Which solar panel orientation and tilt is best for your residential, commercial or utility-scale plant?
1 Jun, 21
- The role of orientation and tilt of solar panels
- Favouring East-West structures
- Utility-scale Applications
- Residential Applications
- Commercial Applications
- Where will this lead us
The renewable energy sector, within the energy industry, is by nature in constant innovation and evolution. As we evaluated in 5 of the best developments from 2020, now we can see that those developments have progressed extraordinarily, such as floating solarwith planned projects as big as ground-mounted systems (600MW). In the technology side, we have also seen different materials appearing in the market, bigger sized panels and different structures.
In today’s blog post, we wanted to address how the orientation of structures and the tilt of a solar panel may affect productivity and the profitability of a plant. Additionally, the steady decrease in module price’s, the newest structures technologies, and the positioning of the panels may also play an important role in the design of future plant’s.
The driving force of the E-W structures is the rapid increase of land costs, especially in Northern Europe. This results in the necessity to exploit the available terrain to its maximum potential, which is a constant concern for our customers.
PV Project Engineer
The role of orientation and tilt of solar panels
According to experts, the placement and orientation of solar panels is just as important as which type of solar panel is used in a given situation. In order for solar panels to reach their peak generation capacity, a panel must face the correct direction and have the appropriate tilt according to their geographical location and meteorological data. Solar panels will harness the most power when the sun's rays hit its surface perpendicularlyduring the highest intensity of sunlight and for the greatest period of time.
The geographical location will be essential when orientating the panels, and while in the northern hemisphere solar panels should face true south, in the southern hemisphere these must face true north.
Normally, achieving the perfect perpendicularity of the sun's rays is the optimal orientation so that solar panels receive direct light throughout the day. However, according to the University of Calgary, depending on how solar panels are being used, it may also be beneficial to have a slight rotation. By providing the panels this slight rotation, our system would be able to produce more electricity at the hours when it is needed. For example, pointing the panels slightly south-west, in the direction of the setting sun, would allow the panels to produce more energy in the evening, when people are home and using more appliances.
This rotation will cause a decrease in total production, which in reality could make more economical sense for the owners who might prefer to utilize their generated energy when it might be more expensive from the grid (late afternoon before the sun sets).
The angle or tilt of a solar panel is also an important factor. The angle that a solar panel should be set at to produce the most energy in a given year is determined by the geographical latitude. A general rule for optimal annual energy production is to set the solar panel tilt angle equal to the geographical latitude. For example, if the location of the solar array is at 50olatitude, the optimal tilt angle is also 50o. Essentially, the closer a solar panel is located to the equator the more the panel should be pointing straight up. The closer the panel is to the poles, the more they should tilt towards the equator.
Favouring East-West structures
Taking into account the importance of the orientation and the tilt, why then are East-West facing structures on the rise?
Basically, the reason why solar arrays that are situated east-west are becoming an industry trend rapidly is because these structures can squeeze in more rows and panels, and therefore a greater generation capacity than their south-north facing cousins (in terms of the project surface, not generation capacity per module).
Taking into account the continuous drop in module prices (90% in the last decade according to IRENA), it only makes sense that solar developers have started to favour output over panel costs for project profitability.
Additionally, while east-west solar arrays may have a reduced total output (15% less according to Sheffield Solar), the value of the electricity they produce is inherently higher in most markets. This is a result of the smoothing of the array’s generation curve, generating more electricity during the morning and evening hours and less during the midday peak when electricity is at its cheapest.
As an example of a utility scale application of East-West structures, the Neoen's project “Cestas”would generate 15% less total energy than a south-facing plant of the same capacity. However, in terms of LCOE [levelized cost of energy], the plant turned out to be more interesting because of the high fixed costs.
“We found out during our calculations that it was more interesting to pack more power into this site to divide the fixed costs over a larger number of megawatts,” “It was really very specific to that particular plant with very constrained land and very high fixed costs,”
Cestas Project “The most powerful solar farm in Europe”
To understand more about the costs of your utility-scale solar plants, we invite you to download our free costs template.
In the residential sector, east-west estructures are also having an impact as a result of falling feed-in tariffs (FITs) and rising electricity prices.
As in other scenarios, east-west estructures may make more economical sense as people generally leave home in the morning and come back in the afternoon or early evening. Therefore, having PV panels that provide more electricity at these times, rather than at midday when so many properties are empty, could be very beneficial.
In terms of commercial roofs, which tend to be flatter and therefore easier to design, east-west structures allow warehouses, factories and offices to fit as many panels as possible onto their roofs. Additionally, south-facing panels tilted at 30° need heavy concrete ballasts to prevent winds blowing the modules over, or off the roof (fixing panels directly to the roof usually causes waterproofing damage). On the other hand, tightly packed, shallow-tilted panels do not require such heavy ballasting, therefore lightening the load on the roof and cutting costs as a result.
Where will this lead us
As solar modules continue to drop prices, will east-west structures become mainstream as the total yield of a surface surpasses tradicional north-south orientations?
We must not forget that latitude as well as fixed costs such as those of the terrain, will play a crucial role when evaluating the use of east-west structures versus tradicional ones. Will this favour their use only in key strategic areas such as Northern Europe?
Another key consideration to take into account in the analysis of future deployment of this technology is grid instability. This current of thought is driven by industry experts who argue that utility-scale east-west solar farms, with their flatter power curves, will help grid operators balance supply and demand.
As the industry continues to innovate, there are many available possibilities, and we can’t wait to see the newest innovations and trends of the market.
To be informed about the latest news, download our Industry Report 2021for exclusive content.
What you should do now
Whenever you’re ready, here are 4 ways we can help you grow your solar business and reduce LCOE of your PV plants.
- Get hands-on with a free pvDesign demo. If you’d like to learn the ins and outs of how top photovoltaic software can help your engineering team, go ahead and request your free demo. One of our solar experts will understand your current design and engineering workflows, and then suggest practical tips on how to speed up them though the right tool.
- If you’d like to learn insights, ideas and inspiration for the low-carbon energy transition for free, go to our blog or visit our resources section, where you can download guides, templates and checklists solar successful pros use.
- If you’d like to work with other passionate experts on our team, or learn more about our purpose and corporate values, then see our Careers page.
- If you know another solar designer, developer or engineer who’d enjoy reading this page, share it with them via email, LinkedIn or Twitter.
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Solar panel orientation: How using East-West structures improves the performance of your project — RatedPower? ›
Basically, the reason why solar arrays that are situated east-west are becoming an industry trend rapidly is because these structures can squeeze in more rows and panels, and therefore a greater generation capacity than their south-north facing cousins (in terms of the project surface, not generation capacity per ...Is it better to have solar panels facing east or west? ›
Solar panels facing west will generate more energy later in the day, closer to peak use times. Peak production time happens around 4pm, which is about the same time that household usage starts to increase. If your aim is to produce the electricity that you use, then west-facing solar panels can help you meet your goal.What is the performance of East-West solar panels? ›
Still, an exceptional orientation if most of your energy consumption occurs between 10 am and 2 pm daily. However, if your daily situation is working between 9 am – 5 pm, an East and West facing solar panel orientation may save you more money while producing slightly less energy as a whole.What is the best angle for East-West solar panels? ›
But, the rule of thumb is that they should be angled to face as close to the sun as possible. As such, the ideal angle for most people is close or equal to the latitude of your home – typically somewhere between 30 degrees and 45 degrees.Which direction north south east or west is ideal for solar site selection why? ›
The best direction, or azimuth, to face solar panels in the U.S. is true south. By facing in this direction, solar panels can receive sunlight throughout the day.Do solar panels work on an east west roof? ›
For a solar panel to generate the most power, it should ideally be facing true south. Roofs that face south-west and south-east are also considered highly efficient, while properties with an east or west facing roof will lose approximately 15% efficiency compared to a south facing roof.Is east-facing solar worth it? ›
It is the second-best orientation, significantly more effective than west or north. East-facing panels can create only 20% less of what a south-facing system would generate in a region with ideal solar conditions.What direction of house is best for solar panels? ›
With a south-facing roof, your solar panels will produce the greatest amount of energy overall, but east or west-facing roofs can also work well and will produce energy for a large portion of the day. North-facing roofs are the most unfavourable option for solar panels, since they receive very little direct sunlight.What is the best solar orientation for a house? ›
The proper solar panel orientation for homes located north of the equator is facing true south. For homes located south of the equator, it will be the opposite—,facing true north. This will provide the best orientation to allow the most exposure time to the sun and produce the most amount of electricity.What is the perfect direction for solar panels? ›
In the U.S. solar panels perform the best – that is, generate the most power – when they face south. South-facing panels are also best if you use net metering or use solar batteries for energy storage.