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Sustainable Energy Authority of Ireland

A Solar Calculator for SEAI grant applicants

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Promoting the understanding and uptake of renewable energy is a core part of SEAI’s remit. Solar energy is one of those renewable technologies, specifically solar photovoltaic (PV) panels that generate renewable electricity. To support SEAI’s mission, Dept created a simple, user-friendly online calculator that will allow users to understand the payback of Solar PV installation in a short number of steps.

Highlighting the benefits of Solar PV panels

In 2018 SEAI launched a new grant for Solar PV panels. Solar PV panels generate renewable electricity which can be used within the home. The grant is to help homeowners install this technology in their homes. It covers some, but not all, of the cost of installation. Therefore understanding the payback of the installation cost is essential for homeowners. Understanding the payback can be difficult as there are many factors to consider before investing.

It’s important that homeowners receive clear information before investing in the technology and applying for an SEAI administered grant. SEAI want homeowners to make the right renewable energy choices for their home, energy usage and location, among other considerations.


SEAI's Solar Calculator

Promoting low carbon energy sources

Moving beyond the spreadsheet

SEAI had a downloadable Excel version of a payback calculator available. However, this was fairly complicated to use and unsuitable for mobile devices or social media sharing. It was also unwieldy to update from the SEAI point of view.

Simplifying users' decision-making process

The aim of the project was to produce a simple, user-friendly online calculator that will allow users to understand the payback of Solar PV installation in a short number of steps.

The Solar Electricity Payback Calculator simplifies the decision-making process. Using six easy to understand questions, it provides an unbiased estimation of the annual savings and payback period for homeowners.

By providing this simple calculator for use on desktop and mobile SEAI plan to promote the understanding of the benefits of Domestic Solar PV panels. This should help lead to an uptake in installation rates by well informed homeowners.

Delivering a simple yet powerful solution

The first step in the project was to understand the inputs, outputs and calculations being used in the existing Excel version of the payback calculator. This was originally built for a technical audience, so our analyst had to simplify the various inputs required, while ensuring that the results remained accurate. This allowed us to architecture an appropriate data structure.

Next we looked at the user experience and content. It was very important that users would be able to easily understand the questions and what they needed to do. The languages used for the questions and the tooltips were reviewed by the client and the Dept content team to ensure alignment with SEAI’s digital tone of voice.

The calculator was designed to show the user the results of each of the questions immediately. This decision was taken as we expected the user would want to try different combinations of answers to see what the best result was for them. This behaviour has been proven in post-release analysis and measurement.

The UI of the calculator ensured consistency of design and adherence to the SEAI brand guidelines. The design focused on mobile first, to ensure that the calculator worked equally well on mobile devices and desktops. The colours are used to clearly delineate between the inputs and outputs, so the user can clearly understand the results and easily consider various options, and the impact on their savings and payback period.

Cross-device and browser testing was undertaken to ensure consistency of development across a multitude of devices and browsers. User testing was also completed, based on scripts developed during the analysis phase to ensure that the calculations worked correctly, and resulted in the same outputs as the original Excel.

The Solar PV Calculator supports SEAI’s mission and Ireland’s EU targets by promoting the understanding and adoption of low carbon energy sources.

SEAI's Solar Calculator
SEAI's Solar Calculator

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