricity Networks, which sets the export limit for the site. Above 3.68 kW per phase the connection runs under G99, so the export limit is agreed in advance rather than assumed. Where the local network is constrained, an export-limited connection usually still makes the scheme work, because a school uses most of what the roof makes during the working day.

Across Hampshire the planning database records 237 solar schemes totalling 1634 MW, of which 51 are operational (REPD Q1 2026).

Book the survey

Send us the school postcode

We survey school and college roofs throughout Hampshire. We need the postcode, a rough roof area and your half hourly meter data if the trust has it. From that we model what the roof carries, what it generates against the timetable, and which of the funding routes actually suits a school of your size.

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.

What Southampton trusts ask before a survey

How much would a school roof near Southampton generate?: Modelled at 950 kWh per kWp a year, a 280 kWp array on a Southampton school models at about 266,000 kWh. What decides whether that is worth doing is how much of it the school uses itself, not the total. Source: EU PVGIS v5.2, SARAH3, 10 degree pitch, 14 percent system loss.
How does the school year affect a solar scheme in Southampton?: It goes somewhere, just not into the timetable. 25.4 percent of the Southampton generating year lands in July and August (EU PVGIS v5.2), and a closed school still runs servers, comms, refrigeration and ventilation. What that base load does not absorb is either stored, exported under an agreement with Scottish and Southern Electricity Networks, or a sign the array is too big. We test which before sizing anything.
Which network operator handles the connection at a Southampton school?: Applications go to Scottish and Southern Electricity Networks, who run the network across Hampshire. An export-limited offer usually still works for a school, because the summer surplus is the part you were least likely to be paid much for anyway.
What does Southampton require for solar on a school building?: Roof-mounted solar on a non-domestic building often falls within permitted development under Part 14 of the General Permitted Development Order, subject to limits on how far the panels stand proud of the roof plane and, above a threshold, to prior approval from Southampton on siting and design. Listed buildings and conservation areas are the usual exceptions. We put the position to Southampton before a design is finalised.
How many schools are there around Southampton?: Southampton has 75 open state-funded schools and colleges on the DfE register, with 33,440 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.

Nearby

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