Introduction
Renewable energy, particularly solar power, plays a crucial role in the UK’s transition to a sustainable future. However, the performance of solar panels is significantly influenced by weather conditions. In this post, we’ll explore how weather affects solar energy generation, compare data from 2022 to 2023, and project for 2024 based on historical trends.
Solar Panel Orientation and Tilt
The orientation and tilt of solar panels are critical factors in maximising energy production. Panels must face the correct direction to receive optimal sunlight during peak hours. Here are some key considerations:
- Geographical Location: In the northern hemisphere (like the UK), solar panels should face true south, while in the southern hemisphere, they should face true north.
- Optimal Perpendicularity: Panels generate the most power when the sun’s rays hit them perpendicularly. Achieving this optimal orientation ensures direct light throughout the day.
- Slight Rotation: Depending on usage patterns, a slight rotation (e.g., pointing panels slightly southwest) can enhance energy production during specific hours (e.g., evenings when demand is higher).
Let’s explore the differences between east-west and south-facing solar arrays:
- East-West Arrays:
- Orientation: East-west arrays are positioned horizontally, with panels facing east in the morning and west in the afternoon.
- Advantages:
- Even Energy Distribution: These arrays generate more electricity during the middle of the day (when the sun is overhead) and in the afternoon.
- Matching Demand: The evening production aligns well with peak energy usage when people are home and using appliances.
- Cost-Effective: East-west arrays can accommodate more rows and panels, maximizing land use efficiency.
- Disadvantages:
- Overall Efficiency: Over the entire day, they produce less electricity compared to south-facing arrays.
- Less Intense Noon Peak: The noon peak is less pronounced due to the split orientation.
- South-Facing Arrays:
- Orientation: Panels face directly south, maximizing exposure to sunlight during Solar peak hours.
- Advantages:
- Clear Noon Peak: South-facing arrays have a distinct noon peak, capturing maximum sunlight.
- Optimal Efficiency: Panels perform best when perpendicular to the sun’s rays.
- Predictable Output: regularised energy production throughout the day.
- Disadvantages:
- Mismatched Demand: Energy production may not align perfectly with peak usage hours.
- Fewer Rows: Fewer rows of panels compared to east-west arrays.
More on solar panel mounting tilts – Calculate your solar array power
Insolation and Irradiance Data
Let’s delve into real data for insolation (solar energy received per unit area) and irradiance (solar power per square meter) in the UK:
2022 vs. 2023
- In 2022, record-breaking sunlight and favorable weather conditions led to a 22% increase in solar generation during Q1 compared to the same period in 20211.
- However, variations exist due to seasonal changes and weather patterns.
Projecting for 2024
- To project for 2024, we consider historical data from 2019 to date.
- Insolation Maps: Solargis provides solar resource maps and GIS data for the UK. These maps show global horizontal irradiation (GHI) and direct normal irradiation (DNI) levels. GHI represents total sunlight, while DNI focuses on direct sunlight. Both are essential for solar energy estimation2.
- East-West vs. South-Facing Arrays:
- East-West arrays maximize the number of panels by allowing more rows. Although each panel produces less individually, the overall capacity is higher than south-facing arrays (in terms of project surface area).
- South-facing arrays have a clear noon peak but may not match energy usage patterns as well as east-west arrays.
Sunshine over the year (Insolation).
The is the data chart of solar insolation for the UK, or the power of the sun at ground level.
- STC data and ratings for solar panels is tested at 1kW/m2.
- NOCT panel data is “normal operation condition testing”.
- Panel efficiency plays a large part in gathering the suns energy.
| Month | Sun Radiance (kW/m2) |
|---|---|
| Jan | 0.52 |
| Feb | 0.77 |
| Mar | 1.15 |
| Apr | 1.51 |
| May | 1.67 |
| Jun | 1.63 |
| Jul | 1.55 |
| Aug | 1.38 |
| Sep | 1.07 |
| Oct | 0.76 |
| Nov | 0.51 |
| Dec | 0.37 |
Summary
- Weather Matters: Persistent high pressure (summer wind droughts) can reduce energy supply and increase demand for cooling spaces.
- Solar Challenges: Hot summers can overheat panels, affecting efficiency. Solar panels perform optimally when facing true south on a annual basis.
- East-West Arrays: They offer more rows and higher overall capacity, making them cost-effective and suitable for maximizing land use.
In conclusion, understanding weather impacts on solar energy generation is vital for designing efficient and resilient solar projects in the UK. Whether it’s east-west or south-facing arrays, harnessing the sun’s power sustainably remains our goal. There is more to mounting solar that this article can cover. check out the other posts – on the links in this post 🙂
2 Responses
This article is accompanied by a few others in relation to solar panels, I will revisit this article to update information and extend it. But here will be more articles around the solar panels and arrays and which work best, but there is no one solution fits all. South facings is optimal in an average in general. But that doesn’t mean it’s the best.
This post is popular.
While you read or take the information here, this is part of a range of posts in relation to solar panels and the placement of them.
It is not a “meets all” as there is a lot more to consider than what’s set out about. You may want to look through this months post (feb24) so that you get a more rounded view.
Did you know the sun radiance chart in this post is Solar on earth, that’s different to Solar on panel. The math change is the efficiency of the panel, new panels are typically 22% effective. And they are over a m2 in size, at around 2 m2, so they will get twice the radiance, but only 22% of this will be converted in to energy. im sure if you read the post on here, and the videos on youtube, you would have known that right? 🙂