How do we choose a solar panel, but a water pump?

Due to a large number of requests, which I received by e-mail or at fairs, I decided to answer you with this article. I will try to answer as briefly as possible.

I await your questions by e-mail at the address contact@termocasa.ro.

1. Solar panels for domestic hot water or/and Solar panels for heating and DHW (domestic hot water)?

If we want a solar panel system only for domestic hot water we have to think about whether we need it only during (a) spring - autumn or (b) the whole period of the year? This aspect clarified, we will look for a system according to performance or according to price (price is not always a deciding factor when choosing a water pump or a solar panel for our home). A cheap solar panel will have the advantage of a relatively low initial cost, and over time (years or months) an increasingly reduced yield. A high performing solar system is more expensive initially (not by much to afford this product) but comfortable in terms of performance/service over the years, not like buying a cheap solar panel or water pump. The choice in this case is relatively easy because the manufacturers of solar panels already have predefined models according to the water storage capacities, precisely to facilitate the choice by consumers of the right system according to the daily need of hot water. If we still got to these explanations, what would you choose: a cheap solar panel with a shorter lifespan, or a slightly more expensive solar panel/water pump (as much as you can afford to pay in full or in installments) with a duration larger than life? I am waiting for your answer regarding the water pump/solar panels.

2. In general, if we want a system of solar panels or a water pump that will help us with heating and at the same time produce hot water or heat, DHW, it must be known that it will be from the start only throughout the year, no longer less than a year. This is where things get complicated and variables appear such as: what is the surface of the house, what and how do we currently heat it, how can we know concretely what solar input we have in winter? These elements will be professionally evaluated through computer simulation. It is extremely important that in addition to the "words" there is concretely an anticipated evaluation of the energy saved during the winter.