#solarpv — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #solarpv, aggregated by home.social.
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East/South East (8x 400w panels) panels generated - 14.5 kWh
West/North (6x 400w panels) panels generated - 8.3 kWh
Solar generated - 22.8 kWh
Solcast forecasted - 22.44 kWh
Imported from the grid - 15.2 kWh - Cost (inc standing charge) £2.33
Exported 16.6 kWh Export profit - £1.99
10.4 kWh went into the battery
Battery used - 10.5 kWh
House consumed - 18.7 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.34
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 8.48 kWh
Solcast forecast for today (East 4x400w panels) - 5.6 kWh
Solcast forecast for today (West North 6x400w panels) - 8.13 kWh
Solcast forecasting a total of 22.207 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 14.4 kWh
West/North (6x 400w panels) panels generated - 8.2 kWh
Solar generated - 22.6 kWh
Solcast forecasted - 22.54 kWh
Imported from the grid - 16.2 kWh - Cost (inc standing charge) £1.83
Exported 17.5 kWh Export profit - £2.1
11.1 kWh went into the battery
Battery used - 10.5 kWh
House consumed - 18.1 kWh
Electricity cost for the day at 9pm (minus is a profit) is £-0.27
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
We are making a profit. We have exported
£1.84 so far today. -
Solcast forecast for today (South East 4x400w panels) - 8.95 kWh
Solcast forecast for today (East 4x400w panels) - 6.19 kWh
Solcast forecast for today (West North 6x400w panels) - 7.39 kWh
Solcast forecasting a total of 22.5275 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 11.9 kWh
West/North (6x 400w panels) panels generated - 8.5 kWh
Solar generated - 20.4 kWh
Solcast forecasted - 21.96 kWh
Imported from the grid - 21.8 kWh - Cost (inc standing charge) £2.33
Exported 12.0 kWh Export profit - £1.44
14.7 kWh went into the battery
Battery used - 12.1 kWh
House consumed - 24.4 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.89
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 8.32 kWh
Solcast forecast for today (East 4x400w panels) - 5.71 kWh
Solcast forecast for today (West North 6x400w panels) - 7.52 kWh
Solcast forecasting a total of 21.5521 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 12.1 kWh
West/North (6x 400w panels) panels generated - 5.9 kWh
Solar generated - 18.0 kWh
Solcast forecasted - 19.73 kWh
Imported from the grid - 15.5 kWh - Cost (inc standing charge) £1.85
Exported 11.4 kWh Export profit - £1.37
12.6 kWh went into the battery
Battery used - 14.6 kWh
House consumed - 20.8 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.48
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 7.05 kWh
Solcast forecast for today (East 4x400w panels) - 5.54 kWh
Solcast forecast for today (West North 6x400w panels) - 6.84 kWh
Solcast forecasting a total of 19.4303 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 8.3 kWh
West/North (6x 400w panels) panels generated - 6.7 kWh
Solar generated - 15.0 kWh
Solcast forecasted - 19.67 kWh
Imported from the grid - 18.2 kWh - Cost (inc standing charge) £2.07
Exported 8.6 kWh Export profit - £1.03
15.8 kWh went into the battery
Battery used - 13.9 kWh
House consumed - 18.8 kWh
Electricity cost for the day at 9pm (minus is a profit) is £1.04
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
“Put Solar on Roofs Instead” – Does the Maths Add Up?
Opposition to solar farms often centres on two arguments: that panels should go on roofs and car parks instead, and that agricultural land should be reserved for food production. Both concerns are understandable. Yet they are often discussed without considering the scale of energy demand involved, or the practical challenges of deploying solar elsewhere.
So what would happen if every suitable house, warehouse, school and car park did install solar? Would we still need solar farms?
Solar Farm Output per Acre and per Hectare
For a modern UK solar farm a typical generation range is 130,000-220,000 kWh per acre, with 160,000 kWh per old-fashioned acre per year being a reasonable central estiamte. This figure varies with panel efficiency, layout and latitude, but it is widely used across the industry. A hectare is ~2.5 acres, so a hectare of solar farm produces roughly 400,000 kWh per year.
A standard UK domestic rooftop system is, conservatively, ~4 kWp. These installations generate around 3,800 kWh per year depending on roof orientation, shading and local climate. This gives us a clear comparison point: ~40 houses offsets an acre of solar farm.
It would take just 42 homes with a modest 4 kWp rooftop solar system to produce the same amount of electricity as an acre of solar farm, or ~100 homes for a hectare.
The obvious response is that we should install more rooftop solar before covering fields with panels. There is merit in that argument. In fact, the UK has vast untapped opportunities on homes, warehouses, schools, hospitals and car parks. The question is not whether we should use them, but whether they are sufficient on their own. It seems that anyone concerned enough to protest against solar farms would have already taken their own steps to reduce their energy demands and would be encouraging others to do the same.
Some of these concerns are addressed in this blog: https://ferribysustainability.co.uk/2026/04/26/solar-farms-and-farmland/ but there is clearly more to say to provide context around the debate.
The UK’s Commercial and Public Roof Opportunity
Domestic rooftops matter, but the largest untapped solar resource in the UK is on commercial and public buildings.
Warehouse Roofs
The UK has 350 million m² of warehouse roof space. The best 20% (75 million m²) could host around 15 GW of solar. Industry estimates suggest around half of commercial roofs could safely take solar, once structural and shading constraints are considered.
Public Sector Buildings
Hospitals, schools, universities, leisure centres and government offices have similar potential, with large, accessible roofs that are often already maintained to high standards.
Car parks
“We should put them on car parks”.
Well, yes, though that is really a decision for the car park owners; France has mandated that all most new, large car parks should be built like that and it’s hard to disagree. But how big a difference would that make.
A standard UK bay is around 2.4 m × 4.8 m. A well‑designed canopy can host ~3 to 3.5 kWp per bay, giving annual generation per bay around 3,000 kWh/year. So 330 bays are needed per acre. Contextualising that, you need 8 bays for every household system, or a decent sized supermarket car park to match an acre of solar farm.
The issue is the cost. Ground‑mount is about £700-£900/kWp, while the new car park equivalent is 75% more expensive, about £900-1,400kWp; let’s use 1,225/kWp to keep the maths simpler. Retro-fitting solar canopies to carparks is more expensive again at ~£1,500/kWp. That extra 75%-100% cost makes the electricity people buy more expensive at a time when houses are struggling with the cost of energy.
Two independent studies have quantified UK car‑park solar potential.
- The RenEnergy study identifies 629,000 business‑owned parking bays suitable for solar carports; this corresponds to 1.57 GW of capacity and 1.4 TWh per year of generation .
- Energy Systems Catapult estimates that public‑sector parking facilities could theoretically host up to 24 GW of solar capacity .
The 24 GW is a theoretical upper bound, whereas the 1.57 GW is a practical, surveyed subset of private‑sector sites; real deployment would be constrained by:
- retrofit cost
- structural limits
- shading
- planning constraints
- grid connection availability
- disruption to car‑park operations
If we apply a conservative utilisation factor of 25-40 % of the theoretical public‑sector potential, we get 6-10 GWp realistically deployable giving 6-11 TWh per year of generation. That’s another 2-4% of demand, but it’s high cost electricity.
What were those costs again?
Remembersing that we all have to pay for the electricity produced by these solar projects, let’s just remind ourselves of the real-world installation costs.
Domestic lacks the economies of scale, but massively reduces home-owners bills and emissions; they make the investment (though grants are available) and get most of the benefit.
A Perspective on Land Use
Discussions about solar farms often focus on the loss of agricultural land, but it is worth considering the extraordinary energy density of solar generation. A hectare of solar farm producing around 400,000 kWh of electricity each year can generate enough electricity for around 100 average UK homes. By comparison, while a hectare of even high grade farmland provides food that society clearly needs, the usable energy delivered by modern solar photovoltaics is remarkably high for the area occupied.
This is not an argument that food production is unimportant, nor that every field should become a solar farm. Rather, it helps explain why solar developers are interested in relatively small areas of land. The amount of energy that can be generated from a modest area is far greater than many people realise.
Modern solar farms increasingly allow continued agricultural use through grazing, biodiversity enhancement, land recovery and, in some cases, agrivoltaic systems that combine food and energy production on the same land.
Conclusion: combining the alternatives to solar farms
A reasonable estimate suggests commercial + public roofs + car parks could generate: 76–110 TWh per year
With UK electricity demand at 300-330 TWh per year, this represents 25-33% of current national electricity demand from rooftops and car parks alone. This is a transformative figure, achieved without using additional land and capable of substantially reducing pressure on the electricity network. However, these installations are generally more expensive than ground-mounted solar and require millions of individual investment decisions by householders, businesses and public-sector organisations. Not every roof is suitable for solar, and many sites face structural, shading or planning constraints. Furthermore, UK electricity demand is expected to rise as transport, heating and industry electrify, increasing the need for low-carbon generation. Rooftops, warehouses and car parks should therefore be developed wherever practical, but they are unlikely to remove the need for large-scale solar farms. Instead, they are complementary parts of the same solution.
Solar farms are not an alternative to rooftop solar. They are part of the same solution.
Rooftop solar, commercial roofs and solar car parks should absolutely be pursued. They are valuable opportunities that can reduce pressure on the electricity network, lower bills and avoid the need for some ground-mounted schemes. However, not every roof is suitable for solar. Structural limitations, orientation, shading, lease arrangements and planning restrictions mean that the theoretical potential will never be fully realised. Meanwhile, ground-mounted solar farms can also be designed for optimal orientation, spacing and maintenance, typically resulting in more predictable performance than millions of individually designed rooftop installations, providing more reliable generation and lower ongoing costs.
Use every roof and car park we can find. We’ll still need solar farms.
Furthermore, UK electricity demand is expected to rise as transport, heating and industry increasingly electrify. The need for additional low-carbon generation is therefore likely to grow rather than shrink over time. The real question is not whether rooftop solar can replace solar farms, but how many future solar farms can be avoided by making better use of roofs, warehouses and car parks today.
The challenge is one of scale. Even if we successfully exploit the most promising rooftops and parking facilities, the UK will still need substantial additional renewable generation. Solar farms are not an alternative to rooftop solar. They are part of the same solution.
The real choice is not between solar farms and rooftops. It is whether we are prepared to deploy all available low-carbon technologies quickly enough to meet future electricity demand while reducing reliance on fossil fuels.
Sources
Solar Rooftops: https://www.solarenergyuk.org
Warehousing sector in Government’s Clean Power Action Plan: https://www.ukwa.org.uk/breakthrough-for-warehousing-sector-in-governments-clean-power-action-plan/
Solar Carport vs Solar Farm: Per-kWp Economics Compared: Solar Carport vs Solar Farm: Per-kWp Economics Compared
How Many Solar Panels Fit on a Car Park? How Many Solar Panels Fit on a Car Park? | Solar Canopy UK
Solar car park potential: https://cdn.prod.website-files.com/66282d14aaf9d7429d404be3/685e9d29694aea9d4b3f8179_Solar-Carport-White-Paper%20(1).pdf
#climateChange #Energy #Environment #renewableEnergy #SolarFarms #SolarPV #Sustainability -
Solcast forecast for today (South East 4x400w panels) - 6.7 kWh
Solcast forecast for today (East 4x400w panels) - 4.73 kWh
Solcast forecast for today (West North 6x400w panels) - 8.11 kWh
Solcast forecasting a total of 19.5439 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 5.3 kWh
West/North (6x 400w panels) panels generated - 4.2 kWh
Solar generated - 9.5 kWh
Solcast forecasted - 12.21 kWh
Imported from the grid - 20.1 kWh - Cost (inc standing charge) £2.14
Exported 5.1 kWh Export profit - £0.61
13.2 kWh went into the battery
Battery used - 13.8 kWh
House consumed - 21.5 kWh
Electricity cost for the day at 9pm (minus is a profit) is £1.53
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 3.58 kWh
Solcast forecast for today (East 4x400w panels) - 3.33 kWh
Solcast forecast for today (West North 6x400w panels) - 5.4 kWh
Solcast forecasting a total of 12.3051 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 11.0 kWh
West/North (6x 400w panels) panels generated - 6.4 kWh
Solar generated - 17.4 kWh
Solcast forecasted - 15.92 kWh
Imported from the grid - 17.2 kWh - Cost (inc standing charge) £1.94
Exported 11.6 kWh Export profit - £1.39
14.0 kWh went into the battery
Battery used - 13.6 kWh
House consumed - 19.3 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.55
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 5.5 kWh
Solcast forecast for today (East 4x400w panels) - 4.6 kWh
Solcast forecast for today (West North 6x400w panels) - 5.39 kWh
Solcast forecasting a total of 15.4969 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 8.8 kWh
West/North (6x 400w panels) panels generated - 6.4 kWh
Solar generated - 15.2 kWh
Solcast forecasted - 16.6 kWh
Imported from the grid - 22.6 kWh - Cost (inc standing charge) £3.2
Exported 12.4 kWh Export profit - £1.49
16.3 kWh went into the battery
Battery used - 16.7 kWh
House consumed - 22.3 kWh
Electricity cost for the day at 9pm (minus is a profit) is £1.71
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 4.8 kWh
Solcast forecast for today (East 4x400w panels) - 4.04 kWh
Solcast forecast for today (West North 6x400w panels) - 7.52 kWh
Solcast forecasting a total of 16.3613 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 9.3 kWh
West/North (6x 400w panels) panels generated - 7.4 kWh
Solar generated - 16.7 kWh
Solcast forecasted - 19.39 kWh
Imported from the grid - 18.2 kWh - Cost (inc standing charge) £1.99
Exported 11.4 kWh Export profit - £1.37
13.3 kWh went into the battery
Battery used - 12.3 kWh
House consumed - 19.5 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.62
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 6.2 kWh
Solcast forecast for today (East 4x400w panels) - 4.92 kWh
Solcast forecast for today (West North 6x400w panels) - 8.02 kWh
Solcast forecasting a total of 19.1344 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 14.7 kWh
West/North (6x 400w panels) panels generated - 8.8 kWh
Solar generated - 23.5 kWh
Solcast forecasted - 23.18 kWh
Imported from the grid - 22.4 kWh - Cost (inc standing charge) £2.32
Exported 13.3 kWh Export profit - £1.6
14.3 kWh went into the battery
Battery used - 11.4 kWh
House consumed - 26.5 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.72
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 8.45 kWh
Solcast forecast for today (East 4x400w panels) - 5.59 kWh
Solcast forecast for today (West North 6x400w panels) - 8.85 kWh
Solcast forecasting a total of 22.8908 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 15.1 kWh
West/North (6x 400w panels) panels generated - 9.5 kWh
Solar generated - 24.6 kWh
Solcast forecasted - 24.49 kWh
Imported from the grid - 17.7 kWh - Cost (inc standing charge) £1.97
Exported 13.4 kWh Export profit - £1.61
13.3 kWh went into the battery
Battery used - 12.9 kWh
House consumed - 25.2 kWh
Electricity cost for the day at 9pm (minus is a profit) is £0.36
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
Solcast forecast for today (South East 4x400w panels) - 8.83 kWh
Solcast forecast for today (East 4x400w panels) - 5.95 kWh
Solcast forecast for today (West North 6x400w panels) - 9.56 kWh
Solcast forecasting a total of 24.3367 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 15.5 kWh
West/North (6x 400w panels) panels generated - 8.5 kWh
Solar generated - 24.0 kWh
Solcast forecasted - 23.83 kWh
Imported from the grid - 12.9 kWh - Cost (inc standing charge) £1.55
Exported 17.4 kWh Export profit - £2.09
9.2 kWh went into the battery
Battery used - 11.0 kWh
House consumed - 18.7 kWh
Electricity cost for the day at 9pm (minus is a profit) is £-0.54
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
We are making a profit. We have exported
£1.56 so far today. -
Solcast forecast for today (South East 4x400w panels) - 8.72 kWh
Solcast forecast for today (East 4x400w panels) - 5.75 kWh
Solcast forecast for today (West North 6x400w panels) - 9.36 kWh
Solcast forecasting a total of 23.8358 kWh
#Solar #SolarGeneration #Solcast #SolarPV -
East/South East (8x 400w panels) panels generated - 15.7 kWh
West/North (6x 400w panels) panels generated - 10.5 kWh
Solar generated - 26.2 kWh
Solcast forecasted - 25.26 kWh
Imported from the grid - 16.2 kWh - Cost (inc standing charge) £1.96
Exported 17.2 kWh Export profit - £2.06
11.6 kWh went into the battery
Battery used - 10.1 kWh
House consumed - 20.8 kWh
Electricity cost for the day at 9pm (minus is a profit) is £-0.1
#Solar #SolarGeneration #Solcast #OctopusAgile #SolarPV -
We are making a profit. We have exported
£1.97 so far today. -
Solcast forecast for today (South East 4x400w panels) - 8.85 kWh
Solcast forecast for today (East 4x400w panels) - 5.94 kWh
Solcast forecast for today (West North 6x400w panels) - 10.43 kWh
Solcast forecasting a total of 25.2168 kWh
#Solar #SolarGeneration #Solcast #SolarPV