Get our free book (in Spanish or English) on rainwater now - To Catch the Rain.

# Design guide for small-scale solar photovoltaic applications

 By Michigan Tech's Open Sustainability Technology Lab. Wanted: Students to make a distributed future with solar-powered open-source 3-D printing. Contact Dr. Joshua Pearce - Apply here MOST: Projects & Publications, Methods, Lit. reviews, People, Sponsors, News Updates: Twitter, Instagram, YouTube

## Background

While considering the power consumed by us we often forget or neglect to count in our electronic devices like the wireless internet router which runs for almost 24 hours a day and 7 days a week. Though it consumes very small amount of power it amounts to a lot, the following statics will give a clearer view of the scenario.

Assuming you do not turn your router off, this would equate to 0.24kWh / day and 87.6kWh annually, costing approximately 5.25\$ per year to run and emitting 48kg of CO2. Approximately there are 81,744,000 households in the USA with a broadband connection, if each of these used wi-fi and never turned it off we would be using 7160MWh per year, spend 429,646,464\$ per annum, and emit 3923712 tonnes of CO2.

So instead of using conventional sources to power the wireless routers we can do that using solar photovoltaics, there by reducing CO2 emissions completely, and saving a lot of money.

## Basic considerations and assumptions

In this discussion I am assuming a “Net gear CG3000D” type wireless router with a supply requirement of 12V DC and a line current of 1.5A which amounts to around 18W of power. The Photovoltaic array needs to be modeled so that it gives out more than 12V and 1.5A for the battery system to charge. The Constraint here is to develop a system which is completely independent of AC power so the battery must be taken of sufficient amp-hours to meet the daily requirement of power so 1.5A for 24 hours essentially requires at least 36A-h capacity battery.

## Design of Photovoltaic system

The system is developed using PVSYST software taking into consideration the Solar radiation data for HOUGHTON. File:Pvsystem.jpg