We hear about photovoltaics more and more often. The carobollette is directing us towards a series of more sustainable choices that, especially in the long term, allow us to save on the costs of household consumption.

The installation of a photovoltaic system has considerable costs, especially if you choose to make a system that can support the needs of an entire home. However, there are do-it-yourself solutions, useful to cover part of the needs, especially in places such as holiday homes.

But how to understand what is the need and therefore the type of system that must be installed for a single structure? Before installing a photovoltaic system, some points must be clear:
- the need for electricity
- the position of the structure considering latitude and orientation
- the space for the installation of the panels
- do you need an energy accumulator for the night?

A first estimate of consumption can be read from the bill. There is a lot of useful information there, especially if you refer to the individual periods of the year (summer and winter for example, when you use different appliances, one for all? The air conditioner), in order to know the number of KWh which you need. The consumption in watts is indicated on each appliance. A first calculation consists in multiplying the data by the number of hours of use per day. Of course, this is an estimate that many times gives a higher result than the real use, just think of a light bulb that may not be on all day. And this procedure should be applied to every appliance that you use, from the washing machine to the electric oven, from the electric boiler to the computer, just to give a few examples.

But it does not end here because to obtain the estimate in KWh , the result obtained from the sum of the different consumptions must be divided by 1000, after which one last operation follows, multiplying by the number of days of the month.

Here is your consumption and what you should achieve with your photovoltaic system. So the suggestion is to get a clear idea of what you want to power, remembering that the installation of any type of system, do it yourself or installed by a specialized company, works only in optimal light conditions and, to be operational even at night and on days when the sun does not shine high in the sky, it needs a storage battery.