What is the payback period of your solar panels?

Suppose you have three solar panels with 90 Watt peak power each on a small southwest facing roof in Delft. The Dutch PV portal calculates that averaged over a one-year period, the three panels will produce 708 kWh, which is 24% of the average Dutch household demand. The initial investment is € 1,090, and the profit made over 25 years is € 2,925. The website confirms Dr Olindo Isabella’s rule of thumb: if a household invests € 5,000 in solar energy, it will become self-sufficient in power.

As an Associate Professor of the Photovoltaic Materials and Devices (PVMD) department at the EWI Faculty, Dr Olindo Isabella has initiated and supervised the PV portal. The first version was made by the master student, Arianna Tozzi, in 2014. The updated version, made by another master student, Veikko Schepel, was launched recently.

The PV portal is aimed at: people working in the solar energy sector; citizens who want to find out what they may expect from PV panels on their roof; and at policymakers who can calculate the effect of a large-scale solar power installation.

The updated version combines the real-time and climate weather databases from the Dutch meteorological institute KNMI. It models the entire efficiency chain from photons-to-electrons to power conversion into AC. Thus, both instantaneous power production and energy yield can be shown for any location in the Netherlands.