The main aim of the research is to determine the conditions under which it would be possible to increasingly cover as much electricity demand of Latvia as possible by the electricity generated by solar panels. A Microsoft Excel model was developed with an assumption that it would be efficient to install solar panels if the investments returned in a five-year period or sooner. A restriction was set that only household users with solar panels would be taken into account. The model included data from 15 case studies. Based on the collected data, the average monthly electricity bill was calculated before and after installing the solar panels and subsequently the return of investments period in years was calculated. Several model’s positions were variated – the solar panels’ efficiency rate, the price of the solar panels, etc. – to find out which combination of changes would result in a five-year return of investments period.