Posts with «solar power» label

Energy Harvesting Design Doesn’t Need Sleep

Every scrap of power is precious when it comes to power harvesting, and working with such designs usually means getting cozy with a microcontroller’s low-power tricks and sleep modes. But in the case of the Ultra Low Power Energy Harvester design by [bobricius], the attached microcontroller doesn’t need to worry about managing power at all — as long as it can finish its job fast enough.

The idea is to use solar energy to fill a capacitor, then turn on the microcontroller and let it run normally until the power runs out. As a result, a microcontroller may only have a runtime in the range of dozens of microseconds, but that’s just fine if it’s enough time to, for example, read a sensor and transmit a packet. In early tests, [bobricius] was able to reliably transmit a 16-bit value wirelessly every 30 minutes using a small array of photodiodes as the power supply. That’s the other interesting thing; [bobricius] uses an array of BPW34 photodiodes to gather solar power. The datasheet describes them as silicon photodiodes, but they can be effectively used as tiny plastic-enclosed solar cells. They are readily available and can be arranged in a variety of configurations, while also being fairly durable.

Charging a capacitor then running a load for a short amount of time is one of the simplest ways to manage solar energy, and it requires no unusual components or fancy charge controllers. As long as the load doesn’t mind a short runtime, it can be an effective way to turn even indoor light into a figuratively free power source.

How to monitor a domestic photovoltaic plant with Arduino


ArdaSol is the name of a project for a solar energy monitoring system based on Arduino Mega and UNO, made by Heinz Pieren. It’s a system built to monitor energy production and consumption of a domestic photovoltaic plant:

The ArdaSol Energy Monitoring System has 3 devices:

- ArdaSol Display based on a Arduino Mega Board
The master of the system, it collects the data from the two other ArdaSol devices, shows the data on the display, stores it on a SD card and sends it to a server in the internet.

- ArdaSol Energy Monitor based on a Arduino Uno
Measures the consumption of the energy, shows energy values on local display and delivers it on request to the ArdaSol Display.

- ArdaSol Remote PVI Interface based on a Arduino Uno
The photovoltaic inverter (PVI) has a RS485 interface, this is connected to ArdaSol Remote, which interacts as a gateway to ArdaSol Display. It converts the requests, coming with a radio signal to the PVI and vice versa.