Solar Proposal Software

Solar Design Tools, What Is Right For You?

Solar Photovoltaic has become the lowest LCOE of all the available electricity generating methods in the world, making it the obvious choice for all but there are still a few things that need to be considered before one takes the step to invest one’s hard earned money into a solar system. As a solar installation company picking the right software tools help you get one step closer to being the right partner for your customer’s journey to a solar future. Here is a overview of solar design, energy simulation, finance estimation & solar sales proposal tools available; what to look for and how to pick the software that is right for you.

Considerations When Choosing Solar Simulation and Sales Proposals Software

A good solar estimation software will give you the user the right tools to estimate viability. Here are a few things to consider when choosing the correct solar proposal software;

Ease of use

From a business operations point of view easy is efficient, efficient is faster and faster is profitable. Therefore creating and editing solar design proposals with ease allows the sales team to respond to a customer’s email query with more detailed information about features, pricing, utility rate comparisons, government incentives, loan payments and carbon offsets.


Solar software applications differ based on the business model of the solar companies, the granularity of the data and the type of information that is required from the proposal.

1. Installers

Installers require the solar software to provide design of the solar system, components, technical specifications, delivery schedule, project management plan, layouts, drawings, single line diagrams, certification reports and approved permits.

2. Sales

Solar sales teams on the other hand require the solar design software to compare designs of different solar systems, the energy produced, the space utilised and the estimated price. So that they can have an informed discussion with the customer about the net benefit of investing in solar systems.

3. Investors

The proposal software is required to assess initial viability, an estimation of the amount of energy that can be generated given a particular location & space constraints or an investment decision based on the conclusion drawn by the generation value, the investment required, the return on investment or payback period based on the current utility rates and the lifetime cost of the solar project based on the government incentives, loan payments & carbon offsets applicable to the projects under consideration.

4. Asset Management

An asset management software monitors the solar installation and measures the margin of error as compared to the estimates in the proposal. The accuracy of the simulation of energy generated by the solar design software becomes vital to project managers concerned with delivering contracted energy generation goals.


Interoperability or compatibility of the software between various devices, other solar software and operating systems is also to be considered. Including the ability to use browsers, mobile devices and importing/exporting PV Module .PAN files, Inverter .OND files & Typical Meteorological Year (TMY) data.


Solar industry peers and decision makers need to acknowledge the validity and accuracy of the results produced by the solar simulation and proposal software. This is particularly important in the final stages of the financial analysis of a commercial solar project, where the results of the simulation form the basis of the contract.


The ability of engineers & solar PV designers to learn the solar software quickly, the ability of the solar proposal software provider to train the sales team if required and/or easily hireable solar professionals well versed with the software is vital to the adoption of the software platform.


More often than not there is a lack of complete data or information, which makes the ability of the software to fill in the proverbial gap by extrapolating available data and applying algorithms to improve the PV design a valuable requirement. The threshold for accuracy, however, is determined by the business application.

Solar Proposal Tools Available

Prospect – SolarGIS

SolarGIS is a company renowned for its accuracy in irradiation and meteorological data, a solid foundation upon which to build your solar systems. Performance of the solar system can vary quite widely due to minor changes in irradiation and meteorological figures.

The Prospect tool is tailored towards acquiring a broader feasibility with the focus being on the accuracy of the irradiation and meteorological data. What we get is a generic PV-Si option and the type of inverter: small, string or central. The choice does exist for the type of application, the capacity of the system and a few other broader input options. The options for details of the cost of installation, annual costs and losses due to soiling and unavailability can be added.

The end result is a document that summarises the type of system, great amount of detail on the effects of solar irradiance, and the generation over the year, by month and daily energy profiles presented in a easy to understand infographic which makes it simple to grasp and economic values that broadly outline the IRR and expected NPV. Sufficient from a technical standpoint to decide if a particular location is suitable for solar.

The simplest tool is free, the basic and the professional costing an annual fees of $1800 and $3600 respectively for 3 users.

RETScreen Expert

The RETScreen is built by the canadian renewable energy program and is suitable for creating complex proposals. The software goes into a lot of detail and requires several layers of data to get the proposal completed. The metorological data is sourced from NREL, NASA and other reliable sources. While the software is free for viewer only version, it does a look a bit dated and also limited by there being only one version which is compatible with Windows. This does not bode well for the possibility of growth and increasing adoption by other users.


Built by NREL and available for free and used mostly in the US, SAM is a software that covers several aspects of designing for energy projects not just solar and as such is bloated for strictly solar applications. The solar section alone has several options and allows for accommodation of different project types such as PPA with several sub categories of financing options. Once again slightly dated and limited from the global applicability point of view, which I believe is rather the point because the target market is an American audience.

PV Watts is a browser based NREL software created to provide quick and basic estimates that builds on NREL’s extensive database of energy simulation and electricity consumption and tariff rates. The cloud based software allows for a quick estimation which useful for sales and preliminary requirements that prioritises speed over information detail.


The most well known of the software available in the PV simulation market. PVSYST reports are valued by many project developers and solar companies as an accurate solar design tool. A PVSYST report is known to be included in several PPA agreements as supporting documentation for the pre-installation feasibility study and the generation guarantees form the basis of the financial analysis.

The software allows for choice in the specific type of PV modules and inverters. The solar design can be compared to the design data of the PV module and through the design process PVSYST will indicate aspects of the design that exceed acceptable limits such as the possibility of exceeding design voltage limits of solar modules when sizing a string. Creating shading models and using meteorological data PVSYST will provide a report that is specific to the finalised design. This creates a great confidence in the results of a PVSYST solar simulation.

PVSYST does not factor in the financial implications at all, the focus is on system design and system performance. Which is slightly disappointing from a software company that has produced a software that is often treated as the de facto standard by many solar professionals. The PVSYST software does have limitations which is mitigated by the software developers allowing you to import all the data you would require from PAN and OND files for solar panels and inverters to TMY data. Manufacturers and creators of the data are happy to provide files and links to the data which can be imported to increase the accuracy of the result.

Like any tool PVSYST is only as good as the user and if the solar engineer does not put in the correct data the value of the software’s capabilities is lost. Due to the large acceptability and preference of PVSYST there are plenty of trained engineers who know how to use the software effectively. The price is $682 per year per user.


Helisocope built by Folsom Labs is a close albeit more flexible option to PVSYST and the the comparison does not stop there. As per Helioscope which offers a convenient article providing comparison with PVSYST, which could probably be considered as tacit acknowledgement of the preeminence of PVSYST, states that the same equations are used for calculating the energy yield and has been confirmed by DNV-GL that the resultant values are within 1% of each other for identical design and simulation.

Where Heliscope does well is the browser based interface which allows for use across multiple devices. In the use of Helioscope the design and configuration is quite capable and does not seem to be in any way affected by the browser type or computer hardware. This flexibility and portability comes at a price of $95/month which seems high in comparison to PVSYST.

Helioscope and its proponents are building the case for the bankability of its energy and simulation reports. This will certainly make increased adoption of the design tool across the solar energy industry.


Solar Pro Tool by LevaSoft is a fully integrated sophisticated solar design, estimation, simulation, proposal creation and project management tool. Solar Pro Tool has integrated CRM, solar design and project management that allows an estimation tool to be embedded on the installer’s website enabling the end customer to begin their design which can then be built upon by the design team. Thus enhancing the sales process and simplifying system design for the solar sales team. Integration of ERP abilities allow management of partners, vendors and suppliers; compatibility with PolySun is available for energy simulation and a cloud based software platform that is compatible with multiple platforms including usage through browsers makes it a versatile tool. Solar Pro Tool is something to be considered for a company that is a full service operation that takes a project from solar design to execution in one platform. Other features include wind or snow load calculations, energy production simulations and engineering documentation at various stages. With a unique billing method based on your customer billing for the month by leads created through your website and using the Solar Pro Tool. It stands apart from industry peers in that respect, full details for pricing are available on request.


A software for designing micro-grid energy solutions which involve multiple energy sources. Developed by NREL to create engineering, simulation and economics. Now as part of United Laboratories (UL) HomerPro is a software that is likely to have strong support, validity and legitimacy because of its parent company. Homer Pro is a desktop Windows based software that starts at $65 a month.

Homer QuickStart is a basic estimation tool that is entirely browser based, albeit currently in development beta, looks promising. The data of Homer QuickStart can be imported into HomerPro and for the moment available without a fee. HomerPro is targeted for solving micro-grid solutions and as such has a unique use case.

Aurora Solar

An up and coming full feature cloud based solar proposal tool that includes modelling, design, simulation, financing and CRM requirements. Aurora solar is a software platform that can be used to run the entirety of the solar installation business process. Aurora solar is tailored more towards the US market, as illustrated by their permitting feature, but the ambitions are certainly global and they do have global customers. Their algorithm creates a model of the customers annual energy consumption with a single months utility bill which becomes more accurate as additional months are provided.

Being able to look at energy consumption from a non-electric energy source, such as heating and other features such as modelling electric vehicle and battery storage charging requirements allows for more granularity to the consumption model. Automatic designs based on generic or pre-set parameters, multiple report formats and file types make it a robust software platform for the creation of solar proposals.

The price is reasonably competitive at $135 – $220 and the 3D LIDAR assisted modelling is something to consider. However, the software platform does favour the residential customer more than the commercial customer.


The software available for estimating, determining and executing solar projects are as diverse as the solar companies that serve the energy market. This makes the choice for adoption or the recommendation of a single solution difficult.

One would caution against choosing a single software that covers all aspects of the solar company’s requirements. The good news is that there is something for every unique circumstance and there is good interoperability between the various platforms and support tools. Therefore, it would be good to adopt the best tool for each specific part of the company’s requirement and thereby adopting a solar software toolset that gets the best result.