How to Design a Solar-Diesel-Hybrid-System Easily by Yourself

Solar hybrid system planning with Sunny Design

Designing a solar-diesel-hybrid-system is quite complex. There are many values that have to be taken into account such as meteorological data, electrical parameters, sizing of the components, profitability and many more. Sunny Design is a free tool that makes designing a solar-diesel hybrid system super easy. This article is a guide on how to design a hybrid system with Sunny Design to easily create offers for your customers, project documentation or suggestions for improvement for your existing diesel grid.

 

About this article

This article is meant to be a guide on planning a hybrid system with Sunny Design. If you like, you can open Sunny Design in a second browser window and try all the steps yourself. Enjoy planning your own solar-diesel hybrid system 🙂

 

Login

Sunny Design login screen

Sunny Design login screen

First of all, the advanced features of Sunny Design, such as designing hybrid systems, are only available to registered users. So you have to register and lo gin to start planning your first hybrid system. It is free of charge.

A Sunny Design registration provides you with additional advantages, including an online place to store your projects, so that you can design multiple projects, subsequently change them or duplicate popular designs for new projects. You are also able to personalize the design outcomes to make offering solar hybrid systems to your customers even easier.

 

Welcome screen

Sunny Design welcome screen

Sunny Design welcome screen

The welcome screen allows you to manage your projects. You can add new projects, handle your projects and templates, and adjust the very basic settings. You can store your own locations, load profiles and price lists for use in all of your projects.

To get started quickly, I would suggest you skip these advanced functions for the moment and just start creating your first new hybrid project 🙂 You can easily dive deeper into all the options of configuring Sunny Design later on.

 

Project type

Sunny Design project type selection

Sunny Design project type selection

Sunny Design supports different solar project types such as rooftop solar systems, large-scale solar plants, systems with self-consumption, island systems and solarhybrid systems. You can use Sunny Design to design the layout for all of these systems. This article focuses on hybrid systems, so please choose PV (photovoltaic) hybrid system as your projects type.

 

Basic settings

Configuration of basic hybrid system parameters

Configuration of basic hybrid system parameters

On this page, you are able to set many basic parameters for the project. You can define a project name to easily identify your project from other projects you have created as well as the location of the project.

Now you have to choose for which voltage level you want to design your hybrid system. This already narrows down the choice of solar inverters for your project. If you choose “low voltage” (less than 280 V per phase) here, only low-voltage inverters can be used in your project. If you choose “medium voltage” you are able to use either a multitude of decentralized small inverters (this is useful as maintenance only affects small parts of the system or in case where the solar field is scattered with physical distance between the field segments, but is a little bit more expensive) or centralized large inverters up to 2.5 MW (better efficiency, slightly lower costs).

The “Advanced project data” section contains many more options for fine-tuning. The location, basics for profitability calculation, temperature settings, electrical inverter connection and line losses can be adjusted to get a better profitability estimate at the end.

Project details can be given, which are used to personalize the printable report that can be downloaded when the project design is complete.

 

Meteorological data

Meteorological data is already available in Sunny Design

Meteorological data is already available in Sunny Design

For a realistic profitability analysis, it is very important to set the correct location. You may choose a place that is near to where your hybrid system is to be built. The locations provided by Sunny Design are linked to meteorological data like irradiation and temperatures so that the solar energy generation can be estimated accurately.

You can proceed to the next page by clicking “Define load profile”.

 

Load profile

Define or select a load profile

Define or select a load profile

Here you can define the load characteristics you expect your hybrid grid to have. For ease of use, there are some load profiles provided that you can simply apply. Or, if you have already loaded data from the grid of your project, you can simply import this data. You can find information on how the data for Sunny Design imports should look here.

You can set the annual consumption here. The load profiles are scaled so that the resulting load profile fits the annual consumption you have set.

The three graphs below the load configuration show the load powers resulting from profile and scaling.

 

Create your own load profile

Create your own load profile

Create your own load profile

You can also create your own load profile easily.

So that you can reuse it in other projects, you can give your load profile a name and a description. The annual energy consumption is the energy amount that the profile is scaled to fit. Now you can define season durations for summer and winter. Spring and fall are added accordingly.

Now you can add daily profiles and go into as much detail as you like. In the picture on the right, there is just one profile for weekdays and another for weekends. But you can easily add more and create profiles for individual weekdays and seasons.

 

Genset configuration

Configuration of gensets

Configuration of gensets

On this page, you can configure the gensets that are available, as well as the operation conditions they can be driven in. Some values affect profitability significantly.

A minimum genset load can be defined for each genset. This is the minimum power at which a genset can be continuously driven. This especially affects how much solar power/energy can be integrated into the grid at peak times. When the genset reaches this minimum genset load limit, the solar power is curtailed.

The load-related minimum power defines when another genset is started in the Sunny Design simulation. The preset value is 110% – this means that if the load rises and the nominal power of the currently running genset(s) can provide less than 110% of the current load, another genset is started.

The “Minimum PV power to be expected” value determines how large a drop in solar production can be attributed to clouds. The preset value of 20% is based on experiences in different systems and should stay untouched.

Let’s continue with the configuration of the solar-diesel hybrid system on the next page.

 

PV share proposal

Proposal of PV share based on economic aspects

Proposal of PV share based on economic aspects

Sunny Design now performs a quick profitability analysis and shows which nominal solar power provides a financial advantage. Depending on load and gensets, the PV system has to be curtailed the more nominal solar power is installed. The green field indicates where the financial advantage rises with more solar power, whereas the red field shows where the financial advantage does not rise significantly with more nominal power due to curtailment.

This page mentions a technical maximum of 60% solar power of the apparent power of the gensets. This is only true as long as no storage system is involved. We have different systems running at a PV share of as much as 90% with batteries, but storage solutions are not yet included in Sunny Design.

 

Solar inverter configuration

Selection of solar inverters

Selection of solar inverters

Now it is time to configure the PV system. The PV share proposal already provides a number of solar modules is already provided. You are free to choose specific manufacturers (Sunny Design has a large module database) or to split the solar field into smaller parts.

Next you can configure the solar inverters. There are many different inverter models and depending on your design, there could be a large range from 1 to more than 100 inverters needed to realize your design. To make this as easy as possible, there is a button “Design suggestions”-button that gives a recommendation on which inverters to use – default is sorted by profitability. Just select a suggestion you like and click on “Adopt design”. That’s it!

Now you can see how the inverters you selected will perform in your hybrid system.

 

Optimizing transfer losses by adapting wire size

Optimizing transfer losses by adapting wire size

Wire sizing

You can optimize your design further by selecting appropriate wiring for your hybrid system. Sunny Design calculates the losses for energy transportation on cables with the selected cross sections. If you have selected this during project configuration, this will also be taken into account in the profitability analysis. So choosing another cable cross-section or material can sometimes compensate for the higher costs.

Wiring can be configured for the DC side as well as the AC side with or without sub-distribution.

 

Profitability analysis

Profitability analysis

Profitability analysis

Now all the information is compiled and we can see what we can expect from the solar-diesel-hybrid system in terms of economic advantage compared with the previous genset-only grid.

Topmost, there are the pure numbers. What are the investment costs and how long does amortization take? And which financial advantages does the hybrid system provide? You will find answers to this in the “Profitability” section.

In the “cash flow” section the graph in the middle is particularly interesting as it shows the break-even point at which the hybrid system outperforms the conventional genset system and starts saving real money.

The graphs below show the sensitivity of the fuel price assumptions on the amortization period. The more expensive the fuel gets, the smaller the amortization period will be.

 

Overview of the planned hybrid project

Overview of the planned hybrid project

Results overview

On this page, Sunny Design reshows all the settings made during the design process, which are displayed as a one-page overview. Here you can check your settings again to ensure they are valid.

Proceeding to “Project documentation” will provide you with a pdf download that contains the project setup and the profitability analysis. You can use this to make a suggestion to your grid utility on how to improve your grid or as project documentation for your own customers.

Conclusion

I hope this article demonstrates how easy it is to design a solar-diesel-hybrid-system with Sunny Design. If you have any more questions, feel free to send a comment or share your experiences with Sunny Design for Hybrid Systems here. I’d love to hear from you! 🙂

 

More information

You can find all of our blog posts on the Fuel Save Solution here. It is a great source of information if you are interested in saving fuel or planning to integrate solar energy into your grid.

Do you have comments or questions? Great! Just use the comment field below. We look forward to receiving your comments and we will answer each question as best as we can.

You can find even more details on the Fuel Save Solution Product Website.

If you would like our experts to help you lay out your own Fuel Save Solution, just send us an email at FuelSaveSolution@sma.de

51 Comments
  1. John Hicks
    John Hicks says:

    Hey John here,

    Although this is an old post but today also this method is used by several dealers of solar panels.

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello John,

      Thanks for your feedback.
      Due to legal regulations, we had to delete your external link.

      Sunny regards
      Christiane

      Reply
  2. Ka Boon Hyian
    Ka Boon Hyian says:

    Hi, I’m interested in designing an off grid diesel-solar hybrid system for a greenhouse farm. I would like to ask how can I calculate the parameters of the battery and decide which battery to use?

    Reply
  3. Ali Daer
    Ali Daer says:

    Dears
    Greeting from atico power Yemen.
    let me introduce ourselves to you, we As atico work within power sector we are now studying new project of small Power plant of 6*1000 kva diesel power plant working on the principle of synchronization system.
    and we are planning to add more 1000 kva PV power.
    we need your solution for this project if you intersted on this project
    what we can offer are genset and solar power only.

    please your advice.

    BR

    Reply
  4. Ashwin
    Ashwin says:

    Dear SMA Team
    This is Ashwin from UAE. I have got a project where the size of the project is 24Kw and it is to be designed with PV – DIESEL Genset System. What is going to be my proportion when it comes to SOLAR and Diesel in Sizing. Is it possible for me to design for the 24 kW system, is it too low? The number of days without sunlight is to be 2. With this in mind if I am designing the system what will be my Generator Capacity. Looking forward to hearing from you. Thank You.

    Reply
  5. Nisar
    Nisar says:

    Hello Dear Christian,

    I hope this message finds you well.

    I am contacting you from Afghanistan. We are in design phase of 200 KW PV system on rooftop of a cold storage and we are very interested to use SMA PV-Diesel hybrid solution for our project. The cold storage are located in remote area of the country and there is no electric grid therefore, we want to feed the electrical load via output of PV inverter and during night time we run diesel generator to feed the load.

    I need your recommendation for below issue:

    1. Which type of PV-Diesel hybrid solution do you propose which can feed our 200 kw, three phase load and we want our diesel generators be in standby mode (not consuming fuel) in daytime unless in case of cloudy periods to can share the load with PV system?

    Reply
  6. Yariv Edery
    Yariv Edery says:

    Thank you for this excellent article.
    Is there a way to view the cashflow values? Is there a table or a file that can be downloaded?

    Reply
    • Anke Baars
      Anke Baars says:

      Hi Yariv,
      Thanks for your feedback:-) As each system is customized (PV, genset sizes, load data, PV and diesel prices etc.) it´s not helful to have a general cash flow table. With a simulation in Sunny Design (see description in the post), you´ll get the cash flow displayed for your individual system. There you can also simulate different PV sizes and have a closer look at the cashflow values.
      Kind regards,
      Anke

      Reply
      • Yariv Edery
        Yariv Edery says:

        Thanks Anke, great and prompt reply.
        It is the pv cashflow values that I am after.
        I do see the cashflow graph, but not values. Can I kindly ask for directions on how to view this?

  7. Mpho Kheswa
    Mpho Kheswa says:

    Hi Christian,

    We are designing 2Mw offgrid with generator link and battery storage. Mind to assist?

    Reply
  8. Dami
    Dami says:

    Hello Support, Is there any way to simulate on sunny design web with the grid involved in this solution? perhaps ‘add a generator to represent grid’

    I am working on a design for a client and they have 18hrs of grid a day. On my current design using Sunny web I’m getting a low Used PV share because gen covers most of the load(Load runs averagely at the min load of gen). If I could simulate with the grid I would have a more accurate PV share because ideally, the PV would substitute the grid some times.

    Reply
    • Anke Baars
      Anke Baars says:

      Hi Dami,
      In Sunny Design Web you can design systems connected to the grid. You just need to register via e-mail.
      Maybe this article is also helpful for you, there you also find a contact adress for support in system design.
      Kind regards,
      Anke

      Reply
  9. Bernard
    Bernard says:

    Dear support,
    I have a sponsored project for which my client interest is to simply reduce the cost of diesel. How do I handle the “credit period in years” since I have no credit, not interest to pay, etc.
    Regards,

    Reply
    • Anke Baars
      Anke Baars says:

      Hi Joseph,
      Thank you for your request. My colleague will contact you directly via email.
      Kind regards,
      Anke

      Reply
  10. Stanley Vandu
    Stanley Vandu says:

    Hello SMA Team,
    We will like a technical contact to discuss a potential opportunity we have for a solar-diesel hybrid solution for a Water Supply plant in Nigeria.

    I look forward to hearing from you.

    Reply
  11. muayad
    muayad says:

    Hi
    I have a 2 X 500KVA diesel generator supplying a exhibition in Iraq, we want to design a solar system which will work together with one generator as a hybrid.
    The area available for install PV about 100kWp
    Can you help me with our design to get right components.
    Thanks
    Muayad

    Reply
  12. Mario Wiradjaja
    Mario Wiradjaja says:

    Hi Christian,
    I need explanation regarding using Sunny Web Design, specifically at the ‘Cash flow analysis’ in the ‘Profitability’ section.
    Can you please help direct me to the person in charge in SMA for the subject?
    Thank you & best regards,
    Mario

    Reply
  13. Hani
    Hani says:

    HI christian,
    I am designing a off-grid 750Kwatts PV- diesel generator hybrid system in Yemen, using SMA Tripower 25000TL . I need your help to increase PV penetration up to 90% by adding storage batteries.
    Your help is highly appreciated.

    Reply
  14. Rania
    Rania says:

    Hello Christian,

    I am trying to use Sunny Design to size my system including already 5 Gensets (3x455kVA, 1x500kVA, 250kVA)=1365 kVA. We want to install around 550kWp.
    My problem is that I noticed that for these combinaison of gensets, the maximum I can install as PV is 432kWp which is 20% and not 60% of genset apparent power.
    Could you explain to me why it is not possible to have more PV power here please?
    Thank you

    Reply
    • Christian Höhle
      Christian Höhle says:

      Dear Rania,

      thanks for your message. I will contact you via email and see if I can help you.

      Sunny regards,
      Christian

      Reply
      • DAVIS Chesoli
        DAVIS Chesoli says:

        Hello Christian,
        I been going through your posts and am impressed. We are located in kenya. I have once used your sunny SMA inverters on water projects and they have worked well. Please reach us on email info@kgobisawachero.com for further engagement on a proposed hybrid solar power project. Davis Chesoli

      • Christiane Keim
        Christiane Keim says:

        Hello Davis,

        Thanks for your kind feedback.
        We have forwarded it to our local sales team.
        They will get back to you asap.
        In case you need further assistance, please let us know.

        Sunny regards
        Christiane

    • Christian Höhle
      Christian Höhle says:

      Dear Mohammed,

      Fuel Save Controller S and M supports Sunny Tripower STP TL-30, STP US-10 and STP 60.
      Fuel Save Controller L supports the same inverters like S / M plus Sunny Central CP-XT, Sunny Central

      If Storage Support is ordered, then Sunny Central Storage and Sunny Central Storage 2.0 is also supported.

      Hope this helps. Please let me know should further questions arise.

      Sunny regards,
      Christian

      Reply
    • reza
      reza says:

      hello sir, im so interisting for your software. i wanna ask u, thats its can be used for hybrid energy couple a wind turbin and solar pv?

      Reply
      • Christian Höhle
        Christian Höhle says:

        Dear reza,

        as long as the fraction of wind power compared to the load is small, it can be taken into account as a “reduced load” from the Fuel Save Controller’s point of view.
        If larger wind share is desired, there has to be communication between the wind turbine controller and the fuel save controller. In this case, please let us know the manufacturer of wind turbine and system controller in use and we can evaluate how interfacing between the components can be realized.

        Best regards,
        Christian

  15. Jacob
    Jacob says:

    Hello Christian,

    Thanks for your explanation, we have a 340kW diesel generator supplying a village in Tanzania, we want to design a solar system which will work together with existing generator as a hybrid. Can I ask for your help with our design to get right components.
    Thanks
    Jacob

    Reply
  16. Manh
    Manh says:

    Hi Christian,
    Our company is initially deploying solar power projects using SMA’s inverters. Currently we have a small project using about 50kWp PV in Vietnam for family supply. Can I get technical support for this project?

    Reply
  17. Safwat Ullah
    Safwat Ullah says:

    Dear Mr.Christian
    Good Afternoon,We represent one of the leading power generation services organization of Pakistan in the business for the last 20 years.We have executed many Solar off grid key projects using different products including SMA inverters during the last 05 years.SMA Fuel Saver Technology is really wonderful innovation for Solar Hybrid projects,your article in this regards is also very helpful.Presently we are working on providing 3MW Solar Hybrid Solution using SMA Fuel Saver technology to one of the largest industries of Pakistan.Please inform us whether this system can be used for on grid applications also.The industry where we intend to install this hybrid system is using local grid utility power and diesel gen sets as standbye power source.Please inform whether SMA Fuel Saver technology can be used to install Solar Diesel Grid tied hybrid system and how can we proceed further for designing of this system.
    Thanks & awaiting your urgent response

    Reply
    • Christian Höhle
      Christian Höhle says:

      Dear Safwat,

      that is a really interesting project and I am happy to hear that you have chosen our Fuel Save Controller for your project 🙂

      The Fuel Save Controller works in island systems as well as in grid coupled systems that use gensets for backup. For example the system at Krystalline Salt Kenya (1 MWp PV) is working grid coupled with backup on blackouts of the utility grid.

      Of course we very like to help you design that project. I will contact you via email on how to proceed.

      Sunny regards,
      Christian

      Reply
  18. Ravi Sahai
    Ravi Sahai says:

    Hi Christian,

    Thanks for the article, it was really helpful. We are designing a 600 kW off grid hybrid PV-diesel generator system in Peru and am looking for some design support.

    Ravi

    Reply
    • Christian Höhle
      Christian Höhle says:

      Hi Ravi,

      I am happy to hear that this article helped you. Of course we want to help you with your project 🙂 I will send you an email on how we can support your hybrid system design.

      Sunny regards,
      Christian

      Reply
  19. Kukuh Apriyanto
    Kukuh Apriyanto says:

    Hi Christian,

    I’ve been asked by my client to design hybrid PV diesel for mining in Indonesia. Can I get your advise from technical aspect. The plant will go around 1 MWp PV.

    Regard
    Kukuh

    Reply
    • Christian Höhle
      Christian Höhle says:

      Hi Kukuh,

      great to hear about this opportunity. I will send you an email to get you in touch with our technical sales support.

      Sunny regards,
      Christian

      Reply
  20. David Pham
    David Pham says:

    HI christian,
    We are designing a off-grid 300Kwatts w/batteries and diesel generator for a site in Haiti. I think you did a great work at this site in your article. Can I ask for your help with our design using SMA Tripower 25000TL and SMA Sunny Island 8H and SMA MCBOX 36.
    Thank you in advance for your help. David Pham

    Reply
    • Christian Höhle
      Christian Höhle says:

      Hi David,

      that is great to hear. I will contact you by email shortly.

      Sunny regards,
      Christian

      Reply
      • Jide Akin
        Jide Akin says:

        Hi Christian.

        Great article. Very interesting that it is a Lagos site as that is our location.

        Similar to David, we are designing a 2 MW hybrid solar plant with storage (batteries) and diesel generators for a housing estate in Lagos Nigeria.

        We are at the stage of determining the most appropriate power conversion technologies, equipment and design for the plant.

        I am hope we can count on your kind assistance in the design with the use of SMA equipment?

        hope to hear from you ASAP.

      • Christian Höhle
        Christian Höhle says:

        Dear Jide,

        your project sounds very interesting. I will get in contact with you by email.

        Sunny regards,
        Christian

      • Abdelrahman Talaat
        Abdelrahman Talaat says:

        Hi Christian

        Can you help me with a similar design for 2*20000 stp and 6 SI 6H and MC Box 6.3 and opz batteries 48*2600 ah

        Thanks

    • Christian Höhle
      Christian Höhle says:

      Hello Charles,

      thanks a lot for that compliment. Many people think that adding solar to a diesel grid is a complicated thing. I hope that I can show that it is easy to do with the right tools at hand.

      Sunny regards,
      Christian

      Reply
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